CA2144821A1 - Radiation-based laparoscopic method for determining treatment modality - Google Patents

Abstract

A diagnostic method is described for determining the treatment modality for neoplastic (cancer) tissue within the peritoneal cavity of a patient. The method utilizes a laparoscope with a visual display output as well as a radiation responsive instrument.
These instruments are employed first to carry out a visual survey of the colon and then a radionuclide survey of the colon to locate concentrations of radiolabeled locator. A next survey is carried out with the radiation responsive instrument to determine the location of lymph node involvement in the cancer as well as other metastatic disease. Should the latter involvement be found, open laparotomy is indicated as the treatment modality. On the other hand, where no lymph node involvement is determined and the region of locator concentration can additionally be visualized, then conventional laparoscopic resection procedure is the determined treatment modality.

Description

NEO 2-141-, RADIATION-~3ASED LAPAROSCOPlC METHOD
FOR DEIERMINING TREATMENT ~IOD.~LlTY

5 Back~round of the Invention Current and historical procedures for the treatrnent of colon and rectal cancer have been based, for staging purposes, upon the natural history of tumor spread, and thence, upon operative and non-operative options. Operative options generally have looked to the physical location and surgical resection of tumor. A variety of techniques -have been 10 brought to bear in the art with the purpose of aiding the surgeon in detecnng and localizing neoplastic tissue as part of this surgical procedure. ("Neoplastic tissue", for present purposes, often is referred to as cancerous tissue, though malignanl tumor and malignant tumor cells also are found in the terminology of the art. The term "neoplastic tissue"
includes all of these.) A substantial amount of effort in aiding the surgeon in locating 15 neoplastic tissue has been through the utili_ation of radiolabeled antibody for detection - purposes. For example, one technique includes the scintillation scanning of patients injected with relatively high energy, e.g. 13lI labeled antibodies. Such photoscanning or scintillation scanning provides scintigrams diff1cult to interpret because of blood pool background radioactivity. COL1l~Ulef subtraction of radioactive blood pool agents and the 20 use of two labeled antibodies (one specific for the tumor and one non-specific) have been attempted to enhance im~ging Nevertheless, such techniques have been found to provide little, if any, useful information to the surgeon, especially over and above CAT scans, magnetic resonance im~gings~ and like traditional techniques. Typically, large tumor is -readily located by the surgeon by visu~.1i7~tion at the operating theater and, in particular, 25 through palpation, i.e. the feel of a tumor as opposed to that of normal tissue. To achieve operative success, however, it is necessary for the surgeon to somehow locate "occult"
tumor, i.e. tumor which cannot be found by the conventional surgical procedure of sight and feel. Failure to locate and remove such occult tumor generally will result in the continued growth of cancer in the patient, a condition often referred to as "recurrent"
30 cancer. In general, conventional diagnostic techniques as, for example, use of the classic gamma camera and the like, fail to find or locate occult tumor. As tumor sites become smaller, the radionucleide concentrations at a given tumor site will tend to ~e lost, from an im~n~ standpoint, in the background where blood pool radiation necess~. ;ly is present in the patient.
U.S. Pat. No. 4,782,840 by Martin, M.D. and Thurston, Ph.D., entitled "Method for ~ oc~ting~ Differentiating, and Removing Neoplasms, issued Nov. 8, 1988 (the5 disclosure of which is expressly incorporated herein by reference) reviews such scintillation scanning technique and discloses a much improved method for locating, dirÇ~ nti~ting, and removing neoplasms. Such technique utilizes a radio!~beled antibody and a portable radiation detection probe which the surgeon may use intraoperatively in order to detect sites of radioactivity. Because of the pn,Ai~ y of the detection probe to the 10 labeled antibody, the faint radiation çm~n~in~ from occult sites bei::O~f,S detectable, for example, in part bec~.~se of the inherent ~rpli~tion of the a~ru,c;~ ç inver~se square law of r~Ai~tion propagation. The procedure is known as the Radioi.. ~ oguided SurgeryTM
system (RIGS) (Radio;.. -noguided Surgery and RIGS being trad~ of Neoprobe Col~,ulalion, Colllmbus, Ohio) and is succe-s~ful additionally because of a recognition that 15 tumor detection should be delayed until the blood pool background of circulating radiolabeled antibody has had an opportunity to be cleared from the body. As a consequence, the photon emissions or radiation emitted by minor tumors co-"p~,d to surrounding tissue becouæs ~etect~ble in view of the ~lOAill~ty of the probe device to it.
FolLuilously, the '840 patent discloses the ability of the radiolabeled antibody to remain 20 bound to or ~so~t~d with neoplastic tissue for ~ e~ periods of time with the radio tag still bound thereto. Moreover, even though the accretion of Pdio~ctivity at the tumor site decreases over time, the blood pool background and ~uuluunding tissue (relative to the tumor sites) decrease at a much greater rate so that the radioactive sites can be determined readily utilizing a hand held probe positioned in close proximity with the tissue under 25 investi~;~tion Colonic tumor generally ori~in~tes at the mucosa or inner layer of the bowel.
Because of this inte,ll...lin~l location, i.e. within the interior of the colon, early primary - tumor cannot be seen or vi~u~li7e~i by the sulg~l . Thus, the conventional palpation or "feeling" procedures generally are employed to locate the otherwise hidden neoplasm.
30 Vi~u~li7~tion of tumor at the exterior surface of the colon only becollles available as a ~etection technique when the tumor will have grown or matured to an extent that it extends oulwd~dly through the wall of the colon and, thus, its presence is apl)~cnt. One approach to loc~ting the position of essenti~lly hidden tumor or loc~li7ing a hidden lesion has been resort to inllao~lali./e colonoscopy. This technique exhibits ~wbacks due, in part, tO a 35 l~,quil~ nt for the inmffl~tion of air into the colon with attendant luminal distension.
making ~ubse~lu~,nt surgery more ~1iffic--1t In this regard, the technique has a potential for 214~821 çngen.1enng toxicity and breaking the sterile field. Additionally, the added procedure inw~s ~n~ h~ time, total ope.~ g room time, and operative costs.
Tumor which is evidenced or "recurs" following earlier surgery typically is diagnosed by the occurrence of elevating CEA levels (carcinembryonic antigen).
S Gçnçr~lly, this l~ ing cancer is, in effect, hidden cancer which was not found in earlier surgery and now has co....~el ced to mature. The carrying out of a second surgical procedure, a procedure SOI..e!;l~leS referred to as "second look" surgery, has been the subject of study. A high morbidity rate is associated with such procedure. Often the plOC~lUl~ es~ lly is an "open and close" one, the patient exhibiting severe met~cticiC not 10 o~.~.wise detect~ble and not surgically treatable. This dele.lllination of unresectability hluu~;ll open surgery, of course, is ~t~, ~de~l with severe trauma to the patient.
A highly ill~pollant aspect of all procedures associ~ted with colorectal and other cancers resides in the proper staging of the patient accc.l ling to the extent and severity of the ~ice~ce. Such staging aids in ~et~, ...;ning the applopliate post-surgical treatrnent for 15 such p~ti~.nts Stage I and II p~ti~nts are believed to be curable by surgery alone, whereas Stage m patients, i.e. p~ti~ntc det~ ~ined tû have cancer spread to the lymph nodes, are treated with some form of post-operative therapy, such as chemotherapy. Stage IVp~ti~.ntc, i.e. p~ti.-.ntc with m~.t~cticic to other organs, are treated with a variety of methods, in~luAing post-surgical therapy andJor surgical removal of the primary tumor. More severe 20 m~t~cticis typically is not deem~ to be treatable by surgery and thus, surgery is not undertaken in order to spare the pqti~ntc unnecçss~ry trauma. Where the above-noted hidden or occult cancer is not found, residual disease is left behind and is not accounted for with respect to an evaluation of the extent of the disease tO dct~.. ;~-e proper post-surgical therapy.
The contribution of RIGS-based surgery to enhancing the vision-based and touch-based p~c~ s of the su,E,~n has been snbst~nti~l The ~l~t~ion and location approach of this system has ~ the ide~ /tion and removal of hidden or occult tumor under - conditions where otherwise conventional procedures would not have found it.
Additionally, the system has been employed in s~ging, particularly in evaluating Iymph nodes and other metastatic disease for staging procedures. The system has been de~llol~ ated in clinical studies to ~.lb,~ lly improve the staging of primary colorectal cancer p~tiP.ntc which, having been staged by traditional means, were restaged to State III
~lice~se based upon the RIGS system as confirmed by pathology findings. As a conse~luence of such f1ndin~c, patients so re-evaluated are eligible for post-surgical therapy, such as chemotherapy, resulting in improved patient management. The im~l~nce of such staging has been est~bliched in view of the National Institute of Health 21~4821 (NIH) consensus report concerning the ~minictration of adjuvant chemotherapy to ~lul~lialely stage p~tientC "NIH Concenc~s Confe.-_nce: Adjuvant Therapy for Patients wi* Colon and Rectal Cancer", JAMA, l990; 264:l411 50.
Soll,e~Nhat recently, laparoscopic surgery (minim~l access surgery) has become popular as an alternative to traditional open surgery procedures. Particularly with the development of video-based visual systems, lapa~scopic surgical techniques have been employed with more complicated gastro-intestin~l procedures. Such procedures look to savings in total health care costs as a result of shorter hospital stays and a more rapid p-atient return to normal activity. However, these procedures require inst~-m~nt~tion and technique suppl~nting conventional tnree-.1im~ncional viewing and tactile feedback to the aulgeon. Improved inallu~ ntation particularly is called for where these newer surgical techniques are applied to the ~lete~tion and removal of neoplastic tissue.
While a variety of la~aloscopic insllulll~ ts have been developed, such equipment falls into two broad categories: those major pieces of e~uipll~nt that enable the surgeon to ~.Çol.ll laparoscopy and those insllulllenl~ related to the pc.rûlll'ance of specific tasks or procedures, e.g. electrocautery and laser. Generally, vic-l~li7~tion within peritoneal cavity l~uil~s "space" in which to shine light and maneuver. In a standard surgical approach or lapa~utollly this space is created by opening the abdomen and allowing room light and air into the cavity to acco,.l.l,o l~te three-dimensional viewing. In laparoscopic procedures, this is accomplished by filling the ~.i~oneal cavity with a gas that ~licten~s the abdominal wall and provides an area for light and manipulation, a process termed "pneumoperitoneum". Carbon dioxide currently is the standard gas used for pneumo~liloneum. Pneulllo~.iloneum typically is carried out utilizing an instrument referred to as an incllffl~tQr La~a~scopic surgery gçner~lly reatu~s the establic-hm~ont of one or more portals of entry into the abdominal cavity. Mech~ni~mc for inserting and removing various inal~ull~ents through these portals without loss of pne.,moperitoneum are necessary. These - ports are est~bliched by the insertion of a trochar tip through the skin of the patient in conjunction with a port ~lefining c~nnul~ or sheath. The trocar is inserted through the lumen of the c~nn~ as an obturator. Typically, the c~nnul~c have a spring-loaded trumpet valve to permit the introduction of ina~lulllellts into the abdomen and prevent gas from esc~ring Conventionally, the size of the cannula sleeve is 1 mm larger in diameter than the coll~,s~onding inallulll~nt that will traverse it. Diallletela for such insllulllents may reach, for e~mrle, l5 mm or larger in extent.
Employment of the lapal~sco~ic surgical technique in conjunction with the surgical staging and resection of neoplastic tissue poses lirnitations heretofore not encountered by ~,_ 2144821 the sulg~on. With la~a~oscopic surgical ylocelul~s~ sight is constrained to the two ~lim~nsion c available at a video screen and p~lp ~tion or feel e-ssf ~.l ;Ally is lost. In effect, the ~ulgcon is maneuvering along or manipulating tissue through elongate instrumentation from a ~1ict~mx of about 18 inches away.
Where a primary tumor has not developed through the wall of the colon or is in regions of the color ~ln~^cessible to the camera, it will not be seen by video imaging.
Finding this tumor by p~lp?tion is not an option available to the surgeon. The constraints ~soci~teA with lesion demarcation by intraoperative colonoscopy remain, and the pr~luu~ often calls upon the suu~con to strategically guess as to tumor location. Where such unce. t~lly is present, an oppol~u,~ for cutting into neoplastic tissue itself is present, a sitll~tiQn l~l~,SP. .~ g a pot~ nl ;Al for ~.iloneal spread of tumor, or seeding.
The current limit~tion~ of laparoscopic or lap~sco~ic ~csicte~l colon surgery also impose severe limit~tions in carrying out staging of the disease. This again is due p....~-ip~lly to the eYplor~tory con~ inls illlyGsed by the surgical approach wllcrein lymph - 15 node n-et~cticis involvement cannot be adequately ev~h~ted In this regard, visualization alone of the lymph system using laparoscopic video il-sllumelltation generally will be achievable, or if achievable will not locate positive or cancerous Iymph nodes or other el~ ce Should this minim~l access surgery be developed to ov~,l.;Gnle the above-discussed 20 severe limit~tio~s, illlyOl~lt advantage may be evolved with the proçedure. In this regard, the approach plolllises a ~liminished post-operative pain which minimi7es the need for narçotic analgesia. The pr~c~lulc; allows patients to resume an oral diet faster, and gives the patient a shorter hospital stay and a more rapid return to normal açtivities. Some investi~tors are of an oyinion that the inci~iencer5~of post-operative complications such as 25 ~t~lect~cic and p.~ --.oniA~ deep venis thrombosis, wound infections, and the like are less with the lay~scoy c appr ~ach.

- S.l.. i.l~
The present invention is addressed to a method for determining the-treatment m~l~lity for patients ar~liclcd with neoplastic tissue (cancer patients). This diagnostic metho~l comprises the steps of administering to the patient an effective amount of radiol~bele~l loçator which specifically binds a marker produced by or associated with neoplastic tissue. Ayplvpliate loçators include, for example, antibodies, antibody fr~grn~nts, single c~ ed antibodies (SCAs), and like substances which selectively accrete at tumor sites. Following such ~ministration~ time is permitted to elapse for the radiol~beled locator to pl~,fe.entially concentlate at any marker located at neoplastic tissue and for unbound radiolabeled locator to be cleared to as to increase the ratio of photon çmiSciorlc from the marker to background photon emissions in the patient. Thereafter, the peritoneal cavity of the patient is ins~1ffl~ted and access is provided thereto through a plurality of cavity access c~nn~ c For vicu~1i7~tion, a real time laparoscopic camera S ~l~gell~el t is provided with a display. A lapa~scopic radiation detection system is provided which includes a base portion eng~ble by a surgeon, an elongate accessing tube is fixed to the base portion and is ~i1.unc;oned for slidable insertion through a select one of the c~nn~ C, and has a length along a central axis effective to access neoplastic tissue within the ~iiIoneal cavity. The access;11g tube has a passageway extending 10 the~ .,ough and a ~etector support portion in~ ding a window through which photon emicsiollc may pass. ~ crystal mount is included with the system having a crystal - receiving portion positioned at the detector support portion in ~ija~çncy with the window.
A crystal having a l~,~lWdl~l surface ~upl)oltcd on the crystal receiving portion to position a Çolw~.l surface thereof in ~dj~çncy with the window is l.,iponsi~/e to the photon missions 15 passing through the window to derive an output. A tr~ncmission assemblage extending from the crystal through the passageway for ~ ;11g the output is provided and a signal l.e~ -t and control assembly is couple~ with the tr~ncmicsion assemblage for receiving and electrically l~ g the output to provide ~..;~lible output signals l~ ,s~1-t;ng those photon ernissions at predetermined count levels above the count levels of background 20 photon ernissions. The-colon is visually surveyed to the extent possible within the .iloll~l cavity by ~ccessin~ the camera arr~ngem~nt thereto through a select one of the access c-~nnn1~c and detectin~ any visual indication of neoplastic tissue. A radionuclide survey of the colon is carried out within the ~ - ;Io.~1 cavity by manipulating the elongate ~,cess;i-g tube of the r~di~tion detection system through a select one of the access cannulas 25 to maneuver the window along and in subst~nti~1 adjacency with the colon under vicu~1i7~tion to the extent possible with the c~ f ~a arrangement display to detect and dirÇef~,nliate tissue at which the locator has conce~ ated by correlation of the pclcc~lible ~ output signals to the position of the window with respect to the colon. A radionuclide survey of the Iyrnph nodes is carried out within the peritoneal cavity by manipulating the 30 elongate ~ccess;~-g tube of the radiation dete~tion system through a select one of the c~nnn1~c to maneuver the window thereof under vi~u~li7~tion at the camera arrangement display to the extent possible into substantial adja~en.;y with lymph nodes to detect and locate a Iymph node or other metastatic disease at which the locator has concçntTated by correlation of the perceptible output signals to the position of the window. Based upon the 35 above, det~o-~nin~tion of the llG~n1~f nt modality then is carried out.

214~821 Where the patient is diagnosed prior to the noted surveys as presenting neoplastic tissue as primary tumor and the step for visually surveying the colon shows an absence of a visible inrli~Ahon of neoplastic tissue while the step for carrying out a radionuclide survey of the colon has located and dirr~ ted tissue, at which locator has concentrated, and the S step for carrying out a radionuclide survey of the lymph nodes locates no Iymph node or t~ ;C disease at which locator has conce l~ d, then the d~t~ ination of the treatment modality in~ tes that a laya~scoyically Accictç l removal of the located and differell~iAterl neoplastic tissue is beneficial as the treAtm~n~ mo~Ality. Thus, the patient will undergo an effective resec80n of neoplastic tissue with all of the advantages attendant to a minim~lly 10 invasive surgery.
Where the patient is diagnosed prior to the surveys as presçnting neoplastic tissue as plilll~ tumor, and the step for visually surveying the colon shows an absence of a visual in~ Ation of neoplastic tissue; and the radionuclide survey of the colon locates and dirre~ ltiates tissue at which locator is concentrated; and the radionuclide survey of the 15 Iymph nodes locates a lymph node at which locator has concentrated, then the ~eterminAtion of the treatment modality indicates that the carrying out of an open lapar~toll~ to remove the located and dirfel~nl;At~d neoplastic tissue is beneficial as a treA~tm~t modality. Thus, the patient is treated to correct more profound tumor involvement which requires more extensive exploration of the peritoneal cavity with 20 eYpAn-led risk which is ploy~ly undertaken with open surgical procedures.
Where the patient is diagnosed prior to the surveys as yr~se~ g neoplastic tissue as primary tumor; and the step for visually surveying the colon dirr~ ,ntiates the tissue at which locator is col-ce~ lrll, and the radionuclide survey of the Iymph nodes locates no lymph node or motActAtic disease at which locator has concentrated; then the determination 25 of ~ A~ 1 m~Ality in-licates that carrying out a la~al~oscoyically assisted removal of the located neoplasdc tissue is beneficial as the tre~tm~nt m~lity. As before, such treatment affords the patient the o~ ul~ly to gain the advantages of minim~lly invasive surgery.
- Where the patient is liAgnosed prior to the surveys as presel-l;ng the neoplastic tissue as lecull~nt tumor, and the radionuclude survey of Iymph nodes locates a Iymph 30 node or other m'~tA~tAtic disease at which the locator is concen~l~ted, then the determination of l1CA~ n~ m~Ality ;~ A~eS that a procedure employing surgical resection would not be of benefit to the patient. Thus, the patient is spared the trauma and thè risk of major, open surgery which would have no benefi~ effect.
Other objects of the invention will, in part, be obvious and will, in part, appear 35 hereinafter.

The invention, accoldingly, comprises the method possessing the steps which are cYemr!ifi~ in the following det~ Qsllre~
For a fuller underst~n-ling of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with theS acco~ anying drawings.

Brief D~sc. ~;on of the ~rawin~
Flg. 1 is a pf . ..~ e view of a la~aloscopic in..l. ul,lent according to the invention;
Fig. 2 is a side view of the instrument of Fig. 1 showing components therein in p~ o-Fig. 3 is a schP.n~t;r, l~lese~ ;on of the in~ u",ent of Fig. 1 with the access tube thereof in broken fashion showing an opposite side theroef;
Fig. 4 is a partial se~;l;o~l view of the insl,ull,~nt of Fig. 1;
Fig. S is an exploded ~.spe~ /e view of a cr,vstal and associated crystal mount employed with the in~.l.ulll~nt of Fig. 1;
Fig. 6 is a sec~ion~l view taken through the plane 6-6 shown in Fig. 3;
Figs. 7A and 7B combine as labeled to form a block diagram of the functional co.~oncr,Ls of a signal tre~trnellt and cont~.~l system associated with the in~.l,ull~ent of the invention;
Fig. 8 is a partial frontal view of a patient showing portions of the colon in ph~ntom, the location of access ope~ning~ for laparoscopy and instrllm~nt,.tion employed with the invention;
Fig. 9 is a sagital partial view of a patient showing portions of the colon and adjacent organs in conjunction with a positioning of instrumentation employed with the invention;
Fig. 10 is a p~,...~i~e view of a portion of the ascending colon shown in Fig. 9with ~, ~ions broken away to reveal internal tumor, - Flg. 11 is a partial ~n~tomir~l view of the patient of Fig. 8 taken through the section 11-11 therein;
Fig. 12 is a p~ ;./e view of a transverse colon, stomach and liver showing the ~;~;o!ling of an i,l..l,~",~,nl accoldillg to the invention; and Fig. 13 is an enlarged view of the subject of Fig. 12 showing a retraction of the liver and the ~ItPrn~te positioning of in..llu,llcnts according to the invention.

35 Detailed Descri~tion ~ 2144821 The general RIGS ploc~lulc; co~ ces with the ~lminictration to the patient of aneffective amount of a radiol~bell~ locator which specifically binds a marker produced or AcsociAtç~ with neoplastic tissue. A "locator" includes a substance which p~r~r~ntially concentrates at tumor sites by binding with a marker (the cancer cell or product of the 5 cancer, for example) produced by or associated with neoplastic tissue or neoplasms.
Appropriate locators today primarily include antibodies (whole and monoclonal), antibody fr~gm~ntc, chimeric versions of whole antibodies and antibody fragments, humslni7e~i versions thereof, as well as other tumor specific carriers, i.e. locators. It should be appreciated, however, that single chain antibodies (SCAs such as disclosed in U.S. Pat.
10 No. 4,946,778) and like substances have been developed and they primarily prove efficacious. Bioch.omictry and genetic en~ ee.ii1g may yet produce substances which mimic the filn-~ion of antibodies in selectively concentrating at sites of neoplastic tissue, though such substances may not be subsumed within the traditional definition of "antibody". "Locator" is a term chosen to include present day antibodies and equ*alents 15 thereof, as well as those substances yet to be detc~ ed which mimic antibodies in the method of the RIGS system.
An adaptation of radio..~ oguided surgical techniques (RIGS) to lapar~sco~ic procedures involves a need to ~cco.-....~S~tç a variety of aspects associated with each. The hand-held radiation ~etectin~ probe employed conventionally with the RIGS system is 20 described in U.S. Pat. No. 5,070,878 by Denen, issued December 10, 1991, and assigned in CO.. O~l hei1wi~l. This probe utilizes a c~-lmillm t~ -lti~e crystal of adequate surface area which is mounted in a "folwa~d looking" I~ mer. Thus, as the probe is held by the sur~on~ the window co~ )onent thereof at the tip is moved transversely along tissue being evStluS~te~l Because the RIGS surgical approach is one wherein the extent of radiation 25 ç. . lA n,~ .g from a canier located at neoplastic tissue is quite faint, it becomes necessstry that the crystal be of adequate surface area to capture sl-ffl~i~nt radiation emissions. Of simi!ar pol ~ce, because of the rapid fall-off of radiation as the crystal surface is moved away - from that tissue region in consequence of the a~lo~ ate inverse square law of radiation propagation, it is essentiAl that the sulgeo~ intA;n a close proximity between the crystal 30 surface behind the probe window and the radioactive dssue. In effect, this application of the inverse square law of r~ Atior propagation aids in sharply delineating the extent or bolln~lStries of neoplastic tissue.
From the lapaloscopic surgical standpoint, it is necess~ty that the laparoscopicin~llull~nt be maneuverable, having an access tube or the like of diameter limited by the 35 port of a cannula, for example, about 12 mm. It has been determined that the latter metric constraint imposes unwanted limitations on the available surface area of a ~ ~144821 ra~ tion ~letectin~ crystal such as c~ - telluride. As a fvl~a~ looking laparoscopic adaptation of the r~Ai~tion ~,t.~!;.~g prvbe was ernployed, in ~rlition to the low count rates available with smaller ~i~met~ crystals, as the source of radiation was approached, for ~x~mrle in a lollgit l-lin~l direction along the body cavity, in~ll ulllent response diminishes 5 as the crystal moves across the r~ tion source be~ se of the shielding positioned about the crystal itsel The lal,~vscopic instrument intended for radionuclide SC~nning is ~u~d to be configured within the diametric constraints associated with its insertion through a c~nn~ and its anticipated form of maneuvering within the body cavity. Next, the device must be capable of l~,t~ining a crystal such as cadmium-zinc-telluride for 10 detection which has adequate surface area to achieve operationally effective radiation det~ctin~ sensitivity. This insllu~ t then is called upon to locate neoplastic tissue through faint radiadon emissions while being observed, to the extent possible two--limen~ionally with a television carnera which also is inserted through a c~nnllla into that same body cavity. In effect, the insll ull~nt is called upon, inter alia, to replace the ~urgeon~s sense of 15 touch, to ~ul)poll the surgeon's vision, which now is restricted to two ~im~nsions~ and to develop RlGS-based inf - .n~l;on as to the loc~ti- n of cancer involvement.
The metho~lology described in connection with the present invention is one whichemploys RIGS te~hnology in conjunction with certain laparosco~!ic procedures utili7e~ for diagnosis or evaluation of the condition of cancer patients. With the method, trauma 20 otherwise imposed upon a patient by open surgical techniques is avoided through the utili7~tiorl of radionuclide surveys of certain regions within the peritoneal cavity. An appreciation of the ~ gnostic technique necess~rily calls for a cognizance of the internal ~LIU ;lul~, of the patient.
Bec~use of the anatomical structure of the human body, surgical procedures 25 invading the ~ilolleal cavity have an anterior infll1çnce Surgically invasive entry into the - ~bdomçn is one which ellcoullte ~ what may be considered layered regions commencing with the o.. ~-nl.. , an outer ~ t~;li~e curtain-like tissue and ending with the bacLl,one and the pelvis. To reach, evaluate, and perhaps resect at successive regions requires lllarii~ulation of organs such as the lengthy small bowel to locations away from areas of 30 inte,~L This convçntio~lly is carried out by retraction as well as by gravity, the latter being accolllplished through oriçnt~tion~ of the patient's body. As surgical procedures reach deeper into the ~b~o...~l-, they are acco..~l ~nie~l by increasing risk, for example, as cancer involved with tissue is located in proximity to the systems of the aorta and vena - cava. As the latter organs are approached, the delicacy of procedure becolllcs more 35 profound. It also should be borne in mind that the organs encountered in the course of abdominal surgery are not static. In this regard, the terms "dynamic", "slippery" and ~ 2144821 "sliding" are adjectives a~p1op1iate to the desc1i,.)Lion of this task. These accessing con-litions encounte~d by the ~u1geon become sG1-1e~hat exacerbated with laparoscopic surgery.
Referring to Fig. l, a lap~oscopic in~llul~lcnl iwhich may be employed with the S r~ nostic method is revealed in general at lO. Instrument lO includes a hand-grippable cylin-lric~l base portion 12 to which an e1ong~te a~ceccing tube 14 is fixed. Accecsing tube 14 is of a length convenient to the sul~on for ~cess;ng those regions of the abdominal cavity int~n~le~ for neoplastic tissue detection and loc~1i7~tion. This length may, for example, be about 14 inches (36 cm) and extends to a tip 16. Inwardly from this tip 16 10 there is a detector SU1J~)O1I portion r~ sente-d generally at 18 which extends to a union or joint .~e~nt~d at line 20. Tube 14 is cylinflrir~1, having an outer ~i~m~ter, for example, of ll mln such that it is s11it~h1e for insertion through a conventional 12 mm ~i~meter c~nn~ port. This cy1in-1ric~1 confi~aration extends through to the tip 16, however, the d~ t~ U crystal ~ nteA within the h~ ull1enl 10 p~ovides for "side looking" evaluation of 15 ill1pinging r~ tioll This is through a planar or flat window 22 located at the detector SU~1~U1I portion 18 and which is seen to have a SOlll~,~. 1.at elongate rectangular peripheral shape. The crystal d~tec~or which will be seen to be spaced but closely proximate the window 22 is operated in conjunction with signal t~ .t and control ci.cuiL.~ which n11;~ e1y is coupled through a console mounted coi~neclo~ (not shown) to the instrument 20 lO via a ~hi~lded flexible cable 24 e~ctending from the hand-grippable base 12. In general, the control and signal ~ n.~ com~,onents are co1lt~ined within a console to which the cable 24 leads and which is located out of the sterile surgical field. However, some signal n~.h nt co~o1~11ls may be nc~ss;l~ 1 at the ir~ ~nl lO itsel Looking additionally to Fig. 2, a crystal mount arrangement is shown in general in phantom at 26 located within 25 the ~ccessing tube 14 at the detector support portion 18. ~ ted in adjacency with the crystal mount 26 is a pr~.~lification stage ~ ,sente~ generally at 28. Depending upon the co..~l.~.ts of the siæ of the passageway within tube 14, it may be found app1O~1iate to split the p~ amp1ific~tiQn function of the in:,llu.l,~,n~ 10 into two cc.,11ponents. Accordingly, a fc~1wa~ stage 28 is positioned in ~.o~ y to crystal mount 26 and stage 28 then co.. ~ tes for example, with shie1de~ cable as rep~11led by dashed line 30 with a second or final pr~amplifi~tion stage shown in phanto-1l at 32 which is 1-lo~ d within the hand-grirF~b1e base 12. Cable 24 is ele~,~lically c :?nnçctçd with this last amplification stage sen~d at 32.
Referring to Fig. 3, ins~lulllent lO is seen rotated about its longit~1din~1 axis to 35 reveal a thin line 33 formed, for example, by being engraved and e7ctçn~ing along the back surface of ~ccessing tube 14 including the detector support portion 18. This line may be observed by the visual or video portion of la~dloscopic insll.. ~.~t~tion during surgery.
Thus, the surgeon is given visual information as to the orientation of window 22, for eY~mple, even though the tip portion 22 is not camera visible.
~ 4c~ing to Figs.4 and 5, the structuring of the crystal mounting arrangement 26 is 5 revealed at an enhAn~ed level of detail. In the figure, a crystal mount 34 which is formed of a material sel~cte~l to A~ te gamma M~liAtion such as lead is provided which is inserted within the p~sA~,way of rod 14 at the detector support portion 18. This mount 34 is seen to be generally cyli~ ical in shape with a flAtt~ned or trllncAt~ upwardly disposed surface 36 and a stepped down surface portion 38. Formed inwardly from the flat surface 36 is a 10 rectangular crystal receiving and ~.uypolling cavity 40. The mount 34 is seen to be pocihone~ within a se~ ; or discrete cylin-~rir~l tip cc, l-ponellt 42 of the tube 14. In this regard, the col~yonent 42 is seen to be flAtt~nç~l to define the window surface 22 and is slidably mounted over a stepped down surface 44 (Fig. 4) turned within tube 14.
Retention of this tip co,llponent 42 upon the stepped down surface 44, for example, is 15 provided using an electrically conductive epoxy cement. In this regard, the connection must be such as to assure no leakage of body fluids within the passageway 46 forrned within tube 14. Note that the upwardly disposed flat surface 36 of the mount 34 is spaced in close ~j~cency with the underside of the window coll-l,onent 22 of tip coll-l,onent 42.
This permits the positioning of a radiation responsive crystal as cIose as possible to that 20 surface window 22. Fig. 4 shows an opening or conduit 48 formed within the mount 34 which extends from an opening 50 within the rea,ward surface of mount 34 to a cc.ll~slJondi~1g opening 54 at the bottom surface of cavity 40.
The confi~lration thus depicted in connçchon with Figs. 4-6 is one intt-n~le~ for use in ~etecting locators labeled with gamma emitting radiation, and, particularly, emitted from 25 125I which, for the surgical ~lço~ nce contc.~lated will be of very low energy level.
Cadminm-zinc-tellllride det~ctin~ cIystals are employed for this purpose. Such crystals are ul~eted by Aurora Technologies, Inc., San Diego, California. For the present la~ .,scopic insllulllelll, it is desirable that the crystal used for detection have as large a surface area as is practical to improve counting efficiency. Preferably, that active surface 30 area will be equivalent to the surface area of rO~ d looking crystal mounts as are used in conve .~;onAl RIGS surgery. To achieve this requisite active surface area while maintaining nec~ 5S~ ;Iy rest~icted hl~llu~ Amet~rs~ a l~la..gular cA~lmillm-zinc-telluride crystal 60 is employed having a ~ c-ip~l lengthwise d;...f ~ ?n in parallel with the central axis 62 of the tube 14. Because c-a~...;...-- t~ lride crystals exhibit mic~l~honic (piezoelectric) effects, 35 their mounting for the instant use le~uil~s a rigid avoidance of noise generated by rubbing or by the trAn~miCsion of acoustical noise or the like into the crystal 60 from its mounting ,_ 2144821 envir~ ,nt. To achieve this requisite mollnting with an avoidance of microphonicin~uce~3 noise, the cavity 40 is initially covered with an electrically insulative polymeric layer 64. Preferably, the layer 64 is formed of silicone, generally referred to as silicone rubber which is an Çlastom~r in which the C linkages of a polymerized hydrocarbon are S replaced by Si~ linkages. It is sold, for example, under the tr~iem~rk "SILASTIC". In this regard, the layer 64 can be developed as a rectangular receptacle with a rectangular mold carrying a conventio~l mold release. A ne~ess~. y electric~l bias, for example at 60 v, is asserted at the lt,alWdf'~ surface 66 of the crystal 60 by an electrical contact alTangement including multi-strand wire 68 seen exte-n-iing from connection with a circuit board 70 in Fig. 4 and through the opening 50 of passageway 48 to opening 54 within the cavity 40. From this opening 54, the plurality of strands of this wire are "spread out" over the polymeric layer 64 as seen in general at 72 in Fig. 5. Additionally, positioned over the electric~lly insulative polymeric layer 64 at the bottom of the cavity 40 is an electrically co~ ctive c~lshion layer 74 having a lower disposed surface 76 positioned over the strands 15 72 and upon the folwal~lly facing surface of layer 64. To avoid microphonically induced noiæ, this lower disposed surface 76 of the cushion layer 74 is adhered to the upper surface of the heat-stable siliconç rubber. ~ tiol~l alll~unls of the "SILASTIC" material may be used for this purpose. Advantagouesly, the electrically inc~ tive elastomeric adhesive retains its elastic plvp~. lies over time and high lemp~ ture conditions. With the a~ng~m~nt thus shown, çlectric~l bias, as well as electric~l co.. l~in~tion with respect to charge transfer is asserted from the contact strands 72 into this electrically conductive cushion layer to its upwardly disposed surface 78. Preferably, the electrically conductive c--chion layer 74 is provided as a non-woven TEFLON cloth which is carbon filled to the extent ren~ing it an effective conductor of ele~ricity. In general, the material is a carbon 25 co~ ngsll~t~ d,highlycryst~llinç nncinteredpolytetrafluoroethylene,ll~h~tedunder the tr~ -m~rlc "Gore-Tex".
The lower or l`~alW~lld surface 66 of the c ~ -,---zinc-telluride crystal 60 is freely abuttably positioned over the upwardly ~licposesl surface 78 of electrically conductive cuchion layer 74. No adhesive is employed in this union other than some of the silicone 30 adhesive may migrate about the edge of the crystal 60 with be-n~-fici~l effect. This positions the upwardly disposed surface of crystal 60 as at 84 in close ~ cency with the underside of the window 22. To retain the assemblage of crystal 60 and associated mount inposition, a thin elastomerically deformable sheet 86 is stretched over the assembly including the upwardly disposed surface 84 of crystal 60. This cc,~ )r~ssibly urges the 35 crystal dowllw~dly to improve device p~,Ço....~.-ce The thin sheet 86 may be provided as a carbon-filled rubber and thus serves the second purpose of asserting necessary ground at 21~821 the surface 84 of crystal 60. Note in this regard, that in stretching the sheet 86 over the crystal 60, it is f~ctçn~ by ~ hine screw and washer combin~tion 88 at the fol~dltl or tip portion 90 of mount 34 seen in Fig. 4. The opposite end of the sheet 86 is similarly f~ ,ned to surface 38 of mount 34 by a n~^hine screw and washer ar;angement shown at 92 in Figs. 4 and 5. Ground is conveyed to the sheet 86 from the lead mount 34 which, in turn, is coupled to ground through the fol ~ald stage 28 of the pç._al~lifier function. Note that the circuit board 70 is seen att~h~d to surface 38 of mount 34 with a screw 94.
Thus Illoullted within the ~et~l~-l support region 18 of ir.s~ Ulll~ nt 10, the upwardly disposed surface 84 of crystal 60 is spaced from the underside of window 22 by a very small gap 96 to avoid acousti~ or vi'orationally indl~ce~ noise. However, the distance from the ouL~dnlly disposed surface of window 22 to that upwardly disposed surface of crystal 60 is quite small, being, for example, less than 2 mm. This permits the upwardly disposed surface 84 of crystal 60 to be positioned in very close proximity to the tissue under investi~tion It is the flatness of the window 22 within the generally cylindrical insll ulllent 10 which additionally permits this close positioning of the crystal to the tissue under investigation. Such dict~ncing for the pul~ose of the operation of in~LIul~nt 10 is quite illl~l ~ult in view of the low level of r~ tior~ involved and the noted apploAilllale inverse square relationship of r~Ai~tiQn prop~tion with which the system ~"rulms.
Referring to Figs. 7A and 7B, a block dia~.. ~tic represçnt~tion of the signal 20 tl~t~llt and control cil~;uill~ employed with ill~l~ulll~nt 10 is revealed. In Fig. 7A, that crystal which is being employed, for ex~mple crystal 60 as labelled, is shown having one face coupled to ground through line 100, while the opposite, biased face thereof is coupled via lines 101 and 102 to a bias filter l~ ,se,l~d at block 104. Bias Filter 104 is part of the earlier~es~ibe~l fOl~vald ~ pliri~t;on stage 28 herein identified in Fig. 7A by a dashed boundary with the same numeration. The input to the filter 104 is derived nltim~t~ly from cable 24 ~Fig. L) and is l~p~sented in Fig. 7A at line 106 as being applied through that cable again l~ sent~d by numeral 24. Line 101 cc,ll.,;,~onds with line 68 earlier described in connection with Fig. 4 and supplies an app~pliate bias, for example, 60v to the l~,alwald surface of crystal 60. This bias e-m~n~tes from a power supply shown at block 108 in Flg. 7B and ~ ,d at line 110.
Line 101 from crystal 60 is shown e7cten-1in~ to an integrator stage 112 of the first preamplification stage 28. The integrated valuation of a detectçd radiation disturbance or charge cat~goliz~l signal then is shown directed as represented by line 114a to a driver-~mplific~tion nctwolh shown at block 116. Line 114a additionally is a part of the shielded cable 30 extending through the passageway 46 of access tube 14 to the second pre~mplific~tion stage 32 within base 12 as described in connection with Fig. 3. Cable 30 -also may carry gound and +12v supply as shown, r~s~cli~/ely, at lines 114b and 114c.
The noted 12v power supply as ~ ,senl~,d at line 114c is derived for the driver arnplifier stage 116 f~om the power supply 108 (Fig. 7B) as l~ ,senled at line 118 which, as shown in Fig. 7A, is di,~cled to a probe current network represented by block 120. Under S l. ic~co...~ ter control as l~eSe~ by line 122, the nctwo~L 120 develops sign~l~, for eY~Inrle~ d ,t~ll~ining whether the probe insLlu~..ent 10 has been ~ .pclly connected to a console based control system (now shown) described in detail in U.S. Patent No.

4,801,8.03 inco.~o al~d herein by ~,fe,~nce. Delivery of the 12v power supply for the pre~rnrlifiPr stage 32 is ~pr~nted at line 124 as e~ten-ling to the driver-arnplifier 116 via cable 24 and line 126.
Ground to the insLlull.~nt 10 also is developed from the power supply block 108 as le~,esent~d at line 128 shown in Fig. 7A as e~ten-ling to cable 24 and vial ine 130 to the driver-~ntrlific ~tion stage 116.
The output of the driver-amplific~tion stage 116 is ~ senled at line 132 e~ctçn~ing through the cable 24 and then being r~l~,sen~ed as line 134 to the input of a norrn~li7ing ~mplifier l~l~,Sc -tçd at block 136. The network lepl~sented by block 136 functions to amplify or ~ttenl~te~ i.e. scale the noise chal~ istic of any given instrument 10 and norm~li7~ the value thereof or render it conci~tçnt for later col~ison stages. Generally, for example, the 27 kev energy level garnma ray generated pulses in a system employing 125I will be about five ti~mes higher than noise levels. Nonn~li7ing ~mplifi~r network 136 will est~hlich those noise levels at some predç~ ne i level, for example, 200 millivolts, and the result~nt plv~lLional valid gamma related pulses will become about lv high for pUll~O~s of çn~lling colllp&,ison functions. It may be observed that the amplifier network at block 136 is controlled from a digital-to-analog converter network l~r~sented at block 138 via line 140. Network 138, in turn, is controlled from line 142 exte-n-ling, as shown in Fig. 7B, to block 144 l~ senl;n~ a microcG~ ul~r network. The norm~li7e~ output developed from network 136 is presented along lines 146 and 148 to a noise averager circuit as r~l~,sen~ecl at block 150. This network 150 dete.ll~ es an average amplitude value for the noise of a given system with a given instrument 10 and provides a coll~ onding signal as lepl~;senle~ at line 152 (nosie amp) which is employed as above ~e~ibe~l as infol~alion used by the microcolllpul~ 144. This information, in addition to being employed with the norm~li7ing ~mrlifier network representçd at block 136, may be used to develop a low window valuation for the co~ ison function.
Line 148 also extends via line 154 to a pulse acquire network rep~,sented at block 156. This n~,lwolk functions, when activated, by the microco~ ler represented at block 144, to acquire the value of the highest pulse ~mrlinlc~e witnessed at line 154. Periodically, ~ 2144821 this illfol,l,ation then is tr~ncmitted to the microcol~-~ul~,r at block 144 as lG~l~sel1ted by line 158 ff'ulse Am~p.). Re~lcsel-ting a form of peak detetor, the network is sometimes referred to as a "snapshot circuit". Also produced from lien 148, as at line 160 and block 162, is a buffer amplifier which will provide at line 164 an output representing receiéd 5pulses which may be made available to the system, for example, at a console (not shown).
Line 146 extends, as shown at Fig. 7B, at line 166, to one input of an upper window co~ ator ,~p,~,se.lted at block 168 and a lower window col~lpa.alor illustrated at block 170. The threshold level for compa-~ative pull~oses employed by the network at block 170 is shown asserted from line 172 and, preferably, is developed by the logic of 10mic~xo.~lcl nelwulk 152. Of course, manual setting of such windows can be carried out. In similar f~shion the upper window of acceplance for valid radiation interaction is establiched from a col-~,s~onding line 174. This threshold setting may be made from the h~ "~A~;on taken from pulse aoquire network 156.
Returning to Fig. 7A, the upper window and lowe rwindow threshold selections 15are made under the control of the microcGll,~ er r,~,~wolk at block 144 which controls the digital-to-analog nelwolk shown at block 138. It is the characteristic of such networks as at block 138 to provide an output which is cornpri~e~, for example, of 256 steps of arying ~mplitllde The p~lcentage of incle.~,ht;.l;on from step to step will vary solllGwllat over a range of voltage values provided. Accordingly, the outputs from this conversion network 20at block 138, as shown at lines 176 and 178 are dil~,cled to squarer nelwolks shown, respectively, at blocks 180 and 182. These nelwol~s function to square the current outputs at lines 176 and 178 and thus achieve a ullifullll p~ ;en~ge incrçm~nt~tion of the threshold ~efining outputs at lines 172 and 174.
l~tllrning to Fig. 7B, the outputs of the co,ll~ator nelwolks shown at blocks 178 25and 170 represent c~n(~ te pulses which may be above or below the given threshols and are identified as being p~se~-ted as "UV pulse" and "LW pulse" along respective lines 184 and 186. These lines are shown directed to a real time pulse discrimin~tor network - lG~l~,Se~ d at block 188 which canies out Boolean logic to determine the presence or abse-nce of valid pulses. Valid pulses are introduced to the miclucolnpult. network 144 as l~ 1~ by line 190.
The microcol.~pl"~,. nelwulk replesGnt~ at block 144 performs under a number of operational modes to provide both audio and visual outputs to aid the sulgGon in locating and differenti~tin~ ~U~llOlvus tissue. In the former regard, as lcpl~sellted at line 192 and block 194, a volume control function may be asselt~l with amplitude variations controlled 35from a solid-state form of potentiometer replc;sent~d at line 196 and block 198. Control to potentiometer 196 is represented at line 202 to an audio amplification circuit represented at ~ 2144821 block 204 for driving a speaker as ~ se~lle~ at 206 and line 208. With the noted siren arrangçrn~-~t, the frequency output from spe~ker 206 increases as the instrument 10 is moved closer to the situs of concentl~led radiation. Of course, conventional clicks and beeps can be provided at the option of the Op~.~tOI.
S The rniCroCG~n~uler network 144, as ,~pl~sente~l by bus defining arrow 210 and block 212 also addresses an input-output nelwu,k which, as represented at bus arrow 214, functions to provide a pulse count output of varying types as well as outputs representing volume levels, pulse height, noise levels, and battery status. These outputs are provided in visual formal at a visual display lep,~sen~ at block 216. Similarly, the input-output o r.-~ ;0,- Ic~l~,se~lc;d at block 212 provides applopliate sc~nning of switches or the like may be employed with the control system and are l~,pl~sent~d by block 218 and ubs input arrow 220. During a given counting operation, the miCroCGI~lpUtCr network at block 144Ç....- -;ons to control a light emitling diode drive n~,lwu,k l~r~se.lted by block 222 from line 224. The drive nelwo,k lel"~,se- t~l at block 222 is shown providing an input, as 15 ,~,~,sented by line 226, to a light emitting diode (LED) display as ~c~l~.senLed by block 228. A serial output port of convention~l variety also may be provided with the system, such ports being represçnted at block 230 being addressed from the microcomputerrcplese.lte~l at block 144 from line 232 and having output and input components ~prcsented by arrow 234. A real time clock-c~len~r having a non-volatile memory also 20 may be provided in conjunclion with the functions of the microcol"~"lte. network 144 as - lcpf~sellled by block 236 and bus arrow 238. Further, the microcol~uLe. may be employed to n.onilor the ~.Çollllance of the power supply r~p~llted at block 108. This is shown being carried out by the interaction of the microcolllp-lte~ network with a multiplexer ncl"~senl~ at block 240 and having an association represented by arrows 242 25 and 244. It may be observed that the power supply also provides a +5v source for the logic level co- .~l~ne-ntc of the circuit as ~ ~ nl~ by lien 246; a -Sv source at line 248, as well as a -9v source at line 250 fûr ~ulpo3es of display drive, and finally, a 2.5v reference as represente~ at line 252 to provide reference input for the plcall.l)liflcation analog circ utry.
Retl... -.. n~ to Fig. 7A, the mic,~o,ll~ut~,l network as ,-,~,csented at block 144 also provides an input to the digital-to-analog conversion network reprsented at block 138 which cc"l~ ~nds with the insl~n~n~o~s pulse rate and this information is conveyed to a pulse rate and this inrc,l,~dLion is conveyed to a pulse rate amplifier n~,Lw~lk r~lcsentcd at block 254 via line 256. The resllit~n~ output, as l~,plcsclltcd at line 258, may be provided, 35 for example, at a convenient location upon a console. - This circuit Ic~lcscnlcd at block 254 also may be employed to generate a calibrating pulse for testing the downstream co,lll,onent~ of the system. Thus, the mic~~ ut~ pç~sc,-ted at block 184 applies a p~ t~ ;n-l~ pulse level through the digital-to-analog conversion network at block 138 for e~ ;on to the amplifier n~,lw~ ,se.lt~d at block 254. The resultant output at line 260is selectively ~wiLch~d, as l.,~l~senlcd by block 262, to define pulse width from the S microco~ ut~,. input at line 264 to the c~ ~ting pulse at line 266.
The m~tho~ of the invention employs the insl,ulllent 10 and its associated control circuitry in a diagnostic manner wherein the advantageous aspects of laparoscopic pl~lUl~S are utilized to ~et~rmine a subs~uenl ~...f n~ modality. In this regard, where a,.y tumor is in~lir~ted which has not .... ~ l, then a laparoscopic-based resection 10 is called for as the tre~tment mo~l~lity. Under such a diagnosis, the patient then is surgically treated la~ scopically with the avoidance of a substantial trauma of open surgery. On the other hand, where a r~liol...cli~e survey of lymph regions carried out with in~u~f .ll 10 in(1ic~trs that lymph node or mot~t~tic disease involvement is present, then open surgical tre~tm.ont is in-iic~te l Colorectal cancer may spread by local invasion, 15 lyrnphatic extension, hematogenous spread, or implantation. After the initial mucosal growth, a tumor may progress locally in several dir~clions, but usually it protrudes first, as noted above, into the lumen. Mural ~ ~ nl;on may result in local failure or peritoneal se~ling Colorectal cancer first l.,. t~ ~ to the pe,iuc~;~l nodes at the level of the. primary tumor or i.. ~ tely above it. Next, the chain ~rCo~n~ ying the superior h~lllolllloidal vessels is involved. In later stages of ~ e~ce~ when the hemorrhoidal normal lymphatic flow is through the lymphatic ch~nnrls along the major arteries, with three echelons of lymph nodes: pericolic, interrn~ te, and principal. If tumors lie between two major vascular pedicles, lymphatic flow may drain in either or both directions. If the central lymph nodes are blocked by tumor, lymphatic flow can become retrograde along thearginal arcades ~ h~lly and distally. The risk for lymph node m~t~ct~ces increases with in.;l~i lg tumor grade, as does the llt~ f of lymph nodes affected.
The liver is the primary site of hematogenous met~st~ses, followed by the lung.
Involvement of other sites in the absence of liver or lung involvement is rare.
Implantation refers to the release of tumor cells from the primary tumor and ~heir deposition on another surface. Implantation has been reported with tumor cells shed intralnm;n~lly, from the serosal surface through the peritoneum, and by surgicalm~nip~ tion and resnlt~nt deposition on wound snrf~e-s See generally:

~, 2144821 "Second-Look Surgery for Colorectal Cancer, The Second Time Around" by Martin, et al., Ann. Surg.
Vol. 214, No. 3, pp 321-327, Sept. 1991.
"Manual for Staging Cancer" Fourth Ed. Edited by Beahrs, et al., pp. 75-82, 1992, J.B. Lippincott Co., Phil~dçlrhia~ PA.
The method also looks to r~cu~ nt tumor wherein a patient presents the signs of l~u~l~,ncy, for example, through rising CEA levels or from a CAT scan or colonoscopy, then the procedure employs lapdroscopic radionuclide survey to determine whether a met~ctici7~1 condition is at hand and the extent of such met~stisis In the event that the cancer is determined to be too extensive and is thus inoperable, no further surgical ploc~luu~ other than the removal of bloc~in~ lesions is indicted, open lapal~tollly is not resorted to and the trauma ~soçi~ted with an open and close opensurgical procedure is avoided with minimi7ed patient trauma.
The method is co.n.. ,f .-~l with conventional RIGS surgical procedure wherein an effective amount of ra~liol~beled locator which speçific~lly binds a marker produced by or ~csoc~ted with neoplastic tissue is adlnini~tered to the patient. Typically, a monoclonal antibody (MAb) coupled with a radiolabel such as 125I is ~tili7~ 1 Next, the radiolabeled locator is permitted to preferendally concentrate at any of such markers to an extent increasing the ratio of photon emi~sion~ from the marker to bac~glound photon emissions in the padent. Then, following more conventior~l laparoscopic procedure, the peritoneal cavity of the patient is in~uM~ted and access to the insl.M~ted cavity is made through a plurality of-cavity access c~nnnl~c In general, a trochar is associated with the cannulas which provides the opening through ~e abd~ inal wall.
Looking to Fig. 8, cannula positions as may be employed with the instant OCC~ . are l~l~,senled in CQI~ ~!;Oll with the schçm~tic ~l~senl~l;or- of a padent 300.
In general, one opening as at 302 will be provided near the umbilicus. Portals then may be - 30 placed at the left upper quadrant as represented by an X at 304; at the right upper quadrant as ~ ,s~,.l~d symbolically at 306; at the left lower 4u~ t as l~;~r~sentcd by an X at 308;
and at the right lower quadrant as lepresen~e-l symbolically at 310. Shown inserted through a cannula at 310 is the instrument 10, the detector portion 18 of which is ,~sented as being located to carry out a portion of a radionuclide survey in the region ~ n the bladder and sigrnoid colon of padent 300. In the figure, the descen~ling colon is l~,~l~nt~d in l~han~c,lll at 312; the si~noid colon at 316 and the bladder at 318.
Shown inserted through a c~nnnl~ at portal 306 is a laparoscope 314 having an illumin~ting and visu~li7ing tip 315 which is pointed toward the region of survey by det~lo~ ~.U~olL portion 18 of ir,~llulllcnt 10. Generally, the imaging carried out by the ull~nt 314 will be observed by the su~on and ~ccict~nts at a high definition television screen ~dj~lont the o~l~Ling theater.
In accordance with the diagnostic procedure at hand, the real time camera 5 ~ep~senl~ by ins~lu~ nt 314 initially is utili_ed to survey the colon for the purpose of ~etecting any visual in~ tion of neoplastic tissue. Particularly where primary tumor is at hand, that visual survey usually will not locate tumor, in~smllch as the growth of such tumor is intr~ min~l i.e. com---enees within the interior structure of the colon. Thus, a visual survey of the colon typically will not identify tumor. Looking to Fig. 9, a sagital section of a patient 320 is illustrated showing illsllUllle.nt 10 under the visu~li7~tion of laparoscope 314 in the course of carrying out a radionuclide survey of the colon,~se~t~ generally at 322. Colon 322 inchl~les the caecum 324, the ~Ccerlfling colon 326, the transverse colon 328, the desce-n~ing colon 330, the sigmoid colon 332, and the rectum 334. Transverse colon 328 is seen in an upwardly retracted on~nt~tion improving 15 its ~cescibility and a portion of the l..Pse..t~-ly 336 is shown e~ten~ling from the transverse colon. Bdow the c~f-~uu~ 324 is an appendix 338. The retracted transverse colon 328 is seen exten-ling in an u~dly directed arc toward the liver 340 which is seen to extend over a g~llb~ er as at 342 and pancreas 344. A portion of the esophagus is seen r~ len~ g upwardly at 346. Not seen in Fig. 9 is the small intestine as well as the greater 20 Gll~ the former generally filling the space outlined by colon 322 and the latter a~aling so.ll~,~41,at like a curtain of tissue which overlays the organs within the peritoneal cavity.
For a con-lition of ~lhl~ y tumor of s~lfficien~ly early d~,~clopme. t, a visual survey of the colon 3æ with i~llul~nt 314 will reveal no neoplastic tissue, inasmuch as such tumor co.. ~ nces growth within the lumen of the colon and only becomes observable at the outside wall of the colon when it has matured somewhat. However, with the radiolabeled locator approach of the present method, following a visual survey of colon - 322 with in~llume.lt 314, then a radionuclide survey of colon 322 is carried out with ir,~ ,enl 10. The laner survey is carried out under observation from insllument 314 to 30 the extent poscibl~ InsLlulllent 314 is seen in the present illustration as being inserted through a c~nnul~ located at the left lower quadrant, while in~llull,ent 10 has been inserted - through a cannula located in the left upper quadrant. Detector sùl)poll portion 18 of insllulll~nt 10 is seen being maneuvered in ~dj~ency with colon 322, for the present de.ll~ns~lion being located at the lower end of the ~scen~ling colon 326. Looking 35 additionally to Fig. 10, the arrangement of instrument 10 and the lower portion of ~cen~ g colon 326 are reproduced, showing in broken away fashion, a pre-emergent ~_ 214 1821 tumor 348 which cannot be visualized at the outer surface of ascending colon 326.
However, because of the adjacency of detector portion 18 of instrument 10 with the M~liolflbele~l locator detecfe~ tumor 348, the surgeon will be given an immÇ~i~te audible in-lir~tiQn of the presence of tumor 348. By further surveying along the colon 322, a S de~ ation of the range of tumor involvement can be made under the visualization of ins~ulll~nt 10 by inStlu~ l 314. Following an i-ientification of tumor 348, the procedure then provides for carrying out a r~lionllçli~le survey of Iymph nodes within the peritoneal cavity. Initially, the survey will take place in the vicinity of the located tumor 348. Lymph nodes being located, for example within the ...csente.r and elsewhere. Additionally, the radionuclide survey will identify any other m~t~ct~tic disease at which locator will have c~ nC~ t~
Because of the various earlier-described regions of organs- encountered by the sulE,_on in the survey both of the colon 322 and lymph or other m~t~ct~tic disease organ involvement, vicll~li7~tion will not always be available through in~LIull.~ nt 314. P~etl-rning to Fig. 8, non-vicll~li7ing aspect of the prelimin~ry survey of the colon is illustrated. In this regard, the insll ull~nl 1-0 will have been employed to carry out a radionuclide survey of the colon including the desce~-ling colon 312. However, as this survey moves lower into the abdomen, for example, as shown in the region ~t~. ~en the sigmoid colon 316 and bladder 318, the detector support portion 18 of insllulll~nt 10 will not be vicu~li7~ble by ill~llu~ nt 314. Looking to Fig. 11, a more liets~iled le~l~ sæ-~ ;on of this colll~onent of the r~lionucli~e survey is revealed. In the figure, the sigmoid colon 316 again is illustrated as it is adjacent to the rectum 350, bladder 318, and prostate gland 352. During this portion of the radionuclide survey, the de~clol support portion 18 of instrument 10 will have moved into ~j~cencr, for example, with a hidden tumor 354 located at the underside of sigmoid colon 316. Not seen in Fig. 11 are other organs such as the small intestine, the o,.~ ,. .., and the like.
For the forrn of cancer involvement~ for example as IGlllcsentcd at tumor 354, the - Ll~l...----t m~lity indic~ted by the invention calls for an open lap~,lollly in view of the in~ccessible location of tumor 354 with respect to a lapdloscopic-based procedure. The 30 plvcelur~ of the present invention also calls for that open lapar~lollly indiç~tion wherever the survey carried out with instrument 10 shows Iymph node involvement or other 1~ th~ f;C ~lice~ce The deeper regions of the anatomy explored during the radionuclide survey for Iymph node involvement as well as other ...~ th~lA~;c disease additionally looks above the 35 transverse colon and beneath the liver in the region of the g&~llohl~)alic lig~mP,nt Looking to Fig. 12, that region is l~resented at 360, the figure revealing the liver 362 in its more ,_ 214 l821 normal orientation; the ~omach 364 with lesser curvature 366 and greater curvature 368 located above the transverse colon 370. A portion of the gallbladder is seen at 372 and a portion of the greater om~ltllm is shown at 372 draping over the transverse colon 370.
In~uIlle,lt 10 is seen in a process of being use to carry out a radionuclide survey of the S region beneath the liver 362, the device positi~ ng the de~ end beneath the left lobe of the liver 362. The gastrohepatic li~m~nt generally is located above the lesser curvature 366 of stomach 364, for example, at 374.
Should Iymph node involvement or other met~t~tiC disease be determined to be present by this radionuclide survey, then a de t~....;n~tion of tre~tm~nt modality indicates a 10 procedure wherein open la~aro~ y is carried out as representing the most beneficial t modality. The region 360 being explored is involved with highly si~nific~nt organs such that an error in 1~L~&OSCOL c ploce~lur~ may lead to highly undesirable results, for example, the treating of a vein or artery.
Typically, the ~ulgeoll, upon being aypIi~d by the radionuclide survey that lymph 15 node involvement or other met~t~t~tic disease is present, will look further prior to t~-rmin~ting the laparoscopic procedure. For example, in Fig. 13, the liver 362 is shown retracted by a yI~ced~ including the use of retracting inslluIllents such as that shown at 376. This reveals the gastrohepatic li~m~nt 374. Surveyed at the lig~m~nt 374 by, for ex~mrIe, the i l:~llUlll~,nt 10, now id~ntifi~ at 10', are celiac nodes 378 which which are 20 shown in juxtaposition, with the splenic artery 380; the left gastric artery 382; the celiac trunk 384; and the colllluon hepatic artery 386. The delicacy of th~c~ ;s fi ~
brought to light by the pr~ ;on at this region of the inferior vena cava 388 and the abd~lllillal aorta 390. As is app~,nt, a location of lymph node involvement at the ga~l.~ep~tiC ligament 374 will result in a dete~Ilullation that the appropriate treatment 25 modality indicates that an open laparotomy is called for. Fig. 13 also reveals an id~ntifin~tion of an embedded and non-visual tumor shown in phantom at 390 within the interior of the left lobe of liver 362. This ,..~-t~ tic disease involvement will be located.
- for e~ullyle, by the r~di~tion I~yollsi~e iIl~llu~ nt 10 as position~lly Ie~l~,~nted at 10" as its detector support portion here r~I~,sented at 18" is brought into proximity with the 30 region of the underside of the liver 362 which is in the path of radiation em~n~ing from the locator coI-ce~ cl at the neoplastic region 390.
Sullllll~izing the method for dete.I..ining the treatment modality for neoplastic tissue as ~ cusse~ above, the following steps may be observed:
the patient is ~iministered an effective amount of a radiolabeled locator 35 which specifically binds a marker yroduced by or ~ssoci~ with neoplastic tissue;

the radiolabeled locator is p~ d to p,~e.~ ially concentrate at any marker to an extent ~lclcashlg the ratio of photon e ;s~;olls from the marker to background photon emicci~ns in the patient;
after the concent~tion of locator, the peritoneal cavity of the patient is ;..~..rn~ and access thereto is p~vided through a plurality of cavity access c~nn~ s;
a real time l~ u~pic camera arrangei-~Qt is provided with the display for *s~ i7~tion of select regions ûf the cavity by access to one or more of the c~nn~ c;
a la~aloscopic r~diqtion ~let~ o~ system as described is provided;
the colon is visually surveyed within the cavity by ~ccessing the camera 10 ~r~ne~ nl thereto through a select one or more of the access c~nn~ c and a de~ ination is made as to whether any visual in~ t~ of neoplastic tissue is present;
there is then carried out a r~tlion~lclide survey of the colon within the cavityby manipulating the elollg~te a~eC~;ilg tube of the r~ tion detection system through one or rnore of the access c~nn-ll~s to maneuver the window thereof along and in substantial 15 adjar,e-llc~ with the colon under vic~l~li7~tion at the camera display to the extent such visll~li7~tion is possible, to detect and differentiate tissue at which the locator has c~nr~ n~ by co,~ ion of the p~;c~lible output signals of the system to the position of the wih~dow with respect to the colon;
the radionuclide survey of the lymph nodes within the cavities then is 20 carricd out by mqnirlll~tin~ the elong~te. ~ccess;--g tube of the radiation detection system Lh~ one or me of the c~nn~ c to maneuver the window into substantial adjacency with the lymph nodes to detect and locate a lymph node or other ...~ ti~ disease at which the locator is concenl . ~lul by coll~,la~n of the ~lcept;ble output signals of the system to the position of the w-indow as vic~-"1i7~d from the camera ~- ; ngr n ~ nt display; and then a ~c~. --;n,-1;nn of the 1l~ l. nl modality is made based upon the visual survey of the colon and by the 1. l;onnÇ~ t'. surveys of the colon and lymph nodes.
Where the patient is diagnosed prior to the surveys as presenting neoplastic tissue - as ~ umor and the step for visually surveying the colon is calTied out with the ~hsen~e of any visual in~lication of neoplastic tissue; the radionuclide survey of the colon locates and dirr~ ~s tissue at which locator has con~-e nl . ,.I~A; and the step for carrying out the ~ io~ c~ survey of the lymph nodes locates no lymph node or met~st~tic disease at which locator has been concenl,~ted, then the determination of treatment modality in~ tPs that a L~a,oscû~ ~ ~lly assisted removal of the located and differ~nti~t~ neoplastic tissue is be~efi~l as a treatrne-~t modality. Under these conditions, the patient essenti~lly is ~-~ble at .~ trauma utili7ing minim~lly invasive laparoscopic surgery.

~. 21~4821 Where the patient is diagnosed prior to the surveys as presenting neoplastic tissue as primary tumor, and the step of visually surveying the colon is carried out in the absence of a visual indication of neoplastic tissue; and the step for carrying out a radionuclide survey of the colon locates and dirr~.lliates tissue at which locator is concentrated; and the 5 step for carrying out a radionuclide survey of the Iymph nodes locates a lymph node at which locator has c4n~el-1-~tcd, then the de~ .nin~l;on of a 1~ t modality in~ic~tes that the carrying out of an open lapalotollly to remove the located and dirft.~,nti~te~ neoplastic tissue is t~-n~ 1 as a llr~ nt modality.
Where the patient is diagnosed prior to the surveys as presen*ng neoplastic tissue 10 as primary tumor, and the visual surveying of the colon is carried out with the result of a p.~ ce of a visual indiratiorl of neoplastic tissue; and the radionuclide survey of the colon (lirÇ~.en~iates the tissue at which the locator is co~ce-n~ aled; and the step for carrying out radionuclide survey of the Iymph node locates no Iymph node or metastatic disease at which the locator is c~ncenl.àle l, then the d~ t~ n;n~l;on of tl~llnent modality in-lir~tr,c that 15 ca~ g out a la~oscopically ~csi~t~l removal of the located neoplastic tissue is beneficial as a ~ n~ ~l modality.
Where the patient is diagnosed prior to the surveys as presenting the neoplastictissue as l~;ull~,nt tumor; and the r~ion~lcli~e survey of Iymph nodes locates a Iymph node or other m.ot~ct~tic disease at which locator has concentrated; then the determination of 20 treatment m~l~lity indicates a procedure employing surgical resection would not be benrfiri~l to the patient. For this condition, the patient is spared the trauma ~soci~tf~ with an open lapa,oto.ll~ which would represent an "open and close" procedure with perhaps only rninomese~;o~ of blo~l~ing lesions or no further ~ tlnf llt Since certain changes may be made in the above-described method without 25 departing from the scope of the invention herein involved, it is intended that all matter cont~inesl in the description thereof or shown in the accompanying drawings shall be hlt~ ,t~,d as illustrative and not in a limiting sense.

Claims (7)

1. Use of a laparoscopic radiation detection system in which the use comprises providing a laparoscopic radiation detection system including:
a base portion engageable by a surgeon, an elongate accessing tube fixed to said base portion, dimensioned for slidable insertion through a cannula and with a length along a central axis effective to access neoplastic tissue within said peritoneal cavity, having a passageway extending therethrough, and a detector having support portion, including a window having a flat surface parallel with said central axis through which said photon emissions may pass, a crystal mount having a crystal receiving portion positioned at said detector support portion in adjacency with said window and configured of material attenuating radiation, a crystal having a rearward surface supported upon said crystal receiving portion to position a forward surface thereof in parallel adjacency with said window and responsive substantially only to said photon emissions passing through said window to derive an output;
a transmission assemblage extending from said crystal through said passageway for transmitting said output, and a signal treatment and control assembly coupled with said transmission assemblage for receiving and electrically treating said output to provide perceptible output signals representing those photon emissions at predetermined count levels above count levels of background photon emissions;
said system being for the use for determining the presence of photon emissions at lymph nodes so as to derive a treatment modality for neoplastic tissue within the peritoneal cavity of a patient.

2. A method for determining the treatment modality for neoplastic tissue within the peritoneal cavity of a patient, comprising the steps of:
administering to said patient an effective amount of radiolabelled locator which specifically binds a marker produced by or associated with neoplastic tissue;
permitting said radiolabelled locator to preferentially concentrate at any said marker to an extent increasing the ratio of photon emissions from said marker tobackground photon emissions in said patient;
after said concentration, insufflating said peritoneal cavity and providing access thereto through a plurality of cavity access cannulas;
providing a real time laparoscopic camera arrangement with a display for visualization of select regions of said cavity by access through one of said cannulas;
providing a laparoscopic radiation detection system including:
a base portion engageable by a surgeon, an elongate accessing tube fixed to said base portion, dimensioned for slidable insertion through a select one of said cannulas and with a length along a central axis effective to access neoplastic tissue within said peritoneal cavity, having a passageway extending therethrough, and a detector support portion, including awindow through which said photon emissions may pass, a crystal mount having a crystal receiving portion positioned at said detector support portion in adjacency with said window, a crystal having a rearward surface supported upon said crystal receiving portion to position a forward surface thereof in adjacency with said window and responsive to said photon emissions passing through said window to derive an output;
a transmission assemblage extending from said crystal through said passageway for transmitting said output, and a signal treatment and control assembly coupled with said transmission assemblage for receiving and electrically treating said output to provide perceptible output signals representing those photon emissions at predetermined count levels above count levels of said background photon emissions;
visually surveying the colon within said cavity by accessing said camera arrangement thereto through a select one of said access cannulas and detecting any visual indication of neoplastic tissue;

carrying out a radionuclide survey of the colon within said cavity by manipulating said elongate accessing tube of said radiation detection system through a select one of said access cannulas to maneuver said window along and in substantial adjacency with said colon under visualization at said camera arrangement display to detect and differentiate tissue at which said locator has concentrated by correlation of said perceptible output signals to the position of said window with respect to said colon;
carrying out a radionuclide survey of lymph nodes within said cavity by manipulating said elongate accessing tube of said radiation detection system through a select one of said cannulas to maneuver said window under visualization at said camera arrangement display into substantial adjacency with said lymph nodes to detect and locate a lymph node or other metastatic disease at which said locator has concentrated by correlation of said perceptible output signals to the position of said window; and determining the said treatment modality based upon said visual survey of the colon and by said radionuclide surveys of the colon and lymph nodes.

3. The method of claim 2 in which:
said patient is diagnosed prior to said surveys as presenting said neoplastic tissue as primary tumor, said step for visually surveying the colon is carried out with the absence of a said visual indication of neoplastic tissue;
said step for carrying out a radionuclide survey of the colon locates and differentiates said tissue at which said locator has concentrated;
said step for carrying out a radionuclide survey of the lymph nodes locates no lymph node or metastatic disease at which said locator has concentrated; and then said determination of said treatment modality indicates that a laparscopically assisted removal of said located and differentiated neoplastic tissue is beneficial as a said treatment modality.

4. The method of claim 3 in which:
said patient is diagnosed prior to said surveys as presenting said neoplastic tissue as primary tumor, said step for visually surveying the colon is carried out in the absence of a said visual indication of neoplastic tissue;
said step for carrying out a radionuclide survey of the colon locates and differentiates said tissue at which said locator has concentrated;

said step for carrying out a radionuclide survey of the lymph nodes locates a lymph node at which said locator has concentrated; and then said determination of said treatment modality indicates that the carrying out an open laparotomy to remove said located and differentiated neoplastic tissue is beneficial as treatment modality.

5. The method of claim 2 in which:
said patient is diagnosed prior to said surveys as presenting said neoplastic tissue as primary tumor, said step for visually surveying the colon is carried out with the result of a presence of a said visual indication of neoplastic tissue;
said step for carrying out a radionuclide survey of the colon differentiates said tissue at which said locator has concentrated;
said step for carrying out a radionuclide survey of the lymph nodes locates no lymph node or metastatic disease at which said locator has concentrated; and the said determination of said treatment modality indicates that carrying out a laparoscopically assisted removal of said located neoplastic tissue is beneficial as a said treatment modality.

6. The method of claim 2 in which:
said patient is diagnosed prior to said surveys as presenting said neoplastic tissue as primary tumor, said step for carrying out a radionuclide survey of the colon differentiates said neoplastic tissue at which said locator has concentrated; and then said determination of said treatment modality indicates that carrying out a laparoscopically assisted removal of said located neoplastic tissue is beneficial as said treatment modality.

7. The method of claim 2 in which:
said patient is diagnosed prior to said surveys as presenting said neoplastic tissue as recurrent tumor, said step for carrying out a radionuclide survey of lymph nodes locates a lymph node or other metastatic disease at which said locator has concentrated; and then said determination of said treatment modality indicates a procedure employing surgical resection would not be of benefit to said patient.