Radioguided occult colonic lesion identification (ROCLI) during open and laparoscopic surgery

AIMS AND BACKGROUND: Intraoperative localization, during open and laparoscopic surgery, of small, nonpalpable colonic lesions located at peculiar sites or with concurrent inflammatory bowel alterations (diverticulosis, perivisceritis) is often difficult. The aim of our work was to assess the validity of radioguided identification after preoperative labeling. METHODS AND STUDY DESIGN: Patients who were candidates for colon surgery for occult lesions that, because of their size and location, were assumed to be difficult to detect, underwent colonoscopy 1 to 2.5 hours before surgery. A small dose of labeled albumin macroaggregates was injected with a sclerotherapy needle into the subserosa underneath the lesion. Immediately following the injection the lesion was identified with a transcutaneously placed gamma detecting probe. Intraoperative tracer detection was performed either during open surgery or by means of a laparoscopic probe (detection time 3-5 mins). The position of the lesion was marked with a suture or with a clip. Surgery was performed according to the type of lesion to be treated. RESULTS: In our initial clinical experience 15 colon lesions were preoperatively marked in 14 patients and were subsequently detected during surgery (four under laparoscopy) with a gamma detecting probe. This technique allows highly accurate, fast, and inexpensive surgical localization of lesions without irradiation and without complications. CONCLUSION: Our experience shows that preoperative endoscopic marking of nonpalpable colon lesions with 99mTc-labeled albumin macroaggregates followed by intraoperative detection with a gamma probe is a useful clinical method that is highly accurate and without complications.     

The value of immunoscintigraphy for the operative retreatment of colorectal cancer. Limitations of a new diagnostic method

In 42 patients with suspected recurrent colorectal cancer, results of conventional diagnostic methods were compared with those of immunoscintigraphy. In 69% of all cases, the intraoperative findings of a second-look operation served for validation, whereas in 31% close follow-up was used. Recurrent tumors were successfully localized in 83% of patients by conventional methods, whereas immunoscintigraphy was expressive in 57% of cases. Immunoscintigraphy was disappointing especially because of its low sensitivity (23%) and low predictive value (positive, 33%; negative, 37%) with regard to successful diagnosis of extrahepatic tumors compared with the results of conventional methods (77% sensitivity; positive, 94%; negative, 79%). The rate of false-positive results was relatively high with immunoscintigraphy (n = 12), 83% of which were related to extrahepatic recurrent tumors. The value of immunoscintigraphy using an immunococktail of 131-J-labeled F(ab')2 fragments of monoclonal antibodies against CEA, with Ca 19-9 as an additional diagnostic tool for early detection of recurrent colorectal cancer, must therefore be viewed critically.     

Use of radiolabelled monoclonal antibodies in patients with primary and metastatic large bowel cancer.

Accurate assessment of the extent of primary and metastatic large bowel cancer is critical to surgical decision making and to providing reliable prognostic information. This prospective study compared external gamma camera images and an intraoperative hand-held gamma detecting probe for detection of radiolabelled monoclonal antibody (B72.3) in 28 patients with primary and metastatic large bowel cancer. Fourteen patients received 0.2 to 20 mg (2 or 5 mCi) 111indium-labelled monoclonal antibody B72.3 followed by whole body imaging scan with an external gamma detector/camera on two occasions 24 h apart within 7 days after injection. Fourteen patients received 1.0 mg (2.0 mCi) 125iodine-B72.3 followed by intraoperative probe evaluation 2-3 weeks postinjection. Mean patient ages for the two groups were 60 years (range 28-75 years) and 63 years (range 43-77 years), respectively. Disease sites were primary in the large bowel in six patients and primary as well as metastatic in 22 patients. External scanning detected 111indium-B72.3 uptake in 1/5 primary lesions, 1/7 hepatic and 1/3 extrahepatic sites. The intraoperative gamma probe localized disease in 1/3 primary lesions, 7/11 hepatic and 3/3 extrahepatic sites. The intraoperative gamma probe had a sensitivity of 71% for detection of metastases compared with a 20% sensitivity using the external gamma scan method (P = 0.03). 125iodine-labelled B72.3 influenced the extent of the operative procedure in 4/14 (29%) patients; immunolocalization with external gamma detection did not alter the operative procedure in the 14 patients studied.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of surgical gamma probe for the detection of lymph node metastases in differentiated thyroid cancer

BACKGROUND: Patients with differentiated thyroid cancer (DTC) after total or near-total thyroidectomy require 131I therapy. After surgery the persistence of lymph node metastases in our series of patients was frequent (30%). Such patients are preferentially treated with radioiodine and shifted to surgical reintervention when the nodal lesions persist after two 131I treatments. AIM: Use of an intraoperative radioactive probe (C-TraK) to allow a more radical surgical approach in thyroid cancer patients submitted to surgery for lymph node metastases. METHODS AND RESULTS: After adequate withdrawal of L-thyroxine suppressive therapy six patients were given high 131I doses followed by post-therapy WBS which demonstrated cervical activity in 5 patients and peri-jugular activity in 1. Surgery with the help of a gamma probe allowed to detect and remove all metastatic nodes. After excision all surgical specimens showed higher radioactive counts with respect to the background. The post-surgical scan showed the disappearance of all areas of 131I uptake. Histology confirmed the presence of metastatic lesions from papillary thyroid cancer. CONCLUSIONS: We conclude that the use of a gamma probe can be successful in patients with metastatic neck lesions resistant to 131I treatment, particularly in patients with nonpalpable lesions.     

Radioimmunoguided breast surgery using radiolabeled antibody NR-LU-10 FAB: a pilot study

AIM AND BACKGROUND: Radioimmunoguided surgery using radiolabeled NR-LU-10 Fab was evaluated as a method of intraoperative breast cancer detection. METHODS: Breast cancer patients were injected intravenously with 125I (74 MBq) labeled NR-LU-10 Fab (5 mg) and then underwent tumor excision 2, 4 or 7 days later, during which time the gamma detector probe was used to evaluate the primary tumor for evidence of radioactive uptake. RESULTS: Intraoperative probing revealed tumor localization in 7 of 10 patients (70%). Gamma probe counts of the excised tumor were elevated in all patients, although high counts in surrounding non-malignant tissue obscured the ability to detect the tumor in vivo in 3 patients. One patient with bilateral breast cancer was found to have a separate focus of occult tumor in each breast using the gamma detector probe. CONCLUSIONS: Radiolabeled NR-LU-10 Fab possesses favorable pharmokinetics and tumor-binding ability as a targeting agent. However, binding to non-malignant tissue limits its role in the intraoperative evaluation of tumor margins in breast cancer patients. Its role in other malignancies should be explored.     

Intraoperative gamma probe detection of head and neck paragangliomas with 111In-pentetreotide: a pilot study

AIMS AND BACKGROUND: The aim of this study was to assess whether intraoperative radiolocalization of head and neck paragangliomas with 111In-pentetreotide may increase surgical effectiveness, reducing the risk of recurrence. METHODS: Our study included eight patients with untreated, recently diagnosed paragangliomas (four unilateral and four bilateral tumors of the carotid body). After i.v. injection of approximation 150 MBq 111In-pentetreotide, preoperative somatostatin receptor scintigraphy (SRS) was performed. SPECT of the neck was performed at four hours and planar images of the head and neck were also obtained at four and 24 hours post injection. Scintigraphy was always compared with the results of conventional imaging methods (MRI, angiography and sonography). Intraoperative detection was performed on 11 lesions 24 hours after radiopharmaceutical administration using a handheld gamma probe. RESULTS: Preoperative SRS showed high radiotracer uptake in all patients. All the intraoperatively detected lesions were radically resected and histologically confirmed to be involved by tumor. No false positive results were recorded. Gamma probe detection revealed a small intracranial extension not detected by other imaging methods in a patient with a paraganglioma of the right carotid, and partial involvement of the carotid artery in another patient. During follow-up (median 3.5 years; range, 4 months-7 years) all patients remained disease free according to all parameters. CONCLUSIONS: To our knowledge, this is the first experience of radioguided surgery in paraganglioma. Although our study included a relatively small number of patients, we suggest that intraoperative gamma probe detection may be a powerful tool to improve surgical effectiveness.     

Immunoscintigraphy of human lung squamous cell carcinoma using an iodine-131 labelled monoclonal antibody (Po66)

Monoclonal antibody (McAb) Po66 has been obtained by immunisation of mice against a human lung squamous cell carcinoma. The in vitro reactivity of the antibody with cancer cells and its ability to localise in human lung cancer xenografts growing in nude mice have been reported earlier. Presented here is the first clinical evaluation of the antibody for scintigraphic detection of tumours. Thirty-three patients with histologically confirmed primary non-small cell lung carcinoma were investigated. Twenty-seven of them were explored at the preoperative stage and six at 6 months after surgery. Biodistribution results were obtained from seven operated patients by combining injections of 131I-radiolabelled Po66 and of 125I-labelled unrelated immunoglobulin. The localisation index was three times higher for this specific antibody. Immunoscintigraphy detected 78% of primary tumours and 100% of recurrences. In this short series of patients, immunoscintigraphy proved helpful in the assessment of tumour spread in four patients by visualising localisations in the mediastinum or the contralateral lung which the CT scan had failed to demonstrate. Immunoscintigraphy was also more efficient than plain chest X-ray for the detection of local tumour recurrences.     

Detection of sentinel nodes by lymphoscintigraphy and gamma probe guided surgery in vulvar neoplasia

BACKGROUND: Pathologic lymph node status is the most important prognostic factor in vulvar cancer; however, complete inguinofemoral node dissection is associated with significant morbidity. Intraoperative lymphoscintigraphy associated with gamma detecting probe-guided surgery has proved to be reliable in the detection of sentinel node (SN) involvement in melanoma and breast cancer patients. The present study evaluates the feasibility of the surgical identification of inguinal sentinel nodes using lymphoscintigraphy and a gamma detecting probe in patients with early vulvar cancer. METHODS: Technetium-99-labeled colloid human albumin was administered perilesionally in 44 patients. Twenty patients had T1 and 23 had T2 invasive epidermoid vulvar cancer; one patient had a lower-third vaginal cancer. An intraoperative gamma detecting probe was used to identify SNs during surgery. Complete inguinofemoral node dissection was subsequently performed. SNs underwent separate pathologic evaluation. RESULTS: A total of 77 groins were dissected in 44 patients. SNs were identified in all the studied groins. Thirteen cases had positive nodes: the SN was positive in all of them; in 10 cases the SN was the only positive node. Thirty-one patients showed negative SNs: all of them were negative for lymph node metastasis. CONCLUSIONS: Lymphoscintigraphy and SN biopsy under gamma detecting probe guidance proved to be an easy and reliable method for detection of SNs in early vulvar cancer. If these preliminary data will be confirmed, the technique would represent a real progress towards less aggressive treatment in patients with vulvar cancer.     

Performances of a new prototype handheld scintillating probe for the search of sentinel lymph nodes in breast cancer.

AIM: The aim of this study is to evaluate the performances of a new prototype handheld gamma probe in a series of patients with infiltrative breast cancer justifying sentinel lymph node (SLN) excision. METHODS AND PATIENTS: SLN excision was performed on nine patients being treated for infiltrative breast cancer. After preoperative radio-isotope injection and lymphoscintigraphy, individual removal of all radioactive nodes was performed after their localisation using a novel new prototype handheld gamma intraoperative probe named CarolIReS. The activity of SLN following resection has been measured by a gamma ray counter. The mean geometrical detection efficiency of this gamma ray counter has been obtained by Monte Carlo simulation. RESULTS: With respect to the total number of SLNs identified by the CarolIReS probe, the detection probability was 80% for the lymphoscintigraphy. A mean number of 2.2 (1-5) SLNs per patient was detected after the complete SLN procedure. Among the removed SLNs, 19 were axillary SLN, 17 were located in the level I of Berg, two were located in the Rotter area and one was an intramammary SLN (ISLN) located in the lower inner area of the breast. The detection efficiency of the CarolIReS probe ranged from 2.1 to 100.0cpskBq(-1) referred to the activity of the SLN at the time of the surgery. CONCLUSION: This study shows that the CarolIReS probe is well adapted to the SLN detection and allows an efficient identification of both axillary and intramammary lymph nodes.     

The intraoperative detection of ovarian adenocarcinoma using radiolabeled CC49 monoclonal antibody and a hand-held gamma-detecting probe

A phase II study to evaluate the safety and efficacy of the 125I-radiolabeled anti-TAG-72 monoclonal antibody, CC49, as a component of a system for the intraoperative detection of occult ovarian cancer deposits was carried out at the University of Nebraska Medical Center. Patients entered into the study were to have surgery for evaluation of their disease status. The primary objective of this study was to determine the ability of a gamma-detecting probe (GDP), the Neoprobe 1000, to intraopertively localize sites of disease not identified by traditional surgical or radiographic evaluation. It was postulated that improved detection of cancer foci might allow for therapeutic excision or might result in an alteration of subsequent treatment. Ten patients were enrolled in the study between May 1993 and March 1994. Nine of the patients were undergoing second-look surgery after completing primary chemotherapy. The remaining patient was having surgery to assess possible cancer recurrence. All patients received an intravenous injection of 2 mCi/1 mg 125I-radiolabeled CC49 without complication. After a mean of 24.5 days, the patients' background radiation counts were deemed low enough for accurate intraoperative cancer localization, and surgery was performed. Any visibly or palpably abnormal areas were biopsied after being evaluated with the GDP. Any areas suspicious for malignancy by GDP evaluation were also biopsied. Two patients without evident disease by radiographic or surgical examination had histologically confirmed metastases localized by the GDP. Four patients had obvious disease at surgery which was variably confirmed by the GDP; two of these patients had baseline elevations in circulating TAG-72 antigen levels that may have affected binding of antibody to the tumor. This system of radioimmunoguided surgery was well tolerated and practical in its application, and it permitted disease detection that resulted in potentially beneficial changes in patient management.     

Improvement in intramammary sentinel lymph node removal using a novel prototype hand held probe during breast conservative surgery

Summary Intramammary sentinel lymph node excision during breast conservative surgery was performed, in this case report, using a prototype intraoperative gamma probe. In contrast to the four axillary sentinel lymph nodes that were subnormal, the excised intramammary sentinel lymph node was massively invaded by cancer cells. Therefore this finding had profound implication for the staging of the tumor and for treatment selection. This case report illustrates that an efficient intraoperative gamma probe is useful to locate and remove intramammary sentinel lymph node in breast cancer patients treated with breast conservation.     

Radioimmunoscintigraphy in Patients with Ovarian Cancer

The use of radiolabeled monoclonal antibodies (MoAbs) has significantly improved the ability to detect tumor antigens, thus improving in vivo tumor diagnosis and treatment. The management of ovarian carcinoma still poses a challenging medical problem. Clinical trials using radioimmunoscintigraphy or a hand-held gamma detection probe intraoperatively were performed in patients with clinical evidence of primary or recurrent ovarian cancer. Immunoscintigraphy of ovarian cancer lesions has been performed mainly with ^99mTc, ¹¹¹In and ¹²³I labeled with HMFG1, HMFG2, OC-125, B72.3, H17E2, OVTL3, MoAb170, Mov18 and other MoAbs. Antibody guided imaging using radioimmunoscintigraphy has demonstrated improved targeting of ovarian cancer, resulting in a highly sensitive and specific method. However, it is not yet known which type of MoAb is the most efficient for radioimmunoscintigraphy. Since these tumors represent a potentially curable disease, radioimmunoscintigraphy could contribute mainly to accurate staging as a supplementary to conventional diagnostic methods, as well as for the localization of active disease after chemotherapy and monitoring for the presence of recurrent disease. Nevertheless, prospective studies in a large number of patients should be undertaken in order to further evaluate the diagnostic contribution of this approach.     

Image-guided tumor resection using real-time near-infrared fluorescence in a syngeneic rat model of primary breast cancer

Tumor involvement of resection margins is found in a large proportion of patients who undergo breast-conserving surgery. Near-infrared (NIR) fluorescence imaging is an experimental technique to visualize cancer cells during surgery. To determine the accuracy of real-time NIR fluorescence imaging in obtaining tumor-free resection margins, a protease-activatable NIR fluorescence probe and an intraoperative camera system were used in the EMR86 orthotopic syngeneic breast cancer rat model. Influence of concentration, timing and number of tumor cells were tested in the MCR86 rat breast cancer cell line. These variables were significantly associated with NIR fluorescence probe activation. Dosing and tumor size were also significantly associated with fluorescence intensity in the EMR86 rat model, whereas time of imaging was not. Real-time NIR fluorescence guidance of tumor resection resulted in a complete resection of 17 out of 17 tumors with minimal excision of normal healthy tissue (mean minimum and a mean maximum tumor-free margin of 0.2 ± 0.2 mm and 1.3 ± 0.6 mm, respectively). Moreover, the technique enabled identification of remnant tumor tissue in the surgical cavity. Histological analysis revealed that the NIR fluorescence signal was highest at the invasive tumor border and in the stromal compartment of the tumor. In conclusion, NIR fluorescence detection of breast tumor margins was successful in a rat model. This study suggests that clinical introduction of intraoperative NIR fluorescence imaging has the potential to increase the number of complete tumor resections in breast cancer patients undergoing breast-conserving surgery.     

FDG-PET probe-guided surgery for recurrent retroperitoneal testicular tumor recurrences

Aim

Tumor marker based recurrences of previously treated testicular cancer are generally detected with CT scan. They sometimes cannot be visualized with conventional morphologic imaging. FDG-PET has the ability to detect these recurrences. PET probe-guided surgery, may facilitate the extent of surgery and optimize the surgical resection.

Methods

Three patients with resectable 2nd or 3rd recurrent testicular cancer based on elevated tumor markers after previous various chemotherapy schedules and resections of residual retroperitoneal tumor masses were included in this study. A diagnostic FDG-PET was performed and a hotspot in previously operated area of the retroperitoneal space in all three patients was visualized. PET probe-guided surgery was performed using a high-energy gamma probe 3 h post-injection of 500 MBq FDG.

Results

All patients showed extended adhesions and scar tissue in the retroperitoneal area due to the previous surgeries. Pre-operative PET/CT scan showed a good correlation with intra-operative PET probe-guided detection of recurrent lesions. There was a high target to background ratio (TGB) of 5:1 during the procedure. In one patient, a 2 cm large lesion, which did not show on pre-operative FDG-PET scan, was detected with the PET probe. Histopathologic tissue evaluation demonstrated recurrent vital tumor in all PET probe positive lesions.

Conclusions

PET probe-guided surgery seems to be a promising tool to localize FDG-PET positive lesion in recurrent testicular cancer in hardly accessible surgical locations. PET probe-guided surgery might be a useful technique in surgical oncology for recurrent testicular cancer and has the potential to be applied in surgery of other malignant diseases.     

Usefulness of a solid-state gamma camera for sentinel node identification in patients with breast cancer

BACKGROUND: A solid-state gamma camera was recently developed. This tool may enable intra-operative imaging of sentinel nodes in breast cancer. The aim of the present study was to evaluate the usefulness of a solid-state gamma camera for the pre- and intra-operative identification of sentinel nodes in patients with breast cancer. METHODS: Breast cancer patients with clinically negative nodes underwent sentinel node biopsy using dye and radioisotopes. Lymphoscintigraphy using both the conventional Anger camera and the solid-state gamma camera was performed the day before surgery. Sentinel nodes were intra-operatively identified using the gamma probe and imaged with a solid-state gamma camera, and then excised. When several sentinel nodes were present, these steps were repeated. RESULTS: Twenty-nine patients (30 basins) were enrolled in the study. The mean patient age was 54 years and the mean tumor size was 16 mm. A total of 41 sentinel nodes were identified using the Anger camera or the solid-state gamma camera pre-operatively. Thirty-eight sentinel nodes (92.7%) were identified using both the Anger camera and the solid-state gamma camera, 1 sentinel node (2.4%) was identified using the Anger camera alone, and 2 sentinel nodes (4.9%) were identified using the solid-state gamma camera alone. A total of 63 sentinel nodes were identified using the gamma probe or the solid-state gamma camera intra-operatively, and were excised. Fifty-seven sentinel nodes (90.5%) were identified using both the gamma probe and the solid-state gamma camera, 3 sentinel nodes (4.8%) were identified using the gamma probe alone, and 3 sentinel nodes (4.8%) were identified using the solid-state gamma camera alone. CONCLUSIONS: The solid-state gamma camera is useful for pre- and intra-operative identification of sentinel nodes in breast cancer. The significance of the solid-state gamma camera could be that it compensates for the gamma probe when the gamma probe cannot identify some sentinel nodes because of the shine through effect, and avoids leaving the residual sentinel nodes behind the axilla intra-operatively.     

Intraoperative radiochromoguided mapping of sentinel lymph node in colon cancer

AIMS AND BACKGROUND: The aim of our study was to assess the feasibility of sentinel lymph node (SLN) detection in colon cancer using a radiochromoguided technique. The regional lymph node status is crucial for colorectal cancer staging and the stage of disease at the time of diagnosis is the main factor influencing therapeutic decision-making and patient survival. METHODS AND STUDY DESIGN: Between April and June 2001 eight patients with colon cancer were studied by radiochromoguided sentinel lymph node mapping. At the time of surgery 2 ml of patent blue dye was injected around the tumor, followed after 10 minutes by 2 ml of 99mTc-labeled albumin. After 30 minutes the SLN was identified by a gamma probe. Surgery was completed by standard resection. The SLN was processed for permanent hematoxylin and eosin staining and for immunohistochemical examination with anti-CEA and anti-cytokeratin antibodies. RESULTS: SLNs were identified in six patients; two were negative for metastasis by hematoxylin-eosin and immunohistochemical examination, two were positive for metastasis by both methods, and two were negative for metastasis by hematoxylin-eosin but positive by immunohistochemical examination. There were no false negative SLNs and no complications occurred. CONCLUSION: The actual utility of SLN detection for prognostic purposes is still unknown, but intraoperative radiochromoguided SLN mapping is technically feasible in colon cancer, although it is associated with more technical difficulties than in breast cancer and malignant melanoma.     

Dye- and gamma probe-guided sentinel lymph node biopsy in breast cancer patients: using patent blue dye and technetium-99m-labeled human serum albumin

BACKGROUND: Sentinel lymph node (SLN) biopsy is a promising method for the diagnosis of the axillary nodal status. We examined the availability of the SLN biopsy using two mapping procedures: the dye- and gamma probe-guided method, and preoperative lymphoscintigraphy by gamma camera imaging. METHODS: We enrolled 48 patients with breast cancer. Technetium-99m-labeled human serum albumin was injected into the subdermal tissue above the primary tumor or biopsy cavity, and preoperative gamma camera imaging was performed. After induction of general anesthesia, patent blue dye was injected into the peritumoral area prior to the surgical procedure. A handheld gamma-detection probe was used to assist in SLN detection. Careful dissection was performed to identify blue-stained afferent lymphatic vessels and nodes. An SLN was defined as any blue and/or radioactive node, and was excised. After SLN biopsy, axillary lymph node dissection of level I, II, and III was completed, in order to confirm the diagnostic ability of the SLN biopsy. RESULTS: Intraoperative SLN identification of axillary lesions was successful in 43 of 48 patients (90%). The dye- and gamma probe-guided method was successful in 25 patients (52%), the dye-guided method alone succeeded in 11 patients (23%), and the gamma probe-guided method alone succeeded in 7 patients (15%). Preoperative lymphoscintigraphy revealed axillary focal accumulations in 29 of 48 patients (60%). All patients who underwent successful preoperative SLN identification by lymphoscintigraphy had successful intraoperative SLN identification. A diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100% were achieved in the diagnosis of axillary metastasis. Internal mammary SLNs were identified in four patients intraoperatively, but we could not detect cancer metastasis in the internal mammary SLNs. CONCLUSIONS: The dye-guided and gamma probe-guided methods were complementary. Preoperative lymphoscintigraphy was useful to predict intraoperative SLN identification. Further study is necessary to assess the role of SLN biopsy of the internal mammary lymph nodes.     

Bone Marrow Immunoscintigraphy Compared with Conventional Bone Scintigraphy for the Detection of Bone Metastases

Immunoscintigraphy of haematopoetic bone marrow was compared to conventional bone scanning in 141 patients with malignant disease. Forty patients had breast cancer, 25 prostatic carcinoma, 14 kidney or bladder cancer, 13 bronchial carcinoma, 39 malignant lymphoma and 10 multiple myeloma. A total of 18 800 skeletal regions were evaluated. Marrow scans showed more metastatic lesions than bone scanning in all patient subgroups. Computerized tomography was concordant with bone marrow scintigraphy in 83.3% of 323 skeletal sites. Bone marrow scans in 30 control patients with fever of unknown origin were abnormal only in 3 patients and in only 7 out of 2 135 skeletal regions examined. In patients with malignant lymphoma, bone marrow histology or aspiration cytology was concordantly positive in 14 and concordantly negative in 17 patients. We conclude that immunoscintigraphy of haematopoetic bone marrow provides a reliable, sensitive and safe novel approach for non-invasive detection of metastatic spread to the skeleton.     

Sentinel lymph node detection with Tc-99m tin colloids in patients with esophagogastric cancer

BACKGROUND: The aim of this study was to determine by radioisotope use whether the sentinel lymph node concept is applicable to esophagogastric cancers. In addition, we examined radioactivities of hot nodes and compared them with the sensitivity of a gamma probe. METHODS: The subjects were 44 patients, 23 with esophageal cancer and 21 with gastric cancer. The day before surgery, patients underwent endoscopic submucosal injection of 184 MBq of Tc-99m tin colloids into sites surrounding the tumor. Radioisotope activities of lymph nodes dissected at surgery were measured with a well-typed gamma detector and each lymph node was categorized as a hot or cold node. Histopathology of the lymph nodes was examined by hematoxylin and eosin staining. Radioisotope activities and histopathological results were compared to determine whether radioisotope flow reflects lymphatic flow to regional lymph nodes. The sensitivity of a gamma probe was measured in a laboratory study and the relation between the radioisotope activities of hot nodes and the detection sensitivity of the gamma probe was examined. RESULTS: Histopathological examination revealed lymph node metastasis in 18 of the 44 patients. In 15 of these 18 patients, metastatic foci were recognized in at least one hot node. Subsequent analysis was performed on the 36 patients in whom tumor invasion was confined to the muscle layer and in whom endoscopic clippings had not been applied. Lymph node metastases were observed in 12 of these 36 patients. In these 12 patients, at least one hot node was positive for metastasis. The laboratory study revealed that the gamma probe was able to detect radioisotope activities of >/=0.02 micro Ci. Thirty-two of 63 (51%) esophageal cancer hot nodes and 16 of 86 (19%) gastric cancer hot nodes showed radioisotope activities below the detection sensitivity of the gamma probe. CONCLUSION: The sentinel lymph node concept is applicable to patients with esophageal and gastric cancers; however, further studies are necessary to identify hot nodes accurately using gamma probes.     

Radioimmunoguided surgery in primary colon cancer

Radioimmunoguided surgery (RIGS), the intraoperative use of a hand-held gamma detecting probe (GDP) to identify tissue containing radiolabeled monoclonal antibody (MAb), was performed upon 30 patients with primary colon carcinoma. Each patient received an intravenous injection of MAb B72.3 (1.0 to 0.25 mg) radiolabeled with 125I (5.0 to 1.0 mCi) 8 to 34 days before exploration. The GDP was used to measure radioactivity in colon tissue, tumor bed, nodal drainage areas, and areas of suspected metastases. Antibody localized to histologically documented tumor in 23 of 30 patients (77%). Tumor margins were more clearly defined in 20 of 30 patients (67%). GDP counts led to major alterations in surgical resection in five patients (17%) and changes in adjuvant therapy in four (14%). GDP counts identified occult liver metastases in two patients (7%) and correctly indicated the benign nature of liver masses in three (10%). In four patients (13%), occult nodal metastases were identified. RIGS can precisely delineate tumor margins, define the extent of nodal involvement, and localize occult tumor, providing a method of immediate intraoperative staging that may lessen recurrences and produce higher survival rates.