Neurologic complications of gastric partitioning.

Six patients who had gastric reduction for morbid obesity suffered severe complex neurologic disturbances that included confusion and inappropriate behavior. All were profoundly weak or paraplegic, and recovery was delayed and incomplete. Encephalopathy was documented by EEG and neurologic examination. The cause is uncertain. Acute catabolism of lipid may predispose to damage of the nervous system, but relative vitamin deficiency is a more obvious and treatable explanation.

Radioimmunoguided surgery challenges traditional decision making in patients with primary colorectal cancer.

BACKGROUND: Initial experience with the radioimmunoguided surgery system (RIGS) has been found to impact on decision making in patients with recurrent colorectal cancers. Reported here is experience with RIGS-influenced therapeutic decisions in patients with primary colorectal cancer. METHODS: Thirty-six evaluable patients with primary cancers were injected with the second-generation anti-tumor-associated glycoprotein antibody CC49 labeled with 1 to 2 mCi iodine 125. Pharmacokinetic determination and precordial counts were obtained after injection and weekly until levels were less than 20 counts/2 sec. At surgery abdominal and pelvic explorations were performed, first traditionally by inspection and palpation and then with the hand-held, gamma-detecting probe. RIGS-positive tissue was considered cancerous and removed if possible. RESULTS: Thirty patients (83%) had positive antibody localization at surgery. Of those patients with localization, in 24 (80%) additional information was obtained at the time of surgery. In 11 patients (34%) staging changes were made as a result of RIGS exploration. New findings resulted in operative changes in nine patients (25%). Eleven (30%) of the original 36 patients became eligible for adjuvant chemotherapy based on current recommendations because of RIGS findings. CONCLUSIONS: In conclusion, the RIGS system provides immediate staging information that impacts on therapeutic interventions, challenging the adequacy of traditional procedures alone for primary colorectal cancer exploration.

Intraoperative localization of neuroendocrine tumors with 125I-TYR(3)-octreotide and a hand-held gamma-detecting probe.

BACKGROUND: This study evaluates a novel method of intraoperative localization of endocrine gastroenteropancreatic tumors with a hand-held gamma-detecting probe to detect in situ tumor binding of the radioiodinated somatostatin analog 125I-TYR(3)-octreotide. METHODS: Seven patients with biochemical and radiologic evidence of a specific endocrine tumor, one patient with biochemical evidence of gastrinoma but no tumor localized by conventional imaging techniques, and four patients with equivocal preoperative biochemical or radiologic study results but suspected of harboring a neuroendocrine tumor underwent abdominal exploration with intraoperative injection of 125I-TYR(3)-octreotide. 298 +/- 63 microCi. A hand-held gamma-detecting probe was used during operation to determine whether gross tumor accumulated the radiolabeled analog and occult tumor could be detected. Positive uptake was defined as tumor/background ratios exceeding 2:1. RESULTS: The tumor in all seven patients with gross disease accumulated 125I-TYR(3)-octreotide. Occult tumor beyond that appreciated with preoperative imaging or by routine operative exploration was detected in a patient with carcinoid tumor. In the patient with the occult gastrinoma the probe detected the lesion within the duodenal bulb before duodenotomy and also predicted what proved histologically to be positive peripancreatic adenopathy. There was a single false-positive reading from the stomach in a patient with suspected carcinoid tumor in whom no tumor could be found grossly or histologically. A pancreatic mass that probed negative proved to be an adenocarcinoma of ductal origin. CONCLUSIONS: Tumor-specific peptide-receptor binding can be detected in situ with 125J-TYR(3)-octreotide and a hand-held gamma-detecting probe. This technique may facilitate neuroendocrine tumor localization and operative cytoreduction.

Pilot study evaluating the intraoperative localization of radiolabeled monoclonal antibody CC83 in patients with metastatic colorectal carcinoma.

BACKGROUND: CC83, a second-generation monoclonal antibody (MAb) against tumor-associated glycoprotein TAG-72 has been shown to have a higher affinity constant than the anti-TAG MAbs CC49 and B72.3. Clinical studies have shown the effectiveness of both CC49 and B72.3 radiolabeled MAbs in localizing colorectal carcinoma with a hand-held gamma-detecting probe during operation. This current study was designed to assess the safety and tumor-binding ability of radiolabeled CC83 MAb in this setting. METHODS: Seventeen patients with recurrent colorectal cancer underwent intravenous injection with CC83 MAb radiolabeled with iodine 125 (2.0 mCi125I/0.2 mg CC83 MAb). Exploratory laparotomy was carried out 21 to 28 days after injection, consisting of a thorough traditional exploration followed by a survey with a hand-held gamma-detecting probe. All traditionally suspicious and probe-positive tissue was either biopsied or resected and subsequently examined for the presence of carcinoma by using routine histochemical staining techniques. RESULTS: Thirty-two sites were identified as suspicious for cancer by traditional surgical exploration and 39 through intraoperative survey with a hand-held gamma-detecting probe in the seventeen patients completing the study. Biopsy or resection yielded 27 tumor sites when tissue was evaluated by using routine hematoxylin-eosin staining. All 27 tumor sites were localized by the radiolabeled CC83 MAb, whereas 12 additional sites were RIGS positive but hematoxylin-eosin negative, resulting in a sensitivity and positive predictive value of 100% and 69%, respectively. Traditional methods of exploration detected 23 of 27 tumor sites (85% sensitivity), and nine false-positive sites were recorded (72% positive predictive value). Occult tumor was found by using CC83 MAb in four (15%) of 27 sites, altering the surgical plan in three patients. CONCLUSIONS: This initial study indicates that CC83 MAb, when used with RIGS, is safe and sensitive in detecting recurrent intraabdominal colorectal cancer.

Intraoperative radioimmunodetection of ovarian cancer using monoclonal antibody B72.3 and a portable gamma-detecting probe.

To assess the value of radioimmunoguided surgery in the intraoperative detection of ovarian cancer, we used monoclonal antibody B72.3, radiolabeled with 125I, and a hand-held gamma-detecting probe in 13 women with ovarian cancer undergoing exploratory laparotomy. B72.3, which recognizes a tumor-associated glycoprotein, TAG 72, was injected 12-29 days preoperatively (intraperitoneally in four cases, intravenously in nine, and by both routes in one). Intraoperatively, the abdomen was surveyed with the probe and probe counts were correlated with biopsies and excised specimens studied by routine histologic stains. Probe counts were positive in four of seven evaluable patients with histologically confirmed disease. In three of these four patients, the probe detected cancer in specimens interpreted as normal on frozen histologic sections. The probe also identified microscopic cancer in the one patient who had no gross disease. The specificity of the probe was 70%. Preoperative computed tomography was normal in all patients, including those with tumors as large as 3 cm. This pilot study shows the ability of radioimmunoguided surgery to detect occult ovarian cancer.

Intra-abdominal recurrence of colorectal cancer detected by radioimmunoguided surgery (RIGS system).

Since 1986, 32 patients with metastatic colorectal cancer have undergone second-look radioimmunoguided surgery (RIGS system). The primary tumor was located in the right and transverse colon in 11 patients, left and sigmoid colon in 16, and rectum in five. The carcinoembryonic antigen level was elevated in 30 patients (94%); all patients underwent a computed tomographic scan of the abdomen and pelvis. The overall sensitivity of the computed tomographic scan was 41% (abdomen other than liver, 27%; liver, 58%; and pelvis, 22%). The RIGS system identified recurrent tumor in 81% of the patients. The most common site of metastasis was the liver (41%), independent of the primary location. Local/regional recurrences alone accounted for 40% of all recurrences. In six patients (18%), recurrent tumor was found only with the RIGS system. The RIGS system is more dependable in localizing clinically obscure metastases than other methods, and carcinoembryonic antigen testing remains the most accurate preoperative method to indicate suspected recurrences.

Radioimmunoguided surgery using iodine 125 B72.3 in patients with colorectal cancer.

Preliminary data using B72.3 murine monoclonal antibody labeled with iodine 125 suggested that both clinically apparent as well as occult sites of colorectal cancer could be identified intraoperatively using a hand-held gamma detecting probe. We report the preliminary data of a multicenter trial of this approach in patients with primary or recurrent colorectal cancer. One hundred four patients with primary, suspected, or known recurrent colorectal cancer received an intravenous infusion of 1 mg of B72.3 monoclonal antibody radiolabeled with 7.4 x 10 Bq of iodine 125. Twenty-six patients with primary colorectal cancer and 72 patients with recurrent colorectal cancer were examined. Using the gamma detecting probe, 78% of the patients had localization of the antibody in their tumor; this included 75% of primary tumor sites and 63% of all recurrent tumor sites; 9.2% of all tumor sites identified represented occult sites detected only with the gamma detecting probe. The overall sensitivity was 77% and a predictive value of a positive detection was 78%. A total of 30 occult sites in 26 patients were identified. In patients with recurrent cancer, the antibody study provided unique data that precluded resection in 10 patients, and in another eight patients it extended the potentially curative procedure.

Prevention of early failure of stapled gastric partitions in treatment of morbid obesity.

Clinical observations and data obtained in animal experiments indicate that the gastric partition is most susceptible to the stresses of solid food boluses between the second and sixth postoperative weeks, predisposing the operation to early failure. Tensiometer studies indicate that by the sixth to the eighth postoperative week, the staple line is as strong as uninjured stomach. Liquid diet restriction for eight weeks after gastric partitioning reduces the incidence of early operative failure. Until safe and effective methods of increasing staple line strength are established, all patients having gastric partitioning should be restricted to a liquid diet for eight weeks after operation.

Intraoperative probe-directed immunodetection using a monoclonal antibody.

To assess monoclonal antibody (MAb) 17-1A and its F(ab')2 fragment in intraoperative radioimmunodetection and to evaluate further the clinical usefulness of a hand-held gamma-detecting probe (GDP), we injected radiolabeled monoclonal antibody 17-1A three to six days preoperatively or its F(ab')2 fragment two to three days preoperatively into 18 patients with colorectal cancer. Intraoperative GDP counts with tumor-tissue ratios of 1.5:1 or greater were obtained from 15 (75%) of 20 tumor sites, with ratios averaging 2.3:1 for fragments and 3.4:1 for whole antibody. The GDP counts contributed to intraoperative decision making in three patients, either by localization of tumor not identified by inspection or palpation or by mapping margins of resection with histologic confirmation of a local/regional recurrence. These preliminary data demonstrate that probe-directed, intraoperative radioimmunodetection can assist the surgeon in detecting subclinical tumor deposits and thus better evaluate the extent of primary or recurrent colorectal cancers intraoperatively.

Reoperation directed by carcinoembryonic antigen level: the importance of a thorough preoperative evaluation.

Many asymptomatic patients suspected to have recurrent colorectal cancer based on an elevated carcinoembryonic antigen level will be spared unnecessary operation if strict attention is paid to their preoperative evaluation. Liver and renal function should be assessed. Unresectable extraabdominal and intraabdominal recurrence or metastases should be excluded. Patients being evaluated for recurrence after curative resection of a rectosigmoid cancer should undergo a bone scan. Having satisfactorily ensured normal results for these investigations, the surgeon should then proceed to search for an intraabdominal source of tumor recurrence.

Radioimmunoguided surgery using monoclonal antibody.

The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery.

Complications of gastric restrictive operations in morbidly obese patients.

After gastric restrictive procedures in morbidly obese persons, the reported morbidity is 15 per cent, and mortality is 1 per cent. Pulmonary embolism continues to be the most serious complication. Gastric perforations must be recognized early and treated promptly, as must the common postoperative complications: pneumonia, atelectasis, and wound infection.

An assessment of prolonged reactivity of seven monoclonal antibodies against CX-1 tumor xenografts using a hand-held gamma-detecting probe.

The biodistribution and kinetics of 7 monoclonal antibodies (MAb) with known reactivity against CX-1 tumor were examined over 21 days using a hand-held gamma-detecting probe (Neoprobe system). Twenty-eight immuno-deprived (athymic) nude mice implanted with human colon adenocarcinoma CX-1 xenografts were injected intraperitoneally with 50 microCi of 125I-labeled antibodies (4 mice/antibody). Of the 7 monoclonal antibodies, 4 were anti-CEA (MA, MB, MC, and MD), 2 were anti-TAG 72 (B72.3 NCI and B72.3 fermented) and one was anti-colorectal cancer (17-1A). Daily probe counts were recorded in duplicate over the tumor site and the contralateral nontumor site (background), and tumor-to-background (Tu/Bkg) ratios were calculated. Animals were sacrificed on day 21, and blood, heart, liver, spleen, lungs, kidneys, intestine, muscle, and the tumor were removed for gamma well counting. All antibodies identified the tumor as early as 24 h postinjection and specific tumor localization improved over time. Patterns of prolonged tumor binding varied considerably from one antibody to another, although all but one (MB) showed continuously increasing Tu/Bkg ratios. These data indicate progressive clearance of the antibodies from the background tissue and a persistence of labeled MAb activity in tumor resulting in improved tumor localization with increasing postinjection time.

Radioimmunoguided surgery (RIGS) in recurrent colorectal cancer.

Since 1986, 191 patients with recurrent colorectal cancer have undergone surgical exploration 2 to 43 days after injection of 1.0 to 0.25 mg of monoclonal antibody (MAb) (B72.3 or 17-1A) radiolabeled with 5.0 to 1.0 mCi of 125I. The intraoperative use of a hand-held gamma detector (Neoprobe 1000) demonstrated that MAb identified tumor in 73% of cases. Clearer intraoperative definition of tumor margins and identification of occult tumor assisted the surgeon in the resection of liver metastases as well as nodal and pelvic disease. Unsuspected nodal disease was identified. The external use of the Neoprobe to scan the sacral region and intrarectal and intravaginal use led to the avoidance of operative procedures by defining inoperable disease. In approximately 25% of cases, the surgical procedure was modified based on Neoprobe findings. RIGS system provides a method of immediate intraoperative staging which may prevent additional recurrences, lead to earlier institution of adjuvant therapy, and result in improved survival.

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.

Identification of occult micrometastases in pericolic lymph nodes of Duke's B colorectal cancer patients using monoclonal antibodies against cytokeratin and CC49. Correlation with long-term survival.

BACKGROUND: Patients with transmurally invasive, lymph node negative colorectal carcinoma (Dukes' B) have a 5-year survival rate ranging from 53.9% to 84.9%. The authors postulate that patients with Dukes' B colon cancer who die of their disease have occult micrometastases in their pericolic lymph nodes at the time of original diagnosis. In an attempt to identify these occult micrometastases, pericolic lymph nodes from Dukes' B colon cancer resections were stained retrospectively with antibodies against cytokeratin (anti-keratin AE1/AE3, Boehringer Mannheim, Indianapolis, IN) and CC49 (a second-generation monoclonal antibody directed against TAG-72. METHODS: The authors reviewed all Dukes' B (transmurally invasive, lymph node negative) primary colorectal carcinoma resection specimens from the surgical pathology files of the Ohio State University Hospitals between 1984 and 1987. Survival data were obtained from the Tumor Registry of the Arthur G. James Cancer Hospital and Research Institute, Columbus, Ohio. The results were analyzed by univariate and multivariate analysis. RESULTS: Fifty cases with 568 lymph nodes (11.3 per case) were examined with each antibody using standard immunoperoxidase techniques. Positive staining for cytokeratin was seen in 14 patients (33 lymph nodes), 6 of whom died of colon cancer within 66 months (43%). Only 1 of the 36 patients with cytokeratin-negative lymph nodes died of colon cancer over the same time period (3%, P = 0.0009 univariate, P = 0.0013 multivariate). There was no significant difference in survival between the CC49-positive and CC49-negative groups. CONCLUSION: Immunoperoxidase techniques are capable of identifying micrometastatic disease in lymph nodes missed by routine hematoxylin and eosin staining. Further, the presence of cytokeratin-positive cells within lymph nodes correlated with a significantly poorer prognosis. Therefore, cytokeratin staining of pericolic lymph nodes in patients with Dukes' B colorectal cancer is recommended. Larger multicenter studies are needed, however, to confirm these results and to evaluate the appropriateness of adjuvant chemotherapy in patients whose disease is upstaged by immunohistochemical staining.