PREOPERATIVE SCINTIGRAPHY AND OPERATIVE PROBE SCINTIMETRY OF COLORECTAL-CARCINOMA USING TECHNETIUM-99M-88BV59

We report a pilot study of radioimmunoscintigraphy (RIS) and operative gamma probe scintimetry (OPS) using a Tc-99m-labeled anti-cytokeratin human monoclonal antibody (MAb) (Tc-99m-88BV59) in patients with newl y diagnosed, recurrent or metastatic colorectal cancer. Methods: Twelv e presurgical patients with biopsy- or contrast radiographic-proven co lorectal cancer or recurrent colorectal carcinoma were studied. After chest roentgenography and abdominopelvic CT, Tc-99m-88BV59 was adminis tered intravenously, planar and SPECT external imaging was performed 3 to 6 hr after injection and planar imaging was performed 18 to 24 hr after injection. Surgery was performed immediately after late planar i maging. OPS of a standardized list of sites to document background rad iation activity and of tumor sites, resection margins and tumor beds w as performed. Results: The patients had 23 histologically proven tumor sites. Overall sensitivity for CT, planar RIS, SPECT, surgery and OPS was 43%, 61%, 78%, 96% and 91%, respectively. SPECT was superior to C T for imaging extrahepatic abdominal and pelvic disease. OPS detected all liver and extrahepatic abdominal tumor sites and correctly predict ed histological tumor-free margins and tumor beds in all cases. OPS di d not identify tumor deposits that the surgeon could neither see nor f eel. No patient demonstrated human anti-human immune responsiveness 1 and 3 mo after Tc-99m-88BV59 infusion. Conclusion: Technetium-99m-88BV 59 is a safe, effective radioimmunoconjugate for colorectal cancer ima ging, with superior sensitivity as compared to CT.