Preoperative Scintigraphy and Operative Probe Scintimetry of Colorectal Carcinoma Using Technetium-99m-88BV59

We report a pilot study a radioimmunoscintigraphy (RIS) and operative gamma probe scintimetry (OPS) using a 99m Tc-labeled anti-cytokeratin human monoclonal antibody (MAb) ( 99m Tc-88BV59) in patients with newly diagnosed, recurrent or metastatic colorectal cancer. Methods: twelve presurgical patients with biopsy- or contrast radiographic-proven colorectal cancer or recurrent colorectal carcinoma were studied. After chest roentgenography and abdominopelvic CT, 99m Tc-88BV59 was administered intravenously, planar and SPECT external imaging was performed 3 to 6 h after injection. Surgery was performed immediately after late planar imaging. OPS of a standardized list of sites to document background radiation activity and of tumor sites, resection margins and tumor beds was 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 CT for imaging extrahepatic abdominal tumor sites and correctly predicted histological tumor-free margins and tumor beds in all cases. OPS did not identify tumor deposits that the surgeon could neither see nor feel. No patient demonstrated human immune responsiveness 1 and 3 mo after 99m Tc-88BV59 infusion. Conclusion: Technetium-99m-88BV59 is a safe, effective radioimmunoconjugate for colorectal cancer imaging, with superior sensitivity as compared to CT