[Does immunoscintigraphy improve early diagnosis of metastatic or recurrent cancer?]

In 42 patients with suspicion of recurrent colorectal cancer results of conventional diagnostic methods were compared to those of immunoscintigraphy. In 69% of all cases the intraoperative findings of a second-look operation served for validation, in 31% the follow-up was controlled. Localization of recurrent tumors was successful in 83% using conventional methods versus 57% by immunoscintigraphy. This procedure disappointed especially by a low sensitivity (23%) and low predictive parameters (pos.: 33%; neg.: 37%) in regard to diagnosis of extrahepatic tumors compared to results of conventional methods (77%), 94% respectively 79%). The quote of false positive results was surprisingly high in immunoscintigraphy (n = 12), 83% of these especially in localization of extrahepatic tumors. Therefore, the validity of immunoscintigraphy as an additive diagnostic tool for early detection of recurrent colorectal cancer must be regarded critically.