Radioimmunoguided imaging of prostate cancer foci with histopathological correlation

Purpose: We have previously presented a technique that fuses ProstaScint an d pelvic CT images for the purpose of designing brachytherapy that targets areas at high risk for treatment failure. We now correlate areas of increas ed intensity seen on ProstaScint-CT fusion images to biopsy results in a se ries of 7 patients to evaluate the accuracy of this technique in localizing intraprostatic disease. Methods and Materials: The 7 patients included in this study were evaluated between June 1998 and March 29, 1999 at Metrohealth Medical Center and Uni versity Hospitals of Cleveland in Cleveland, Ohio. ProstaScint and CT scans of each patient were obtained before transperineal biopsy and seed implant ation. Each patient's prostate gland was biopsied at 12 separate sites dete rmined independently of Prostascint-CT scan results. Results: When correlated with biopsy results, our method yielded an overall accuracy of 80 %: with a sensitivity of 79 %, a specificity of 80 %, a pos itive predictive value of 68 %, and a negative predictive value of 88 %. Conclusion: The image fusion of the pelvic CT scan and ProstaScint scan hel ped identify foci of adenocarcinoma within the prostate that correlated wel l with biopsy results. These data may be useful to escalate doses in region s containing tumor by either high-dose rate or low-dose rate brachytherapy, as well as by external beam techniques such as intensity modulated radioth erapy (IMRT). (C) 2001 Elsevier Science Inc.