Yield of imaging and scintigraphy assessing biochemical failure in prostate cancer patients

A retrospective study was undertaken to determine the diagnostic yield of computed tomography (CT) and bone scan in patients with biochemical failure after definitive therapy for prostate cancer. The records of the Radiation Oncology Division were screened for patients presenting with prostate cancer between January 1, 1993, and December 31, 1996. Of 198 patients, 44 developed biochemical failure postoperatively (n = 24) or postradiotherapy (n = 20), and were not treated with hormones prior to restaging. Review was made of restaging studies performed at the time of biochemical failure. Postoperatively, 5% (1 of 20) of bone scans and 11% (2 of 18) of CT scans were positive. Postradiotherapy, 30% (6 of 20) of bone scans and 30% (3 of 10) of CT scans were positive. Our study showed that imaging studies are of low utility in the evaluation of patients with biochemical failure after definitive therapy of prostate cancer given that most patients begin hormonal therapy irrespective of the results of restaging studies. If salvage therapy is considered, imaging results may have a role in the decision-making process.