Interpreting a rising prostate-specific antigen after brachytherapy for prostate cancer

Abstract

The aim of the present study was to review the English language literature on the topic of prostate-specific antigen bounce after brachytherapy and present a summary of the current knowledge. Although ultimately prostate-specific antigen is a reliable measure of success after prostate brachytherapy, it can be very misleading in the first 3 years because of the frequency with which temporary benign rises in prostate-specific antigen occur. We have reviewed the English language literature on the topic of prostate-specific antigen bounce under the following headings: prostate neoplasms, brachytherapy, biochemical definition of prostate-specific antigen failure, "benign prostate-specific antigen bounce" and "prostate-specific antigen spike". We included brachytherapy delivered as either low dose rate or high dose rate, and either as monotherapy or as a boost combined with external beam radiotherapy. A benign self-limited rise in prostate-specific antigen after prostate brachytherapy is seen in an average of 35% of patients, but increases in frequency with younger age. In patients aged less than 55 years, it is observed in up to 68%. Other factors, such as sexual activity, dose, prostate volume and the use of high dose rate versus low dose rate have been implicated in affecting the frequency of the benign bounce. Benign increases in prostate-specific antigen are frequent after prostate brachytherapy. It is important to recognize and correctly diagnose this phenomenon in order to avoid unnecessary salvage treatment.