Salvage radiotherapy for biochemical recurrence after radical prostatectomy

Abstract

To evaluate the clinical outcome of salvage radiotherapy (RT) for biochemical recurrence after radical prostatectomy (RP) at our institution. Between March 1999 and January 2004, 37 patients had salvage RT for prostate-specific antigen (PSA) failure after RP, including eight who had had neoadjuvant hormone therapy. After surgery, PSA was measured with ultrasensitive immunoassays. In all patients RT was delivered to the prostatic bed at a total dose of 60 Gy with a four-field box technique. The median (range) PSA level before salvage RT was 0.146 (0.06-3.216) ng/mL and RT was started at a PSA level of <0.5 ng/mL in 34 of the 37 patients (92%). With a median follow-up of 31.9 (0-69.8), months, 11 patients (30%) had disease progression after RT and the 3- and 5-year progression-free probability was 74% and 54%, respectively. Univariate analysis showed that clinical and pathological tumour stages and PSA level before RT (>0.15 vs < or = 0.15 ng/mL) were significant predictors of disease progression. There were no late adverse events related to RT. Salvage RT for biochemical failure after RP at a low PSA level, using ultrasensitive immunoassays for monitoring, is a reasonably effective treatment. A relatively low radiation dose (60 Gy) seems to be effective.