Outcome and Prognostic Factors of Salvage Radiotherapy for Biochemical Failure after Radical Prostatectomy: A Single Institute Experience

Kang, Taejin; Song, Cheryn; Kim, Jong Hoon; Kim, Choung Soo; Ahn, Hanjong

Abstract

PURPOSE: To assess the prognostic factors for recurrence-free survival after salvage radiotherapy (RT).
MATERIALS AND METHODS
Between 1990 and 2003, 20 patients underwent RT for biochemical failure after a radical prostatectomy (prostate-specific antigen; PSA>0.2ng/ml). The biochemical failure developed at a mean of 17.3 months (3-58) after the RP, and the mean PSA level at failure was 0.62ng/ml (0.4-1.0). All patients received curative radiation (mean dosage 64.5Gy); with a mean follow-up of 42.7 months after the RT. The pre-RT clinical and pathological parameters were evaluated to find prognostic factors affecting the biochemical recurrence-free survival (bRFS) after RT.
RESULTS
The mean time to RT from biochemical failure was 5.1 months (1-21), with a mean PSA level at the commencement of RT of 1.39ng/ml (0.36-6.70). In 18 patients, the serum PSA declined to an undetectable level, at a mean of 4.9 months (1-12) after RT. Of these, 8 (44.4%) showed a biochemical relapse, at a mean of 19.3 months (1-38). The actuarial 1, 3 and 5-year bRFS were 75.0, 48.5 and 39.0%, respectively. The bRFS was significantly increased with an interval to RT after failure of within 3 months (p=0.002) and the PSA level at RT was below 0.7ng/ml (p=0.036). No other clinicopathological factors had a significant influence.
CONCLUSIONS
Salvage RT for biochemical failure provides effective local tumor control, with a modest durable biochemical response. A more favorable outcome may be expected when the RT is instituted earlier, with a lower PSA level after failure.