Radiation therapy (RT) after prostatectomy: The case for salvage therapy as opposed to adjuvant therapy.

Patients with pathologic stage T3 or T4 prostate cancer who have undetectable PSA levels following radical retropubic prostatectomy (RRP) have a substantial risk of recurrence. Radiotherapy (RT) can be administered immediately following the RRP (immediate adjuvant RT) or may be postponed until the PSA level has risen to a level that is indicative of residual or recurrent prostate cancer (salvage RT). Immediate adjuvant RT can significantly reduce the risk of relapse, but does not appear to increase the rate of survival. Approximately two-thirds of patients with rising PSA levels after RRP can be salvaged with RT alone. This result was achieved in patients treated with an adequate dose of radiation before the PSA rose to > 1.1 ng/ml. While no one can be certain which approach (adjuvant or salvage RT) is better, future studies should examine this issue. Whether immediate postoperative adjuvant RT is of value to patients is the subject of two randomized prospective studies. The benefit of adjuvant RT is a matter of controversy. Salvage RT treats only those patients with proven residual prostate cancer. The salvage RT approach has several advantages. This approach spares approximately 40% of patients who have had an RRP for T3 or T4 prostate cancer and eliminates the risks and costs associated with adjuvant RT. Additionally, it appears that the results of immediate adjuvant RT are similar to those achieved with early salvage RT.