When is it appropriate to do immediate radiation therapy (RT) for patients with high-risk pathology instead of waiting for PSA to rise?


After radical prostatectomy the patient might have some risk for disease recurrence. The recurrence usually is located in the peri-urethral anastomotic area, then it is most commonly a local recurrence. 

Local recurrence is usually treated by radiation therapy. In high risk patients, who have positive margin, extraprostatic extension, and/or seminal vesicle invasion, but undetectable serum PSA level, the timing of radiation therapy is questionable. Based on 3 randomized trials, these patients have approximately 60% risk for recurrence; these patients need to be told of this recurrence risk in order to make an informed decision regarding whether to pursue immediate RT (called adjuvant) or to wait for increasing serum PSA (called early salvage RT).

However, randomized trials show that adjuvant RT reduces the risk of recurrence significantly, but may not reduce the risk for mortality.

Based on this, my opinion is that only in well informed patients, the option of delay the radiation therapy is the only recommended presumably to maximize their chance for "cure". The patient has to be well informed about the risks of the radiation therapy that, at this point, might not be balanced by the expected benefits.