A definitive conclusion about the value of ART is not possible from the data available: Both the methods of radiation therapy and the techniques in the diagnosis of locally persistent disease have evolved over the years. Currently, the data lead to the conclusion that ART decreases local recurrence but does not improve overall survival. Yet the PSA data strongly suggest that only locally persistent disease is a common event after radical prostatectomy (particularly in margin-positive disease only) and that current ART techniques are inadequate in many but not all of these patients. Certainly some men seem to have their local disease eliminated by ART to remain NED, but it is unclear exactly how to select them. Many experts also believe that keeping the PSA as low as possible for as long as possible, with sequential applications of ART and then androgen ablation as necessary, is a good emotional if not medical strategy. For example, all patients now wish to know their PSA level and worry about it. Also, potency can be maintained or regained after ART but becomes improbable after androgen ablation because of loss of libido. Clearly, a study randomizing high-risk postoperative patients into observation versus ART is needed and indeed such a study is under way in the Southwestern and Eastern Cooperative oncology groups, but to date accrual is inadequate (Ian Thompson, Jr, MD, personal communication, May 1994). This study must be supported. When participation in the randomized study is not possible, we believe four tentative recommendations about the application of ART can be made based on the available data (Fig. 1): (1) For high-risk patients (e.g., high Gleason score and/or high pathologic stage) with initially undetectable PSA levels, we recommend instituting ART before any rise in postoperative PSA levels because low-volume disease may best respond to this therapy. (2) For patients with rapidly rising or initially detectable postoperative PSA levels (especially if NBA is negative), we believe that the disease has most likely already spread to distant sites and would initiate therapy aimed at systemic disease. (3) For those patients with rapidly rising postoperative PSA but with positive NBA, we recommend local irradiation. (4) if the postoperative PSAlevels rise gradually, we would initiate ART regardless of the needle biopsy result because of the possibility of NBA sampling error and the fact that the gradual increase in PSA suggests that the disease is still local.(ABSTRACT TRUNCATED AT 400 WORDS)