RADICALS RT: Timing of Adjuvant Radiotherapy Following Radical Prostatectomy

Dr. Sartor: At ESMO 2023, an important long-term follow-up was presented with the RADICALS-RT study. This examined the optimal timing of radiotherapy after radical prostatectomy. It has been common in years past to give adjuvant therapy for patients who had poor-risk disease at the time of radical prostatectomy; things like positive margins, pathologic T3/T4, Gleason 7 to 10 disease.

In this study, patients were randomized to receive adjuvant radiation or radiation at the time of PSA failure. Now, PSA failure was defined by a PSA of greater than 0.1 ng per mL, or three consecutive rises.

This was a large study, 1396 patients. The primary endpoint was metastasis-free survival, which, as you probably know, has been linked to overall survival in a variety of studies.

No advantage gained with adjuvant radiation

What did they find? They found that there was no advantage to giving adjuvant radiation. The overall survival at 10 years was 88% versus 87%. And the freedom from metastatic disease at 10 years was 93% versus 90% — no difference. And I'm simply going to say that waiting until PSA relapse is perfectly appropriate for patients after radical prostatectomy; that you do not have to use adjuvant therapy.

Adjuvant radiation led to greater toxicity

By the way, and I didn't mention this, urinary incontinence and fecal incontinence were worse with adjuvant radiation therapy. So, the patients not only did the same, they actually had more toxicity.

This is the largest study ever conducted with adjuvant radiotherapy and prostate cancer. And these results show no evidence of a meaningful benefit for adjuvant as compared to salvage therapy. And in my opinion, salvage radiotherapy, not adjuvant, should be the standard of care.