Radiation therapy post radical prostatectomy: who, when and why?

Area of Science:

• Oncology
• Radiation Oncology
• Urology

Background:

• Adjuvant radiotherapy (ART) has been the standard post-surgery treatment for prostate cancer based on historical randomized clinical trials (RCTs).
• The optimal timing for initiating radiotherapy, specifically comparing ART with early salvage radiotherapy (SRT), remains a subject of ongoing clinical debate.
• Pathological risk factors such as high Gleason score, pT3 stage, and positive margins are key considerations in treatment decisions.

Approach:

• A meta-analysis of three RCTs (ARTISTIC) compared ART and SRT in postprostatectomy patients with adverse pathological features.
• The RTOG 0534 trial investigated the addition of pelvic lymph node radiotherapy, particularly in patients with elevated pretreatment prostate serum antigen (PSA) levels.
• Current research explores the correlation between radiotherapy parameters (dose, volume) and androgen deprivation therapy (ADT) duration with SRT timing.

Key Points:

• The ARTISTIC meta-analysis showed comparable 5-year biochemical recurrence-free survival rates between ART and SRT (89% vs. 88%).
• SRT demonstrated significantly lower rates of late genitourinary toxicity compared to ART, suggesting a potential benefit for early intervention.
• The RTOG 0534 trial indicated improved freedom from progression with the addition of pelvic lymph node radiotherapy, especially for patients with PSA > 0.35 ng/ml.

Conclusions:

• Early salvage radiotherapy (SRT) is a viable option for most patients, contingent upon vigilant PSA monitoring and prompt treatment upon recurrence.
• Further research incorporating genomic tests and advanced imaging modalities is expected to refine criteria for optimizing radiotherapy timing and treatment strategies.
• The duration of androgen deprivation therapy (ADT) in conjunction with radiotherapy remains an area requiring further investigation and consensus.