Timing of radiotherapy after radical prostatectomy (RADICALS-RT): a randomised, controlled phase 3 trial

Area of Science:

• Oncology
• Radiation Oncology
• Urology

Background:

• Optimal timing of radiotherapy post-radical prostatectomy for prostate cancer remains unclear.
• Comparison of adjuvant radiotherapy versus observation with salvage radiotherapy for PSA biochemical progression is needed.

Purpose of the Study:

• To compare the efficacy and safety of adjuvant radiotherapy against an observation policy with salvage radiotherapy for prostate-specific antigen (PSA) biochemical progression after radical prostatectomy.

Main Methods:

• Randomized controlled trial (RADICALS-RT) involving patients with risk factors for biochemical progression.
• Patients were randomized to adjuvant radiotherapy or observation with salvage radiotherapy for PSA progression (PSA ≥0.1 ng/mL).
• Primary outcome was freedom from distant metastases; secondary outcomes included biochemical progression-free survival and safety.

Main Results:

• 5-year biochemical progression-free survival was 85% for adjuvant radiotherapy vs. 88% for salvage radiotherapy (HR 1.10, p=0.56).
• No significant difference in freedom from hormone therapy at 5 years (93% vs. 92%, HR 0.88, p=0.53).
• Adjuvant radiotherapy group reported worse urinary incontinence (p=0.0023) and higher rates of Grade 3-4 urethral stricture (6% vs. 4%, p=0.020).

Conclusions:

• Initial results do not support routine adjuvant radiotherapy after radical prostatectomy.
• Adjuvant radiotherapy is associated with increased urinary morbidity.
• Observation with salvage radiotherapy for PSA progression should be the standard approach post-prostatectomy.