Benefits of Elective Para-Aortic Radiotherapy for pN1 Prostate Cancer Using Arc Therapy (Intensity-Modulated or...

Area of Science:

• Oncology
• Radiation Oncology
• Urologic Oncology

Background:

• Prostate cancer (PCa) patients with pelvic lymph node metastasis (pN1) after extended pelvic lymph node dissection (ePLND) have high relapse rates.
• Multimodality treatment including whole pelvic radiotherapy (WPRT) and androgen deprivation therapy (ADT) improves survival but 40% still relapse.
• Relapse often involves para-aortic lymph nodes (M1a disease) or distant metastasis.

Purpose of the Study:

• To test the hypothesis that elective para-aortic radiotherapy (PART) reduces retroperitoneal and distant metastasis in pN1 PCa patients.
• To evaluate if PART can postpone the need for palliative ADT and prolong time to castration-refractory disease.
• To assess the efficacy of PART in pN1 patients compared to historical controls treated with WPRT alone.

Main Methods:

• Prospective, nonrandomized phase II trial.
• Inclusion of 137 patients with PCa and pN1 disease after ePLND.
• Comparison of outcomes with historical data of patients treated with adjuvant WPRT alone.

Main Results:

• Patient recruitment began in 2017 and was expected to conclude by March 2020.
• The study is designed to detect a 15% improvement in 5-year clinical relapse-free survival.
• Results are anticipated for publication in a peer-reviewed journal.

Conclusions:

• This is the first phase II trial examining the benefits of elective PART in PCa patients.
• Findings may provide a foundation for future randomized phase III trials.
• Informed consent is obtained from all participants.