To evaluate the efficacy of 25Gy/5# prophylactic pelvic nodal irradiation for regional control during stereotactic radiotherapy (SBRT) for high risk prostate cancer.
The multinational XXXX consortium database of patients treated with curative-intent prostate SBRT for high risk prostate cancer was queried for prophylactic radiotherapy 25Gy/5# to the pelvic lymph nodes. Details of Phoenix-defined biochemical failure, and location of recurrence (local, regional, or distant) were extracted. Five-year biochemical failure-free survival (BFFS), metastasis-free survival (MFS), and overall survival (OS) were estimated by Kaplan Meier method. Impact of potential prognostic factors (tumour stage, grade group (GG), prostate radiotherapy dose, and ADT duration) was analysed using Cox proportional hazards model.
A total of 171 patients were eligible for analysis. Two-thirds of the patients had GG 4-5 cancer. Prostate was irradiated to 40Gy/5# in 51.5% of the cohort, while the rest received 35-36.25Gy/5#. Median ADT duration was 15 months (IQR 9-24). Over a median follow up of 51 months, biochemical failure was recorded for 19 (11.1%) patients. Restaging with PSMA-PETCT showed recurrence within the pelvic nodes in three patients, all with co-occurring distant metastases. Overall pelvic control was 98.2%, with 5-year BFFS and OS being 86.1% and 89.3% respectively. None of the prognostic factors showed a statistically significant impact on BFFS, except GG (adjusted HR 3.6 (95% CI 0.9-13.0), p=0.06).
For high-risk prostate cancer treated with SBRT, prophylactic pelvic nodal irradiation with 25Gy/5# achieved near universal regional control.
International journal of radiation oncology, biology, physics. 2025 Jan 02 [Epub ahead of print]
Vedang Murthy, Indranil Mallick, Priyamvada Maitre, Gargee Mulye, Moses Arunsingh, Luca Valle, Michael Steinberg, Thomas Kennedy, Andrew Loblaw, Amar U Kishan
Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India. Electronic address: ., Tata Medical Center, Kolkata, India., Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., University of California, Los Angeles, CA USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA USA., University of California, Los Angeles, CA USA., University of Toronto, Toronto, Canada.