Abstract

Objectives: Purpose/Objective(s): Stereotactic Body Radiation Therapy (SBRT) is a standard therapeutic option for men with prostate adenocarcinoma. Over 27,000 kidney transplants were done in 2024. There is a paucity of data on the outcomes of patients treated with SBRT who have had prior renal transplantation. This study reports outcomes on patients who have had prior renal transplant treated with SBRT at a single institution with pelvic placement of the transplanted kidney.

Methods: Materials/Methods: Between April 2006 and September 2025, 6666 patients with prostate cancer were treated with inhomogeneous-dosed SBRT alone using a robotic linear accelerator at a single institution. All patients were treated in 5 fractions to a median dose of 3625 cGy (range 3500-4000cGy) prescribed to the 83-87% isodose line. 5 consecutive patents were identified who had renal transplantation prior to undergoing SBRT. All patients had all or part of the transplanted kidney located below L5 in the pelvis. The kidney mean dose was < 3.9Gy in all patients and the kidney max dose was < 10Gy in all patients. No beams were allowed to enter or exit through the transplanted kidney.

Results: Results: The pretreatment median pretreatment PSA was 5.85 for this subset of patients. With median follow up of 10 months for this subset of patients, the median posttreatment PSA was 0.58. The median glomerular filtration rate was 40.9 pre SBRT and 40.1 post SBRT. No patients had any significant worsening of renal function after SBRT.

Conclusion(s): Conclusion: This series evaluated outcomes in patients with prior renal transplantation with placement of the transplanted kidney in the pelvis treated with definitive SBRT for prostate cancer. With short term follow up, SBRT remains a safe and effective treatment for this subset of patients. Continued follow up will be required to see if these results remain durable and renal function remains stable.