To evaluate the effectiveness and safety of salvage stereotactic ablative body radiotherapy (SABR) for recurrent renal cell carcinoma (RCC) after thermal ablation (TA).
This study was a multi-institutional retrospective analysis of patients with recurrent RCC following TA who received SABR between 2016 and 2020.
The primary study outcome was freedom from local failure, evaluated radiographically based on Response Evaluation Criteria in Solid Tumours (RECIST) v1.1. Distant failure, cancer-specific survival (CSS), overall survival (OS), treatment-related toxicity and renal function changes following SABR were the secondary outcomes. The Kaplan-Meier method was used to estimate freedom from local and distant failure, CSS and OS.
Seventeen patients with 18 biopsy-confirmed RCCs were included, with a median (interquartile range [IQR]) age at time of SABR of 75.2 (72.6-68.7) years, a median (IQR) tumour size of 3.5 (1.9-4.1) cm and follow-up (reverse Kaplan-Meier method) of 3.36 (95% confidence interval [CI] 1.6-4.1) years. Six of the 17 patients had a solitary kidney. Five patients had failed repeat TA prior to SABR. The median (IQR) time from TA procedure to SABR was 3.03 (1.5-5.1) years. No patient experienced local progression, with a local control rate of 100%. Four patients, two with baseline metastatic disease, experienced distant progression. The distant progression-free survival, CSS and OS at 3 years were 72.1% (95% CI 51.9%-100%), 92.3% (95% CI 78.9%-100%) and 82.1% (95% CI 62.1%-100%), respectively. The median (IQR) glomerular filtration rate before SABR was 58 (40-71) mL/min, and at last follow-up, it was 48 (33-57) mL/min. No patient experienced grade 3+ toxicity or went on to develop end-stage renal disease.
The results showed that SABR appears to be an effective and safe salvage strategy in patients with recurrent RCC following TA.
BJU international. 2024 Aug 26 [Epub ahead of print]
Muhammad Ali, Young Suk Kwon, Kendrick Koo, Anna Bruynzeel, David Pryor, Daniel G Schep, Michael Huo, Maggie Stein, Anand Swaminath, Raquibul Hannan, Shankar Siva
Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia., Department of Radiation Oncology, UT Southwestern Medical Centre, Dallas, TX, USA., Department of Radiation Oncology, Cancer Center Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands., Department of Radiation Oncology, Princess Alexandra Hospital, Brisbane, Queensland, Australia., Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, Ontario, Canada.