Stereotactic ablative radiotherapy (SABR) is an emerging treatment for renal cell carcinoma (RCC). Our study objective was to evaluate SABR in patients with a solitary kidney, focusing on oncological and renal function outcomes.
Individual patient data from nine IROCK institutions in Germany, Australia, USA, Canada and Japan were pooled. Median follow-up was 2.6 years. Baseline characteristics and outcomes were compared between solitary and bilateral kidney cohorts. Predictors of post-SABR renal function were assessed by logistic regression modelling.
81 solitary kidney patients underwent SABR. Mean age was 67.3 years and 97.5% had good performance status (ECOG 0-1 or KPS ≥70%). Median tumour diameter was 3.7cm [IQR: 2.5-4.3], with 37% of tumours ≥4cm. Patients in the bilateral cohort (n=138) harbored larger tumours and were older (p<0.001) with lower baseline eGFR (p=0.024). In the solitary cohort, post-SABR eGFR decrease (mean±SD) was -5.8±10.8 mL/min (or -9%). No solitary kidney patients required dialysis. Tumour size ≥4cm was associated with post-SABR eGFR decreases of ≥15mL/min [OR 4.2, p=0.029]. Local control, progression-free survival, cancer-specific survival, and overall survival in the solitary cohort were 98.0%, 77.5%, 98.2% and 81.5% at 2 years, respectively. There were no significant differences in renal function or oncological outcomes between cohorts (p>0.05).
In this analysis of the IROCK database, SABR in solitary kidney patients yielded acceptable impact on renal function and achieved excellent oncological outcomes, similar to those in patients with bilateral kidneys. SABR thus represents a viable management option in patients with solitary kidney RCC.
The Journal of urology. 2019 Feb 05 [Epub ahead of print]
Rohann J M Correa, Alexander V Louie, Michael Staehler, Andrew Warner, Senthilkumar Gandhidasan, Lee Ponsky, Rodney Ellis, Irving Kaplan, Anand Mahadevan, William Chu, Anand Swaminath, Hiroshi Onishi, Bin S Teh, Simon S Lo, Alexander Muacevic, Shankar Siva
Department of Radiation Oncology, London Regional Cancer Program, London, ON, Canada., University of Munich Hospitals, Munich, Germany., Division of Radiation Oncology & Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne, Australia., University Hospitals Seidman Cancer Center, Case Comprehensive Cancer Center, Cleveland, OH, USA., Beth Israel Deaconess Medical Center, Boston, MA, USA., Geisinger Health, Danville, PA, USA., Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario, Canada., Division of Radiation Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada., Department of Radiology, University of Yamanashi, Yamanashi, Japan., Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX, USA., Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington, USA.