Renal function preservation is particularly important following nonoperative treatment of localized renal cell carcinoma (RCC) since patients are often older with medical comorbidities. Our objective was to report long-term renal function outcomes after stereotactic ablative radiotherapy (SABR) including patients with a solitary kidney.
Patients with primary RCC treated with SABR with ≥2 yr of follow-up at 12 International Radiosurgery Consortium for Kidney institutions were included. Renal function was measured by estimated glomerular filtration rate (eGFR).
In total, 190 patients (56 with a solitary kidney) underwent SABR and were followed for a median of 5.0 yr (interquartile range [IQR]: 3.4-6.8). In patients with a solitary kidney versus bilateral kidneys, pre-SABR eGFR (mean [standard deviation]) was 61.1 (23.2) versus 58.0 (22.3) ml/min (p = 0.32) and the median tumor size was 3.65 cm (IQR: 2.59-4.50 cm) versus 4.00 cm (IQR: 3.00-5.00 cm; p = 0.026). At 5 yr after SABR, eGFR decreased by -14.5 (7.6) and -13.3 (15.9) ml/min (p = 0.67), respectively, and there were similar rates of post-SABR dialysis (3.6% [n = 2/56] vs 3.7% [n = 5/134]). A multivariable analysis demonstrated that increasing tumor size (odds ratio [OR] per 1 cm: 1.57; 95% confidence interval [CI]: 1.14-2.16, p = 0.0055) and baseline eGFR (OR per 10 ml/min: 1.30; 95% CI: 1.02-1.66, p = 0.034) were associated with an eGFR decline of ≥15 ml/min at 1 yr.
With long-term follow-up after SABR, kidney function decline remains moderate, with no observed difference between patients with a solitary kidney and bilateral kidneys. Tumor size and baseline eGFR are dominant factors predictive of long-term renal function decline.
With long-term follow-up, stereotactic ablative radiotherapy (SABR) yields moderate long-term renal function decline and low dialysis rates even in patients with a solitary kidney. SABR thus represents a promising noninvasive, nephron-sparing option for patients with localized renal cell carcinoma.
European urology oncology. 2024 Jul 09 [Epub ahead of print]
Vivian S Tan, Rohann J M Correa, Andrew Warner, Muhammad Ali, Alexander Muacevic, Lee Ponsky, Rodney J Ellis, Simon S Lo, Hiroshi Onishi, Anand Swaminath, Young Suk Kwon, Scott C Morgan, Fabio L Cury, Bin S Teh, Anand Mahadevan, Irving D Kaplan, William Chu, Raquibul Hannan, Michael Staehler, Nicholas G Zaorsky, Alexander V Louie, Shankar Siva
London Health Sciences Centre, London, ON, Canada., Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria, Australia., University of Munich Hospitals, Munich, Germany., University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA., GenesisCare USA, Fort Myers, FL, USA; Northeast Ohio Medical University Rootstown, OH, USA., University of Washington School of Medicine, Seattle, WA, USA., University of Yamanashi, Yamanashi, Japan., Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada., University of Texas - Southwestern Medical Center, Dallas, TX, USA., The Ottawa Hospital, Ottawa, ON, Canada., McGill University Health Centre, Montreal, QC, Canada., Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX, USA., NYU Langone Health - Laura and Isaac Perlmutter Cancer Center, New York, NY, USA., Beth Israel Deaconess Medical Center, Boston, MA, USA., Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, ON, Canada., London Health Sciences Centre, London, ON, Canada; Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, ON, Canada., Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria, Australia. Electronic address: .