The following is a summary of “Long-term Renal Function Outcomes After Stereotactic Ablative Body Radiotherapy for Primary Renal Cell Carcinoma Including Patients with a Solitary Kidney: A Report from the International Radiosurgery Oncology Consortium of the Kidney,” published in the July 2024 issue of Urology by Tan et al.

Preserving renal function is crucial following nonoperative treatment of localized renal cell carcinoma (RCC), especially in older patients with comorbidities. The objective was to assess long-term renal outcomes after stereotactic ablative radiotherapy (SABR), including its impact on patients with a solitary kidney.

The researchers analyzed data from 190 patients (including 56 with solitary kidneys) treated with SABR for primary RCC across 12 International Radiosurgery Consortium for Kidney institutions. Renal function was assessed using estimated glomerular filtration rate (eGFR).

Over a median follow-up of 5.0 years (interquartile range [IQR]: 3.4–6.8), patients with solitary kidneys had comparable pre-SABR eGFR (mean [SD]: 61.1 [23.2] ml/min) to those with bilateral kidneys (58.0 [22.3] ml/min; p = 0.32), with slightly smaller median tumor sizes (3.65 cm vs. 4.00 cm; p = 0.026). At 5 years post-SABR, eGFR decreased by –14.5 (7.6) ml/min in patients with solitary kidneys and –13.3 (15.9) ml/min in those with bilateral kidneys (p = 0.67), with similar rates of post-SABR dialysis (3.6% vs. 3.7%). Multivariable analysis identified increasing tumor size (OR per 1 cm: 1.57; 95% 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) as predictors of ≥15 ml/min eGFR decline at 1 year.

Long-term follow-up post-SABR shows moderate kidney function decline, with no significant difference between patients with solitary and bilateral kidneys. Tumor size and baseline eGFR are pivotal factors influencing long-term renal function outcomes, emphasizing the importance of personalized management strategies in SABR for RCC.

Source: sciencedirect.com/science/article/abs/pii/S2588931124001597