Stereotactic Ablative Radiotherapy for Localized Renal Tumors in Nonsurgical Candidates: An Initial Single-Center Case Series
Mounish Nuthalapati, Achuth Ajith Kumar, Simha Swaraj Sirivela, Debnarayan Dutta, Ginil Kumar PooleriAbstract
Introduction:
Surgery remains the standard treatment for localized renal cell carcinoma. However, stereotactic ablative radiotherapy (SABR) has emerged as a promising noninvasive alternative for patients who are medically unfit for surgery or carry a high operative risk. We report our initial institutional experience with SABR for localized renal tumors in nonsurgical candidates.
Materials and Methods:
We retrospectively reviewed consecutive patients with localized renal tumors treated with definitive SABR between January 2021 and July 2023 at a tertiary care center. Demographic, clinical, radiological, treatment, oncological, and renal functional data were collected. Tumor response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST, developed by the RECIST Working Group, coordinated through the European Organisation for Research and Treatment of Cancer, Brussels, Belgium), version 1.1, and renal function was evaluated using the estimated glomerular filtration rate (eGFR).
Results:
Five male patients with a mean age of 58.4 years underwent SABR. Clinical stage was cT1a in two patients and cT1b in three, with one patient having a solitary functioning kidney. SABR was delivered as 35–40 Gy in five fractions. The median follow-up duration was 8.5 months. At the last follow-up, all patients demonstrated stable disease by RECIST criteria, with no nodal or distant metastatic progression. The longest tumor diameter decreased in three patients, remained unchanged in one, and increased slightly in one while remaining RECIST-stable. Tumor volume decreased in four lesions. Renal function was preserved, with changes in the eGFR ranging from −2 to +14 mL/min.
Conclusion:
SABR appears to be a feasible and well-tolerated nephron-sparing treatment option for selected nonsurgical patients with localized renal tumors, providing short-term disease control while preserving renal function. Larger prospective studies with longer follow-up are needed to validate these findings.