Imaging and Nonsurgical Management of Renal Masses.

In patients with renal masses, when intervention is warranted, partial nephrectomy is preferred when feasible, especially for T1 renal masses. Thermal ablation, however, has become an accepted alternative treatment of small renal neoplasms with excellent oncologic outcomes. The National Comprehensive Cancer Network guidelines include thermal ablation as a treatment strategy for managing T1a and select T1b masses. Other potential locoregional treatments for malignant and benign renal masses are emerging. Stereotactic body radiation therapy (SBRT) is gaining traction in the management of select localized renal masses and can be considered in patients who are not surgical candidates. Imaging findings after SBRT differ from those after thermal ablation. As this technique becomes more widely used, the temporal evolution of post-SBRT changes needs to be understood to correctly identify local tumor progression. Renal artery embolization is accepted as safe and effective for patients with renal angiomyolipoma. It can also be used in the management of renal cell carcinoma as an adjunct to definitive treatment or for palliation in advanced disease. With the growing acceptance of local-regional treatment of renal masses and the corresponding number of related patients undergoing surveillance and postablation imaging, the diagnostic radiologist will have greater responsibility in the appropriate interpretation of follow-up imaging to accurately assess normal postprocedural findings and define oncologic outcomes. Such interpretations should be based on understanding of the procedure and related imaging findings, both acutely and in the years after treatment. Procedural complications and recurrent tumor are identifiable based on deviations from the expected course. ^©RSNA, 2024 Supplemental material is available for this article.