Rates of volume reduction after selective arterial embolization for renal angiomyolipoma

Area of Science:

• Interventional Radiology
• Urologic Oncology
• Nephrology

Background:

• Renal angiomyolipomas are benign kidney tumors.
• Selective arterial embolization is a treatment option for symptomatic or large renal angiomyolipomas.
• Understanding tumor response to embolization is crucial for treatment planning.

Purpose of the Study:

• To characterize temporal patterns of renal angiomyolipoma volume reduction after selective arterial embolization.
• To identify factors predictive of renal angiomyolipoma volume reduction rates post-embolization.

Main Methods:

• Retrospective review of patients undergoing renal angiomyolipoma embolization from July 2001 to July 2023.
• Tumor measurements extracted from imaging; lipid content scored.
• Monthly tumor volume reduction calculated and compared across follow-up intervals.

Main Results:

• Tumor volumes decreased significantly faster in the first 6 months post-embolization (7.4% per month) compared to years 2 and 3 (0.3% and <0.1% per month).
• Initial 6-month volume reduction was 25% lower in patients requiring repeat embolization.
• Older patients showed a trend towards lower monthly volume reduction.

Conclusions:

• Embolized renal angiomyolipomas involute rapidly in the first 6 months, then stabilize.
• Volume reduction rate approaches 0% per month after 2 years.
• Findings may help clinicians avoid unnecessary repeat embolization for stable tumors.