Sporadic versus Tuberous Sclerosis Complex–Associated Angiomyolipomas: Predictors for Long-Term Outcomes following Transcatheter Embolization

Purpose To evaluate risk factors for long-term outcomes following embolization of sporadic versus tuberous sclerosis complex (TSC)–associated angiomyolipomas (AMLs). Materials and Methods A retrospective review of consecutive transcatheter embolizations of renal AMLs between 2002 and 2014 was performed. Tumor volumetrics including density analysis were obtained. Treatment outcomes were assessed at 1 year after embolization using Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 and volumetric RECIST criteria. A total of 56 patients, 70% (39/56) of whom had TSC, underwent embolization of 72 renal AMLs. Embolization was most commonly performed (70/72, 97%) using microspheres (300–500 μm or 500–700 μm Embosphere). Results Between the sporadic and TSC-associated populations, there was no difference in follow-up time (648 d vs 583 d, P = .78), initial tumor diameter (6.68 cm vs 5.71 cm, P = .09), or percent tumoral fat content (39.5% vs 8.6%, P = .35). Progressive disease was noted in 9 TSC-associated AMLs by volume and 3 TSC-associated AMLs by diameter but in no sporadic AMLs. Growth suppression curves were remarkable for rebound growth in TSC patients, particularly in TSC patients younger than 18 years. Patient age (P = .007) and tumor volume (P = .03) were found to correlate with tumor regrowth within the TSC population. No difference was found in median change in total volume after embolization based on fat content (−57.9% vs −54.2%, P = .68). Conclusions TSC, patient age, and tumoral volume before embolization are risk factors for AML growth following embolization. Intratumoral fat content was not found to predict response to embolization.