Safety and Efficacy of Cryotherapy for the Treatment of Renal Angiomyolipoma Related to Tuberous Sclerosis Complex: The Cryo-TSC Study

Purpose: Tuberous sclerosis complex (TSC) is a rare autosomal dominant inherited disease, in which approximately 60% to 80% of patients have bilateral angiomyolipoma (AML). There is a need for repeatable local treatments of TSC-AML. Cryotherapy is an option for renal tumors; however, its safety and efficacy for vascular tumors, such as TSC-AML, are unclear. The aim of this study was to establish the safety and efficacy of cryotherapy for TSC-AML. Materials and Methods: This was an open-label, single-arm, prospective phase II study to evaluate the safety and efficacy of cryotherapy for TSC-AML of ≤ 4 cm. Cryotherapy was performed using the CryoHit device with a percutaneous approach. Safety was assessed 1, 2, 6, and 9 months after cryotherapy, and efficacy was assessed 3 and 9 months after cryotherapy. The efficacy of cryotherapy was evaluated using the modified RECIST or RECIST criteria by independent central review. The primary end point was the disease control rate, and secondary end points were the overall response rate, safety, renal function, quality of life, and whether additional treatment was required. Results: The disease control rate was 100%, and the overall response rate was 93.3%. After 9 months of follow-up, the median estimated glomerular filtration rate decreased slightly (from 89.2 mL/min/1.73 m 2 to 79.4 mL/min/1.73 m 2 ). Quality of life was stable, and no additional treatment was needed. Three Grade 3 adverse events (hematuria, chronic kidney disease, and elevated aspartate aminotransferase) were observed in 3 patients, respectively, but no additional treatments were required. Conclusions: Cryotherapy for TSC-AML can be performed safely and efficiently. Cryotherapy can be a new therapeutic option for TSC-AML. Trial Registration Number: jRCTs072200039.