Cryoablation for Extra-Abdominal Desmoid Tumors: A Retrospective Study of Clinical and radiological outcomes.

PURPOSE: To determine if image-guided cryoablation achieves durable clinical and radiologic response with an acceptable safety profile in patients with extra-abdominal desmoid tumors, and whether volumetric response assessment concords with mRECIST-based classification MATERIALS AND METHODS: Patients treated between 2020 and 2024 were identified through electronic record. Those who underwent cryoablation were included for analysis. The primary outcome was clinical success, defined as a composite of no disease progression at last follow-up, no additional treatment, and symptom improvement. Secondary outcomes included radiologic response, symptom improvement, progression-free survival (PFS), and safety. Among 208 patients diagnosed with desmoid tumors, 44 (20.7%) underwent cryoablation, and 38 had follow-up data available. 92 cryoablation sessions were performed. Median tumor size was 6.9 cm (IQR 5.5-9.2), and median follow-up duration was 28.9 months (IQR 14.3-37.3). RESULTS: The clinical success rate was 81.1%. Radiologic response at last follow-up was complete in 24.3%, partial in 54.1%, stable in 16.2%, and progressive in 5.4%. Volumetric and mRECIST-based response classification showed almost-perfect agreement (κ = 0.895). Repeat cryoablation was performed in 26.3% of patients due to radiologic progression. Additional treatment modalities were required in 13.2% of cases. The 1- and 2-year PFS rates were 76.5% (95% CI: 58.2-87.6%) and 67.4% (95% CI: 46.5-81.7%), respectively. Major adverse events (SIR ≥3) occurred in 5.3% of patients. CONCLUSION: Cryoablation is a safe and effective treatment option for selected patients with extra-abdominal desmoid tumors, achieving clinical success in the majority of patients. These findings support its role in the multidisciplinary management of desmoid tumors.