Clinical outcomes of percutaneous cryoablation for pulmonary metastases of soft tissue and bone sarcomas under local anesthesia: a single-institution retrospective cohort study

BACKGROUND: The management of pulmonary metastases of soft tissue and bone sarcomas is challenging due to their resistance to chemotherapy and radiotherapy. This study aimed to evaluate local tumor progression, overall survival (OS), and procedural safety after percutaneous cryoablation for pulmonary metastases of soft tissue and bone sarcomas. METHODS: This retrospective cohort study included 28 patients who underwent percutaneous cryoablation for 84 metastatic lung tumors of soft tissue and bone sarcomas during 53 sessions between July 2002 and December 2016. Percutaneous cryoablation was performed under local anesthesia using the CRYOcare system and computed tomography fluoroscopy. Procedural complications within 30 days were assessed using prospectively recorded clinical data and retrospectively graded according to the Common Terminology Criteria for Adverse Events version 5.0. The time to local progression of the treated tumors and overall survival were estimated using the Kaplan-Meier method. RESULTS: All cryoablation procedures were performed under local anesthesia. The median tumor diameter was 1.1 cm (range: 0.4-6.5 cm). Twelve tumors (14.3%) showed local tumor progression after initial cryoablation during the median follow-up duration of 16 months (range: 0-216 months). The primary efficacy rates were 88.8%, 79.1%, and 79.1% at 1, 3, and 5 years, respectively. After repeat cryoablation for four tumors with local progression, the assisted efficacy rates were 95.6%, 82.8%, and 77.9% at 1, 3, and 5 years, respectively. Three tumors in two patients had no local progression for more than 10 years. A tumor diameter of ≤ 2 cm was significantly associated with improved primary and assisted efficacy rates (P = 0.024 and P = 0.015, respectively). The median OS was 34 months (range, 2-155 months), and the OS rates were 75.0%, 52.8%, and 28.8% at 1, 3, and 5 years, respectively. Adverse events occurred in 31 sessions (58.5%); all were grade 1 or 2, and no grade ≥ 3 adverse events or 30-day mortality were observed. CONCLUSIONS: In this selected single-institution cohort of nonsurgical candidates with pulmonary metastases of soft tissue and bone sarcomas, percutaneous cryoablation was feasible and was associated with local tumor control and an acceptable safety profile.