Safety and Efficacy of Percutaneous Cryoablation for Recurrent or Metastatic Soft Tissue Sarcoma in Adult Patients

Background: 
Treatment options are limited in patients with recurrent or metastatic disease after initial treatment of soft tissue sarcoma (STS) by surgical resection, radiation, or systemic therapy. Percutaneous cryoablation may provide a complementary minimally invasive option in this setting.

Objective: 
To assess the safety and efficacy of percutaneous cryoablation performed for local control of treatment-refractory recurrent or metastatic STS.

Methods: 
This single-institution retrospective study included adult patients who underwent percutaneous cryoablation from March 2016 to April 2023 to achieve local control of recurrent or metastatic STS after earlier treatment (surgery, radiation, or chemotherapy). For each treated lesion, a single interventional radiologist re-reviewed intraprocedural images to assess for adequate coverage by the ice ball of the entire lesion and a ≥5-mm margin in all dimensions. Complications and outcomes were extracted from medical records. The primary endpoint for procedure efficacy was 1-year local progression-free survival.

Results: 
The study included 141 patients (median age, 66 years; 90 female, 51 male) who underwent 217 cryoablation procedures to treat 250 recurrent or metastatic STS lesions. The most common STS histologic types were leiomyosarcoma (56/141) and liposarcoma (39/141). Lesions had a mean long-axis diameter of 2.0 cm (range, 0.4-11.0 cm). Adequate ice-ball coverage was achieved for 82% (204/250) of lesions. The complication rate was 2% (4/217), entailing three major complications and one minor complication. Patients' median post-ablation follow-up was 25 months (range, 3-80 months). Local progression-free survival was 86% at 1 year and 79% at 2 years. Chemotherapy-free survival was 45% at 1 year and 31% at 2 years. Overall survival (OS) was 89% at 1 year and 80% at 2 years.
In Kaplan-Meier analysis, leiomyosarcoma, in comparison with liposarcoma, had significantly higher local progression-free survival, but no significant difference in OS. In multivariable analysis, factors independently associated with an increased risk for local progression included inadequate ice-ball coverage (HR=7.73) and a lesion location of peritoneum (HR=3.63) or retroperitoneum (HR=3.71) relative to lung.

Conclusion: 
Percutaneous cryoablation has a favorable safety and efficacy profile in patients with recurrent or metastatic STS after earlier treatments.