CT Guided Percutaneous Cryoablation of Thoracic Tumors: Technical Feasibility, Early Efficacy and Imaging of 27 Treated Tumors

F. Abtin, Ali Golshan and Robert D. Suh. University of California at Los Angeles, Ronald Reagan UCLA Medical Center.

Purpose of the Study: Cryoablation for solid tumors including liver, kidney and prostate is well recognized and has been increasingly used to treat thoracic tumors, as an alternative to heat-based thermal ablation. In this study, we will present single institution experience with image-guided cryoablation.

Methods: Since July 2007, 27 lesions were treated in 15 patients for palliation. Treated tumors included recurrences or metastases involving the pleura or chest wall (18/27 or 66%), the lung (6/27 or 22%) and the mediastinum (3/27 or 3%). All sessions were performed with local anesthesia and conscious sedation. Clinical and imaging data were evaluated for baseline size, duration of ablation, immediate or delayed minor and major complications and post ablation tumor response.

Results: The largest tumor measured 57 x 42 mm and the smallest 6 x 6 mm, average diameter 30 mm. All lesions were ablated under standard protocol with the exception of 2 lesions, the first due to its small size and the second due to pain. Minor complications included 2 (7%) pneumothoraces, 2 (7%) pleural effusions and 1 (3%) skin erythema and swelling. Major complications included 1 (3%) hemothorax requiring chest tube insertion and transfusion, 1 (3%) hemopneumothorax requiring chest tube insertion and 1 (3%) reactive pleural effusion treated with thoracentesis. Of the 12 lesions treated for pain control, all patients had improvement, some with immediate relief. 14 lesions received one follow-up CT between 1 to 6 months after treatment: 13 decreased in size and 1unchanged. 4 lesions were scanned within 1 month of ablation, all 4 increased in size, although none with metabolic activity. 6 lesions received a second follow-up CT, all showing further decrease in ablation zone size.

Conclusions: As an alternative to heat-based ablation, cryoablation offers promising and potentially effective treatment of thoracic tumors for local tumor control and palliation with acceptable complication rates.

** POSTED OCTOBER 13, 2009 **