Local control of lung tumors by percutaneous fluoroscopic computer tomography guided cryoablation

7186 Background: Cryoablation is reestablishing itself as a potential tool in multi-modality treatment against cancer in organs such as liver, kidney, prostate, and uterus. We found only one clinical report of cryoablation against lung tumors, performed through a thoracotomy (Xiang J et al, 1995). Percutaneous cryoablation of lung tumors with the help of recent high resolution fluoroscopic computed tomography (FCT), offers potential local tumor control in patients with prohibitive surgical risks. In the present study, we evaluated local control using FCT guided cryoablation in lung tumors less than 3 cm in diameter. Methods: Primary or metastatic lung tumors less than 3 cm in diameter which were not candidates for surgical resection were included in this study. These tumors were treated locally with curative intent by cryoablation, and followed up for 6 months or more. To evaluate local control, dynamic CT scan was taken every 3 months after cryoablation. A single cryoprobe was inserted into the center of the tumor percutaneously with FCT guidance under local anesthesia. Freeze-thaw cycles were repeated 3 times. This study was approved by the School of Medicine Keio University institutional review board. Written consent was obtained from all patients. Results: 61 tumors were cryoablated in 32 cases. Age 36–79 (58), 1 was primary lung cancer, and 31 were lung metastases. Up to 5 tumors were treated in one session. Local recurrence was experienced in 5 tumors(8.2%). Additional cryoablation was performed against 4 of these tumors successfully, and follow up is being continued. Further treatment was not possible in 1 tumor due to psychosis. Pneumothorax requiring chest tube drainage occurred in 3 procedures. Phrenic nerve paralysis occurred in 1, and segmental atelectasis occurred in 1 procedure with a centrally located tumor. Conclusions: The present study suggests that percutaneous FCT guided cryoablation against lung tumors is feasible. Local control for lung tumors within 3cm in diameter was 92% in this set of patients. Locally recurrent tumors could be treated by additional cryoablation. In order to further improve local control, we are currently inserting multiple probes adjacent to the tumor, so as to encase the tumor. No significant financial relationships to disclose.