[Clinical Investigation on CT guided cryoablation for treating invasive chest wall or pleural tumors].

Objective: To evaluate the feasibility and short-term effect of CT guided cryoablation for malignant chest wall or pleural involvement. Methods: To follow up 22 patients with chest wall or pleural involvement of various malignancies who underwent cryoablation from January 2012 to January 2015 by conducting postoperative 1-, 3- and 6-month enhanced CT, MRI or PET-CT examinations, respectively, evaluate local curative effect, and observe their progression-free survival (PFS), postoperative pain remission and complications after the cryoablation. Results: A total of 22 patients with 27 lesions received 26 times of argon-helium cryoablation. According to the coverage situation of immediate postoperative ice balls on the lesions, they were divided into a complete coverage group (Group A with 18 patients) and a partial coverage group (Group B with 4 patients). 1 month later, 15 patients' tumors were completely ablated, and 3 had residue and thus received the second cryoablation in Group A, while all patients' tumors had residue in Group B. 3 months later, 17 patients' tumors were completely ablated, and 1 had residue and thus received another cryoablation in Group A, while all patients' residual tumors enlarged in different extent in group B. 6 months later, all lesions were ablated in group A while all patients' residual tumors enlarged in group B. For the 22 patients, their preoperative, and postoperative 1-week, 1-month, 3-month, and 6-month VAS scores were 4.95±0.57, 1.45±0.35, 1.45±0.35, 1.64±1.71, and 2.00±2.35, respectively. The differences in the preoperative, postoperative 1-week, and postoperative 1-month scores are significant statistically (P<0.05), and the difference in the postoperative 1-month and 6-month scores is also with statistical significance (P=0.03). For all patients, their post-operative 1-week, 1-month, 3-monte and 6-month pain remission rates are 90.9%(20/22), 90.9%(20/22), 86.4% (19/22)and 81.8%(18/22), respectively. With a median follow-up of 13.5 months, the median PFS is 7 months. The adverse effect after argon-helium cryoablation involved transitory worsened pain (16 cases), pleural effusion (5 cases, including 3 underwent closed drainage), fever (5 cases), and hemoptysis (3 cases). Conclusion: CT guided argon-helium cryoablation is a safe and effective method to treat malignant chest wall or pleural involvement.