[Radiofrequency ablation of malignant lung tumors--preliminary report of 12 cases]

Percutaneous CT fluoroscopy-guided radiofrequency ablation (RFA) was performed in 12 patients with 4 primary and 8 metastatic lung cancers as a pilot study. The main complication was a pneumothorax, which occurred in six cases and 2 of them required a chest tube drainage. Four patients died of extrapulmonary tumor progression at 3-17 months after RFA. The remaining 8 patients were alive with the disease and their median follow-up period was 12 months (range, 6-39 months). An overall survival rate was 75% at 6 months, 63% at 1 year and 43% at 2 years. A local progression occurred in 4 cases at 4-17 months after RFA and the cause of relapse was considered as insufficient ablation due to tumor localization close to the trachea, SVC or intrapulmonary vessels and bronchi. A local control rate was 92% at 6 months, 64% at 1 year and 35% at 2 years.

CONCLUSION

RFA of lung tumors is a safe and minimally invasive therapeutic intervention with a good local control for sufficiently ablated lesions. So it appears to be a favorable treatment option for high-risk patients or those with multiple lesions.

[Two cases of pulmonary metastases from colorectal cancer successfully treated by radiofrequency ablation therapy]

BACKGROUND

To date, several studies have evaluated an efficacy of radiofrequency ablation (RFA) for liver tumor. However, there are few reports on RFA for metastatic pulmonary tumor. We experienced two patients whose pulmonary metastases from colorectal cancer were treated with RFA. Case 1: A 70-year-old man who had undergone surgery for rectal cancer was followed up in our out-patient clinic. Eleven months after the surgery, a pulmonary metastasis 10 mm in diameter at the left S10 segment was found. Systemic chemotherapy started. However, the chemotherapy had to be stopped due to grade 3 neutropenia. So, 17 months after the surgery, RFA was performed for the pulmonary metastasis without any complications. Now, he remains in good condition without any evidence of pulmonary recurrence for 20 months after the RFA. Case 2: A 65-year-old man who had undergone sigmoidectomy for sigmoid colon cancer was followed up in our out-patient clinic. Ten months after the surgery, three pulmonary metastases were found. Systemic chemotherapy started. However, because of adverse events, the chemotherapy had to be stopped. So, 15 months after the surgery, RFA was performed for the pulmonary metastases. Slight pneumothorax, which was observed after RFA, was conservatively treated. Now, he remains in good condition without any evidence of pulmonary recurrence for 3 months after the RFA.

CONCLUSION

RFA could be performed safely. Although a long-term prognosis after RFA remains unclear, it may be an effective and minimally invasive technique for the treatment of pulmonary metastasis.