RADIO FREQUENCY ABLATION OF LUNG METASTASES FROM RENAL CELL CARCINOMA

Abstract

Radio frequency ablation is an imaging guided percutaneous procedure using thermal energy to treat focal malignancies. It has been used to treat neoplasms in the liver, bone, head and neck, and lung.1, 2 Surgical resection is considered the only possibly curative treatment for pulmonary metastases from renal cell carcinoma. We report a case of lung metastases from renal cell carcinoma treated successfully with radio frequency ablation. CASE REPORT A 52-year-old man presented with 2 lung nodules considered to be pulmonary metastases from renal cell carcinoma. He had renal cell carcinoma of the left kidney diagnosed 2 years earlier, and was treated for relief of flank pain and hematuria with left radical nephrectomy. Two pulmonary metastases were present at radical nephrectomy. Chemotherapy with interferon, interleukin-2, vinblastine and 5-fluorouracil was prescribed within 4 months after nephrectomy because of pulmonary metastases. The pulmonary nodules initially grew while the patient was being treated with immunotherapy but decreased in size with fluorouracil. Chemotherapy was completely discontinued 14 months before the ablative therapy for the lung metastases. Physical examination was unremarkable. Plain radiograph and chest computerized tomography (CT) showed 2 parenchymal, peripheral pulmonary nodules, 2.4 1.9 cm. and 1.8 2 cm., in the right lower lobe (part A of figure). Pulmonary nodules were confirmed as metastatic renal cell carcinoma on a CT guided percutaneous biopsy of 1 lesion. Due to the high risk of recurrence and patient refusal to undergo further chemotherapy and surgery, percutaneous ablation was offered as a treatment option. CT guided percutaneous radio frequency ablation of the pulmonary nodules was performed with the patient under general anesthesia. A 17 gauge radio frequency electrode was inserted into the larger nodule and 2, 12-minute cycles of radio frequency treatment were applied. The radio frequency needle was then repositioned in the smaller nodule and a single 12-minute cycle of treatment was applied. After the procedure CT revealed a tiny pneumothorax and some perilesional ground-glass attenuation indicating thermal damage. The patient tolerated the procedure well and was sent home the same day. An asymptomatic pleural cutaneous fistula developed evidenced by subcutaneous gas seen on a followup chest radiograph, which resolved spontaneously without further treatment. Followup chest CT 12 months later showed no recurrence or new metastatic lesions either at the ablation treated sites or elsewhere in the lung (part B of figure). The patient was asymptomatic 16 months later with no evidence of recurrence or new metastases, and no additional treatment since tumor ablation.