Purpose: The standard treatment of stage I non-small cell lung cancer (NSCLC) is surgical resection. Some patients are poor surgical candidates due to severe comorbid medical conditions. Radiotherapy alone has historically been used in this patient population with limited success. Radiofrequency ablation (RFA) is an image-guided, thermally mediated ablative technique recently applied to lung tumors. Combination therapy with both these treatments has not been previously performed. We report our experience with combined CT-guided RFA and conventional radiotherapy in 24 medically inoperable patients with a minimum of 2-year study follow-up in surviving patients.
Patients and methods: Twenty-four consecutive, medically inoperable patients with biopsy-proven, stage I NSCLC were treated with CT-guided RFA followed by radiotherapy to a dose of 66 Gy. RFA was performed with a single or cluster cool-tip F electrode; 21 patients were staged before therapy using fluorodeoxyglucose-positron emission tomography.
Results: There were 14 women and 10 men (median age, 76 years; range, 58 to 85 years). The histologic subtypes were squamous cell (n = 13), adenocarcinoma (n = 5), and undifferentiated (n = 6). All patients received RFA followed by three-dimensional conformal radiotherapy. There were no treatment-related deaths or grade 3/4 toxicities. Pneumothorax requiring chest tubes developed in three patients (12.5%). At a mean follow-up period of 26.7 months (range, 6 to 65 months), 14 patients (58.3%) died, with cumulative survival rates of 50% and 39% at the end of 2 years and 5 years, respectively. Ten of the deaths were cancer related. Two patients had local recurrence (8.3%), while nine patients had systemic metastatic disease. Three patients died of respiratory failure with no evidence of active disease, and one patient died of a cerebrovascular accident at 18-month follow-up. Pleural effusions developed after treatment in six patients (25%), which proved to be malignant in one patient.
Conclusion: RFA followed by conventional radiotherapy is feasible in this population of medically inoperable stage I NSCLC patients. Procedural complication rates are low, and no additional major toxicities were seen despite the addition of RFA. Local control and survival rates appear to be better than with radiotherapy alone.