Clinical evaluation of proton radiotherapy for non-small-cell lung cancer.

Abstract

To evaluate the clinical results of proton radiotherapy for patients with non-small-cell lung cancer (NSCLC). Between 1983 and 2000, 51 NSCLC patients were treated with proton beams at the University of Tsukuba. There were 28 patients in Stage I, 9 in Stage II, 8 in Stage III, 1 in Stage IV, and 5 with recurrent disease. Thirty-three patients had squamous cell carcinoma, 17 had adenocarcinoma, and 1 had large-cell carcinoma. Median fraction and total doses given were 3.0 Gy (range 2.0-6.0 Gy), and 76.0 Gy (range 49.0-93.0 Gy), respectively. The 5-year overall survival rate was 29% for all patients, 70% for 9 Stage IA patients, and 16% for 19 Stage IB patients, respectively (IA vs. IB: p < 0.05). The 5-year in-field local control rate was higher in patients with Stage IA (89%) when compared with those with Stage IB (39%). Forty-seven patients (92%) experienced acute lung toxicity of Grade 1 or less; 3 had Grade 2, 1 had Grade 3, and none experienced Grade 4 or higher. Patients in the present series showed very little late toxicity. Proton therapy is a very safe and effective treatment for patients with NSCLC, especially for those with early stages. The relative merit of proton therapy in comparison with stereotactic photon radiotherapy or three-dimensional conformal photon radiotherapy remains to be defined through future clinical trials.