High dose hypofractionated proton beam therapy is a safe and feasible treatment for central lung cancer.
There were few reports about high total dose hypofractionated proton beam therapy for central lung cancer. The aim of this study was to examine retrospectively the safety and efficacy of high total dose hypofractionated proton beam therapy for central lung cancer. Patients treated by proton beam therapy for central lung cancer located less than 2 cm from the trachea, mainstem bronchus, or lobe bronchus were included in this study. All patients received 80 Gy relative biological dose effectiveness in 25 fractions proton beam therapy over 5 weeks between January 2009 and February 2015. The toxicities were evaluated using the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer criteria. Twenty patients, including 14 clinically inoperable patients (70%), received proton beam therapy for central lung cancer. The median age was 75 years (63-90 years), the median follow up time was 27.5 months (range: 12-72 months), and the median tumor diameter was 39.5 mm (24-81 mm). All patients were followed for at least 20 months or until death. The 2-year overall survival rate was 73.8% (100% in operable patients, and 62.5% in inoperable patients). The 2-year local control rate was 78.5%. There were no Grade 3 or higher toxicities, including bronchial stricture, obstruction, and fistula. The present study suggests that a high total dose hypofractionated proton beam therapy for central lung cancer was safe and feasible.