title: Preliminary results of proton-beam therapy for stage III non-small-cell lung cancer.
abstract: BACKGROUND
  We conducted a preliminary retrospective evaluation of the efficacy and toxicity of proton-beam therapy (pbt) for stage iii non-small-cell lung cancer.
  
  
  METHODS
  Between January 2009 and August 2013, 27 patients (26 men, 1 woman) with stage iii non-small-cell lung cancer underwent pbt. The relative biologic effectiveness value of the proton beam was defined as 1.1. The beam energy and spread-out Bragg peak were fine-tuned such that the 90% isodose volume of the prescribed dose encompassed the planning target volume. Of the 27 patients, 11 underwent neoadjuvant chemotherapy. Cumulative survival curves were calculated using the Kaplan-Meier method. Treatment toxicities were evaluated using version 4 of the Common Terminology Criteria for Adverse Events.
  
  
  RESULTS
  Median age of the patients was 72 years (range: 57-91 years), and median follow-up was 15.4 months (range: 7.8-36.9 months). Clinical stage was iiia in 14 patients (52%) and iiib in 13 (48%). The median dose of pbt was 77 GyE (range: 66-86.4 GyE). The overall survival rate in the cohort was 92.3% at 1 year and 51.1% at 2 years. Locoregional failure occurred in 7 patients, and distant metastasis, in 10. In 2 patients, initial failure was both locoregional and distant. The 1-year and 2-year rates of local control were 68.1% and 36.4% respectively. The 1-year and 2-year rates of progression-free survival were 39.9% and 21.4% respectively. Two patients experienced grade 3 pneumonitis.
  
  
  CONCLUSIONS
  For patients with stage iii non-small-cell lung cancer, pbt can be an effective and safe treatment option.
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: Y
authors.initials: Y
authors.lastname: Hatayama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: Y
authors.initials: Y
authors.lastname: Azami
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: H
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: I
authors.initials: I
authors.lastname: Tsukiyama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: M
authors.initials: M
authors.lastname: Hareyama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, Koriyama, Japan;
authors.forename: Y
authors.initials: Y
authors.lastname: Kikuchi
authors.affiliation: Department of Radiology and Radiation Oncology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
keywords: Proton-beam therapy; chemotherapy; stage iii non-small-cell lung cancer