title: Clinical Outcomes and Prognostic Factors of High-Dose Proton Beam Therapy for Peripheral Stage I Non-Small-Cell Lung Cancer.
abstract: The efficacy, toxicity, and prognostic factors of high-dose proton beam therapy (PBT) for peripheral stage I non-small-cell lung cancer were assessed in this retrospective study.
  
  
  
  Fifty patients with peripheral stage I non-small-cell lung cancer, two of whom had heterochronic multiple lung cancers, underwent high-dose PBT between January 2009 and September 2014. The relative biological effectiveness of the proton beam was defined as 1.1. The beam energy and spread-out Bragg peak were fine-tuned for the 90% isodose volume of the prescribed dosage to encompass the planning target volume. The 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, version 4.
  
  
  
  The study included 35 males and 15 females with a median age of 72.5 years. The median follow-up period was 22.8 months. The clinical stage was IA in 44 (85%) and IB in eight (15%) tumors. The total dose of PBT was 66 GyE in 10 fractions in all tumors. Three-year overall survival rate among all patients was 87.9% (95% confidence interval [CI], 94.8%-73.2%). Forty-five patients were alive, and 5 were dead. Three-year local control and progression-free survival rates were 95.7% (95% CI, 98.9%-83.8%) and 76.3% (95% CI, 86.9%-59.3%), respectively. Only one patient experienced Grade 2 pneumonitis.
  
  
  
  High-dose PBT may be an effective and safe treatment option for patients with stage I non-small-cell lung cancer.
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan. Electronic address: yonoki2005@gmail.com.
authors.forename: Yoshiomi
authors.initials: Y
authors.lastname: Hatayama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Motohisa
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Azami
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ono
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yabuuchi
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hirose
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Wada
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Hareyama
authors.affiliation: Department of Radiation Oncology, Southern Tohoku Proton Beam Therapy Center, Koriyama, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kikuchi
authors.affiliation: Department of Radiology and Radiation Oncology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods*; D017564:Radiation Pneumonitis / Q000453:epidemiology*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate
keywords: High-dose; Peripheral lesion; Prognostic factors; Proton beam therapy; Stage I non-small-cell lung cancer