title: A Dose Escalation Clinical Trial of Single-Fraction Carbon Ion Radiotherapy for Peripheral Stage I Non-Small Cell Lung Cancer.
abstract: Our objective was to report initial results of a dose escalation trial of single-fraction carbon ion radiotherapy for peripheral stage I NSCLC.
  
  
  
  Between April 2003 and February 2012, a total of 218 patients were treated. The total dose was raised from 28 to 50 Gy (relative biological effectiveness [RBE]). There were 157 male and 61 female patients, with a median age of 75 years. Of the tumors, 123 were stage T1 and 95 were stage T2. A total of 134 patients (61.5%) were medically inoperable. By histological type, there were 146 adenocarcinomas, 68 squamous cell carcinomas, three large cell carcinomas, and one mucoepidermoid carcinoma.
  
  
  
  The median follow-up was 57.8 months (range 1.6-160.7). The overall survival rate at 5 years was 49.4%. The local control (LC) rate was 72.7%. A statistically significant difference in LC rate (p = 0.0001, log-rank test) was seen between patients receiving 36 Gy (RBE) or more and those receiving less than 36 Gy (RBE). In 20 patients irradiated with 48 to 50 Gy (RBE), the LC rate at 5 years was 95.0%, the overall survival rate was 69.2%, and the progression-free survival rate was 60.0% (median follow-up was 58.6 months). With dose escalation, LC tended to improve. As for adverse lung and skin reactions, there were no patients with grade 3 or higher reactions, and less than 2% had a grade 2 reaction. Regarding chest wall pain, only one patient had grade 3 late toxicity.
  
  
  
  We have reported the outcome of a dose escalation study of single-fraction carbon ion radiotherapy for stage I NSCLC, showing the feasibility of obtaining excellent results comparable to those with previous fractionated regimens.
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan. Electronic address: yamamoto.naoyoshi@qst.go.jp.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Miyamoto
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Nakajima
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Karube
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hayashi
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tsujii
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
authors.affiliation: Chiba Foundation for Health Promotion and Disease Prevention, Chiba, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Fujisawa
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000473:pathology / Q000532:radiotherapy*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D063193:Heavy Ion Radiotherapy; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal; D015996:Survival Rate
keywords: Carbon ion radiotherapy; Lung cancer; Single fraction; Stage I NSCLC