title: Clinical outcomes using carbon-ion radiotherapy and dose-volume histogram comparison between carbon-ion radiotherapy and photon therapy for T2b-4N0M0 non-small cell lung cancer-A pilot study.
abstract: The safety and efficacy of carbon-ion radiotherapy for advanced non-small cell lung cancer have not been established. We evaluated the clinical outcomes and dose-volume histogram parameters of carbon-ion radiotherapy compared with photon therapy in T2b-4N0M0 non-small cell lung cancer. Twenty-three patients were treated with carbon-ion radiotherapy between May 2011 and December 2015. Seven, 14, and 2 patients had T2b, T3, and T4, respectively. The median age was 78 (range, 53-91) years, with 22 male patients. There were 12 adenocarcinomas, 8 squamous cell carcinomas, 1 non-small cell lung carcinoma, and 2 clinically diagnosed lung cancers. Eleven patients were operable, and 12 patients were inoperable. Most patients (91%) were treated with carbon-ion radiotherapy of 60.0 Gy relative biological effectiveness (RBE) in 4 fractions or 64.0 Gy (RBE) in 16 fractions. Local control and overall survival rates were calculated. Dose-volume histogram parameters of normal lung and tumor coverages were compared between carbon-ion radiotherapy and photon therapies, including three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT). The median follow-up of surviving patients was 25 months. Three patients experienced local recurrence, and the 2-year local control rate was 81%. During follow-up, 5 patients died of lung cancer, and 1 died of intercurrent disease. The 2-year overall survival rate was 70%. Operable patients had a better overall survival rate compared with inoperable patients (100% vs. 43%; P = 0.04). There was no grade ≥2 radiation pneumonitis. In dose-volume histogram analysis, carbon-ion radiotherapy had a significantly lower dose to normal lung and greater tumor coverage compared with photon therapies. Carbon-ion radiotherapy was effectively and safely performed for T2b-4N0M0 non-small cell lung cancer, and the dose distribution was superior compared with those for photon therapies. A Japanese multi-institutional study is ongoing to prospectively evaluate these patients and establish the use of carbon-ion radiotherapy.
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Shirai
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kawashima
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Saitoh
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Abe
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Fukata
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Shigeta
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Irie
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Shiba
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Okano
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohno
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy*; D005260:Female; D063193:Heavy Ion Radiotherapy / Q000009:adverse effects; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D017785:Photons; D010865:Pilot Projects; D015996:Survival Rate; D016896:Treatment Outcome