title: Proton radiation therapy offers reduced normal lung and bone marrow exposure for patients receiving dose-escalated radiation therapy for unresectable stage iii non-small-cell lung cancer: a dosimetric study.
abstract: BACKGROUND
  The purpose of this study was to determine the potential benefit of proton radiation therapy over photon radiation therapy in patients with unresectable stage III non-small-cell lung cancer.
  
  
  METHODS
  Optimized 3-dimensional conformal photon (3DCRT), intensity-modulated radiation therapy (IMRT) and proton therapy (PT) plans were generated for 8 consecutive patients with unresectable stage III non-small-cell lung cancer using the same target goals and normal tissue constraints. The radiation exposure to non-targeted normal structures, including lung, bone marrow, esophagus, heart, and spinal cord, were compared. Photon doses are expressed in gray (Gy). Proton doses are expressed in cobalt gray equivalents (CGE).
  
  
  RESULTS
  In all patients, 3DCRT, IMRT, and PT plans, achieved the dose goals for the target volumes. Compared with the 3DCRT plans, proton plans offered a median 29% reduction in normal lung V(20) Gy (CGE), a median 33% reduction in mean lung dose (MLD), and a median 30% reduction in the volume of bone marrow receiving a dose of 10 Gy (CGE). Compared with the IMRT plans, the proton plans offered a median 26% reduction in normal lung V(20) Gy (CGE), a median 31% reduction in MLD, and a median 27% reduction in the volume of bone marrow receiving a dose of 10 Gy (CGE).
  
  
  CONCLUSIONS
  By reducing the volumes of normal structures irradiated, protons can potentially improve the therapeutic index for patients with unresectable stage III non-small-cell lung cancer receiving combined radiation therapy and chemotherapy.
authors: University of Florida Proton Therapy Institute, University of Florida College of Medicine, Jacksonville, USA. rnichols@floridaproton.org
authors: R Charles
authors: RC
authors: Nichols
authors: Soon N
authors: SN
authors: Huh
authors: Randal H
authors: RH
authors: Henderson
authors: Nancy P
authors: NP
authors: Mendenhall
authors: Stella
authors: S
authors: Flampouri
authors: Zuofeng
authors: Z
authors: Li
authors: Harry J
authors: HJ
authors: D'Agostino
authors: J Davis
authors: JD
authors: Cury
authors: Dat C
authors: DC
authors: Pham
authors: Bradford S
authors: BS
authors: Hoppe
mesh_terms: D001853:Bone Marrow / Q000528:radiation effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D009367:Neoplasm Staging; D061766:Proton Therapy; D050397:Radiotherapy, Intensity-Modulated; D015996:Survival Rate; D016896:Treatment Outcome; D011522:Protons
chemical_list: D011522:Protons