title: Carotid-Sparing TomoHelical 3-Dimensional Conformal Radiotherapy for Early Glottic Cancer.
abstract: OBJECTIVE
  The purpose of this study was to investigate the dosimetric benefits and treatment efficiency of carotid-sparing TomoHelical 3-dimensional conformal radiotherapy (TH-3DCRT) for early glottic cancer.
  
  
  METHODS
  Ten early-stage (T1N0M0) glottic squamous cell carcinoma patients were simulated, based on computed tomography scans. Two-field 3DCRT (2F-3DCRT), 3-field intensity-modulated radiation therapy (3F-IMRT), TomoHelical-IMRT (TH-IMRT), and TH-3DCRT plans were generated with a 67.5-Gy total prescription dose to the planning target volume (PTV) for each patient. In order to evaluate the plan quality, dosimetric characteristics were compared in terms of conformity index (CI) and homogeneity index (HI) for PTV, dose to the carotid arteries, and maximum dose to the spinal cord. Treatment planning and delivery times were compared to evaluate treatment efficiency.
  
  
  RESULTS
  The median CI was substantially better for the 3F-IMRT (0.65), TH-IMRT (0.64), and TH-3DCRT (0.63) plans, compared to the 2F-3DCRT plan (0.32). PTV HI was slightly better for TH-3DCRT and TH-IMRT (1.05) compared to 2F-3DCRT (1.06) and 3F-IMRT (1.09). TH-3DCRT, 3F-IMRT, and TH-IMRT showed an excellent carotid sparing capability compared to 2F-3DCRT (p < 0.05). For all plans, the maximum dose to the spinal cord was < 45 Gy. The median treatment planning times for 2F-3DCRT (5.85 minutes) and TH-3DCRT (7.10 minutes) were much lower than those for 3F-IMRT (45.48 minutes) and TH-IMRT (35.30 minutes). The delivery times for 2F-3DCRT (2.06 minutes) and 3F-IMRT (2.48 minutes) were slightly lower than those for TH-IMRT (2.90 minutes) and TH-3DCRT (2.86 minutes).
  
  
  CONCLUSIONS
  TH-3DCRT showed excellent carotid-sparing capability, while offering high efficiency and maintaining good PTV coverage.
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Chae-Seon
authors.initials: CS
authors.lastname: Hong
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dongryul
authors.initials: D
authors.lastname: Oh
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang Gyu
authors.initials: SG
authors.lastname: Ju
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Ahn
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae Myoung
authors.initials: JM
authors.lastname: Noh
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kwangzoo
authors.initials: K
authors.lastname: Chung
authors.affiliation: Department of Radiation Oncology, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jin Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering and Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea.
authors.forename: Tae-Suk
authors.initials: TS
authors.lastname: Suh
mesh_terms: D006801:Humans; D007822:Laryngeal Neoplasms / Q000532:radiotherapy*; D011874:Radiometry; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated
keywords: Carotid sparing; Early glottic cancer; Intensity-modulated radiotherapy; TomoHelical three-dimensional conformal radiotherapy