title: Dosimetric and efficiency comparison of high-dose radiotherapy for esophageal cancer: volumetric modulated arc therapy versus fixed-field intensity-modulated radiotherapy.
abstract: The aim of this study was to compare high-dose volumetric modulated arc therapy (VMAT) and fixed-field intensity-modulated radiotherapy (ff-IMRT) plans for the treatment of patients with middle-thoracic esophageal cancer. Eight patients with cT2-3N0M0 middle-thoracic esophageal cancer were enrolled. The treatment planning system was the version 9 of the Pinnacle(3) with SmartArc (Philips Healthcare, Fitchburg, WI, USA). VMAT and ff-IMRT treatment plans were generated for each case, and both techniques were used to deliver 50 Gy to the planning target volume (PTV(50)) and then provided a 16-Gy boost (PTV(66)). The VMAT plans provided superior PTV(66) coverage compared with the ff-IMRT plans (P = 0.034), whereas the ff-IMRT plans provided more appropriate dose homogeneity to the PTV(50) (P = 0.017). In the lung, the V(5) and V(10) were lower for the ff-IMRT plans than for the VMAT plans, whereas the V(20) was lower for the VMAT plans. The delivery time was significantly shorter for the VMAT plans than for the ff-IMRT plans (P = 0.012). In addition, the VMAT plans delivered fewer monitor units. The VMAT technique required a shorter planning time than the ff-IMRT technique (3.8 ± 0.8 hours vs. 5.4 ± 0.6 hours, P = 0.011). The major advantages of VMAT plans are higher efficiency and an approximately 50% reduction in delivery time compared with the ff-IMRT plans, with comparable plan quality. Further clinical investigations to evaluate the use of high-dose VMAT for the treatment of esophageal cancer are warranted.
authors.affiliation: Department of Radiation Oncology, Chang Gung Memorial Hospital-Linkou, Chang Gung University, Taoyuan, Taiwan; Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Lin
authors.forename: W-Y
authors.initials: WY
authors.lastname: Huang
authors.forename: Y-M
authors.initials: YM
authors.lastname: Jen
authors.forename: C-M
authors.initials: CM
authors.lastname: Chen
authors.forename: Y-F
authors.initials: YF
authors.lastname: Su
authors.forename: H-L
authors.initials: HL
authors.lastname: Chao
authors.forename: C-S
authors.initials: CS
authors.lastname: Lin
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D004938:Esophageal Neoplasms / Q000532:radiotherapy*; D006321:Heart; D006801:Humans; D008168:Lung; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D013116:Spinal Cord; D013997:Time Factors
keywords: dosimetric comparison; esophageal cancer; intensity-modulated radiotherapy; volumetric modulated arc therapy