title: Left-sided whole breast irradiation with hybrid-IMRT and helical tomotherapy dosimetric comparison.
abstract: OBJECTIVE
  Limited-tomotherapy and hybrid-IMRT treatment techniques were compared for reductions in ipsilateral and contralateral lung, heart, and contralateral breast radiation doses.
  
  
  METHODS
  Thirty consecutively treated left-sided early-stage breast cancer patients were scheduled for lTomo and hIMRT. For the hIMRT plan conventional tangential-field and four-field IMRT plans were combined with different weightings in the prescribed dose. For the lTomo plan a geometrically limited arc was designed for the beamlet entrance. A D p of 50.4 Gy in 28 fractions was used for the PTV. The dose coverage, homogeneity index, conformity index of the target, and the dose volumes of critical structures were compared.
  
  
  RESULTS
  Both modalities presented similar target coverage. The homogeneity and conformity were improved for lTomo with P < 0.001 and P = 0.006, respectively. In the lTomo plan a concave dose distribution was generated with significant dose reductions in both high and low dose regions for ipsilateral lung and heart (P < 0.001). Conclusions. lTomo plan can have similar dose coverage and better homogeneity and conformity to the target. By properly designing the directionally and completely blocked structure, lTomo plan was developed successfully in reducing doses to the healthy tissues for early-stage left-sided breast cancer radiotherapy.
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan ; Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung 404, Taiwan ; Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan.
authors.forename: An-Cheng
authors.identifier: 0000-0001-5583-9979
authors.initials: AC
authors.lastname: Shiau
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan.
authors.forename: Chen-Hsi
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan.
authors.forename: Hui-Ju
authors.identifier: 0000-0002-5908-5278
authors.initials: HJ
authors.lastname: Tien
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan.
authors.forename: Hsin-Pei
authors.identifier: 0000-0003-3784-3709
authors.initials: HP
authors.lastname: Yeh
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan.
authors.forename: Chi-Ta
authors.initials: CT
authors.lastname: Lin
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan ; Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan.
authors.forename: Pei-Wei
authors.identifier: 0000-0003-2051-364X
authors.initials: PW
authors.lastname: Shueng
authors.affiliation: Division of Radiation Oncology, Department of Radiology, Far Eastern Memorial Hospital, Section 2, Nan-Ya South Road, Banqiao, New Taipei City 220, Taiwan.
authors.forename: Le-Jung
authors.initials: LJ
authors.lastname: Wu
mesh_terms: D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*