title: Image-guided volumetric modulated arc therapy for breast cancer: a feasibility study and plan comparison with three-dimensional conformal and intensity-modulated radiotherapy.
abstract: OBJECTIVE
  To test the feasibility of volumetric modulated arc therapy (VMAT) in breast cancer and to compare it with three-dimensional conformal radiotherapy (3D-CRT) as conventional tangential field radiotheraphy (conTFRT).
  
  
  METHODS
  12 patients (Stage I, 8: 6 left breast cancer and 2 right breast cancer; Stage II, 4: 2 on each side). Three plans were calculated for each case after breast-conserving surgery. Breast was treated with 50 Gy in four patients with supraclavicular lymph node inclusion, and in eight patients without the node inclusion. Multiple indices and dose parameters were measured.
  
  
  RESULTS
  V95% was not achieved by any modality. Heterogeneity index: 0.16 (VMAT), 0.13 [intensity-modulated radiotherapy (IMRT)] and 0.14 (conTFRT). Conformity index: 1.06 (VMAT), 1.15 (IMRT) and 1.69 (conTFRT). For both indices, IMRT was more effective than VMAT (p=0.009, p=0.002). Dmean and V20 for ipsilateral lung were lower for IMRT than VMAT (p=0.0001, p=0.003). Dmean, V2 and V5 of contralateral lung were lower for IMRT than VMAT (p>0.0001, p=0.005). Mean dose and V5 to the heart were lower for IMRT than for VMAT (p=0.015, p=0.002).
  
  
  CONCLUSIONS
  The hypothesis of equivalence of VMAT to IMRT was not confirmed for planning target volume parameter or dose distribution to organs at risk. VMAT was inferior to IMRT and 3D-CRT with regard to dose distribution to organs at risk, especially at the low dose level.
  
  
  CONCLUSIONS
  New technology VMAT is not superior to IMRT or conventional radiotherapy in breast cancer in any aspect.
authors.affiliation: Department of Radiation Oncology, Charité School of Medicine and University Hospital Berlin, Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Badakhshi
authors.forename: D
authors.initials: D
authors.lastname: Kaul
authors.forename: J
authors.initials: J
authors.lastname: Nadobny
authors.forename: B
authors.initials: B
authors.lastname: Wille
authors.forename: J
authors.initials: J
authors.lastname: Sehouli
authors.forename: V
authors.initials: V
authors.lastname: Budach
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D015412:Mastectomy, Segmental; D008875:Middle Aged; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*