title: Clinical applications of volumetric modulated arc therapy.
abstract: OBJECTIVE
  To present treatment planning case studies for several treatment sites for which volumetric modulated arc therapy (VMAT) could have a positive impact; and to share an initial clinical experience with VMAT for stereotactic body radiotherapy (SBRT).
  
  
  METHODS
  Four case studies are presented to show the potential benefit of VMAT compared with conformal and intensity-modulated radiotherapy (IMRT) techniques in pediatric cancer, bone marrow-sparing whole-abdominopelvic irradiation (WAPI), and SBRT of the lung and spine. Details of clinical implementation of VMAT for SBRT are presented. The VMAT plans are compared with conventional techniques in terms of dosimetric quality and delivery efficiency.
  
  
  RESULTS
  Volumetric modulated arc therapy reduced the treatment time of spine SBRT by 37% and improved isodose conformality. Conformal and VMAT techniques for lung SBRT had similar dosimetric quality, but VMAT had improved target coverage and took 59% less time to deliver, although monitor units were increased by 5%. In a complex pediatric pelvic example, VMAT reduced treatment time by 78% and monitor units by 25% compared with IMRT. A double-isocenter VMAT technique for WAPI can spare bone marrow while maintaining good delivery efficiency.
  
  
  CONCLUSIONS
  Volumetric modulated arc therapy is a new technology that may benefit different patient populations, including pediatric cancer patients and those undergoing concurrent chemotherapy and WAPI. Volumetric modulated arc therapy has been used and shown to be beneficial for significantly improving delivery efficiency of lung and spine SBRT.
authors.affiliation: Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073-6769, USA.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Matuszak
authors.forename: Di
authors.initials: D
authors.lastname: Yan
authors.forename: Inga
authors.initials: I
authors.lastname: Grills
authors.forename: Alvaro
authors.initials: A
authors.lastname: Martinez
mesh_terms: D000328:Adult; D001853:Bone Marrow / Q000528:radiation effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002675:Child, Preschool; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010386:Pelvic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000517:prevention & control; D011859:Radiography; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*; D012208:Rhabdomyosarcoma / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D013125:Spinal Neoplasms / Q000556:secondary / Q000601:surgery*; D013679:Technology, Radiologic; D013997:Time Factors