title: Tangential volumetric modulated arc therapy technique for left-sided breast cancer radiotherapy.
abstract: BACKGROUND
  The aim of the present study was to introduce a new restricted tangential volumetric modulated arc therapy (tVMAT) technique for whole breast irradiation and compare its dosimetric properties to other currently used breast cancer radiotherapy techniques.
  
  
  METHODS
  Ten consecutive women with left-sided breast cancer were enrolled in this retrospective study. Four treatment plans were generated for each patient: 1) standard tangential field-in-field (FinF), 2) tangential intensity modulated radiotherapy (tIMRT), 3) tangential VMAT (tVMAT) with two dual arcs of 50-60° and 4) continuous VMAT (cVMAT) with a dual arc of 240°. The plans were created with Monaco® (tIMRT, tVMAT and cVMAT) and Oncentra® (FinF) treatment planning systems.
  
  
  RESULTS
  With both VMAT techniques significantly higher cardiac avoidance, dose coverage and dose homogenity were achieved when compared with FinF or tIMRT techniques (p < 0.01). VMAT techniques also decreased the high dose areas (above 20 Gy) of ipsilateral lung. There were no significant differences in the mean dose of contralateral breast between the tVMAT, tIMRT and FinF techniques. The dose coverage (V47.5 Gy) was greatest with cVMAT. However, with cVMAT the increase of contralateral breast dose was significant.
  
  
  CONCLUSIONS
  The present results support the hypothesis that the introduced tVMAT technique is feasible for treatment of left-sided breast cancer. With tVMAT dose to heart and ipsilateral lung can be reduced and the dose homogeneity can be improved without increasing the dose to contralateral breast or lung.
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Tuomas.Viren@kuh.fi.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Virén
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Janne.Heikkila@kuh.fi.
authors.forename: Janne
authors.initials: J
authors.lastname: Heikkilä
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Kimmo.Myllyoja@kuh.fi.
authors.forename: Kimmo
authors.initials: K
authors.lastname: Myllyoja
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Kristiina.Koskela@kuh.fi.
authors.forename: Kristiina
authors.initials: K
authors.lastname: Koskela
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Tapani.Lahtinen@kuh.fi.
authors.forename: Tapani
authors.initials: T
authors.lastname: Lahtinen
authors.affiliation: Cancer Center, Kuopio University Hospital, PO Box 100, FI-70029, Kuopio, Finland. Jan.Seppala@kuh.fi.
authors.forename: Jan
authors.initials: J
authors.lastname: Seppälä
mesh_terms: D000368:Aged; D005260:Female; D006321:Heart / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000528:radiation effects; D011379:Prognosis; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D000069584:Unilateral Breast Neoplasms / Q000532:radiotherapy*