BACKGROUND: The purpose of this study was to assess the feasibility of deep inspiration breath-hold (DIBH) based volumetric modulated arc therapy (VMAT) for locally advanced left sided @entity0 @entity1 undergoing radical mastectomy. DIBH immobilizes the @entity5 bed providing dosimetric benefits over free breathing (FB). MATERIALS AND METHODS: Ten left sided post mastectomy @entity1 were immobilized in a supine position with both the arms lifted above the head on a hemi-body vaclock. Two thermoplastic masks were prepared for each @entity1 , one for normal free breathing and a second made with breath-hold to maintain reproducibility. DIBH CT scans were performed in the prospective mode of the Varian real time position management (RPM) system. The planning target volume ( @entity343 ) included the left chest wall and supraclavicular nodes and @entity343 prescription dose was 5000cGy in 25 fractions. DIBH-3DCRT planning was performed with the single iso-centre technique using a 6MV photon beam and the field-in-field technique. VMAT plans for FB and DIBH contained two partial arcs (179o-300oCCW/CW). Dose volume histograms of @entity343 and OAR's were analyzed for DIBH-VMAT, FB-VMAT and DIBH-3DCRT. In DIBH mode daily orthogonal (0o and 90o) KV images were taken to determine the setup variability and weekly twice CBCT to verify gating threshold level reproducibility. RESULTS: DIBH-VMAT reduced the lung and heart dose compared to FB-VMAT, while maintaining similar @entity343 coverage. The mean heart V30Gy was 2.3%   2.7, 5.1%   3.2 and 3.3%   7.2 and for left lung V20Gy was 18.57%   2.9, 21.7%   3.9 and 23.5%   5.1 for DIBH-VMAT, FB-VMAT and DIBH-3DCRT respectively. CONCLUSIONS: DIBH-VMAT significantly reduced the heart and lung dose for left side chest wall @entity1 compared to FB-VMAT. @entity343 conformity index, homogeneity index, ipsilateral lung dose and heart dose were better for DIBH-VMAT compared to DIBH-3DCRT. However, contralateral lung and breast volumes exposed to low doses were increased with DIBH-VMAT.

Feasibility study of deep inspiration breath-hold based volumetric modulated arc therapy for locally advanced left sided XXXX @entity1 .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor'] @entity343 :: ('187978', 'Species') :: ['PTV'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer']
@entity0 :: (MESH:D001943,Disease) :: ['breast cancer']
