Volumetric modulated arc therapy and breath-hold in image-guided locoregional left-sided breast irradiation.
OBJECTIVE
To investigate the effects of using volumetric modulated arc therapy (VMAT) and/or voluntary moderate deep inspiration breath-hold (vmDIBH) in the radiation therapy (RT) of left-sided breast cancer including the regional lymph nodes.


METHODS
For 13 patients, four treatment combinations were compared; 3D-conformal RT (i.e., forward IMRT) in free-breathing 3D-CRT(FB), 3D-CRT(vmDIBH), 2 partial arcs VMAT(FB), and VMAT(vmDIBH). Prescribed dose was 42.56 Gy in 16 fractions. For 10 additional patients, 3D-CRT and VMAT in vmDIBH only were also compared.


RESULTS
Dose conformity, PTV coverage, ipsilateral and total lung doses were significantly better for VMAT plans compared to 3D-CRT. Mean heart dose (D(mean,heart)) reduction in 3D-CRT(vmDIBH) was between 0.9 and 8.6 Gy, depending on initial D(mean,heart) (in 3D-CRT(FB) plans). VMAT(vmDIBH) reduced the D(mean,heart) further when D(mean,heart) was still >3.2 Gy in 3D-CRT(vmDIBH). Mean contralateral breast dose was higher for VMAT plans (2.7 Gy) compared to 3DCRT plans (0.7 Gy).


CONCLUSIONS
VMAT and 3D-CRT(vmDIBH) significantly reduced heart dose for patients treated with locoregional RT of left-sided breast cancer. When Dmean,heart exceeded 3.2 Gy in 3D-CRT(vmDIBH) plans, VMAT(vmDIBH) resulted in a cumulative heart dose reduction. VMAT also provided better target coverage and reduced ipsilateral lung dose, at the expense of a small increase in the dose to the contralateral breast.
Department of Radiation Oncology, Institute Verbeeten, Tilburg, The Netherlands.
Sarah O S
SO
Osman
Department of Radiation Oncology, Institute Verbeeten, Tilburg, The Netherlands.
Sandra
S
Hol
Department of Radiation Oncology, Institute Verbeeten, Tilburg, The Netherlands.
Philip M
PM
Poortmans
Department of Radiation Oncology, Institute Verbeeten, Tilburg, The Netherlands. Electronic address: essers.m@bvi.nl.
Marion
M
Essers
D000328:Adult; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D062485:Breath Holding; D066126:Cardiotoxicity / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006331:Heart Diseases / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008171:Lung Diseases / Q000209:etiology / Q000517:prevention & control*; D008198:Lymph Nodes; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D016896:Treatment Outcome
Breast cancer; Breath-hold; Cardiac toxicity; Locoregional lymph nodes; VMAT