Dosimetric comparison between intensity-modulated radiotherapy and volumetric-modulated arc therapy in patients of left-sided breast cancer treated with modified radical mastectomy: CONSORT

Volumetric-modulated arc therapy (VMAT) is a novel treatment strategy that protects normal tissues and enhances target volume coverage during radiotherapy. This study aimed to clarify whether VMAT is superior to intensity-modulated radiotherapy (IMRT) in treatment planning for left-sided breast cancer patients after modified radical mastectomy. Left-sided breast cancer patients treated with modified radical mastectomy were eligible for analysis. The dose distribution of both planning target volume and organs at risk were analyzed by using dose volume histograms. Twenty-four patients were eligible for analysis. Both VMAT and IMRT plans were sufficient in planning target volume coverage. In terms of conformity, VMAT was superior to IMRT (P = .034). D(mean), V(5), and V(10) of the heart were significantly decreased in VMAT plans when compared with IMRT plans. VMAT was as effective as IMRT plans in sparing of other normal tissues. In addition, both the mean number of monitor units and treatment time were significantly reduced when VMAT was compared with IMRT. VMAT plans was equivalent or superior to IMRT plans in dose distribution, and was associated with slightly advantage in sparing of the heart and coronary arteries. Our analyses suggested VMAT as a preferred option in left-sided breast cancer patients treated with modified radical mastectomy.