title: The choice of multi-beam IMRT for whole breast radiotherapy in early-stage right breast cancer.
abstract: The aim of this study was to identify a rational strategy for the selection of multi-beam IMRT in patients with right breast cancer through the comparison of dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) using five different radiotherapy modalities. This was a retrospective study using computed tomography scans from ten patients with early-stage right breast cancer who had been treated previously. Three dimensional conformal radiotherapy (3DCRT), forward-planned IMRT (for-IMRT), inverse-planned IMRT (inv-IMRT), helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT) were planned for each patient. The plans were compared according to dose-volume histogram analysis. The most significant impact of inverse-planned multi-beam modalities for right breast cancer was the reduction of Dmax, Dmean, V53.5 and prescribed dose volume (cc) outside of the PTV (breast) (OB-V50) of the PTV. HT decreased the ipsilateral OAR volumes receiving higher doses. In exchange, HT also increased the volumes receiving low doses, which is known to lead to an increased rate of radiation-induced secondary malignancies. The heart, LAD, and contralateral doses for 3DCRT and for-IMRT were significantly lower than those for inv-IMRT, HT, and VMAT. In addition, inv-IMRT demonstrated an increase in exposed volume of heart, LAD, ipsilateral lung, and contralateral lung compared with those parameters for HT or VMAT. Although it is known to reduce cardiac toxicity with breath hold technique in left sided breast cancer, similarly it is possible for 3DCRT and for-IMRT techniques in right sided breast cancer even in free breathing.
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Emel
authors.initials: E
authors.lastname: Haciislamoglu
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Colak
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Emine
authors.initials: E
authors.lastname: Canyilmaz
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Kanuni Research and Education Hospital, Trabzon, Turkey.
authors.forename: Ahmet Yasar
authors.initials: AY
authors.lastname: Zengin
authors.affiliation: Department of Nuclear Physics, Faculty of Science, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Ahmet Hakan
authors.initials: AH
authors.lastname: Yilmaz
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Adnan
authors.initials: A
authors.lastname: Yoney
authors.affiliation: Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Zumrut
authors.initials: Z
authors.lastname: Bahat
keywords: Doses to the heart and LAD; Helical tomotherapy; Multi-beam inverse planning; Right breast cancer; Volumetric arc therapy