Low-Dose-Area-Constrained Helical TomoTherapy-Based Whole Breast Radiotherapy and Dosimetric Comparison with Tangential Field-in-Field IMRT

Abstract EN

Background and Purpose.

To present a novel helical TomoTherapy-based method for whole breast radiotherapy that has better dosimetry and also has acceptable low-dose regions for lungs, heart, and contralateral breast compared with tangential field-in-field IMRT (FIF-IMRT).

Material and Methods.

Ten patients with left-side breast cancer were planned with low-dose-area-constrained helical TomoTherapy (LDC-HT) and FIF-IMRT.

Dosimetry was compared for all techniques.

Results.

Coverage of the whole breast was adequate with both techniques.

Homogeneity index (HI) and conformity index (CI) were better with LDC-HT.

LDC-HT showed dosimetry advantages over FIF-IMRT for ipsilateral lung and heart in not only high-dose levels but also in low-dose levels such as V10 Gy and V5 Gy.

For contralateral lung, both techniques can provide good protection, although the mean dose of LDC-HT is higher than that of FIF-IMRT.

Conclusions.

With LDC-HT, we obtained adequate target coverage, better HI and CI of target volume, better sparing of organs at risk, and acceptably low-dose areas compared with FIF-IMRT.

LDC-HT could be a feasible method in whole breast radiotherapy.

Clinical benefits of LDC-HT need further investigation.