PO-1645 Dosimetric comparison of radiotherapy techniques for left breast, axilla and supraclavicular fossa

Whole‐breast irradiation with lumpectomy cavity boost and regional nodal irradiation: Dosimetric comparison of 3D‐CRT using sequential boost and dual partial‐arc VMAT using simultaneous integrated boost

“…This finding could be owing to one or more of the following reasons: (1) the use of more fields (4–8 fields) in 3D‐CRT planning to irradiate whole breast volumes, boost volumes, and RNI; and (2) relatively larger breast and boost volumes in our study. While reviewing the literature, our study could not be directly compared to most IMRT studies on the breast because many studies did not report MUs 10,11,19,21,22 . Our study design was relatively novel because few studies used IMRT for SIB but not for RNI, 14,18,19,21,23 whereas others used IMRT for RNI with WBRT but did not use the SIB technique 10–13 .…”

“…While reviewing the literature, our study could not be directly compared to most IMRT studies on the breast because many studies did not report MUs 10,11,19,21,22 . Our study design was relatively novel because few studies used IMRT for SIB but not for RNI, 14,18,19,21,23 whereas others used IMRT for RNI with WBRT but did not use the SIB technique 10–13 . In addition, few studies have used hypofractionated doses with RNI 11,13 as hypofractionated radiation doses to the axillary and/or SCF regions are not currently recommended because of the theoretically increased risk of late toxicities.…”

“…Our study design was relatively novel because few studies used IMRT for SIB but not for RNI, 14,18,19,21,23 whereas others used IMRT for RNI with WBRT but did not use the SIB technique 10–13 . In addition, few studies have used hypofractionated doses with RNI 11,13 as hypofractionated radiation doses to the axillary and/or SCF regions are not currently recommended because of the theoretically increased risk of late toxicities. Only two studies, 22,24 to our knowledge, have planned SIB‐IMRT with RNI using various IMRT techniques (Supplementary Table 1).…”

“…Recently published results of an RCT 9 comparing SIB‐IMRT in the breast with 3D‐CRT with a sequential boost showed encouraging short‐term results in terms of breast cosmesis with similar disease control rates; however, long‐term data are still needed. In addition to improving homogeneity within the breast, IMRT can potentially improve the target coverage of regional nodal volume, including the entire axillary node and SCF, without increasing critical OAR doses 10–13 …”