%0 Journal Article
%T Hypofractionated proton therapy in breast cancer: where are we? A critical review of the literature.
%A Alterio D
%A La Rocca E
%A Volpe S
%A Camarda AM
%A Casbarra A
%A Russell-Edu W
%A Zerella MA
%A Orecchia R
%A Galimberti V
%A Veronesi P
%A Leonardi MC
%A Jereczek-Fossa BA
%A Alterio D
%A La Rocca E
%A Volpe S
%A Camarda AM
%A Casbarra A
%A Russell-Edu W
%A Zerella MA
%A Orecchia R
%A Galimberti V
%A Veronesi P
%A Leonardi MC
%A Jereczek-Fossa BA
%J Breast Cancer Res Treat
%V 192
%N 2
%D Apr 2022
%M 35025004
%F 4.624
%R 10.1007/s10549-022-06516-4
%X <B>OBJECTIVE: </B>To critically review available literature on hypofractionated (≥ 3 Gy/fraction) proton therapy (PT) for breast cancer (BCa).<BR><B>METHODS: </B>A systematic screening of the literature was performed in April 2021 in compliance with the preferred reporting items for systematic reviews and meta-analyses recommendations. All full-text publication written in English were considered eligible. Acute and late toxicities, oncological outcomes and dosimetric features were considered for the analysis.<BR><B>RESULTS: </B>Twelve publications met the inclusion criteria; all studies but one focused on accelerated partial breast irradiation (APBI). Eleven works considered post-operative patients, one referred to ABPI as a curative-intent modality. The dosimetric profile of PT compared favorably with both photon-based 3D conformal and intensity-modulated techniques, while a more extended follow-up is warranted to fully assess both the long-term toxicities and the non-inferiority of oncological outcomes.<BR><B>CONCLUSIONS: </B>Our work shows that results on PT for BCa are currently only available for APBI applications, with dosimetric analyses demonstrating a clear advantage over both 3D conformal and intensity modulated X-rays techniques, especially when ≥ 2 treatment fields were used. However, further evidence is needed to define whether such theoretical benefit translates into clinical improvements, especially in the long-term.