Proton arc therapy reduces the dose delivered to circulating blood compared to intensity-modulated proton therapy for head-and-neck cancer.

Document Type

Article

Publication Date

11-2026

Publication Title

Journal of applied clinical medical physics [electronic resource] / American College of Medical Physics

Abstract

BACKGROUND: Compared to intensity-modulated proton therapy (IMPT), proton arc therapy (PAT) has various dosimetric advantages. However, questions have been raised over whether the larger low-dose bath during PAT may increase radiation-induced lymphocyte killing, which is correlated with adverse clinical outcomes.

PURPOSE: The purpose of this study is to quantitatively compare radiation dose delivery to circulating blood during IMPT and PAT.

METHODS: For each of 10 head-and-neck cancer patients, one IMPT and one PAT treatment plan were created, and the hematological dose (HEDOS) blood dose model was used to simulate radiation dose delivery to circulating blood. HEDOS simulations utilized gantry angle-wise dose distributions (including for PAT) and considered gantry rotation and energy layer switching as well as irradiation times. Blood dose histograms as well as the mean dose to all simulation blood particles (D

RESULTS: For IMPT, blood dose metrics (in the form of mean over all patients ± one standard deviation) were (0.522 ± 0.204)Gy(RBE) for D

CONCLUSIONS: Compared to IMPT, proton arc therapy was associated with significantly lower radiation dose delivery to circulating blood across a variety of different metrics. Proton arc therapy for head-and-neck cancer is therefore not expected to result in higher radiation-induced killing of circulating lymphocytes compared to IMPT.

Volume

27

Issue

11

First Page

e70864

DOI

10.1002/acm2.70864

ISSN

1526-9914

PubMed ID

42900560

Link to Full Text

Share

COinS