Vascular and Circulating Blood Exposure to Proton or Photon Irradiation: Differentials in Lymphocyte Subsets Metrics in Cancer Patients

Background

/Objectives: Radiation-induced lymphopenia is consistently associated with adverse outcomes across solid tumours, yet the vascular compartment that carries the irradiated lym-phocyte pool is not common delineated during treatment planning. The VASA project makes blood vessels an explicit, measurable structure in that process. We report Phase II, relating dose–volume metrics computed on MRI-segmented vessels to serial immunophenotyping in patients treated with protons or photons.