Understanding the impact of patient-specific geometries on Cherenkov emission-to-dose relationship during external beam radiation therapy (EBRT)

Cherenkov photons generated during External Beam Radiation Therapy (EBRT) provide real-time optical feedback on the radiation field distribution. While Cherenkov emission correlates with radiation dose, patient-specific anatomical variations, particularly breast geometry, introduce inconsistencies in the Cherenkov emission-to-dose ratio. This study investigates the influence of breast contour, specifically curvature, on the accuracy of Cherenkov-based dosimetry. To address these variations, patient-specific Cherenkov imaging data is corrected using Lambertian geometric correction and compared with the planned radiation dose to derive a correction function as a function of breast curvature. Additionally, scintillator-based Cherenkov imaging data is analyzed and compared with in vivo dosimetry to assess the feasibility of scintillators as real-time dosimeters for EBRT.