The present study investigates the dose readout characteristics of Gafchromic EBT3 films over a dose range of 0.5–5 Gy using two flatbed scanners in-built with different light sources, Epson Expression 11000XL and 12000XL. Film readouts were acquired repeatedly at varying scan positions and film orientations to evaluate scanner-related non-uniformities. At 0.5 Gy, the maximum variation in optical density over the entire scan frame was 15.5
Small-field dosimetry is clinically challenging because of volume averaging, loss of lateral charged-particle equilibrium, and beam-quality changes, especially for multi-leaf collimator (MLC)-defined fields and flattening-filter-free (FFF) beams. This study derived machine-specific IAEA TRS-483 output correction factors for a PTW 60,019 microDiamond detector on an Elekta Versa HD linac for 6 MV and 10 MV photons in both flattened filter (FF) and FFF modes, using square fields down to 1 × 1 cm². A detailed GATE/Geant4 Monte Carlo model of the treatment head (including the Agility MLC) was validated against 10 × 10 cm² percentage depth doses (PDDs) (mean absolute differences 0.20–0.29
In this study, nanostructured hydroxyapatite (HAp) doped with lanthanide elements (Ce, Dy, Gd, and La at various concentrations of 1, 2, and 5 mol T_m ) remains independent of the absorbed dose. The TL behaviour of co-doped systems (Ce2Dy2, Ce2La2, La2Dy2, and Ce2Gd5) was also investigated. While co-doping altered the glow-peak structure and dosimetric properties, it generally exhibited an intermediate dosimetric performance between the corresponding single-doped constituents rather than a distinct synergistic enhancement. The co-doped compositions maintained higher TL sensitivity than the heavily quenched 5 mol
This study aimed to evaluate the effects of different CBCT (Cone-beam computed tomography) protocols defined by device type, field of view (FOV), and dose settings on organ-specific radiation doses and inter-/intra-observer agreement in the assessment of impacted mandibular third molars. A total of 168 CBCT scans (NewTom 7G and NewTom Go) were retrospectively analyzed. Each device included six protocols (different FOVs and dose levels: low, regular, best). Organ and effective doses were calculated using the Monte Carlo PCXMC 2.0 Rotation software. Three observers independently assessed five anatomical parameters related to surgical risk. Inter- and intra-observer agreement was analyzed using Fleiss’ and Cohen’s kappa. Effective doses ranged from 8.65 to 376.96 µSv, a more than 40-fold difference between the lowest- and highest-dose protocols. NewTom Go protocols with limited FOV and low/regular doses yielded the lowest effective doses without a corresponding loss of observer agreement. Observer agreement was substantial to almost perfect for most parameters (kappa: 0.541–0.915), although agreement for periodontal ligament visibility and root resorption was partly driven by shared “not visible”/“uncertain” ratings rather than confident structure identification. As no clinical or surgical reference standard was used, these findings reflect observer agreement and diagnostic interpretability rather than confirmed diagnostic accuracy. Limited FOV and optimized dose settings reduced radiation exposure while preserving observer agreement, supporting ALADAIP (As Low As Diagnostically Acceptable being Indication-oriented and Patient-specific) principles.
Accurate anatomical modelling is important for reliable Monte Carlo (MC) proton dosimetry, yet the influence of computational phantom selection on clinically relevant dose prediction remains insufficiently quantified. In this study, an anatomically extended Medical Internal Radiation Dose (MIRD) computational phantom was developed for passive scattering proton therapy of prostate cancer and systematically compared with the anatomically realistic reference male phantom recommended by the International Commission on Radiological Protection using a validated Geant4 MC simulation framework. The extended phantom incorporated the prostate, bladder, rectum, urethra, and intraprostatic tumour volumes. At the same time, a clinical passive-scattering beamline at the CATANA proton therapy facility was modelled to generate spread-out Bragg peaks for treatment planning. The simulation framework demonstrated excellent agreement with experimental depth–dose measurements, yielding a practical proton range (R90) deviation of 1.10 mm and a gamma passing rate of 98.63
