Development, Construction, and Evaluation of an Alternative Dosimetry Phantom for Computed Tomography.

This article aims to present the development, construction, and evaluation of an alternative computed tomography dose index (CTDI) phantom. Epoxy resin was mixed with an iodine-based contrast agent to produce radiological characteristics resembling polymethyl methacrylate (PMMA) as a standard CTDI phantom. As a preliminary study, testing was carried out using computed tomography images (80 and 120 kVp) on 12 variations of epoxy-iodine resin mixtures to obtain relative electron density () values and effective atomic numbers () of the samples.

A multicenter study of modified electron beam output calibration.

Purpose: This study aims to assess the accuracy of a modified electron beam calibration based on the IAEA TRS-398 and AAPM-TG-51 in multicenter radiotherapy.

Methods: This study was performed using the Elekta and Varian Linear Accelerator electron beams with energies of 4-22 MeV under reference conditions using cylindrical (PTW 30013, IBA FC65-G, and IBA FC65-P) and parallel-plate (PTW 34045, PTW 34001, and IBA PPC-40) chambers. The modified calibration used a cylindrical chamber and an updated based on Monte Carlo calculations, whereas TRS-398 and TG-51 used cylindrical and parallel-plate chambers for reference dosimetry.