Radiotherapy X-ray facilities require structural barriers to reduce radiation. To calculate the thickness of these barriers, rather conservative limits are normally set to ensure that the radiation limits are not exceeded. Recently, members of our department published a more exact method for calculating the thickness of primary barriers, which took into account the scatter radiation generated i...

The Technical Report Series 398 (TRS-398), Electron Dosimetry Working Party (EWDP), and Task Group 51 (TG 51) are the most important protocols for reference dosimetry. In case of electron beam dosimetry, these recommend using parallel-plate ionization chambers beams with R50 values below specific thresholds. However, recent papers suggested cylindrical dosimetry all energies. Here we compared d...

Linear accelerators used in radiation therapy treatments usually provide the capability of irradiating with different dose rates. The medical physicist may choose arbitrary the dose rate to use, although the relative biological effectiveness (RBE) varies with this physical parameter. In this work the measurements of absorbed dose of the x-ray beams from a Varian 6 MV linear accelerator CLINAC 6...

A great challenge in simulations in the area of radiotherapy is to character the source, since the equipment’s manufacturers don’t provide specifics information about this. This work presents an empiric method for characterization of the ray-X beams of 6,0 MV and 10 MV originating from a linear accelerator of the mark Varian model 2100C. The experimental values of the percentage of deep dose (P...

Arc-modulated radiation therapy (AMRT) is a novel rotational intensitymodulated radiation therapy (IMRT) technique developed for a clinical linear accelerator that aims to deliver highly conformal radiation treatment using just one arc of gantry rotation. Compared to fixed-gantry IMRT and the multiplearc intensity-modulated arc therapy (IMAT) techniques, AMRT promises the same treatment quality...

Radiotherapy employs high energy radiation for the purpose of cancer treatment. Precise patient positioning is essential with the current use of complicated treatment plans. Portal imaging is often used for pre and during treatment anatomical setup verification. Currently the most advanced and widely used amorphous silicon Electronic portal imaging device (EPID) (aSi 1000) and the TrueBeam line...

Intensity-modulated radiotherapy (IMRT) for complex sites such as tumors of the head and neck requires a level of accuracy in dose calculation beyond that currently used for conformal treatment planning. Recent advances in treatment planning systems have aimed to improve the dose calculation accuracy by improving the modeling of machine characteristics such as interleaf leakage, tongue and groo...