MR-linac MLC positioning QA by digitally stitching dual double-exposed films.

Purpose: The picket fence (PF) test is highly recommended for multi-leaf collimator (MLC) quality assurance. However, since the electronic portal imaging device (EPID) on the Elekta Unity only covers a small area, it is not feasible to perform the PF test for the entire MLC. Here, we propose a technique for the PF test by stitching two double-exposed films.

Comparison of skin dose calculated by the dose tracking system (DTS) with a beam angular correction factor and that calculated by Monte-Carlo.

Skin dose is dependent on the incident beam angle and corrections are needed for accurate estimation of the risk of deterministic effects of the skin. Angular-correction factors (ACF) were calculated and incorporated into our skin-dose-tracking system (DTS) and the results compared to Monte-Carlo simulations for a neuro-interventional procedure. To obtain the ACF's, EGSnrc Monte-Carlo (MC) software was used to calculate the dose averaged over 0.

The effect of underlying bone on the beam angular correction in calculating the skin dose of the head in neuro-interventional imaging.

Skin dose depends on the surface shape, underlying tissue, beam energy, field size, and incident beam angle. These dependencies were determined in order to apply corrections in the skin-dose-tracking system (DTS) for accurate estimation of the risk of deterministic skin effects during fluoroscopically-guided neuro-interventional procedures. The primary-plus-scatter dose was calculated averaged over the skin thickness with underlying subcutaneous fat, and various thicknesses of skull bone on the surface of a cylindrical water phantom to simulate the head.

A parametric fitting technique for rapid determination of a skin-dose correction factor for angle of beam incidence during image-guided endovascular procedures.

Skin dose is dependent on the incident beam angle and corrections are needed for accurate estimation of the risk of deterministic effects of the skin. To obtain the angular correction factors (ACF's), EGSnrc Monte Carlo (MC) software was used to calculate the skin dose as a function of incident x-ray beam angle at the center of the field for beam energies from 60 to 120 kVp, field sizes from 5 to 15 cm, and thicknesses of Cu beam filters from 0.2 to 0.