Occupational Radon Assessment in Underground Storage Facilities in Saudi Arabia.

An occupational radon assessment was conducted at five underground storage facilities in the Kingdom of Saudi Arabia to evaluate the radon concentration and determine if remedial action is required to ameliorate conditions and ensure compliance with international guidance on acceptable radon levels in working environments. The assessment was carried out in four operational areas in the underground storage facilities routinely occupied or visited by workers. Initial radon concentrations were obtained using 293 passive CR-39 Nuclear Track Detector (NTD) radon dosimeters installed in the four operational areas for all the underground storage facilities.

Clinical Implementation of a Model-Based In Vivo Dose Verification System for Stereotactic Body Radiation Therapy-Volumetric Modulated Arc Therapy Treatments Using the Electronic Portal Imaging Device.

Purpose: To report findings from an in vivo dosimetry program implemented for all stereotactic body radiation therapy patients over a 31-month period and discuss the value and challenges of utilizing in vivo electronic portal imaging device (EPID) dosimetry clinically.

Methods And Materials: From December 2013 to July 2016, 117 stereotactic body radiation therapy-volumetric modulated arc therapy patients (100 lung, 15 spine, and 2 liver) underwent 602 EPID-based in vivo dose verification events. A developed model-based dose reconstruction algorithm calculates the 3-dimensional dose distribution to the patient by back-projecting the primary fluence measured by the EPID during treatment.

The influence of a novel transmission detector on 6 MV x-ray beam characteristics.

The purpose of this work was to investigate the influence of a new transmission detector on 6 MV x-ray beam properties. The device, COMPASS (IBA Dosimetry, Germany), contains 1600 plane parallel ionization chambers with a detector spacing of 6.5 mm and an active volume of 0.