This study extends the 'zero scan' method for CT imaging of polymer gel dosimeters to include multislice acquisitions. Multislice CT images consisting of 24 slices of 1.2 mm thickness were acquired of an irradiated polymer gel dosimeter and processed with the zero scan technique. The results demonstrate that zero scan-based gel readout can be successfully applied to generate a three-dimensional...

Background: Over recent decades, modern protocols of external beam radioÂ‌therapy and radiation techniques such as intensity-modulated radiotherapy (IMRT) have been developed. These methods are extremely sensitive to errors in treatment delivery, so that it is essential to apply a high resolution 3D dosimetry system that has high sensitivity and is capable of measuring and verifying the complex...

introduction: different dosimetric modalities (e.g., ionization chambers, semiconductors, tlds, radiographic films) often have some problems determining isodose curves and percentage depth doses in high dose gradient regions. research has been ongoing to develop portable high resolution dosimetry devices with accurate absolute dosimetry capabilities and easy data analysis. the ‘presage’ dosimet...

In this work we use a 3D quantitative CT imaging ultrasound system to characterise polymer gel dosimeters. The system comprises of two identical 5 MHz 128 element phasedarray ultrasound transducers co-axially aligned and submerged in water as a coupling agent. Rotational and translational movement of the gel dosimeter sample between the transducers were performed using a robotic arm. Ultrasound...

Oxygen contamination of a polyacrylamide gel (PAG) dosimeter can have a significant detrimental effect upon the performance characteristics of the gel as a dosimeter. Oxygen contamination can occur during preparation, but can also arise from the diffusion of atmospheric oxygen through vessel walls. Even 'trace' amounts of oxygen present in any gaseous space (usually nitrogen filled) between the...

PURPOSE To obtain and assess the accuracy of 3D dose distributions and LET maps from a passively-scattered proton beam through the use of LET-dependent and LET-independent polymer gel formulations. METHODS Dose measurements were performed with BANG3-Pro2 (MGS Research, Inc, Madison, CT) polymer gel dosimeters. The dosimeters were mixed from kits and were poured into 14.5 cm high by 15 cm diam...

Radiation sensitive polymer gels are among the most promising three-dimensional dose verification tools developed to date. Polymer gel dosimeter known by the acronym MAGIC has been tested for evaluation of its use in boron neutron capture (BNCT) dosimetry. We irradiated a large (diameter 10 cm, length 20 cm) cylindrical gel phantom in the epithermal neutron beam of the Finnish BNCT facility at ...

Changes in the linear attenuation coefficient of polymer gel dosimeters post-irradiation enable the imaging of dose distributions by x-ray computed tomography (CT). Various compositions of polymer gel dosimeters manufactured from acrylamide (AA), and N,N'-methylene-bis-acrylamide (BIS) comonomers and gelatin or agarose gelling agents were investigated. This work shows that increasing the comono...