Radiation dose measurements with alanine/agarose gel and thin alanine films around a¹⁹²Ir brachytherapy source, using ESR spectroscopy

Abstract

Alanine/agarose gel and alanine films in stacks have been used for measurements of absorbed dose around an HDR 192Ir source in a vaginal cylinder-applicator, with and without a 180 degrees tungsten shield. The gel and the films were analysed by means of ESR spectroscopy and calibrated against an ion chamber in a 4 MV photon beam to obtain absolute dose values. The gel serves as both dosimeter and phantom material, and the thin (130 microm) films are used to achieve an improved spatial resolution in the dose estimations. Experimental values were compared with Monte Carlo simulations using two different codes. Results from the measurements generally agree with the simulations to within 5%, for both the alanine/agarose gel and the alanine films.

First-principles studies of pure and fluorine substituted alanines

“…The calculated bond angles are in agreement with the experimental results. The difference between our result and other theoretical data 13 of C-C-C is because that the reported work based on local density approximation overestimated the C-C-C bond. The calculated bond lengths of L-alanine are in agreement with the experimentally measured values, those of monofluoroalanine are compared with the theoretical results and no data is available for the bond lengths of difluoroalanine.…”

“…8 Alanine has promising nonlinear, optical, elastic, piezoelectric and dielectric properties 9,10 and has applications in laser technology, optical communication, data computing technologies and radiotherapy. [11][12][13] Change in the alanine cycle is linked to the development of type II diabetes. 5 It boosts up the immune system by producing antibodies and provides energy to muscles, brain and central nervous system.…”

Evaluation of a lithium formate EPR dosimetry system for dose measurements around brachytherapy sources

“…10 Alanine, the most common material in electron paramagnetic resonance ͑EPR͒ dosimetry, has been used for measurements around 192 Ir brachytherapy sources. [11][12][13] A drawback of EPR dosimetry is the need for high doses ͑above around 1-2 Gy͒ while an advantage is the system's linear response over a large dose interval 14 making it easy to measure doses around pulsed dose rate ͑PDR͒ and high dose rate ͑HDR͒ 192 Ir sources at their clinical strength. The verification of doses at several distances from an implant with a single ir-radiation will not be a problem and doses large enough for the source transit dose [15][16][17] to be negligible can easily be administered.…”

In vivo dosimetry in brachytherapy

“…In spite of these limitations, some feasibility studies were conducted to evaluate its usefulness in BT. Apart from the phantom studies aimed mostly at the characterization of the radioactive sources, [85][86][87] few reports exist on using alanine for IVD of gynecological treatments. 39,88 Alanine is commercially available, but the tedious readout procedure needs to be established individually in each department.…”