Preliminary analysis of N-vinylpyrrolidone based polymer gel dosimeter

Juliana Rosada Dias,Roseany De Vasconcelos Vieira Lopes,Artemis Marti Ceschin,Maria José Araújo Sales,Thyago Fressatti Mangueira

doi:10.1590/0104-1428.01718

Juliana Rosada Dias, Roseany De Vasconcelos Vieira Lopes + Show 3 more

Open Access

https://doi.org/10.1590/0104-1428.01718

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Abstract

Abstract This paper aims to evaluate the dosimetric characteristics of modified VIPARnd for radiotherapy dosimetry using optical investigations. The absorbance spectrum of the irradiated gel dosimeter was evaluated optically with spectrophotometer techniques and with a CMOS imaging system. The useful dose range for the peak value and the relative area under the absorbance curve is 3-20 Gy. The dose-response curve for CMOS readout has an interval of linearity from 3-20 Gy. The modified VIPARnd developed has a good dose range and good temporal stability in the spectrophotometric analysis of the intervals studied. The CMOS readout is transportable, cheaper, easier to use and an excellent alternative for dosimetry.

Highlights

Recent technological advances in radiotherapy require relaxation rates[1,4,5]
The interval of linearity for high-energy photon (6 MV) extends from 3 Gy up to 20 Gy for analyses using the spectrophotometric technique and from 3 Gy up to 20 Gy for data obtained with the imaging device developed
The data for the area under absorbance curve presented the highest sensitivity for dose-reponse

Summary

Introduction

Recent technological advances in radiotherapy require relaxation rates[1,4,5]. Fricke gel exhibits high ion diffusion that quality assurance (QA) that needs accurate and precise causes low spatial resolution. Dose measurement usually falls into two of Fricke gel dosimeters based on PVA-GTA The reference dosimetry alcohol-glutaraldehyde) were developed[6]. These materials aims to produce accurate and consistent values relative to are not toxic and have a lower diffusion coefficient than the the primary standards, this allows the comparison of results standards Fricke gels. To ensure safe operation of the equipment in order to verify dose calculations and verify the dose administered in vivo, measurements are required in a range of conditions covering all aspects of clinical use, the conditions of reference. A possibility for measuring dose distributions is gel dosimetry[1,2]

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