RESUMO
The aim of the present work is to determine dosimetric characteristics of commercial optically stimulated luminescence dosimeter (OSLD) to estimate equivalent dose in the patient undergoing panoramic radiography procedure. Digital panoramic unit "Instrumentarium OP200D" was used. OSL dosimeters were optically bleached before any exposure procedure. InLight™ OSL nanodosimeters were placed on the thyroid surface between the head and neck. The exposure parameters for all measurements was standard value consisted in 66â¯kV, 5â¯mA, and 14.1â¯s. Standard size field of view (FOV) scanning mode was used. Dosimeters were calibrated for the air kerma. Reported male adult equivalent doses from 21 to 45⯵Sv for each scanning for standard size field of view (FOV). Meanwhile reported female adult equivalent doses from 28 to 75⯵Sv for standard size field of view (FOV) considering all heights. The lowest equivalent dose (21⯵Sv) was observed in the male thyroid gland surface (S) position for medium height. The highest equivalent dose (75⯵Sv) was for female small height in the right parotid surface (R) position. In conclusion, the results demonstrate that OSL dosimeters are appropriate in vivo dosimetry system for dental panoramic dose measurements.
Assuntos
Dosimetria por Luminescência Estimulada Opticamente/instrumentação , Radiografia Panorâmica , Adulto , Calibragem , Feminino , Humanos , Masculino , Dosimetria por Luminescência Estimulada Opticamente/normas , Dosimetria por Luminescência Estimulada Opticamente/estatística & dados numéricos , Glândula Parótida/efeitos da radiação , Imagens de Fantasmas , Doses de Radiação , Dosímetros de Radiação , Radiografia Panorâmica/normas , Radiografia Panorâmica/estatística & dados numéricos , Reprodutibilidade dos Testes , Glândula Tireoide/efeitos da radiaçãoRESUMO
The principle of IMRT is to treat a patient from a number of different directions (or continuous arcs) with beams of nonuniform fluences, which have been optimized to deliver a high dose to the target volume and an acceptably low dose to the surrounding normal structures (Khan, 2010). This study intends to provide information to the physicist regarding the application of different dosimeters type, phantoms and analysis technique for Intensity Modulated Radiation Therapy (IMRT) dose distributions evaluation. The measures were performed using dosimeters of LiF:Mg,Ti and Al2O3:C evaluated by techniques of thermoluminescent (TL) and Optically Stimulated Luminescence (OSL). A polymethylmethacrylate (PMMA) phantom with five cavities, two principal target volumes considered like tumours to be treated and other three cavities to measure the scattered radiation dose was developed to carried out the measures.