Novel composition of polymer gel dosimeters based on N-(Hydroxymethyl)acrylamide for radiation therapy

•This manuscript relates to polymer gel dosimeter for used in radiotherapy.•Polymer gel containing N-(Hydroxymethyl)acrylamide has been introduced.•Polymerization of NHMA gel increases gradually with increasing absorbed dose.•Response of NHMA gel was slightly affected by dose rate and energy of radiation.

A new composition of polymer gel dosimeters is developed based on radiation induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) for radiotherapy treatment planning. The dosimeters were irradiated by 10 MV photon beam of a medical linear accelerator at a constant dose rate of 600 cGy/min with doses up to 20 Gy. The polymerization occurs and increases with increasing absorbed dose. The dose response of polymer gel dosimeters was studied using nuclear magnetic imaging (NMR) for relaxation rate (R2) of water proton. Dose rate, energy of radiation and the stability of the polymerization after irradiation were investigated. No appreciable effects of these parameters on the performance of the novel gel dosimeters were observed.