Gel dosimeters are sensitive chemical dosimeters that aim at measuring the dose in three dimensions(3D). This study aims to evaluate the performance of a commercially available BANG® polymer gel. BANG® gels were irradiated using 6MV photon beams from 0.5Gy to 60Gy. The magnetic resonance(MR)spin-spin relaxation rate(R2=1/T2) of the protons indicates dose response and has a linear relationship to dose. The dose response curve by BANG® gel appeared approximately linear over the 0.5Gy and 20Gy region. The slope of the dose-R2 curve is 0.9s−1Gy−1, and the relative dose distribution can be reproduced with an overall uncertainty of about 2%. R2 was found to increase with increasing time after irradiation. BANG® gels are of comparable quality to MOSFET or PLD in terms of overall dosimetric accuracy and have the advantage of measuring continuous, cumulative 3D dose distributions.