Thermoluminescence (TL) properties (radiation sensitivity, dose response, signal fading) of Nd-doped SiO2 optical fibers irradiated with 1.25MeV photons to 1-50Gy were studied. The peak of the glow curve is around 190°C regardless of the dose. The dose response is linear up to 50Gy. The radiation sensitivity is 219nCmg(-1)Gy(-1). The fiber can be a potential candidate for photon radiotherapy dosimetry due to its high radiation sensitivity, linear dose response in a wide range, slow fading, and high spatial resolution due to the small size of the fiber.