Abstract: Radiation therapy is an important method for tumor treatment. Dose verification is a statutory quality control method for radiation therapy. With the development of radiation therapy technologies such as 3D intensity modulated radiation therapy, etc. and increased emphasis of patients’ health, conventional 2D stationary dose verification methods become unequal to the challenges of completed 3D distributions brought by the novel radiation therapy techniques. Optical-CT based 3D dose gel dosimetry combines together gel dosimetry, which utilizes gel dosimeters to save the 3D dose distribution by optical property changes, and optical-CT to scan the dosimeters, reconstruct dose tomographic images, and plot 3D isodose maps. This technique provides a novel method to measure 3D dose distributions quickly, precisely and accurately. This paper reviews the background, theories and recent advances. As this technique is still in its early stages with series of scientific issues to address, it is very prospective in further research and development.