US Patent 6904162 Film phantom for three-dimensional dosimetry

A method and system for recording and verifying three-dimensional dose distributions a film phantom uses a phantom which includes a cavity for receiving film sheets. A three-dimensional radiation dose described by a stereotactic radiosurgery plan can be delivered to the phantom while the cavity is loaded with film. The film can be developed to provide multiple dose images. Thereafter, based on the multiple dose images, a measured three-dimensional dose distribution map is obtained. The phantom may have a pattern of translucent areas which expose fiducial marks on the film. The fiducial marks may be used to determine a position and orientation of the film relative to the phantom.