1. A film phantom system for recording and verifying three-dimensional dose distributions, the film phantom system comprising: a body of tissue-equivalent material, the body surrounding a cavity capable of receiving a stack of sheets of film separated by tissue-equivalent spacers; the cavity having walls, the walls including at least one translucent area which extends through at least one opaque area of the walls, the at least one translucent area configured to intersect edges of different sheets of film in a stack of sheets of film in the chamber at different locations.