Absorption dose measuring apparatus for intensity modulated radio therapy

摘要

An IMRT dosimeter is capable of measuring a three-dimensional absorption dose distribution in a transparent plastic phantom (202a) readily and accurately. In the IMRT dosimeter, radiation beams (201a, 201b) are directed to a phantom assembly having a scintillation fiber block (204a) sandwiched between two blocks of the phantom (202a). As an intensity of light proportional to the radiation beam is emitted from one side of the scintillation fiber block (204a), its profile is measured by an image sensor (205). Then, the three-dimensional absorption dose distribution is obtained from the light intensity distribution data. By summing the three-dimensional absorption dose distribution data measured through the radiation beam at different angles, an integrated three-dimensional absorption dose distribution in the phantom (202a) can be calculated readily and accurately.