Adjustable portal film cassette holder for radiation therapy

An adjustable portal film cassette holder has been designed and constructed. The holder provides for: holding portal film perpendicular to and centered with the central axis of the beam film-to-patient distance to minimize magnification; angling (swivel) film to match collimator angle; and ease of correct repositioning of arrangement when frequent filming is required. This device has now been in use for several months with good results.