title: An application of film dosimetry for helium ion radiotherapy.
abstract: Clinical dosimetry of complex dose distribution associated with charged particle radiotherapy requires a rapid and convenient technique with a spatial resolution of 3 mm or better. Radiographic film stacks have been evaluated for three-dimensional dosimetry of charged particle beams. Sheets of Cronex 4 film are placed between lucite spacers in a light-tight box and the beam is directed perpendicularly to the film surface. Optical densities on each sheet are digitized with a video digitizer and corrected for density-dose nonlinearity and LET effects. A three-dimensional matrix of the measured dose is constructed and compared with calculated values. Both transverse and depth dose data recorded by film have been compared with diode measurements and generally shown agreement within 5%. The present technique appears to be an effective method to generate experimentally measured dose distributions.
authors.affiliation: Biology and Medicine Division, Lawrence Berkeley Laboratory, Berkeley.
authors.forename: M
authors.initials: M
authors.lastname: Endo
authors.forename: G T
authors.initials: GT
authors.lastname: Chen
authors.forename: J M
authors.initials: JM
authors.lastname: Collier
authors.forename: S R
authors.initials: SR
authors.lastname: Zink
mesh_terms: D005373:Film Dosimetry / Q000379:methods*; D006371:Helium / Q000627:therapeutic use*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008905:Minicomputers; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage
chemical_list: D006371:Helium