title: Reliability of clinical port films for measuring dose inhomogeneities in radiotherapy for head and neck tumours.
abstract: Reproducibility and reliability of film dosimetry are evaluated in clinical circumstances. Optical densities were read on 82 routinely taken verification films of Ear-Nose-Throat (ENT) treatment fields and corrected with the sensitometric curve to obtain relative dose values. Off-axis ratios measured on 10 successive films of one specific field were compared with each other and show a good reproducibility (s = 1.7%). Reliability was assessed by comparing 82 off-axis ratios obtained on the films with off-axis ratios obtained by simultaneously performed diode measurements. Only small relative differences were detected (mean = 1.1%, s = 3.0).
authors.affiliation: Department of Radiotherapy, University Hospital Sint Rafael, University of Leuven, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Weltens
authors.forename: J
authors.initials: J
authors.lastname: van Dam
authors.forename: G
authors.initials: G
authors.lastname: Leunens
authors.forename: A
authors.initials: A
authors.lastname: Dutreix
authors.forename: E
authors.initials: E
authors.lastname: van der Schueren
mesh_terms: D005373:Film Dosimetry / Q000592:standards*; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D011882:Radiotherapy, High-Energy; D015203:Reproducibility of Results