title: Corrugated fiberboard as a positioning insert for patients undergoing radiotherapy.
abstract: We have developed a new body fixation system for single patient use, which consists of a vacuum cushion, a thermoplastic fixation sheet which is used to suppress involuntary and voluntary patient movement, and a triple-wall corrugated fiberboard base plate to which both the vacuum cushion and the thermoplastic sheet are affixed. To evaluate the characteristics of the fiberboard as a patient-positioning insert, the photon beam attenuation of a fiberboard base plate, a carbon-fiber base plate, and a vacuum-formed cushion were compared. The strength of the fiberboard was also evaluated. The attenuation for the carbon-fiber base plate was 3.7% and 2.6% in 4 MV and 10 MV photon beams, respectively, while the results were less for the fiberboard base plate, i.e. 1.9% and 1.6%. The vacuum-formed cushion had a minimal effect on transmission. None of the materials subsided under the weight loading of 20 g/cm(2). There was no difference between the thicknesses of the fiberboard before and after a 50 times daily load with the 60 kg weight of a volunteer. Corrugated fiberboard is a robust and low attenuating material that functions well as a patient-positioning insert.
authors.affiliation: Department of Radiology, Kyushu University Hospital at Beppu, Beppu, Japan. nakam@radiol.med.kyushu-u.ac.jp
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Nakamura
authors.forename: Haruo
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Akai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nomoto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shioyama
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Kengo
authors.initials: K
authors.lastname: Yoshimitsu
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007103:Immobilization / Q000295:instrumentation* / Q000379:methods; D008420:Manufactured Materials; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D020266:Radiotherapy, Conformal / Q000295:instrumentation*