title: The Usefulness of Using Fiducial Marker in Proton Therapy for Locally Advanced Pancreatic Cancer.
abstract: Though the dosimetric criteria for the gastrointestinal tract were met, late gastrointestinal toxicity was seen in several cases. Therefore, we thought that it was caused by the positional variation of gastrointestine surrounding pancreatic cancer because of peristalsis.
  
  
  
  They were confirmed by CT image regularly. And we evaluated that how much the difference of matching methods for correcting the positional variation influenced dose distribution.
  
  
  
  The fiducial markers could follow the position of pancreatic cancer and the duodenum. But it could reproduce the dose distribution to pancreatic cancer and the duodenum.
  
  
  
  In proton therapy, the reproducible improvement of the duodenum position did not make the dose of the duodenum same as planning dose because the matching of fiducial markers made the positional relations between beam compensator and the duodenum change.
  
  
  
  The fiducial markers are useful for correcting the position of pancreatic cancer and the duodenum. But in proton therapy, it could not reproduce the dose distribution to pancreatic cancer and the duodenum.
authors.affiliation: Department of Radiation Technology, Hyogo Ion Beam Medical Center.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Shimizu
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sato
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Sawa
authors.forename: Kazuki
authors.initials: K
authors.lastname: Terashima
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yanou
authors.forename: Ryoji
authors.initials: R
authors.lastname: Ida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004386:Duodenum / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D061766:Proton Therapy / Q000295:instrumentation; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome