title: Clinical use of a concomitant boost technique using a gypsum compensator.
abstract: OBJECTIVE
  To develop a clinical procedure to treat field within a field (concomitant boost) portals with a single compensated field.
  
  
  METHODS
  An ordinary manual cerrobend block former was used to produce styrofoam molds from simulator film data. A special gypsum compound was poured into the molds. The compensator block is independently mounted to the treatment machine via a custom-made compensator holder.
  
  
  RESULTS
  Measurements confirm that the inhomogeneous dose distribution has been reliably delivered via this technique. The accuracy of placement of the high dose region is sufficient for clinical use.
  
  
  CONCLUSIONS
  The procedure enables the concomitant boost effect to be easily implemented in the clinic without increasing clinical setup time.
authors.affiliation: Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710.
authors.forename: K J
authors.initials: KJ
authors.lastname: Weeks
authors.forename: V R
authors.initials: VR
authors.lastname: Arora
authors.forename: K A
authors.initials: KA
authors.lastname: Leopold
authors.forename: K L
authors.initials: KL
authors.lastname: Light
authors.forename: S C
authors.initials: SC
authors.lastname: King
authors.forename: S K
authors.initials: SK
authors.lastname: Ray
authors.forename: M R
authors.initials: MR
authors.lastname: Sontag
authors.forename: K D
authors.initials: KD
authors.lastname: Smith
mesh_terms: D002133:Calcium Sulfate; D002277:Carcinoma / Q000532:radiotherapy*; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D011878:Radiotherapy / Q000295:instrumentation*; D011879:Radiotherapy Dosage
chemical_list: D002133:Calcium Sulfate