title: Applications of asymmetric collimation on linear accelerators.
abstract: Frequency of use of asymmetric collimation (AC) at an academic radiation oncology center equipped with AC-capable linear accelerators was determined, and the type of use was cataloged. Records of patients beginning radiation treatment at U.C. Davis Cancer Center within a 3-month period (3/1/92 to 5/31/92) were reviewed. Forty-seven percent of 102 patients and 56% of 123 courses of treatment involved AC. Six common uses of AC were identified: beam-split field matching, planned boosts, other field size changes, adjustments to match divergent fields, matchline feathering, and opposed tangential fields. This study demonstrates that asymmetric collimation is a useful and powerful clinical treatment tool with widespread applications to radiation therapy.
authors.affiliation: Department of Surgery, University of California at Davis, Sacramento 95817, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Stern
authors.forename: S A
authors.initials: SA
authors.lastname: Rosenthal
authors.forename: E C
authors.initials: EC
authors.lastname: Doggett
authors.forename: J K
authors.initials: JK
authors.lastname: Mangat
authors.forename: T L
authors.initials: TL
authors.lastname: Phillips
authors.forename: J K
authors.initials: JK
authors.lastname: Ryu
mesh_terms: D015331:Cohort Studies; D006801:Humans; D010315:Particle Accelerators; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000295:instrumentation* / Q000379:methods