title: Monitor unit calculations for breast or chest wall treatments.
abstract: Tangential breast fields always "flash" beyond the surface of the patient. Since the portion of the beam that is in air does not contribute scatter, external beam treatment planning computers that utilize stored beam data can lead to dose errors of up to 10%. These errors can be reduced by using an irregular field calculation program to adjust the monitor units to account for the loss of scatter.
authors.affiliation: Albany Regional Radiation Oncology Program, Cooperative Program of Albany Medical Center Hospital, St. Peter's Hospital, Albany, NY 12208.
authors.forename: P C
authors.initials: PC
authors.lastname: Cheng
authors.forename: T
authors.initials: T
authors.lastname: Ames
authors.forename: T
authors.initials: T
authors.lastname: Howard-Ames
authors.forename: H
authors.initials: H
authors.lastname: Kohut
authors.forename: V
authors.initials: V
authors.lastname: Heleba
authors.forename: J
authors.initials: J
authors.lastname: Krishnamoorthy
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008961:Models, Structural; D011834:Radiation Monitoring / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D011881:Radiotherapy, Computer-Assisted; D011882:Radiotherapy, High-Energy; D012542:Scattering, Radiation; D013899:Thoracic Neoplasms / Q000532:radiotherapy*