title: Radiation associated brainstem injury.
abstract: Publications relating brainstem radiation toxicity to quantitative dose and dose-volume measures derived from three-dimensional treatment planning were reviewed. Despite the clinical importance of brainstem toxicity, most studies reporting brainstem effects after irradiation have fewer than 100 patients. There is limited evidence relating toxicity to small volumes receiving doses above 60-64 Gy using conventional fractionation and no definitive criteria regarding more subtle dose-volume effects or effects after hypofractionated treatment. On the basis of the available data, the entire brainstem may be treated to 54 Gy using conventional fractionation using photons with limited risk of severe or permanent neurological effects. Smaller volumes of the brainstem (1-10 mL) may be irradiated to maximum doses of 59 Gy for dose fractions <or=2 Gy; however, the risk appears to increase markedly at doses >64 Gy.
authors.affiliation: Department of Radiation Oncology, University of Massachusetts Medical School, Worcester, MA 01655, USA. charles.mayo@umassmemorial.org
authors.forename: Charles
authors.initials: C
authors.lastname: Mayo
authors.forename: Ellen
authors.initials: E
authors.lastname: Yorke
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Merchant
mesh_terms: D000328:Adult; D000367:Age Factors; D001933:Brain Stem / Q000528:radiation effects*; D002648:Child; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D020714:Maximum Tolerated Dose; D017785:Photons / Q000009:adverse effects; D011522:Protons / Q000009:adverse effects; D011832:Radiation Injuries / Q000209:etiology*; D011836:Radiation Tolerance; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods
chemical_list: D011522:Protons