Title: Fractionation Spares Mice From Radiation-Induced Reductions in Weight Gain But Does Not Prevent Late Oligodendrocyte Lineage Side Effects.

Authors: Begolly, Sage; Shrager, Peter G; Olschowka, John A; Williams, Jacqueline P; O'Banion, M Kerry

Published In Int J Radiat Oncol Biol Phys, (2016 Oct 01)

Abstract: To determine the late effects of fractionated versus single-dose cranial radiation on murine white matter.Mice were exposed to 0 Gy, 6 × 6 Gy, or 1 × 20 Gy cranial irradiation at 10 to 12 weeks of age. Endpoints were assessed through 18 months from exposure using immunohistochemistry, electron microscopy, and electrophysiology.Weight gain was temporarily reduced after irradiation; greater loss was seen after single versus fractionated doses. Oligodendrocyte progenitor cells were reduced early and late after both single and fractionated irradiation. Both protocols also increased myelin g-ratio, reduced the number of nodes of Ranvier, and promoted a shift in the proportion of small, unmyelinated versus large, myelinated axon fibers.Fractionation does not adequately spare normal white matter from late radiation side effects.

PubMed ID: 27478169

MeSH Terms: Animals; Cell Lineage/radiation effects*; Cells, Cultured; Cranial Irradiation/adverse effects*; Dose Fractionation, Radiation*; Dose-Response Relationship, Radiation; Mice; Oligodendroglia/pathology; Oligodendroglia/radiation effects*; Organ Sparing Treatments/methods; Organs at Risk/radiation effects; Radiation Dosage; Radiation Protection/methods; Weight Gain/radiation effects*; White Matter/pathology; White Matter/radiation effects*