title: Improved survival of mice after total body irradiation with 10 MV photon, 2400 MU/min SRS beam.
abstract: OBJECTIVE
  We evaluated the radiobiological effects of stereotactic radiosurgery (SRS) photon beams on survival of C57BL/6NTac mice following total body irradiation.
  
  
  METHODS
  Survival of Lewis lung carcinoma (3LL) cells was tested after irradiation using 6 MV: 300 MU/min or 1400 MU/min; or 10 MV: 300 MU/min or 2400 MU/min. Survival of C57BL/6NTac mice after a dose which is lethal to 50% of the mice in 30 days (LD50/30) (9.25 Gy) total body irradiation (TBI) and 21 Gy to orthotopic 3LL tumors was tested. We quantitated levels of organ-specific gene transcripts by Real Time Polymerase Chain Reaction (RT-PCR).
  
  
  RESULTS
  While 3LL cell survival and inhibition of orthotopic tumor growth was uniform, 10 MV photons at 2400 MU/min TBI led to significantly greater survival (p=0.0218), with higher levels of intestinal (Sod2), (Gpx1), (Nrf2), and (NFκB) RNA transcripts.
  
  
  CONCLUSIONS
  Clinical 10 MV-2400 cGy/min SRS beams led to unexpected protection of mice on TBI and increased radioprotective gene transcripts.
authors.affiliation: Professor and Chairman, Department of Radiation Oncology, University of Pittsburgh Cancer Institute, UPMC Cancer Pavilion, 5150 Centre Avenue, Rm. 533, Pittsburgh, PA 15232, U.S.A. greenbergerjs@upmc.edu.
authors.forename: Ronny
authors.initials: R
authors.lastname: Kalash
authors.forename: Hebist
authors.initials: H
authors.lastname: Berhane
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Michael W
authors.initials: MW
authors.lastname: Epperly
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Tracy
authors.initials: T
authors.lastname: Dixon
authors.forename: Byung
authors.initials: B
authors.lastname: Rhieu
authors.forename: Joel S
authors.initials: JS
authors.lastname: Greenberger
authors.forename: Mohammed Saiful
authors.initials: MS
authors.lastname: Huq
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D006801:Humans; D051379:Mice; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D014916:Whole-Body Irradiation
keywords: Stereotactic radiosurgery; dose rate; photon energy