title: Biological effectiveness of neutrons and pi-mesons in gut, bone, and transplantable tumours.
abstract: At the Munich RENT-facility a screening project was performed to define the biological characteristics of a fission neutron beam envisaged for radiotherapy. The quantitative endpoints used were jejunal crypt survival, late rectal stenosis in rats, osseous healing in traumatized rat femur and regrowth delay of murine transplantable tumours. The results obtained in normal tissues (with the possible exception of bone) demonstrate a high RBE, in accordance with the well documented dependence of RBE on neutron energy. The RBE-values measured in tumours after single dose treatment endorsed the high effectiveness, although--as has been the case with other beams--they gave no conclusive evidence of a therapeutic advantage. Nevertheless, the specific beam characteristics, i.e. a high RBE at the surface and a fast decline of the biologically effective depth dose suggest possible advantages of the RENT beam when applied in the treatment of selected superficial tumours.
authors.affiliation: Gesellschaft für Strahlen- und Umweltforschung, Neuherberg, FRG.
authors.forename: J
authors.initials: J
authors.lastname: Kummermehr
authors.forename: H
authors.initials: H
authors.lastname: Schraube
authors.forename: G
authors.initials: G
authors.lastname: Ries
authors.forename: L
authors.initials: L
authors.lastname: Köster
authors.forename: K H
authors.initials: KH
authors.lastname: Höver
authors.forename: H
authors.initials: H
authors.lastname: Blattmann
authors.forename: P
authors.initials: P
authors.lastname: Stas
authors.forename: G
authors.initials: G
authors.lastname: Burger
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000293:injuries / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D003251:Constriction, Pathologic / Q000209:etiology; D004601:Elementary Particles; D004735:Energy Transfer; D005214:Fast Neutrons; D005260:Female; D005720:Gamma Rays; D007583:Jejunum / Q000528:radiation effects*; D008651:Mesons; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000532:radiotherapy*; D009502:Neutrons; D010315:Particle Accelerators; D011833:Radiation Injuries, Experimental / Q000209:etiology; D051381:Rats; D012007:Rectum / Q000528:radiation effects; D012062:Relative Biological Effectiveness; D014945:Wound Healing / Q000528:radiation effects