Changes in bone volume after irradiation with carbon ions.
The effects of carbon ions on bone volume were studied by histological and morphometrical methods. Anesthetized rats irradiated with three different single doses (15, 22.5, or 30 Gy) of either carbon ions or gamma rays were sacrificed (5 rats/group) at 10 time points together with non-irradiated controls. Carbon ion-induced bone responses were qualitatively and quantitatively different from those induced by gamma irradiation at the same dose level. Irradiation with carbon ions resulted in a dose-dependent increase in bone volume, while gamma irradiation induced loss of bone volume, which was found to be independent of dose in the range studied over the same time course. After irradiation with carbon ions, bones showed thickening of the trabeculae, and the bone marrow became fibrous with fewer vessels. Carbon ion irradiation showed a greater effect on the bone-absorbing capability of osteoclasts than gamma irradiation. These observations suggest that irradiation with carbon ions may produce differential modulation of radiation-induced growth factor expression.
Sawajiri
Masahiko
M
Department of Oral and Maxillofacial Radiology, Hiroshima University Hospital, Kasumi 1-2-3 Minami-ku, 734-8553 Hiroshima, Japan. jiri@hiroshima-u.ac.jp
Mizoe
Jun'etsu
J
D000818:Animals; D015519:Bone Density / Q000528:radiation effects; D001853:Bone Marrow / Q000473:pathology / Q000528:radiation effects; D002244:Carbon; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006132:Growth Plate / Q000473:pathology / Q000528:radiation effects; D020450:Heavy Ions; D008297:Male; D010010:Osteoclasts / Q000473:pathology / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D013977:Tibia / Q000473:pathology / Q000528:radiation effects*; D013997:Time Factors
D002244:Carbon