Radiation therapy is an important tool in the treatment of women with gynecologic cancers. An increased incidence of spontaneous hip fractures is observed in women after receiving therapeutic irradiation.

In this study, we explored the relationship between dosage and bone health by exposing sixteen-week-old C57BL6/J mice to both acute and fractionated dosages of ionizing radiation. The mice were divided into three groups -- 18 Gy single acute dose, 3 x 6 Gy fractionated dose and non-irradiated controls. Bones were collected 14 days after irradiation. MicroCT and finite element analyses were used to characterize microarchitectural and structural changes in the proximal metaphysis of the tibia.

Trabecular volume, connectivity density and bone mineral density all declined in the irradiated groups. The fractionated dose group did not demonstrate different bone loss than the single acute dose group in a statistically significant way. Further work is required to elucidate the complex relationship between single acute dose and its fractionated counterpart.