Cortical Bone Modifications after Radiotherapy: Cortex Porosity and Osteonal Changes Evaluated Over Time

Abstract Aiming to evaluate cortical bone microarchitecture and osteonal morphology after irradiation, twelve male New Zealand rabbits were used. The animals divided: control group (no radiation-NIr); 3 irradiated groups, sacrificed after: 7 (Ir7d); 14 (Ir14d) 21 (Ir21d) days. A single radiation dose of 30 Gy was Computed microtomography analyzed the microarchitecture: thickness (CtTh), volume (BV), total porosity (Ct.Po), intracortical (CtPo-cl), channel/pore number (Po.N), fractal dimension (FD) degree anisotropy (Ct.DA). After scan, histologically assessed by means: area perimeter osteons (O.Ar; O.p) Haversian canals (C.Ar; C.p). Microtomographic analysis performed ANOVA, followed Tukey Dunnet tests. Osteon analyses Kruskal-Wallis, test Dunn’s. Cortical significant difference (p<0.010) between NIr with thicker cortex at Ir7d (1.15±0.09). revealed (p<0.001) groups NIr, lower value for (0.29±0.09). Bone in Ir14d compared control. Area statistically different (p<0.0001) Ir7d. also values (80.57±9.3; 31.63±6.5) groups. affected radiation, effects appear be time-dependent, mostly regarding initial Cortex structure Ir21d similarities suggesting that resembles normal condition a period.