Journal article
Effects of Radiotherapy Upon Bone Structure-Strength Relationships Vary With Sex and Fractionation of Dosing
The Iowa orthopaedic journal, Vol.43(1), pp.77-86
01/01/2023
PMCID: PMC10296472
PMID: 37383848
Appears in Diamond Open Access
Abstract
Background: Radiotherapy for tumor treatment in or near bones often causes osteopenia and/or osteoporosis, and the resulting increased bone fragility can lead to pathologic fractures. Bone mineral density (BMD) is often used to screen for fracture risk, but no conclusive relationship has been established between BMD and the microstructural/ biomechanical changes in irradiated bone. Understanding the effects of radiation dosing regimen on the bone structure-strength relationship would improve the ability to reduce fracture-related complications resulting from cancer treatment.
Methods: Thirty-two C57B6J mice aged 10 - 12 weeks old were randomized to single dose (1 x 25 Gy) and fractionated dose (5 x 5 Gy) irradiation groups. Right hindlimbs were irradiated while the contralateral hindlimbs served as the non-irradiated control. Twelve weeks after irradiation, BMD and bone microstructure were assessed with micro-computed tomography, and mechanical strength/stiffness was assessed with a torsion test. The effects of radiation dosing regimen on bone microstructure and strength were assessed using ANOVA, and bone strength-structure relationships were investigated through correlation analysis of microstructural and mechanical parameters.
Results: Fractionated irradiation induced significantly greater losses in BMD in the femur (23% - male mice, p=0.016; 19% - female mice) and the tibia (18% - male mice; 6% - female mice) than the single-dose radiation. The associated reductions in trabecular bone volume (-38%) and trabecular number (-34% to -42%), and the increase in trabecular separation (23% to 29%) were only significant in the male mice with fractionated dosing. There was a significant reduction in fracture torque in the femurs of male (p=0.021) and female (p=0.0017) mice within the fractionated radiation group, but not in the single dose radiation groups. There was moderate correlation between bone microstructure and mechanical strength in the single-dose radiation group (r = 0.54 to 0.73), but no correlation in the fractionated dosing group (r=0.02 to 0.03).
Conclusion: Our data indicate more detrimental changes in bone microstructure and mechanical parameters in the fractionated irradiation group compared to the single dose group. This may suggest the potential for protecting bone if a needed therapeutic radiation dose can be delivered in a single session rather than administered in fractions.
Details
- Title: Subtitle
- Effects of Radiotherapy Upon Bone Structure-Strength Relationships Vary With Sex and Fractionation of Dosing
- Creators
- Maxwell Y. Sakyi - University of IowaBenjamin J. Miller - University of IowaMitchell C. Coleman - Department of Orthopedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA Radiation Oncology Department, University of Iowa, Iowa City, Iowa, USASamuel N. Rodman - Radiation Oncology Department, University of Iowa, Iowa City, Iowa, USAMarc J. Brouillette - University of IowaJoshua E. Johnson - Department of Orthopedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USADouglas C. Fredericks - University of IowaJessica E. Goetz - Department of Orthopedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
- Resource Type
- Journal article
- Publication Details
- The Iowa orthopaedic journal, Vol.43(1), pp.77-86
- PMID
- 37383848
- PMCID
- PMC10296472
- NLM abbreviation
- Iowa Orthop J
- ISSN
- 1541-5457
- eISSN
- 1555-1377
- Publisher
- Dept. of Orthopaedics, The University of Iowa; United States
- Language
- English
- Date published
- 01/01/2023
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Orthopedics and Rehabilitation; Radiation Oncology; Craniofacial Anomalies Research Center
- Record Identifier
- 9984438857902771
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