Bone changes in patients undergoing pelvic radiotherapy remain unclear. This study initially utilized high-resolution peripheral quantitative computed tomography (HR-pQCT) to assess the dynamic changes in bone microarchitecture and volumetric bone mineral density (BMD) in patients with cervical cancer before and after concurrent chemoradiotherapy. This prospective, observational study included patients with squamous carcinoma of the cervix scheduled for concurrent chemoradiotherapy. Patients underwent HR-pQCT, dual-energy X-ray absorptiometry (DXA) and laboratory tests before chemoradiotherapy, and at three and six months post-chemoradiotherapy. DXA, serving as the clinical standard for measuring BMD, was employed alongside HR-pQCT to provide complementary insights into bone micro-changes. The primary endpoint comprised changes in total (Tt.vBMD), trabecular (Tb.vBMD) and cortical (Ct.vBMD) volumetric BMD at the distal radius and tibia between pre-chemoradiotherapy and 6 months post-chemoradiotherapy. A total of 21 patients were enrolled, and one patient chose to withdraw (median age: 54.5 years). Tt.vBMD significantly decreased three months (distal radius: -1.65%, P = 0.008
distal tibia: -2.4%, P <
0.001) and six months (distal radius: -3.03%, P = 0.003
distal tibia: -2.69%, P = 0.002) post-chemoradiotherapy compared to baseline. Similarly, Tb.vBMD and Ct.vBMD demonstrated a significant downward trend post-chemoradiotherapy, with mean percent changes at three months of -0.73% and - 1.59% for the distal radius, and - 1.95% and - 1.50% for the distal tibia, respectively. The trends in BMD changes measured by DXA align with those observed using HR-pQCT. Regarding the laboratory tests, estradiol levels significantly decreased post-chemoradiotherapy, while follicle stimulating hormone and luteinizing hormone levels significantly increased. The results found that concurrent chemoradiotherapy was associated with the changes in bone volume, microstructure and BMD, especially in BMD three months post-chemoradiotherapy. Most of the bone micro-changes had not reverted by six months. This study explored the feasibility of early fracture risk identification post-chemoradiotherapy, aiding physicians in taking timely measures to improve prognosis.