Gaddipati Ravi, Jensen Garrett L, Swanson Gregory, Hammonds Kendall, Morrow Andrew
Radiation Oncology, Baylor Scott & White Health, Temple, USA.
Biostatistics, Baylor Scott & White Health, Temple, USA.
Cureus. 2022 Feb 24;14(2):e22565. doi: 10.7759/cureus.22565. eCollection 2022 Feb.
Objective Increased rates of insufficiency fractures are reported after radiation therapy without well-defined causality. Here, we conduct a cross-sectional study on the density change of a non-lesioned vertebral bone after irradiation relative to a control bone in patients with spinal metastases. Methods Patients were identified who received radiation therapy for spinal metastases to a region, including an adjacent vertebra without identifiable malignancy on pre-treatment CT. Every patient had an untreated vertebra of a similar type available as a control. A Hounsfield-density calibration curve was used to measure the vertebral body density before and after treatment. Analysis of covariance was used to model vertebral bone density changes with respect to treatment status. Significance was established as < 0.05. Results We identified 36 patients who fit the study criteria. The irradiated healthy bone received a median dose of 30 Gy. The median biologically effective dose (BED) was 60 Gy (α/β = 3) and 39 Gy (α/β = 10). Median follow-up imaging intervals between pre-treatment and follow-up CT scans was 13.4 months. Levene's test was used to confirm the equality of error variance assumption of ANCOVA (p = 0.093). The mean change in the density of the irradiated vertebral bone was -3.59% (95% CI = -8.51% - 1.32%, p = 0.149). Conclusions We found no significant change in vertebral bone density attributable to radiation treatment. Further work is needed to elucidate if increased fracture rates after radiation are due to factors other than bone density.
目的 据报道，放射治疗后不全骨折发生率增加，但因果关系尚不明确。在此，我们对脊柱转移瘤患者照射后未发生病变的椎骨密度变化与对照骨进行了一项横断面研究。方法 确定接受脊柱转移瘤放射治疗的患者，照射区域包括治疗前CT上未发现恶性肿瘤的相邻椎体。每位患者都有一个未治疗的类似类型椎体作为对照。使用Hounsfield密度校准曲线测量治疗前后椎体密度。采用协方差分析对椎体骨密度变化与治疗状态进行建模。显著性设定为<0.05。结果 我们确定了36例符合研究标准的患者。接受照射的健康骨中位剂量为30 Gy。中位生物等效剂量（BED）为60 Gy（α/β = 3）和39 Gy（α/β = 10）。治疗前和随访CT扫描之间的中位随访影像间隔为13.4个月。使用Levene检验确认协方差分析误差方差齐性假设（p = 0.093）。照射椎体骨密度的平均变化为-3.59%（95%CI = -8.51% - 1.32%，p = 0.149）。结论 我们发现放射治疗后椎体骨密度无显著变化。需要进一步研究以阐明放射治疗后骨折率增加是否是由骨密度以外的因素引起的。
