Radiation therapy (RT) is a treatment option for head and neck cancer (HNC), but 2% of RT patients may experience damage to the jawbone, resulting in osteoradionecrosis (ORN). The ORN can manifest years after RT exposure. Changes in the local microchemical bone quality prior to the clinical manifestation of ORN could play a key role in ORN pathogenesis. Chemical bone quality can be analyzed using Fourier transform infrared spectroscopy (FTIR), that is applied to examine the effects of cancer, chemotherapy, and RT on the quality of human mandibular bone. Cortical mandibular bone samples were harvested from dental implant beds of 23 individuals, i.e., patients with surgically and radiotherapeutically treated HNC (RT-HNC, n=7), surgically and radiochemotherapeutically treated HNC (CH-RT-HNC, n=3), only surgically treated HNC (SRG-HNC, n=4), and healthy controls (n=9). Infrared spectra were acquired from two representative regions of interest in cortical mandibular bone. Spectral parameters, i.e., mineral-to-matrix ratio (MM), carbonate-to-matrix ratio (CM), carbonate-to-phosphate ratio (CP), collagen maturity (cross-linking), crystallinity, acid phosphate substitution (APS), and advanced glycation end products (AGEs), were analyzed for each sample. Amide I region of the CH-RT-HNC group differed from the control group in cluster analysis (p=0.02). Apart from a minor variation trend in collagen maturity (p=0.07), there were no other significant differences between the groups. Thus, the effect of radiochemotherapy on mandibular bone composition should be further investigated. In future trials, this study design is potential when the effects of the cancer burden and different HNC treatment modalities on jawbone composition are studied, in order to reveal ORN pathogenesis.

中文翻译：

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放射治疗后下颌骨微化学质量的长期变化和潜在的全身恶性肿瘤：一项初步研究

放射治疗 (RT) 是头颈癌 (HNC) 的一种治疗选择，但 2% 的放疗患者可能会出现颌骨损伤，导致放射性骨坏死 (ORN)。ORN 可以在 RT 暴露后数年出现。ORN临床表现之前局部微化学骨质量的变化可能在ORN发病机制中起关键作用。可以使用傅里叶变换红外光谱 (FTIR) 分析化学骨质量，该光谱可用于检查癌症、化疗和放疗对人类下颌骨质量的影响。下颌骨皮质骨样本取自 23 个人的种植牙床，即接受手术和放射治疗的 HNC (RT-HNC,n=7), 手术和放化疗治疗的 HNC (CH-RT-HNC,n=3), 仅经过手术治疗的 HNC (SRG-HNC,n=4) 和健康对照 (n=9）。从皮质下颌骨中的两个代表性感兴趣区域获得红外光谱。光谱参数，即矿物质与基质的比率 (MM)、碳酸盐与基质的比率 (CM)、碳酸盐与磷酸盐的比率 (CP)、胶原成熟度（交联）、结晶度、酸性磷酸盐取代 (APS) ) 和晚期糖基化终产物 (AGEs) 对每个样品进行了分析。CH-RT-HNC组的酰胺I区在聚类分析中与对照组不同（p=0.02）。除了胶原成熟度的微小变化趋势（p=0.07)，各组之间没有其他显着差异。因此，应进一步研究放化疗对下颌骨组成的影响。在未来的试验中，当研究癌症负担和不同 HNC 治疗方式对颌骨组成的影响时，该研究设计是可能的，以揭示 ORN 发病机制。