目的探讨鼻咽癌(NPC)根治性放疗不同阶段颅底骨髓腔CT值变化的趋势,为NPC患者放疗后CT诊断提供依据并为放疗后颅底骨质改变的长期随访提供参考。方法选取130例NPC患者为研究对象,其中60例放疗前和完成20 Gy、60 Gy剂量治疗时行CT平扫,另70例在放疗前和完成40 Gy剂量治疗时以及完成治疗3个月后行CT增强扫描,在同一断层图像上以颅底骨枕骨斜坡髓腔勾画感兴趣区,并计算出平均CT值,统计CT值不同阶段的变化,动态观察枕骨斜坡骨髓腔对放疗后的急性反应。结果患者在放疗前和完成20 Gy、60 Gy剂量治疗行CT平扫时,斜坡髓腔的平均CT值分别为(177.46±82.62)HU、(175.11±80.17)HU和(160.31±80.70)HU;患者在放疗前和完成40 Gy剂量治疗时以及完成治疗3个月后增强CT扫描时,斜坡髓腔的平均CT值分别为(191.68±82.25)HU、(166.44±77.92)HU和(152.30±80.87)HU;经Anova分析发现,放疗前后颅底骨髓腔的CT值急性期普遍减低,差异有统计学意义(P<0.05),放疗前组与20 Gy组之间的差异没有统计学意义(P>0.05)。结论放疗辐射导致颅底骨髓腔的CT值相应减低,提示放疗后短期内颅底骨质有骨质疏松的变化趋势,对于放疗后出现的放射性骨损伤和病理性骨折的诊断有一定的提示意义,为NPC患者放疗后颅底骨质的长期随诊观察提供了帮助。 Objective To investigate the trend of CT value of skull base marrow cavity in different stages of radical radiotherapy for nasopharyngeal carcinoma (NPC), to provide basis for CT diagnosis after radiotherapy for NPC patients and to provide a reference for long-term follow-up of skull base bone after radiotherapy. Methods A total of 130 patients with NPC were enrolled in this study. Sixty patients underwent CT scan before radiotherapy and at the dose of 60 Gy and 60 Gy. Another 70 patients underwent CT scan before radiotherapy and at the dose of 40 Gy, and three months after completion of treatment Line CT enhanced scan, sketching the cranial base of the occipital bone slope in the same tomographic image of the region of interest, and calculate the average CT value, CT value changes in different stages of dynamic observation of the occipital slope of the bone marrow cavity acute response after radiotherapy . Results The mean CT values ​​of the medullary canal were (177.46 ± 82.62) HU, (175.11 ± 80.17) HU and (160.31 ± 80.70) HU, respectively, before CT and at the time of 20 Gy and 60 Gy CT scan. The average CT values ​​of the medullary canal were (191.68 ± 82.25) HU, (166.44 ± 77.92) HU and (152.30 ± 80.87), respectively, at the time of 40 Gy dose pretreatment and 3 months after the completion of treatment. ) HU; Anova analysis showed that the CT value of the skull base marrow cavity before and after radiotherapy generally decreased in acute phase (P <0.05), but there was no significant difference between the pre-radiotherapy group and the 20 Gy group (P > 0.05). Conclusions Radiotherapy radiation leads to a corresponding decrease of CT value in the skull base marrow cavity, which indicates that there is a tendency of osteoporosis in the skull base bone after radiotherapy for a short period of time, which has some implications for the diagnosis of radiological bone injury and pathological fracture after radiotherapy , NPC patients with radiotherapy for skull base bone after long-term follow-up observation provided help.