METHODS: We first searched for cervical lymph nodes interested in static PET-CT, measured their SUV-Max values, and found the corresponding lymph nodes in magnetic resonance images before and after treatment. The valid or invalid groups were included according to the changes in lymph node size before and after treatment. If the change in the product of the maximum diameter and maximum vertical transverse diameter of the lymph node before and after treatment was greater than or equal to 50%, they would be included in the valid group. If the change was less than 50%, they would be included in the invalid group. Their Ki values were measured on dynamic PET-CT and compared under different conditions. Then, we conducted a correlation analysis between various factors and Ki values. Finally, diagnostic tests were conducted to compare the sensitivity and specificity of Ki and SUV-Max.
RESULTS: We included 67 cervical lymph nodes from different regions of 51 nasopharyngeal cancer patients and divided them into valid and invalid groups based on changes before treatment. The valid group included 50 lymph nodes, while the invalid group included 17. There wer significant differences (p < 0.001) between the valid and the invalid groups in SUV-Max, Ki-Mean, and Ki-Max values. When the SUV-Max was ≤4.5, there was no significant difference in the Ki-Mean and Ki-Max between the two groups (p > 0.05). When the SUV-Max was ≤4.5 and pre-treatment lymph nodes were <1.0 cm, the valid group had significantly higher Ki-Mean (0.00910) and Ki-Maximum (0.01004) values than the invalid group (Ki-Mean = 0.00716, Ki-Max = 0.00767) (p < 0.05). When the SUV-Max was ≤4.5, the pre-treatment lymph nodes < 1.0 cm, and the EBV DNA replication normal, Ki-Mean (0.01060) and Ki-Max (0.01149) in the valid group were still significantly higher than the invalid group (Ki-Mean = 0.00670, Ki-Max = 0.00719) (p < 0.05). The correlation analysis between different factors (SUV-Max, T-stage, normal EB virus DNA replication, age, and pre-treatment lymph node < 1.0 cm) and the Ki value showed that SUV-Max and a pre-treatment lymph node < 1.0 cm were related to Ki-Mean and Ki-Max. Diagnostic testing was conducted; the AUC value of the SUV-Max value was 0.8259 (95% confidence interval: 0.7296-0.9222), the AUC value of the Ki-Mean was 0.8759 (95% confidence interval: 0.7950-0.9567), and the AUC value of the Ki-Max was 0.8859 (95% confidence interval: 0.8089-0.9629). After comparison, it was found that there was no significant difference in AUC values between Ki-Mean and SUV-Max (p = 0.220 > 0.05), and there was also no significant difference in AUC values between Ki max and SUV-Max (p = 0.159 > 0.05). By calculating the Youden index, we identified the optimal cut-off value. It was found that the sensitivity of SUV-Max was 100% and the specificity was 66%, the sensitivity of Ki-Mean was 100% and the specificity was 70%, and the sensitivity of Ki-Max was 100% and the specificity was 72%. After Chi-Square analysis, it was found that there was no significant difference in specificity between Ki-Mean and SUV-Max (p = 0.712), and there was also no significant difference in specificity between Ki-Max and SUV-Max (p = 0.755).
CONCLUSIONS: Dynamic PET-CT has shown a significant diagnostic value in diagnosing cervical lymph node metastasis of nasopharyngeal cancer, especially for the small SUV value, and lymph nodes do not meet the metastasis criteria before treatment, and EBV DNA replication is normal. Although the diagnostic accuracy, sensitivity, and specificity of dynamic PET-CT were not significantly different from traditional static PET-CT, the dynamic PET-CT had a more accurate tendency.
方法:我们首先搜索对静态PET-CT感兴趣的颈部淋巴结,测量了他们的SUV-Max值,并在治疗前后的磁共振图像中发现相应的淋巴结。根据治疗前后淋巴结大小变化分为有效组或无效组。如果治疗前后淋巴结的最大直径和最大垂直横径的乘积的变化大于或等于50%,他们将被包括在有效组中。如果变化小于50%,他们将被包括在无效组中。在动态PET-CT上测量它们的Ki值,并在不同条件下进行比较。然后,我们进行了各因素与Ki值的相关性分析.最后,进行诊断测试以比较Ki和SUV-Max的敏感性和特异性。
结果:我们纳入51例鼻咽癌患者不同部位的67个颈淋巴结,根据治疗前的变化分为有效组和无效组。有效组包括50个淋巴结,而无效组包括17。SUV-Max中有效组和无效组之间存在差异(p<0.001),Ki-Mean,和Ki-Max值。当SUV-Max≤4.5时,两组Ki-Mean和Ki-Max差异无统计学意义(p>0.05)。当SUV-Max≤4.5且治疗前淋巴结<1.0cm时,有效组的Ki-Mean(0.00910)和Ki-Maximum(0.01004)值显著高于无效组(Ki-Mean=0.00716,Ki-Max=0.00767)(p<0.05).当SUV-Max≤4.5时,治疗前淋巴结<1.0cm,EBVDNA复制正常,有效组Ki-Mean(0.01060)和Ki-Max(0.01149)仍显著高于无效组(Ki-Mean=0.00670,Ki-Max=0.00719)(p<0.05)。不同因素之间的相关性分析(SUV-Max,T-stage,正常的EB病毒DNA复制,年龄,和治疗前淋巴结<1.0cm)和Ki值显示SUV-Max和治疗前淋巴结<1.0cm与Ki-Mean和Ki-Max相关。进行诊断测试;SUV-Max值的AUC值为0.8259(95%置信区间:0.7296-0.9222),Ki-Mean的AUC值为0.8759(95%置信区间:0.7950-0.9567),Ki-Max的AUC值为0.8859(95%置信区间:0.8089-0.9629)。经过比较,发现Ki-Mean和SUV-Max之间的AUC值没有显着差异(p=0.220>0.05),Kimax和SUV-Max之间的AUC值也没有显着差异(p=0.159>0.05)。通过计算Youden指数,我们确定了最佳临界值。结果发现SUV-Max的敏感性为100%,特异性为66%,Ki-Mean的敏感性为100%,特异性为70%,Ki-Max的敏感性为100%,特异性为72%。经过卡方分析,发现Ki-Mean和SUV-Max之间的特异性没有显着差异(p=0.712),Ki-Max和SUV-Max之间的特异性也没有显着差异(p=0.755)。
结论:动态PET-CT对鼻咽癌颈淋巴结转移具有重要的诊断价值。特别是对于小型SUV的价值,淋巴结不符合治疗前的转移标准,EBVDNA复制正常.虽然诊断的准确性,灵敏度,动态PET-CT的特异性与传统静态PET-CT无显著差异,动态PET-CT具有更准确的趋势。