Clinical Value Of MRI-DWI In Predicting Pelvic Lymph Node Metastasis Of Cervical Cancer

Objective:The value of traditional MRI sequence and DWI image-derived apparent diffusion coefficient（ADC）in predicting pelvic lymph node metastasis in patients with cervical cancer was studied.Methods:Data of 263 patients admitted to Shenzhen People’s Hospital from December2012 to January 2020 withⅠA 2～ⅡA2 period of cervical cancer confirmed by surgery and pathology were collected.All patients underwent preoperative MRI examination and surgical treatment of the pelvic cavity in our hospital,and all underwent systematic pelvic lymphadenectomy during the operation.Preoperative MRI recucleated films were taken from 263 patients and ADC images of the primary lesion of cervical cancer and positive pelvic lymph nodes were constructed to calculate the ADC_meanvalue.MRI and postoperative pathology of metastatic and non-metastatic pelvic lymph nodes were analyzed.Pelvic lymph nodes were divided into left and right general iliac,external iliac,internal iliac,obturator and deep inguinal lymph nodes groups.The factors of pelvic lymph node metastasis and various pathological factors were analyzed by single-factor analysis,and the relevant factors were screened out.The ROC curve was plotted by combining the ADC value of the primary tumor.Results:1.Among the 263 cases ofⅠA 2～ⅡA2 period of cervical cancer,the number of cases with pelvic lymph node metastasis confirmed by surgery and pathology was 49,and the number of cases without metastasis was 214.The sensitivity,specificity,positive predictive value and negative predictive value of preoperative pelvic and abdominal MRI in diagnosing pelvic lymph node metastasis of cervical cancer were 73.5%,93.9%,73.5%and 93.9%,respectively.After grouping pelvic lymph nodes,the above indexes were 68.0%,98.7%and 68.6%,respectively,and the negative predictive value was 98.7%.2.The number of metastatic pelvic lymph nodes was ranked as follows:obturator group（36.7%）>internal iliac group（24.3%）>general iliac group（19.1%）>external iliac group（12.8%）>deep inguinal group（7.1%）.Preoperative pelvic and abdominal MRI evaluation of sensitivity,specificity,positive predictive value and negative predictive value of pelvic lymph node metastasis in each group were:general iliac group:81.3%,99.6%,86.7%and 99.4%,respectively.External iliac group:66.7%,97.3%,50.0%,98.6%;Internal iliac group:75.0%,98.1%,72.4%,98.4%;Obturator group:70.0%,98.3%,72.4%,98.1%;Groin group:33.3%,99.6%,60.0%,98.0%.3.The short diameters of metastatic and non-metastatic pelvic lymph nodes were8.85±5.11mm²/s and 6.47±2.58mm²/s,respectively（P<0.05）.4.The ADC values of primary tumors of cervical cancer with or without pelvic lymph node metastasis were 821.59±142.48 mm²/s and 1061.12±344.61mm²/s,respectively.The optimal diagnostic threshold was 921.5 mm²/s,the sensitivity was81.6%,the specificity was 53.1%,and the accuracy was 0.710.The ADC values of metastatic and non-metastatic pelvic lymph nodes were 865.48±188.93mm2/s and1126.27±380.56mm²/s,respectively.The optimal diagnostic threshold was 928.5mm²/s,the sensitivity was 70.3%,the specificity was 61.5%,and the accuracy was 0.709.5.The clinicopathological risk factors for pelvic lymph node metastasis of cervical cancer were tumor size（the maximum diameter line≥4cm）,cervical muscular infiltration depth（≥1/2 muscular infiltration）,vaginal vault involvement,lymphatic vascular clearance involvement,and paracasal involvement（P<0.01）.6.The maximum diameter of the primary tumor of cervical cancer was less than2cm and≥2cm,but the ADC values of<4cm and≥4cm were 1207.09±358.85mm²/s,989.80±312.87mm²/s and 841.94±195.28mm²/s,respectively,showing differences（P<0.01）.The ADC values of muscle layer infiltration depth≥1/2 and<1/2 were 905.39±248.76mm²/s and 1172.04±366.47mm²/s,respectively,with significant differences（P<0.01）.The former was lower than the latter.The diagnostic threshold was1001.0mm²/s,the sensitivity was 81.0%,the specificity was 62.4%,and the accuracy was 0.719.The ADC values of whether or not the lymph vessel clearance was involved were 877.08±189.20mm²/s and 1102.27±367.60mm²/s,respectively.The diagnostic threshold was 975.5mm²/s,with a sensitivity of 83%,specificity of 53.7%and accuracy of 0.659.The ADC values of whether the vaginal fornix was involved or not were897.13±241.75mm²/s and 1065.93±349.26mm²/s,respectively.The diagnostic threshold was 918.0 mm²/s,with a sensitivity of 72.7%,specificity of 56.8%and accuracy of 0.646.The paracentral ADC values were 905.20±52.60mm²/s and1018.48±332.85mm²/s,respectively.Conclusion:1.Pelvic abdominal MRI has good value for the overall qualitative assessment and grouping assessment of pelvic lymph node metastasis of cervical cancer.2.ADC value can be used to quantify the evaluation of pelvic lymph node metastasis of cervical cancer and improve the accuracy of prediction.3.The maximum diameter of tumor≥4cm,lymphatic vascular space involvement,≥1/2 muscle layer infiltration,vaginal vault involvement and parathyroid involvement were independent risk factors for pelvic lymph node metastasis.ADC values can be used as imaging markers to evaluate the above pathological factors to stratify the risk of pelvic lymph node metastasis of cervical cancer and optimize clinical treatment decisions.