Applycation Of The Two-step SLN Mapping With Double-tracer And Pathologic Ultrastaging In Early Stage Endometrial Cancer

Objective To explore the feasibility and clinical value of applying two tracers for sentinel lymph node mapping through cervical-uterine combined injection in patients with early endometrial cancer.Methods From June 2019 to April 2021,73 patients included who required surgery for early endometrial cancer,including 56 patients with low-risk postoperative pathology and 17 patients with medium-high risk,in the Department of Gynecology of Qingdao University Affiliated Hospital.The patients were divided into three groups according to the different tracer injection site:(1)Cervical injection group(25 cases): 1m L of nano-carbon was used to inject at 3 and 9 o’clock in the cervix;(2)Uterine injection group(21 cases): The MRI examination was performed to determine the location of the lesion,and the uterine body at 2sites where the lesion was located injected 4m L of methylene blue.(3)Combined injection group(27 cases): Cervical injection of nano-carbon combined with uterine injection of methylene blue for SLN imaging.All patients underwent laparoscopic staging surgery,during which tracer was injected under direct vision under laparoscopy.Within 30 minutes after tracer injection,the developed sentinel lymph nodes were identified by laparoscopy and labeled with the first developed sentinel lymph node.All the developed sentinel lymph nodes were removed and frozen pathological examination was performed.No matter whether freezing the sentinel lymph node positive pelvic lymph nodes were performed for further lymph node resection plus or minus abdominal aorta,will the rest of the specimens were routine pathologic examination,of marking the first development and routine pathological examination negative SLN row HE staining and immunohistochemical study AE1 / AE3,pathological staging of tests.Overall sentinel lymph node(SLN)detection rate,bilateral pelvic detection rate,sensitivity,negative predictive value and SLN distribution were calculated and compared.Results(1)The total detection rate of SLN in the three groups of patients was 87.67%(64/73),and the detection rate of bilateral pelvic cavity was 67.12%(49/73).Among them,the total detection rate of SLN and the detection rate of bilateral pelvic cavity were the highest in the combined injection group,which were 96.30%(26/27)and 77.78%(21/27),respectively.The cervical injection group was followed by 92.00%(23/27)and 76.00%(19/25).The uterine injection group was the lowest,71.43%(15/21)and 42.86%(9/21),which were significantly lower than the other two groups and the difference was statistically significant(P<0.05).(2)The total detection rate of para-abdominal aorta SLN was 49.32%(36/73),and the detection rate of para-abdominal aortic SLN in the combined injection group was the highest 66.67%(18/27),followed by 52.38% in the uterine injection group(11/21).The cervical injection group was only 28%(7/25),which was significantly lower than the other two groups and the difference was statistically significant(P<0.05).(3)Nine patients had postoperative pathologically confirmed lymph node metastasis,of which eight were SLN positive and one was false negative.The sensitivity was 88.89%(8/9),and the negative predictive value was 98.46%(64/65).Among them,the sensitivity and negative predictive value of the cervical injection group and the combined injection group were both 100%.One patient in the uterine injection group had a false negative SLN,with a sensitivity of 66.67%(2/3)and a negative predictive value of 94.74%(18/19).(4)Among 56 low-risk patients,only one had lymph node positive,with a metastasis rate of 1.79%,and both SLN sensitivity and negative predictive value were 100%.Of 17 medium-high-risk patients,8 had lymph node positive,and 1 was false-negative for SLN,with sensitivity It was 87.5%(7/8),and the negative predictive value was 90%(9/10).The rate of lymph node metastasis in the high-risk group was 47.06%(8/17).Among them,there were 2 cases of isolated para-aortic lymph node metastasis,with an incidence rate of 11.76%(2/17).(5)A total of 459 SLNs were detected,of which the most common site was the external iliac 33.55%(154/459),followed by the obturator 25.05%(115/459),the para-aortic 19.61%(90/459),common iliac 11.98%(55/459)and sacral area 9.80%(45/459).The most common site in the cervical injection group was the external iliac 35.50%(60/169),followed by obturator 29.59%(50/169).The most common site in the uterine injection group was the para-aortic area 27.31%(26/95),followed by the obturator 25.26%(24/95).The most common site in the combined injection group was the external iliac 36.92%(72/195),followed by the para-aortic area 22.05%(43/195).(6)In this study,a total of 64 patients were negative for routine pathological examination after surgery,and all sentinel lymph nodes were sent for pathological hyper-staging examination,and 7.81%(5/64)of the patients were detected with sentinel lymph node micrometastasis,including 3 medium-high risk patients and 2 low-risk patients.Conclusion1)Sentinel lymph node mapping has high sensitivity and negative predictive value in patients with early endometrial cancer and can be used as an alternative to systematic lymph node dissection in low-risk patients.2)The SLN mapping through cervical-uterine combined injection can further improve the detection rate effectively and avoid the missed detection of positive para-aortic lymph node,especially for high-risk patients or tumors involving the fundus can be considered.3)Pathological ultrastaging technology can detect micrometastases or isolated tumor cells that cannot be detected by conventional pathology,which plays a guiding role in the treatment and prognosis of patients with early endometrial cancer.