Abstract: Objective To evaluate the clinical value of sentinel lymph node (SLN) detection using carbon nanoparticles in the diagnosis and treatment of cervical cancer and the value of lymph node pathological ultrastaging detection. Methods A total of 79 patients with cervical cancer in IA2, IB1, IB2, IIA1 and IIICp1 stages admitted to the Department of Gynecology and Obstetrics, Nanfang Hospital between June, 2018 and January, 2021 were included in this study. During the operation, the patients were injected with a total of 0.25 mL carbon nanoparticles at 3 and 9 o'clock of the normal cervix after general anesthesia. The first black-dyed lymph nodes were identified as SLNs and removed one by one. All the patients underwent pelvic lymph node dissection and radical hysterectomy with or without para-aortic lymphadenectomy. The black-dyed SLNs were removed for routine pathological examination. Thirty patients with negative SLNs were randomly selected for pathological ultrastaging. Results In 67 of the 79 patients, a total of 417 SLNs were detected with a detection rate of 84.8%; in each patient, at least 1 SLN was detected with a mean SLN number of 5.28. After the operation, 5 patients were found to have positive SLNs; 1 patient was negative for SLN but positive for non- SLN. The sensitivity of SLN biopsy was 83.3% with a specificity of 100% , false negative rate of 16.7% , an accuracy of 98.5% and a negative predictive value of 98.4% . SLN was distributed mainly in the obturator region, the external iliac region, the internal iliac region and the total iliac region (15.11%). Univariate and multivariate analyses suggested that preoperative cervical coning (P=0.045 and 0.009) and tumor size (P=0.033 and 0.008) significantly affected the overall detection rate of SLN. Kappa test showed a high consistency between SLN and pelvic lymph node metastasis status (Kappa value=0.901, P<0.001). In 30 patients with negative pathological results of SLN, pathological ultrastaging detection identified no micrometastases or isolated tumor cells. Conclusion Carbon nanoparticle tracing of the SLNs is safe and feasible in the diagnosis and treatment of cervical cancer, and SLN detection is safe in patients with primary lesion size below 2 cm or without cervical conization. SLN combined with pathological ultrastaging detection does not improve the detection rate of isolated tumor cells or micrometastases.

Key words: cervical cancer; sentinel lymph node; carbon nanoparticles; ultrastaging