RESUMO
Objective The aim of this study was to investigate the feasibility and clinical value of detecting sentinel lymph node (SLN) with combined radioisotope and blue dye method in early stage cervical cancer. Methods Between March 2005 and April 2006, 50 patients with cervical cancer, who were staged Ⅰ b and Ⅱ a by International Federation of Gynecology and Obstetrics (FIGO), underwent SLN detection with preoperative lymphoscintigraphy. A dose of 148 MBq (4×10-4L) 99Tcm-sulfur colloid (SC) was injected into the uterine cervix at 3 and 9 o'clock position with lymphoscintigraphy taken at 15-60 min after injection. Intraoperative detection of "hot spot" lymph nodes was performed with a handheld gamma probe (γ-detection). During operation, 2-4 ml metend blue dye (BD-detection) was injected into the uterine cervix at the same positions. All patients underwent hysterectomy and pelvic lymphadenectomy. The spatial and pathological relationships of the SLN samples were compared between the two methods. SPSS 13.0 was used for statistical analysis. Results The detection rate of SLN with combined radioisotope and blue dye was 96.0% (48/50). γ-detection alone was 92.0% (46/50) and BD-detection alone was 70.0% (35/50, x2=4.92, P<0.05). In 37 patients lymphoseintigraphy showed the same SLN as γ-detection did, with a coincidence rate of 74.0% (37/50). The SLN with metastases were confirmed by histopathology in 11/48 (22.9%) patients. In the remaining 37 patients with SLN negative for metastasis, there was 1 case with non-SLN showing metastasis. In the 2 patients negative for SLN, 1 was positive for non-SLN metastasis. The SLN accuracy rate was therefore 97.9% (47/48), and the negative predictive value was 97.3% (36/37) with one patient false negative. About 72.3 % (115/159) of SLN were found in obturator region, 5.0% (8/ 159) in iuteriliac region, 12.0% (19/159) in external iliac chain, 6.9% (11/159) in common iliac region and 3.8% (6/159) in parametrium. The number of left-sided SLN detected was more than that of the right (x2=5.06, P=0.021 ). Conclusion Combined radioisotope and blue dye technique is a feasible and valuable tool to detect pelvic SLN in patients with early uterine cervical malignancy.
