Sentinel lymph node detection in early cervical cancer with combination 99mTc phytate and patent blue

Abstract

Objective: The purpose of this study was to examine sentinel lymph node (SLN) detection in patients with early stage cervical cancer using (99m)Tc phytate and patent blue dye and to compare our method with published findings utilizing other radioisotopic tracers.

Patients and methods: A total of 20 consecutive patients with cervical cancer scheduled for radical hysterectomy and total pelvic lymphadenectomy at our hospital underwent SLN detection study. The day before surgery, lymphoscintigraphy was performed with injection of 99m-technetium ((99m)Tc)-labeled phytate into the uterine cervix. At surgery, patients underwent lymphatic mapping with a gamma-detecting probe and patent blue injected into the same points as the phytate solution.

Results: At least one positive node was detected in 18 patients (90%). A total of 46 sentinel nodes were detected (mean, 2.3; range, 1-5). Most sentinel nodes were in one of the following sites: external iliac (21 nodes), obturator (15 nodes), and parametrial (7 nodes). Eleven (24%) sentinel nodes were detected only through radioactivity and two (4%) were detected only with blue dye. The sensitivity, specificity, and negative predictive value for SLN detection were all 100%. Nine published studies involving 295 patients had a summarized detection rate of 85%. Summarized sensitivity, specificity, and negative predictive value were 93%, 100%, and 99%, respectively.

Conclusion: Combination of (99m)Tc phytate and patent blue is effective in SLN detection in early stage cervical cancer.