Sentinel lymph node biopsy in early stage ovarian cancer: A prospective observational study

Abstract

Objective: Sentinel lymph node (SLN) biopsy is a technique to assess lymph node status in various cancers to avoid systematic lymphadenectomy and limit morbidity. This study aimed to evaluate the role of SLNB in epithelial ovarian cancer using a combination of radioactive tracer and blue dye.

Methodology: This prospective observational study included 29 patients with suspected stage I and II epithelial ovarian cancer. The tracer was injected subperitoneally at the utero-ovarian and infundibulopelvic ligaments. SLNs were identified followed by systematic lymphadenectomy. SLNs were subjected to ultrastaging. Detection rate, sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of SLNB was calculated.

Results: SLN detection was performed using combination of tracers for 10 cases while SLN detection was performed using methylene blue alone for 19 cases. The SLN detection rate was 100 % using both tracers while it was 89.5 % using methylene blue alone. Detection rate was 37.9 % (n = 11/29) in the para-aortic region alone, 20.7 % (n = 6/29) in the pelvic region alone and 34.5 % (n = 10/29) in both. There were 21 cases with malignant histology while there were 4 cases each of benign and borderline histology. The overall sensitivity, specificity, positive predictive value, and negative predictive value of SLNB were 100 % when sentinel node was detected in a patient. Ultrastaging detected isolated tumor cells (ITC) in five cases. No complications related to SLNB were observed.

Conclusion: SLNB is a feasible and accurate technique to assess lymph node status in epithelial ovarian cancer using a combination of radioactive tracer and blue dye. Ultrastaging detected ITCs, however their clinical implication is not yet known.

Keywords: 99mTc-sulphur colloid; Lymphadenectomy; Methylene blue; Ovarian neoplasm; Sentinel lymph node.