Sentinel Lymph Node Detection in Early-stage Ovarian Cancer Using Radionuclide Technetium-99m Sulfur Colloid - A Feasibility Study.

Purpose of the study: This study evaluates the feasibility and diagnostic accuracy of Tc-99 m sulfur colloid as a tracer for sentinel lymph node (SLN) mapping in early-stage epithelial ovarian cancer (EOC) with the aim to explore SLN mapping as a less invasive alternative to traditional lymphadenectomy.

Materials and methods: This prospective observational study involved 10 patients with early-stage EOC or suspicious ovarian masses. Tc-99 m S colloid (37 mBq) was injected subperitoneally at infundibulopelvic and ovarian ligaments near the ovary, followed by SLN detection with a gamma probe. SLNs were analyzed using ultrastaging. Diagnostic accuracy metrics, including sensitivity, specificity, positive predictive value, and negative predictive value, were calculated.

Results: SLN detection was achieved in 100% of cases, with detection rates of 10% in the pelvic region and 30% in the para-aortic region alone and in both in 60%. The time for SLN detection was 14.2 ± 4.89 min. Histopathology revealed isolated tumor cells in two cases, with no false negatives observed. Postoperative complications included surgical site infections, transfusions, and paralytic ileus, but no SLN-specific complications were reported.

Conclusions: This study demonstrates the feasibility and diagnostic accuracy of SLN detection using technetium-99m sulfur colloid in early-stage ovarian cancer. The findings indicate a high detection rate, no false negatives, and the potential to reduce the need for systematic lymphadenectomy. Further research is required to validate these findings and evaluate their impact on long-term clinical outcomes.