Introduction/Background Sentinel lymph node (SLN) detection in early-stage epithelial ovarian cancer (EOC) has been investigated in various trials, showing disparities in detection outcomes. Evidence suggests that using a combination of two tracers (radiotracer and indocyanine green (ICG)) yields enhanced results compared to using a single tracer. The objective of this study is to evaluate and compare the performance of these tracers in the context of the MELISA trial.

Methodology Patients with suspected malignancy in ovarian masses or undergoing restaging surgery were enrolled. Prior to adnexal tumor removal, a radiotracer was injected into the infundibulo-pelvic and utero-ovarian ligament. Following a 15-minute interval, the adnexal tumor was removed and sent for frozen section. Upon confirmation of malignancy, ICG was injected into the ligament stumps. SLN detection was guided using a gamma-detector probe, gamma-camera, and near-infrared camera, followed by ultrastaging.

Results Between September 2021 and March 2023, 63 patients were included. The SLN was detected in 56/63 (89%) patients, with exclusive para-aortic drainage in 54/56(96%), pelvic in 3/56 (5%), and both territories in 28/56 (50%). Thirty(47.6%) patients had EOC; 27 patients had at least one SLN detected using 99mTc and/or ICG tracer. The tracer performance showed a SLN detection with the radiotracer in 24/30(80%) patients and with ICG in 17/29(59%). In 12 patients, only one of the two tracers detected the SLN, whereas in 15 patients, both tracers identified the SLN. Among these, 5 patients had both tracers detecting at least 1 SLN on the pelvic side with concomitant detection. However, among the 15 patients where both tracers detected at least 1 SLN, in 4/11(36%) patients, the detection occurred in different SLNs. SLN metastases were identified in 5/27(19%) patients.

Conclusion The radiotracer appears to perform more effectively than ICG in SLN detection for early-stage EOC. Nevertheless, the combined use of both tracers shows potential for improved outcomes.

Disclosures No disclosures.