The Detection of Sentinel Nodes in Ovarian Cancer: A Feasibility Study

Abstract

Few sentinel node (SN) studies in ovarian cancer have been reported, mainly because of the risk of tumor dissemination associated with the injection of tracers into the ovarian cortex. To our knowledge, the injection of tracers into the ovarian ligaments has not been explored. The aim of this study was to determine the feasibility of the SN procedure in ovarian cancer with tracer injection into the ovarian ligaments and to establish whether the procedure is safe for the healthcare workers. Methods: The study included patients who were at high risk of ovarian malignancy. Blue dye and radioactive colloid were injected into the proper ovarian ligament and suspensory ligament of the ovary. To measure professional radiation exposure, ring dose meters were worn by the surgeon, theater nurse, and pathologist during 3 procedures. Results: An SN procedure was performed in 21 patients, and at least 1 SN location was identified in all patients using the γ probe before retroperitoneal exploration. SNs were located in the paraaortic and paracaval regions only in 67% of the patients, in the pelvic region only in 9%, and in both the paraaortic/paracaval and the pelvic regions in 24%. All but 2 SNs were found on the ipsilateral side. In 6 patients who underwent retroperitoneal exploration, 1-4 SNs were identified using the γ probe and resected. Blue-stained SNs were detected in 2 patients. Positive SNs were detected in 1 patient with lymph node metastases. The amount of radiation exposure to the surgeon, theater nurse, and pathologist did not exceed the safe limit. Conclusion: The identification of SNs in all cases suggests that the SN procedure performed by injection of tracers in the ovarian ligaments is feasible and promising. The procedure is safe for the involved personnel. Further investigation is necessary to determine the clinical application of this new technique.

Comparison of Intraoperative γ-Probe Imaging and Postoperative SPECT/CT in Detection of Sentinel Nodes Related to the Ovary

“…As previously reported, retroperitoneal exploration was more successful than transperitoneal examination in detecting SNs (11). This finding could be explained by better, more precise accessibility of the lymph node locations but possibly also by a longer interval after injection of the tracer.…”

“…The 5 patients with ovarian cancer were incorporated in a previous report describing the feasibility of the intraoperative SN detection (11). In none of the patients did a preoperative CT scan, acquired as part of the diagnostic work-up, show signs of tumor spread (either intraabdominal or pathologic lymph nodes).…”

“…As described previously, patients diagnosed with a pelvic mass suggestive of a malignant ovarian tumor, and patients with high-grade endometrial cancer planned for staging laparotomy, were eligible to participate in the study (10,11). We included both patients with suspected ovarian malignancy and patients with a high-grade uterine carcinoma.…”

“…The surgical procedure has been described in detail in previous reports (10,11). Briefly, in patients with an adnexal tumor, tracer was injected on the dorsal and ventral sides of both the proper ovarian ligament and the suspensory ligament.…”

“…In a previous pilot study, we avoided possible tumor cell spillage by injection of tracers into the ovarian ligaments rather than into the ovarian cortex (10). We identified at least one SN in all patients with suspected ovarian cancer (n 5 21) (11). However, by the nature of this approach without preoperative imaging of the SN locations, we were conscious that the single use of a g-probe or blue color to detect hotspots during surgery could lead to missed SNs.…”