Background: Lymph node status has a prognostic role in endometrial cancer patients and
it determines the adjuvant therapy to be administered postoperatively. Complete lymphadenectomy
carries the risk of serious complications. Sentinel Lymph Node mapping (SLN) may be a good option
to reduce these complications. Cervical injection of methylene blue may be a suitable technique
for SLN mapping, which can be applied in low-resource institutes.
Objective: Assessment of the detection rate, sensitivity and false negative rate of SLN mapping
using cervical injection of methylene blue
Methods: A total of 76 patients with early stage endometrial cancer were included. Methylene blue
was injected into the cervix prior to surgery and open surgical approach was used. SLNs were detected
by direct visualization of stained lymph nodes after opening of pelvic spaces. SLNs were
excised and pelvic lymphadenectomy was performed. Para-aortic lymphadenectomy was performed
when indicated and surgically feasible. Specimens were examined by H&E staining.
Results: The SLN detection rate was 47.4% and all detected SLNs were pelvic nodes. All patients
with lymph node metastasis had metastatic disease in their SLNs. The technique had 100% sensitivity,
100% negative predictive value and a 0% false-negative rate. An inverse relationship between
SLN detection and BMI was detected.
Conclusion: Cervical injection of methylene blue dye with an open approach to detect SLNs in
patients with early stage endometrial cancer has a low detection rate. The most important factor
associated with failed mapping is increased BMI. Further trials are needed to investigate the usefulness
of this technique.