Preoperative Detection of Sentinel Lymph Node in Patients with Endometrial Cancer - Comparison of Planar Lymphoscintigraphy, Spect and SPECT/CT.

Background: Sentinel lymph node (SLN) mapping allows minimal invasive assessment of lymph node status in patients with early-stage endometrial cancer (EC). Intraoperative detection of SLNs is based on the results obtained from preoperative nuclear medical images. The purpose of this study was to compare the data obtained from planar lymphoscintigraphy (PL), single-photon emission computed tomography (SPECT), and SPECT with computed tomography (SPECT/CT) for preoperative SLN detection in patients with EC. Material and methods: A total of 44 images in 22 patients with early-stage EC (22 PL, 9 SPECT and 13 SPECT/CT) were analyzed. The scans were performed in the period 2018-2020 at the Institute of Pathophysiology and Nuclear Medicine in Skopje. Thirteen patients underwent PL and SPECT/CT and nine patients underwent PL and SPECT after cervical injection of 4 mCi 99mTc-SENTI-SCINT on the day of surgery. Descriptive statistics, Wilcoxon Matched Pairs Test, and Spearman rank R coefficient were used for data analyses. Results: Twenty-two patients with mean age of 61.1 +/- 7.5 and body mass index (BMI) 34.62 +/- 6.4 kg/m(2) were included in the study. In four patients (18.2%) SLN was not detected on PL. Detection rate on SPECT and SPECT/CT was 100%. The average number of detected SLN was 1.4 +/- 1.05, 2.2 +/- 1.1 i 2.15 +/- 1.1 on PL, SPECT and SPECT/CT respectively. We found a statistically significant difference in the number of detected SLNs on PL vs. SPECT/CT (p = 0.0077). The most common SLN location on SPECT/CT was the right internal iliac followed by the left common iliac region. Conclusions: The results of the presented study indicate a higher diagnostic value of SPECT/CT in terms of SLN detection and exact anatomic localization as compared to planar lymphoscintigraphy (PL).