Combining positron emission tomography/computed tomography, radiomics, and sentinel lymph node mapping for nodal staging of endometrial cancer patients

Abstract

ObjectiveTo evaluate the combination of positron emission tomography/computed tomography (PET/CT) and sentinel lymph node (SLN) biopsy in women with apparent early-stage endometrial carcinoma. The correlation between radiomics features extracted from PET images of the primary tumor and the presence of nodal metastases was also analyzed.MethodsFrom November 2006 to March 2019, 167 patients with endometrial cancer were included. All women underwent PET/CT and surgical staging: 60/167 underwent systematic lymphadenectomy (Group 1) while, more recently, 107/167 underwent SLN biopsy (Group 2) with technetium-99m +blue dye or indocyanine green. Histology was used as standard reference. PET endometrial lesions were segmented (n=98); 167 radiomics features were computed inside tumor contours using standard Image Biomarker Standardization Initiative (IBSI) methods. Radiomics features associated with lymph node metastases were identified (Mann-Whitney test) in the training group (A); receiver operating characteristic (ROC) curves, area under the curve (AUC) values were computed and optimal cut-off (Youden index) were assessed in the test group (B).ResultsIn Group 1, eight patients had nodal metastases (13%): seven correctly ridentified by PET/CT true-positive with one false-negative case. In Group 2, 27 patients (25%) had nodal metastases: 13 true-positive and 14 false-negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT for pelvic nodal metastases were 87%, 94%, 93%, 70%, and 98% in Group 1 and 48%, 97%, 85%, 87%, and 85% in Group 2, respectively. On radiomics analysis a significant association was found between the presence of lymph node metastases and 64 features. Volume-density, a measurement of shape irregularity, was the most predictive feature (p=0001, AUC=0,77, cut-off 0.35). When testing cut-off in Group B to discriminate metastatic tumors, PET false-negative findings were reduced from 14 to 8 (-43%).ConclusionsPET/CT demonstrated high specificity in detecting nodal metastases. SLN and histologic ultrastaging increased false-negative PET/CT findings, reducing the sensitivity of the technique. PET radiomics features of the primary tumor seem promising for predicting the presence of nodal metastases not detected by visual analysis.

Additional Value of PET/CT-Based Radiomics to Metabolic Parameters in Diagnosing Lynch Syndrome and Predicting PD1 Expression in Endometrial Carcinoma

“…Compared with CT and magnetic resonance imaging, PET is more sensitive for detecting metastases of endometrial cancer ( 19 ) and is often used preoperatively for this purpose. For patients with endometrial cancer, the analysis of PET parameters or radiomic features is focused on detecting lymph node metastasis ( 20 ), prognostic value ( 21 ) and tissue indentification ( 18 ). To our knowledge, this is the first study to evaluate whether FDG PET/CT can be used to identify Lynch syndrome in patients with endometrial cancer.…”

A Systematic Review of PET Textural Analysis and Radiomics in Cancer

“…We collected 19 publications focusing on gynecological cancers [82,104,[207][208][209][210][211][212][213][214][215][216][217][218][219][220][221][222][223], particularly on cervical (74%), endometrial (16%), epithelial (5%) and vulvar cancer (5%). The average number of patients was 93 (median = 84, range, .…”

Sentinel lymph node mapping in endometrial cancer after 2020 ESGO-ESTRO-ESP consensus update: what will happen in the next few years?

“…Most research was performed on breast cancer patients and preoperative prediction of SLN metastasis [29,30]. So far, there is only one report published on gynaecological cancer patients and it includes EC subjects [31]. One of the aims of the study of Crivellaro et al [31] was to correlate radiomic characteristics extracted from primary tumor PET images and SLN status in women with apparent earlystage endometrial carcinoma.…”

“…So far, there is only one report published on gynaecological cancer patients and it includes EC subjects [31]. One of the aims of the study of Crivellaro et al [31] was to correlate radiomic characteristics extracted from primary tumor PET images and SLN status in women with apparent earlystage endometrial carcinoma. The authors concluded that PET radiomics features of the primary tumor seem promising for predicting the presence of nodal metastases not detected by visual radiologic analysis.…”