Para-aortic Lymph Node Invasion in High-risk Endometrial Cancer: Performance of ¹⁸FDG PET-CT

Abstract

Aim: 18 F-Fluorodeoxyglucose positron-emission tomography integrated with computed tomography ( 18 FDG PET-CT) is a non-invasive examination that could be helpful for the management of endometrial cancer. This study investigated the performance of 18 FDG PET-CT in assessing para-aortic (PA) lymph-node involvement in high-risk endometrial cancer. Materials and Methods: This was a retrospective, single-center study carried out between 2009 and 2018. The inclusion criteria were high-risk and locally advanced type 1 or 2 endometrial cancer with 18 FDG PET-CT before PA lymphadenectomy. Results: During the study period, among 142 patients with high-risk endometrial cancer, 35 patients (24.6%) underwent 18 FDG PET-CT followed by PA lymphadenectomy. In 25% of cases, PA lymphadenectomy was not performed due to the discovery of metastasis. 18 FDG PET-CT had a sensitivity of 50%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 75%, accuracy of 80% and an area under the curve of 0.75 for the evaluation of PA involvement. Conclusion: According to its high specificity in PA lymph-node evaluation, a positive PET scan might allow PA lymphadenectomy to be avoided.Endometrial cancer is the fourth most frequent cancer in women, with more than 8,000 cases per year in France (1). A knowledge of lymph-node status and International Federation of Gynecology and Obstetrics (FIGO) stage is necessary to establish the most appropriate treatment strategy. The risk of lymph-node involvement is strongly correlated with the characteristics of the tumor, and depends on its histological type, grade, the degree of local extension (myometrium and cervical stroma), and the presence of lymphovascular space invasion (2). Since the European Society for Medical Oncology (ESMO) congress of 2009 (3) and the publication of the French National Institute of Cancer (INCA) recommendations in 2010 (4), para-aortic lymphadenectomy (PAL) has been recommended for stage I tumors of histological type 1 (endometrioid adenocarcinoma) with a high risk of recurrence (stage IB and grade 3, or with the presence of lymphovascular space invasion, regardless of grade), for tumors of stage II and above, and for histological type 2 tumors (clear-cell carcinoma, papillary serous carcinoma, and carcinosarcoma) of all stages.PAL is a surgical procedure associated with non-negligible morbidity, particularly in elderly patients with associated comorbid conditions (5). Its therapeutic impact on survival is a matter of debate (6). Knowledge of pelvic and paraaortic (PA) lymph-node status guides therapeutic decisions, determining whether there are indications for more or less extensive radiotherapy and systemic treatment (7). The PORTEC-3 study showed that adjuvant chemotherapy, in addition to radiotherapy, was beneficial in stage III high-risk endometrial cancer (8).18 F-Fluorodeoxyglucose positron-emission tomography integrated with computed tomography ( 18 FDG PET-CT) is a non-invasive examination that can modify the management of endometr...

ESGO/ESTRO/ESP guidelines for the management of patients with endometrial carcinoma

“…Its moderate sensitivity for detecting lymph node metastases during preo-perative staging probably reflects the need for a sufficient number of neoplastic cells to induce 18 F-fluoro-2-deoxy-D-glucose hypermetabolism. [89][90][91][92][93][94][95][96][97][98][99][100] The usefulness of maximal standardized uptake value in classifying patients into predefined risk groups is limited. 101 A pre-operative CT scan has a clinical utility in patients with endometrial carcinoma in detecting metastatic disease.…”

Assessment of Lymph Node Involvement with PET-CT in Advanced Epithelial Ovarian Cancer. A FRANCOGYN Group Study

“…This false negative rate, which is partly related to the spatial resolution of PET-CT, ranges from 10% to 23% in cervical cancer [32,33]. In a study conducted by our team, we found a 20% false negative rate when PET-CT was used for lymph node evaluation in endometrial cancers [22]. This is a PET-CT-specific and cancer-independent limit.…”

“…Positron emission tomography/computed tomography (PET-CT) after 18FDG injection has been shown to be appropriate for lymph node evaluation in early-stage ovarian cancer [20], locally advanced cervical cancer [21], and high-risk type 1 endometrial cancer [22]. Within our center, we have been using PET-CT for many years in the management of EOC for both the initial extension work-up and the evaluation of the response to chemotherapy instead of the thoraco-abdomino-pelvic CT scan (TAP CT).…”

FDG-PET/CT and Para-Aortic Staging in Endometrial Cancer. A French Multicentric Study

“…A previous single-center study found 100% specificity and a positive predictive value with a 92.9% accuracy rate for FDG-PET/CT for the evaluation of para-aortic involvement, particularly in high-risk histological type 1 endometrial cancers [9]. FDG-PET/CT performance was lower in type 2, with an increased risk of false negatives [9]. However, the results were not significant due to a low number of patients and a lack of power and need to be re-evaluated in a larger population.…”