Clinical value of FDG-PET for preoperative evaluation of endometrial cancer

Co-existent abdominoperitoneal tuberculosis with endometrial cancer: A diagnostic and surgical challenge

The presence of abdominoperitoneal tuberculosis (APTB) complicates the diagnosis, staging and management of endometrial cancer. Lymph node involvement in APTB may mimic metastatic lymphadenopathy in patients with endometrial cancer. To our knowledge, there have only been 2 previous case reports on this topic. We will describe 3 cases of endometrial cancer co-existing with APTB. The 1st case is a 57-year-old female who underwent elective total laparoscopic hysterectomy with bilateral salpingo-oophorectomy (TLHBSO) and bilateral pelvic lymph node dissection (PLND). The final diagnosis is Stage 3C1 endometrial endometroid carcinoma with mucinous differentiation. The 2nd case is a 70-year-old female with who underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAHBSO) and PLND. The final diagnosis is a Stage 1A endometrioid adenocarcinoma. The 3rd case is a 63-year-old female who underwent TAHBSO and PLND and the final diagnosis was a mixed high-grade serous (90%) and endometrioid (10%) carcinoma of the endometrium. In these cases, the importance of surgical staging is emphasised to accurately stage endometrial cancer. Moreover, thorough peri-operative optimisations by a multi-disciplinary team are essential to improve the outcomes of surgery.

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

Background: FDG-PET/CT is a noninvasive examination that could be helpful for the management of endometrial cancer. The aim of this study was to evaluate the performance of FDG-PET/CT in assessing para-aortic lymph-node involvement in high-risk endometrial cancer. Methods: We performed a retrospective multicenter study including all patients who had a high-risk endometrial cancer with a preoperative FDG-PET/CT and a para-aortic lymphadenectomy (PAL) between 2009 and 2019. The main objective was to evaluate the overall performance of FDG-PET/CT. The secondary objectives were to evaluate its performances according to the histological type and according to FDG-PET/CT date (before or after hysterectomy), and to compare its overall performance with that of the MRI scan. Results: We included 200 patients from six different centers. After the false positive FDG-PET/CT was reread by nuclear physicians, FDG-PET/CT had a sensitivity of 61.8%, a specificity of 89.7%, a positive predictive value of 69.4%, a negative predictive value of 86.1%, and an AUC of 0.76. There were no statistically significant differences in the performances according to either histological type and or FDG-PET/CT date. The sensitivity of FDG-PET/CT was better than that of MRI (p < 0.01), but the specificity was not (p = 0.82). Conclusion: Currently, FDG-PET/CT alone cannot replace PAL for the lymph node evaluation of high-risk endometrial cancers. It seems essential to reread it in multidisciplinary meetings before validating the therapeutic management of patients, particularly in the case of isolated para-aortic involvement.

Initial experience with positron emission tomography/computed tomography in addition to computed tomography and magnetic resonance imaging in preoperative risk assessment of endometrial cancer patients

OBJECTIVE

Improved preoperative evaluation of lymph node status could potentially replace lymphadenectomy in women with endometrial cancer. PET/CT was routinely implemented in the preoperative workup of endometrial cancer at St Olav's University Hospital in 2016. Experience with PET/CT is limited, and there is no consensus about the use of PET/CT in the diagnostic workup of endometrial cancer. The aim of the study was to evaluate the diagnostic accuracy of PET/CT compared to standard CT/MRI in identifying lymph node metastases in endometrial cancer with histologically confirmed lymph node metastases as the standard of reference. We especially wanted to look at PET/CT as a supplement to the sentinel lymph node algorithm in the detection of paraaortic lymph nodes.

STUDY DESIGN

A retrospective study included all women undergoing surgery for endometrial cancer from January 2016 through July 2019 at St Olav's University Hospital. Clinical data, results of CT, MRI, and PET/CT, and histopathological results were analyzed.

RESULTS

Among 185 patients included, 27 patients (15 %) had lymph node metastases. 17 (63 %) had pelvic lymph node metastases, one (4 %) had isolated paraaortic lymph node metastases, and 9 (33 %) had lymph node metastases in both the pelvis and the paraaortic region. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for the detection of lymph node metastases were 63 %, 98 %, 85 %, 94 %, and 93 %, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CT/MRI were 41 %, 98 %, 73 %, 91 %, and 90 %, respectively (p = 0.07). For the 26 pelvic lymph node metastases, PET/CT had a sensitivity of 58 %, compared to 42 % for CT/MRI (p = 0.22). PET/CT detected all 10 paraaortic lymph node metastases, for a sensitivity of 100 %, compared to 50 % for CT/MRI (p = 0.06).

CONCLUSIONS

PET is superior to CT/MRI for detection of lymph node metastases in endometrial cancer, particularly in detecting paraaortic lymph node metastases. The ability of preoperative PET to exclude paraaortic lymph node metastases may strengthen the credibility of the sentinel lymph node algorithm.

Diagnostic Accuracy of Clinical Biomarkers for Preoperative Prediction of Lymph Node Metastasis in Endometrial Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

In endometrial carcinoma (EC), preoperative classification is based on histopathological criteria, with only moderate diagnostic performance for the risk of lymph node metastasis (LNM). So far, existing molecular classification systems have not been evaluated for prediction of LNM. Optimized use of clinical biomarkers as recommended by international guidelines might be a first step to improve tailored treatment, awaiting future molecular biomarkers.

AIM

To determine the diagnostic accuracy of preoperative clinical biomarkers for the prediction of LNM in endometrial cancer.

METHODS

A systematic review was performed according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Studies identified in MEDLINE and EMBASE were selected by two independent reviewers. Included biomarkers were based on recommended guidelines (cancer antigen 125 [Ca-125], lymphadenopathy on magnetic resonance imaging, computed tomography, and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography [¹⁸FDG PET-CT]) or obtained by physical examination (body mass index, cervical cytology, blood cell counts). Pooled sensitivity, specificity, area under the curve (AUC), and likelihood ratios were calculated with bivariate random-effects meta-analysis. Likelihood ratios were classified into small (0.5-1.0 or 1-2.0), moderate (0.2-0.5 or 2.0-5.0) or large (0.1-0.2 or ≥ 5.0) impact.

RESULTS

Eighty-three studies, comprising 18,205 patients, were included. Elevated Ca-125 and thrombocytosis were associated with a moderate increase in risk of LNM; lymphadenopathy on imaging with a large increase. Normal Ca-125, cytology, and no lymphadenopathy on ¹⁸FDG PET-CT were associated with a moderate decrease. AUCs were above 0.75 for these biomarkers. Other biomarkers had an AUC <0.75 and incurred only small impact.

CONCLUSION

Ca-125, thrombocytosis, and imaging had a large and moderate impact on risk of LNM and could improve preoperative risk stratification.

IMPLICATIONS FOR PRACTICE

Routine lymphadenectomy in clinical early-stage endometrial carcinoma does not improve outcome and is associated with 15%-20% surgery-related morbidity, underlining the need for improved preoperative risk stratification. New molecular classification systems are emerging but have not yet been evaluated for the prediction of lymph node metastasis. This article provides a robust overview of diagnostic performance of all clinical biomarkers recommended by international guidelines. Based on these, at least measurement of cancer antigen 125 serum level, assessment of thrombocytosis, and imaging focused on lymphadenopathy should complement current preoperative risk stratification in order to better stratify these patients by risk.

Follicular Lymphoma mimicking Metastatic Nodes on the F-18 FDG PET/CT and MRI for Staging of Endometrial Cancer

A 53-year-old woman was diagnosed with endometrial carcinoma by vaginal bleeding. F-18 fluorodeoxy glucose positron emission tomography PET/CT (F-18 FDG PET/CT) scan for staging showed intense focal FDG uptake in the endometrium suggesting endometrial malignancy. PET/CT showed multiple node uptakes in the pericaval region, paraaortic region, common iliac, and both internal iliac and external iliac regions suggesting multiple pelvic and retroperitoneal node metastases. MRI showed multiple metastatic lymphadenopathy in the retroperitoneum and pelvic cavity. Pathologic diagnosis performed with dissected pelvic and paraaortic nodes was confirmed as a follicular malignant lymphoma positive for B-cell lymphoma-2(Bcl-2) stain, not the metastatic node of primary endometrioid carcinoma.

Different imaging techniques for the detection of pelvic lymph nodes metastasis from gynecological malignancies: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the diagnostic performance of different imaging techniques and the corresponding diagnostic criteria for preoperative detection of pelvic lymph node metastasis from gynecological carcinomas.

METHODS

Six databases were systematically searched for retrieving eligible studies. Study inclusion, data extraction and risk of bias assessment were performed by 2 reviewers independently. STATA 14.0 was used to perform the meta-analysis.

RESULTS

Eighty eligible studies were collected. The pooled sensitivity, specificity, and area under curve (AUC) of CT, MRI and DWI were 47%, 93%, 0.7424; 50%, 95%, 0.8039 and 84%, 95%, 0.9523 respectively. As regards PET, PET-CT and US, the pooled sensitivity, specificity and AUC were 56%, 97%, 0.9592; 68%, 97%, 0.9363 and 71%, 99%, 0.9008 respectively. The summary receiver operating characteristic (SROC) curve indicated that the systematic diagnostic performances of PET, PET-CT, DWI were superior to other imaging modalities.

CONCLUSIONS

The present work demonstrated that DWI, PET, PET-CT were the top-priority consideration of imaging modalities for detecting metastatic pelvic lymph node in gynecological carcinoma. DWI was recommended as the first choice for metastasis exclusion and all the other imaging techniques including CT and MRI were suitable for metastasis conformation. However, for the early stage lymph node malignancy, PET or PET-CT could represent a better choice. More studies exploring the diagnostic efficacy of detailed criteria are required in the future.

High Diagnostic Value of 18F-FDG PET/CT in Endometrial Cancer: Systematic Review and Meta-Analysis of the Literature

The aim of this study was to evaluate the diagnostic performance of (18)F-FDG PET/CT for the preoperative assessment of lymph node metastases (LNM) in endometrial cancer patients and for the assessment of endometrial cancer recurrence (ECR) after primary surgical treatment.

METHODS

A comprehensive search was performed on Pubmed/MEDLINE databases for studies reporting the diagnostic performance of (18)F-FDG PET/CT for assessment of LNM and ECR published up to August 15, 2015. Twenty-one studies (13 for LNM and 8 for ECR) were included in the systematic review and meta-analysis. Pooled estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of the (18)F-FDG PET/CT were calculated along with 95% confidence intervals (CIs). A summary receiver-operating-characteristics curve (SROC) was constructed, and the area under the SROC curve (AUC) was determined along with Q* index.

RESULTS

The overall pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and AUC (with 95% CI) of (18)F-FDG PET/CT for detection of LNM were 0.72 (95% CI, 0.63-0.80), 0.94 (95% CI, 0.93-0.96), 10.9 (95% CI, 7.9-15.1), 0.36 (95% CI, 0.27-0.48), 39.7 (95% CI, 21.4-73.6), and 0.94 (95% CI, 0.85-0.99), respectively, whereas the corresponding numbers for detection of ECR were 0.95 (95% CI, 0.91-0.98), 0.91 (95% CI, 0.86-0.94), 8.8 (95% CI, 6.0-12.7), 0.08 (95% CI, 0.05-0.15), 171.7 (95% CI, 67.9-434.3), and 0.97 (95% CI, 0.95-0.98), respectively. The overall diagnostic accuracy (Q* index) in LNM and ECR were 0.88 and 0.93, respectively.

CONCLUSION

(18)F-FDG PET/CT has an excellent diagnostic performance for detecting LNM preoperatively and disease recurrence postoperatively in endometrial cancer patients.

Diagnostic Performance of Fluorine 18 Fluorodeoxyglucose Positron Emission Tomography Imaging for Detection of Primary Lesion and Staging of Endometrial Cancer Patients: Systematic Review and Meta-Analysis of the Literature

Objectives

Fluorine 18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging has been used for staging of endometrial cancer. In the current study, we systematically searched the available literature on the accuracy of 18F-FDG PET imaging for staging of endometrial cancer.

Methods

PubMed, SCOPUS, ISI Web of Knowledge, Science Direct, and Springer were searched using “endometr* AND PET” as the search terms. All studies evaluating the accuracy of 18F-FDG PET in the staging of endometrial carcinoma were included. Statistical pooling of diagnostic accuracy indices was done using random-effects model. Cochrane Q test and I2 index were used for heterogeneity evaluation.

Results

Sixteen studies (807 patients in total) were included in the meta-analysis. Sensitivity and specificity for detection of the primary lesions were 81.8% (77.9%–85.3%) and 89.8% (79.2%–96.2%); for lymph node staging were 72.3% (63.8%–79.8%) and 92.9% (90.6%–94.8%); and for distant metastasis detection were 95.7% (85.5%–99.5%) and 95.4% (92.7%–97.3%).

Conclusions

Because of low sensitivity, diagnostic utility of 18F-FDG PET imaging is limited in primary tumor detection and lymph node staging of endometrial cancer patients. However, high specificities ensure high positive predictive values in these 2 indications. Diagnostic performance of 18F-FDG PET imaging is much better in detection of distant metastases. Larger studies with better design are needed to draw any more definite conclusion.

Tailoring systematic lymphadenectomy in high-risk clinical early stage endometrial cancer: the role of 18F-FDG PET/CT

OBJECTIVES

To evaluate the role of FDG PET/CT in the preoperative N-staging of high-risk clinical stage I endometrial cancer. The correlation between the metabolic characteristics of endometrial tumor uptake as predictors of a) lymph-node (LN) metastases and b) recurrence, was also evaluated.

METHODS

Seventy-six high-risk (G2 with deep myometrial invasion, G3, serous/clear-cell carcinoma) clinical stage I endometrial cancer patients underwent preoperative PET/CT scan followed by total hysterectomy, bilateral salpingo-oophorectomy and lymphadenectomy. PET/CT images were analyzed and correlated to histological findings. Maximal and mean standardized uptake value (SUVmax, SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG, defined as the product between SUVmean and MTV) of endometrial lesions were calculated and correlated to: a) presence of LN metastases, b) recurrences.

RESULTS

PET/CT resulted positive at LNs in 12/76 patients: 11/12 truly positive, 1/12 falsely positive. Conversely PET/CT was negative in 64/76 patients: 61/64 truly negative and 3/64 falsely negative. On pt-based analysis, sensitivity, specificity, accuracy, positive and negative predictive value of PET/CT in detecting LN metastases were 78.6%, 98.4%, 94.7%, 91.7%, 95.3%, respectively. A significant association was found between the presence of LN metastases and SUVmax (p=0.038), MTV (p=0.007), TLG (p=0.003) of the primary tumor. No correlations were found between the metabolic parameters and relapse (median follow-up 25.4months).

CONCLUSIONS

In high-risk clinical stage I endometrial cancer FDG PET/CT demonstrated moderate sensitivity, high specificity and accuracy for the nodal status assessment. SUVmax, MTV and TLG of the primary tumor are significantly correlated to LN metastases, while none of these parameters is predictor of recurrence.

[Sentinel node procedure and endometrial cancer: senti-endo results]

Based on two randomized trials and a meta-analysis, the recommendations of the National Cancer Institute (INCa) have validated the absence of systematic pelvic lymphadenectomy for patients with endometrial cancer at low risk (type 1 histology stage IA grade 1-2) and intermediate (type 1 histology stage IA grade 3 and IB grade 1-2) but without taking into account the contribution of the sentinel node (SN) procedure. The senti-endo trial assessing the role of the SN procedure in patients with early stages endometrial cancer showed that the detection rate by hemi-pelvis right and left were 77 and 76%, respectively. The detection rate per patient was 89%. Among patients with at least a SN detected, the detection was unilateral in 34 cases (31%) and bilateral in 77 cases (69%). Of the 111 patients with at least a SN detected, 19 had lymph node metastases (17%). Considering the hemi-pelvis right and left as a unit, no false negative case was observed, hence the sensitivity and NPV was 100%. Considering the NPV per patient, three false negative cases were observed. Among the 57 patients at low risk, six (11%) had lymph node metastases on SN with negative non sentinel nodes. Of the 33 patients at intermediate risk, five (15%) had lymph node metastases on SN with negative non sentinel nodes. Senti-endo results emphasize the contribution of the SN procedure to assess the nodal status in patients with low or intermediate risk group raising the issue on new definition of the recommendations of INCa.