The clinical impact of [18F]FDG PET/CT for the management of recurrent endometrial cancer: correlation with clinical and histological findings

Atypical Foot Swelling in Metastatic Endometrial Carcinoma: Role of FDG PET/CT

ABSTRACT

An 83-year-old woman with a history of endometrial carcinoma (EMC), treated with surgery and chemotherapy in August 2020, presented with a 1-year history of left foot swelling, tenderness, and heat. Despite multiple consultations, no diagnosis was made, and she developed painful swelling with a limping gait. A biopsy was done on July 14, 2023, confirmed metastatic EMC. FDG PET/CT revealed widespread metastases, including in the lungs, pleura, mediastinal, hilar, inguinal, right external iliac nodes, left labia majora, left iliac bone, left tibia, and left foot. Excision of left inguinal and vulvar tumors also confirmed metastatic EMC.

18F-FDG PET/MRI and 18F-FDG PET/CT for the Management of Gynecological Malignancies: A Comprehensive Review of the Literature

OBJECTIVE

Positron emission tomography with 2-deoxy-2-[fluorine-18] fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) or magnetic resonance imaging (18F-FDG PET/MRI) has emerged as a promising tool for managing various types of cancer. This review study was conducted to investigate the role of 18F- FDG PET/CT and FDG PET/MRI in the management of gynecological malignancies.

SEARCH STRATEGY

We searched for relevant articles in the three databases PubMed/MEDLINE, Scopus, and Web of Science.

SELECTION CRITERIA

All studies reporting data on the FDG PET/CT and FDG PET MRI in the management of gynecological cancer, performed anywhere in the world and published exclusively in the English language, were included in the present study.

DATA COLLECTION AND ANALYSIS

We used the EndNote software (EndNote X8.1, Thomson Reuters) to list the studies and screen them on the basis of the inclusion criteria. Data, including first author, publication year, sample size, clinical application, imaging type, and main result, were extracted and tabulated in Excel. The sensitivity, specificity, and diagnostic accuracy of the modalities were extracted and summarized.

MAIN RESULTS

After screening 988 records, 166 studies published between 2004 and 2022 were included, covering various methodologies. Studies were divided into the following five categories: the role of FDG PET/CT and FDG-PET/MRI in the management of: (a) endometrial cancer (n = 30); (b) ovarian cancer (n = 60); (c) cervical cancer (n = 50); (d) vulvar and vagina cancers (n = 12); and (e) gynecological cancers (n = 14).

CONCLUSIONS

FDG PET/CT and FDG PET/MRI have demonstrated potential as non-invasive imaging tools for enhancing the management of gynecological malignancies. Nevertheless, certain associated challenges warrant attention.

Role of Imaging in the Management of High-Risk Endometrial Cancer

Endometrial cancer (EC) is the second most frequent gynecological malignancy worldwide with an overall favorable prognosis. However, there is a subgroup of patients with a higher rate of recurrence and worse prognosis who benefit from a specific pre- and post-treatment radiological evaluation that allows the adjustment of the therapeutic attitude towards the biology of the tumor.

The main factors that determine high-risk disease are non-endometrioid tumor histology, histopathological grade 3, lymphovascular space invasion (LVSI), myometrial invasion ≥50%, and cervical stroma involvement. Radiological evaluation helps identify high-risk cases prior to surgical staging and is an important tool both in pre-treatment and in case of clinical recurrence suspicion.

As for imaging techniques, both transvaginal ultrasound and MRI can assess local tumor extent while CT and positron emission tomography/CT (PET/CT) help assess lymph nodes and distant metastases.

The central purpose of this article is to review the specific factors that determine high-risk endometrial cancer, and the main specificities in the pre-treatment and follow-up evaluation according to the most recent international guidelines.

FDG-PET for Assessment of Endometrial and Vulvar Cancer

Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) provides a comprehensive whole body evaluation in patients with endometrial and vulvar cancer. Here, we discuss the role of FDG-PET/CT in defining the disease extent in patients presenting with these cancers. Detection of lymph node and distant metastases has implications for staging, treatment planning, and patient prognosis. Procedures for image acquisition and interpretation for optimum accuracy and essential elements that should be included in the PET-CT report are described. Common imaging pitfalls are presented and illustrated with examples.

Clinical and prognostic value of 18F-FDG PET/CT in recurrent endometrial carcinoma

PURPOSE

Endometrial carcinoma (EC) is a cancer with a good overall prognosis, except in cases of recurrent or advanced EC. The aim of this study was to assess the diagnostic performance, the prognostic value and the impact on therapeutic management of ¹⁸F-FDG PET/CT in suspected recurrent EC.

MATERIALS AND METHODS

We retrospectively evaluated 157 patients with histologically proven EC and restaging ¹⁸F-FDG PET/CT for suspected recurrence. The PET images were analyzed visually and semi-quantitatively by measuring SUVmax, MTV and TLG. A combination of clinical/imaging follow-up and/or histopathology was taken as reference standard. Progression-free survival (PFS) and overall survival (OS) were computed using Kaplan-Meier curves.

RESULTS

Seventy-nine patients had positive ¹⁸F-FDG PET/CT showing the presence of at least one hypermetabolic lesion consistent with recurrence, while the remaining 78 were negative. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ¹⁸F-FDG PET/CT were 96%, 99%, 99%, 96%, 97%, respectively, and were higher compared to conventional imaging: 97%, 62%, 72%, 96%, 80%. After a mean follow-up of 39months, relapse/progression occurred in 58 patients and death in 37 with an average time of 22.1 and 27.6months, respectively. A positive ¹⁸F-FDG PET/CT and advanced FIGO stage were significantly associated with shorter PFS and OS. PET/CT results had a significant impact on therapeutic approach in 33 patients: avoiding unnecessary therapies in 28 and modifying therapy in 5.

CONCLUSIONS

¹⁸F-FDG PET/CT has a very good diagnostic performance in patients with suspected recurrent EC and has an important prognostic value in assessing PFS and OS. Moreover, PET/CT allowed for a change in treatment decision in about 20% of cases.

FDG-PET Assessment of Other Gynecologic Cancers

PET and PET/computed tomography play a role in the staging, monitoring of response to therapy, and surveillance for cervical and ovarian cancers. Currently, it is also an integral part of the assessment of patients with endometrial cancer and other gynecologic malignancies, such as vaginal and vulvar cancers and uterine sarcomas. In this article, we discuss in detail and highlight the potential role of PET and PET/computed tomography in evaluating these gynecologic malignancies using illustrative cases with relevant imaging findings.

Preoperative risk stratification using 18F-FDG PET/CT in women with endometrial cancer

The aim of this study is to evaluate the usefulness of 18F-FDG PET/CT for preoperative stratification of high-risk and low-risk carcinomas in patients with endometrial cancer. Patients, methods: 60 women (mean age 53.8 ± 9.9 years) with endometrial cancer, who underwent 18F-FDG PET/CT for preoperative staging work-up, followed by primary cytoreductive surgery, were enrolled in this study. Maximum and mean standardized uptake values (SUVmax, SUVmean) of endometrial tumors were measured, and compared with the various clinicopathologic findings obtained after surgery. Tumour aggressiveness was classified as high-risk and low-risk carcinomas. Patients with stage I or II, endometrioid adenocarcinoma, histologic grade 1 or 2, invasion of less than half of the myometrium, maximum tumor size less than 2.0 cm, and absence of cervical invasion and lymphovascular space involvement (LVSI) were classified as the lowrisk carcinoma group. The remaining patients were classified as the high-risk carcinoma group. Results: In univariate analysis, SUVmax of the primary endometrial tumor was significantly higher in patients who were in a postmenopausal state (p = 0.047), large (> 2 cm) primary tumor (p <0.001), nonendometrioid subtype (p = 0.024), invasion of more than half of the myometrium (p = 0.020), or LVSI (p = 0.004). SUVmax differed significantly according to FIGO stage (p = 0.013) and histologic grade (p <0.001). In multivariate analysis, FIGO stage, histologic grade, LVSI, and maximum tumor size demonstrated a significant association with SUVmax (p <0.001; r = 0.843, r2 = 0.711). SUVmean showed similar results. Forty-one (68.3%) patients were diagnosed postoperatively as high-risk and 19 patients (31.7%) as low-risk carcinoma. Patients with high-risk carcinoma (12.1 ± 6.1) showed significantly higher SUVmax than patients with low-risk carcinoma (5.8 ± 2.8, p <0.001). The optimal SUVmax cut-off value of 8.7, determined by ROC analysis, revealed 75.6% sensitivity, 89.5% specificity, and 81.7% accuracy for risk stratification. Conclusion: High-risk endometrial cancer might be differentiated by means of higher SUVmax from low-risk endometrial cancer. 18F-FDG FDG PET/CT can be applied preoperatively for stratification of risk in patients with endometrial cancer.

FDG-PET/CT in the Postoperative Period: Utility, Expected Findings, Complications, and Pitfalls

FDG-PET/CT as a modality is increasingly used for detection of recurrence and for restaging in patients with clinical suspicion of malignancy, as well as in patients with elevated tumor markers. However, there are many pitfalls in the interpretation of these scans when the studies are performed after some treatment. Some of these are attributed to normal physiological distribution and are compounded when there are inflammatory changes occurring after surgery. The body's inherent response to the surgical insult results in this inflammation. In addition, there are also complications that can happen following surgery, causing increased FDG uptake. Despite various fallacies, FDG-PET/CT provides valuable information in evaluation of residual and recurrent malignant disease. In this article, we aim to describe some of these postsurgical changes secondary to inflammation, common surgical complications, and finally, the utility of FDG-PET/CT in these patients to detect recurrent disease, even in the background of postsurgical changes.

BGCS uterine cancer guidelines: Recommendations for practice

The British Gynaecological Cancer Society has issued the first Endometrial (Uterine) Cancer guidelines as recommendation for practice for the UK.

Role of PET-CT Scan in Gynaeconcology

THE PURPOSE OF THIS STUDY

This study was undertaken to evaluate the role of positron emission tomography-CT (PET-CT) in diagnosis and management of gynecological malignancies in primary and recurrent settings and also to investigate its role in inappropriately treated patients, for pretreatment evaluation (staging) to help in proper therapeutic management.

METHOD

This is a retrospective study of 56 patients of gynecological malignancy registered in Gujarat Cancer Research Institute from June 2011 to December 2013.

RESULTS

Out of 56 cases where PET was done, the results were as follows: carcinoma cervix-23, carcinoma ovary-20, carcinoma endometrium-9, carcinoma vulva-1, carcinoma vagina-2, and GTN-1. PET scan was negative in 37 % of patients where CT scan was suspicious, which changed the therapeutic modality and prevented further unnecessary interventions. In cases where clinical suspicion of recurrence was high based on rising tumor marker and CT scan was negative, subsequent PET-CT was able to pick up malignancy in 75 % cases. Eleven patients (25 %) with suspected recurrence with inconclusive CT scan and negative PET-CT scan were kept on follow-up, thus reducing further morbidity and cost.

CONCLUSION

Addition of PET-CT, a noninvasive method to the oncologist's imaging armamentarium may ultimately improve both outcomes and costs by altering management strategies in primary and recurrent settings. The potential use of PET-CT appears promising in several decision-making steps in the management of patients with gynecological malignancy. It defines the extent of metastatic disease which enables the clinician to decide regarding salvageable surgical intervention or palliative measures.

Trends in Periodic Surveillance Testing for Early-Stage Uterine Cancer Survivors

OBJECTIVE

To examine the use of periodic surveillance testing for early-stage endometrial cancer survivors.

METHODS

We performed a population-based analysis using the Surveillance, Epidemiology, and End Results-Medicare database, which was used to identify patients with stage I-II endometrioid endometrial cancer treated from 1992 to 2011. Three surveillance periods (7-18, 19-30, 31-42 months) after hysterectomy were examined. Use of vaginal cytology and imaging were quantified.

RESULTS

We identified 17,638 patients. From 1992 to 2011, the use of chest radiography decreased (46.3-34.2%) during the first surveillance period, whereas imaging with chest computed tomography (CT) (0.9-12.6%), abdominopelvic CT (11.7-24.8%), and positron emission tomography (0-2.9%) increased (P<.001 for all). The use of cytology increased from 68.5% in 1992 to 72.3% in 2007 and then decreased to 66.9% in 2011 (P=.02). The mean number of cytologic samples obtained per patient increased from 1.3 in 1992 to 1.6 in 2008 and then declined to 1.3 in 2011, whereas the mean per patient number of chest CTs (0.02-0.2), abdominopelvic CTs (0.2-0.4), and positron emission tomographies (0-0.03) rose from 1992 to 2011. In 2011, 49.3% underwent radiologic surveillance 7-18 months after diagnosis, whereas 11.9% underwent two or more radiologic assessments in combination with cytology. These findings were similar for surveillance periods 2 and 3.

CONCLUSION

The use of chest radiography has decreased and use of cytology has started to decline. However, the use of more costly imaging modalities is increasing despite a lack of evidence for the efficacy of these tests for early-stage endometrial cancer survivors.

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.

Role of 18F-FDG PET/CT in the carcinoma of the uterus: a review of literature

In the present review we reported the value of 18F-fluorodeoxyglucose (FDG) PET/CT in face of uterine cancer, in terms of sensitivity, specificity and accuracy. Moreover, we made a comparison with the other imaging techniques currently used to evacuate these tumors including contrast-enhanced CT, contrast enhanced-MRI and transvaginal ultrasonography. FDG PET/CT has been reported to be of particular value in detecting occult metastatic lesions, in prediction of response to treatment and as a prognostic factor.

[Follow-up of endometrial cancer]

Available data on appropriate follow-up in endometrial cancer highlight the need of well-conducted studies. Most recurrences tend to occur within three years and involve symptoms. Routine tests are not advocated without symptoms. In case of suspicious recurrence, TEP/CT seems to be the most sensitive and specific method. There is limited evidence to decide whether follow-up schedules with multiple visits result in survival benefits. An appropriate follow-up should be discussed based upon the risk of recurrence. Counselling on the potential symptoms of recurrence should be a major aim.

Correlation between expression of biological markers and [F]fluorodeoxyglucose uptake in endometrial cancer

PURPOSE

Positron emission tomography/computer tomography (PET/CT) utilizing [(18)F]fluorodeoxyglucose ((18)F-FDG) has been recommended for the diagnosis, staging, therapy monitoring, prediction of prognosis, and detection of recurrence in endometrial cancer. We aimed to define the correlations of biological markers with (18)F-FDG uptake in endometrial cancer.

METHODS

29 patients (55 ± 8.93 years) with endometrial cancer were included in this study. All patients underwent hysterectomy and bilateral salpingo-oophorectomy with or without para-aortic lymphadenectomy at the department of Obstetrics and Gynecology of Pusan National University Hospital. Immunohistochemical studies were performed for glucose transporter 1 (GLUT-1), hexokinase II (HK-II), hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF) and carbonic anhydrase IX (CA-IX).

RESULTS

There were positive correlations between FDG uptake and GLUT-1 (r = 0.375, p = 0.0452), and HK-II (r = 0.537, p = 0.0027). However, HIF-1α (r = 0.153, p = 0.4283), VEGF (r = -0,101, p = 0.6032) and CA-IX (r = 0.240, p = 0.2105) were not significantly associated with FDG uptake. No significant correlations were found among the expression levels of biological markers.

CONCLUSION

FDG uptake in endometrial cancer was significantly associated with GLUT-1 and HK-II, while HIF-1α, VEGF and CA-IX were not associated with FDG uptake. No significant correlations were found among the expression levels of biological markers.

Typical and atypical metastatic sites of recurrent endometrial carcinoma

The purpose of this article is to illustrate the imaging findings of typical and atypical metastatic sites of recurrent endometrial carcinoma. Typical sites include local pelvic recurrence, pelvic and para-aortic nodes, peritoneum, and lungs. Atypical sites include extra-abdominal lymph nodes, liver, adrenals, brain, bones and soft tissue. It is important for radiologists to recognize the typical and atypical sites of metastases in patients with recurrent endometrial carcinoma to facilitate earlier diagnosis and treatment.

Impact of 18F-FDG PET/CT on target volume delineation in recurrent or residual gynaecologic carcinoma

Background

To evaluate the impact of ¹⁸F-FDG PET/CT on target volume delineation in gynaecological cancer.

Methods

F-FDG PET/CT based RT treatment planning was performed in 10 patients with locally recurrent (n = 5) or post-surgical residual gynaecological cancer (n = 5). The gross tumor volume (GTV) was defined by 4 experienced radiation oncologists first using contrast enhanced CT (GTV_CT) and secondly using the fused ¹⁸F-FDG PET/CT datasets (GTV_PET/CT). In addition, the GTV was delineated using the signal-to-background (SBR) ratio-based adaptive thresholding technique (GTV_SBR). Overlap analysis were conducted to assess geographic mismatches between the GTVs delineated using the different techniques. Inter- and intra-observer variability were also assessed.

Results

The mean GTV_CT (43.65 cm³) was larger than the mean GTV_PET/CT (33.06 cm³), p = 0.02. In 6 patients, GTV_PET/CT added substantial tumor extension outside the GTV_CT even though 90.4% of the GTV_PET/CT was included in the GTV_CT and 30.2% of the GTV_CT was found outside the GTV_PET/CT. The inter- and intra-observer variability was not significantly reduced with the inclusion of ¹⁸F-FDG PET imaging (p = 0.23 and p = 0.18, respectively). The GTV_SBR was smaller than GTV_CT p ≤ 0.005 and GTV_PET/CT p ≤ 0.005.

Conclusions

The use of ¹⁸F-FDG PET/CT images for target volume delineation of recurrent or post-surgical residual gynaecological cancer alters the GTV in the majority of patients compared to standard CT-definition. The use of SBR-based auto-delineation showed significantly smaller GTVs. The use of PET/CT based target volume delineation may improve the accuracy of RT treatment planning in gynaecologic cancer.

Carcinoma endometrium: role of 18-FDG PET/CT for detection of suspected recurrence

OBJECTIVE

Recurrent carcinoma endometrium has a poor prognosis. However, successful salvage with long-term survival has been achieved after hormone therapy, radical surgery, and radiotherapy/chemotherapy in patients with recurrent disease. Conventional imaging (CI) and tumor marker have limited accuracy for detecting recurrence in these patients. The aim of the present study was to evaluate the role of 18-flurodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) in patients suspected to have recurrence of carcinoma endometrium.

METHODS

In this retrospective study, total 101 patients were evaluated. All patients had undergone surgery with/without adjuvant therapy (chemotherapy/radiotherapy/both) for histologically proven carcinoma endometrium. They underwent 18-FDG PET/CT studies for suspected recurrence. Comparable CI (contrast-enhanced CT and/or magnetic resonance imaging) was available for 76 patients. Results of FDG PET/CT were confirmed with clinical/imaging follow-up and/or histopathology.

RESULTS

The mean age was 56.9±8.6 years. 18-FDG PET/CT was positive for recurrence in 51 (50.5%) patients and negative in 50 (49.5%). Locoregional disease was observed in 24 patients, metastatic disease was observed in 10, and 17 showed both locoregional and metastatic disease. The sensitivity, specificity, positive and negative predictive values, and accuracy of 18-FDG PET/CT were 88.9%, 93.6%, 94.1%, 88%, and 91%, respectively. 18-FDG PET/CT showed strong positive correlation with final diagnosis based on reference standard (κ 0.823; P=0.0001). Compared to CI, 18-FDG PET/CT has much higher specificity (62% vs. 96.4%), and accuracy (76.3% vs. 92.1%), with comparable sensitivity (85.1% vs. 89.5%).

CONCLUSION

18-FDG PET/CT is a highly sensitive and specific modality for detecting recurrence in post-therapy patients of carcinoma endometrium with suspected recurrence. It performs better than CI.

The role of FDG-PET/CT in gynaecological cancers

There is now a growing body of evidence supporting the use of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in gynaecological malignancies. Although this molecular imaging technique is becoming increasingly available, PET/CT remains an expensive imaging tool. It is essential to be familiar with the circumstances in which FDG-PET/CT can add value and contribute to patient management and indeed to know when it is unlikely to be of benefit. It is also important to understand and recognize the potential pitfalls. FDG-PET/CT has been most widely adopted for staging patients with suspected advanced disease or in suspected recurrence, offering a whole-body imaging approach. However, there is great potential for this technique to act as a predictive biomarker of response to treatment, as well as a prognostic biomarker. In addition, FDG-PET images may now be incorporated into radiotherapy planning in order to refine the delineation of dose according to metabolically active sites of disease. This article reviews the literature that provides the evidence for the use of FDG-PET in gynaecological malignancies, identifies areas of real benefit and future potential, and highlights circumstances where there is limited value.

Controversies in the management of endometrial carcinoma: an update

Endometrial carcinoma is the commonest type of female genital tract malignancy in the developed countries. Endometrial carcinoma is usually confined to the uterus at the time of diagnosis and as such usually carries an excellent prognosis with high curability. Our understanding and management of endometrial cancer have continuously developed. Current controversies focus on screening and early detection, the extent of nodal surgery, and the changing roles of radiation therapy and chemotherapy and will be discussed in this paper.

PET/CT imaging in gynecologic malignancies: a critical overview of its clinical impact and our retrospective single center analysis

Gynecologic cancers represent a major global healthcare problem since they are associated with a significant mortality and morbidity. Over the last decade, considerable efforts have been spent in the development and optimization of novel diagnostic modalities to achieve an early diagnosis, aid in choosing appropriate treatment, improving long term surveillance, with the ultimate goal of increasing survival of gynecologic cancer patients. A growing body of evidence defines PET/CT as one of the most powerful tools for tumor, nodal and metastasis (TNM) cancer staging both in pre-treatment and in post treatment follow-up settings. At any phase of cancer evaluation, detection of metastasis represents one of the most critical impediments to the cure of tumor; traditional diagnostic imaging modalities, such as computed tomography (CT), are frequently found to inadequately stage the tumor, based on subsequent outcomes. As a consequence, patients may undergo pointless surgery for disease that could be treated with local medical therapies. In the setting of restaging, the ability to describe primary lesion, lymph nodes, possible metastases to peritoneum, bone, liver, lungs and brain renders PET/CT a potential alternative for a series of tests, including bone scanning, MRI or ultrasound, diagnostic CT, lymph node surgical sampling, that need to be used in combination in order to obtain a level of clinical confidence. In this review, we describe, the theoretical advantage and prognostic implications of PET/CT in the management of gynecologic cancer patients.

Preoperative [F]FDG PET/CT predicts recurrence in patients with epithelial ovarian cancer

OBJECTIVE

To determine whether [(18)F]FDG uptake on PET/CT imaging before surgical staging has prognostic significance in patients with epithelial ovarian cancer (EOC).

METHODS

Patients with EOC were imaged with integrated PET/CT before surgical staging. Hypermetabolic lesions were measured as the standardized uptake value (SUV) in primary and metastatic tumors. SUV distribution was divided into two regions at the level of umbilicus, and the impact of the ratio between above and below umbilicus (SUV(location) ratio) on progression-free survival (PFS) was examined using Cox proportional hazards regression.

RESULTS

Between January 2004 and December 2009, 55 patients with EOC underwent preoperative PET/CT. The median duration of PFS was 11 months (range, 3 to 43 months), and twenty (36.4%) patients experienced recurrence. In univariate analysis, high SUV(location) ratio (p=0.002; hazard ratio [HR], 1.974; 95% confidence interval [CI], 1.286 to 3.031) was significantly associated with recurrence. Malignant mixed mullerian tumor compared with endometrioid histology was also shown to have significance. In multivariate analysis, high SUV(location) ratio (p=0.005; HR, 2.418; 95% CI, 1.1315 to 4.447) and histology (serous, mucinous, and malignant mixed mullerian tumor compared with endometrioid type) were significantly associated with recurrence. Patients were categorized into two groups according to SUV(location) ratio (<0.3934 vs. ≥0.3934), and the Kaplan-Meier survival graph showed a significant difference in PFS between the groups (p=0.0021; HR, 9.47, log-rank test).

CONCLUSION

SUV distribution showed a significant association with recurrence in patients with EOC, and may be a useful predictor of recurrence.

[FDG-PET and endometrial cancer]

FDG-PET is widely used for the diagnosis, the staging and the search for recurrence of many tumors. However, there are currently no recommendations for its use in endometrial cancer. This article is an update of the literature data to enable everyone to form an opinion on the subject. Future prospects are considered.

ACR appropriateness Criteria® pretreatment evaluation and follow-up of endometrial cancer of the uterus

Endometrial cancer is one of the common malignancies in the female genital tract. Imaging in pretreatment evaluation may play an important role in an assessment of morphological prognostic factors including tumor size, depth of myometrial invasion, endocervical extent, and lymph node status. Imaging is also useful in posttreatment evaluation of patients with clinically suspected recurrence. Various modalities including MRI, CT ultrasound and FDG PET-CT-CT have been used for evaluation of the endometrial cancer in both before and after treatment settings. Literature on the indications and usefulness of these imaging studies for endometrial cancer is reviewed.

The value of FDG-PET/CT in the post-treatment evaluation of endometrial carcinoma: a comparison of PET/CT findings with conventional imaging and CA 125 as a tumour marker

OBJECTIVES

This retrospective study was designed to assess the value of positron emission tomography/computed tomography imaging (PET/CT) in the post-treatment evaluation of the patients with endometrial carcinoma and to compare PET/CT scan with conventional imaging (CI) including computed tomography (CT), ultrasonography (US) and magnetic resonance imaging (MRI) and CA 125 with both 20U/ml and 35U/ml cut-off values.

MATERIALS AND METHODS

A total of 31 patients who were treated for histopathologically proven endometrial adenocarcinoma, underwent PET/CT examination for restaging and suspected recurrence. Thirty five PET/CT studies were performed in 31 patients. Lesion status was determined on the basis of clinical follow-up including radiological imaging (follow-up CT scan) at least 6 months and response to therapy.

RESULTS

Of the 35 PET/CT studies, 13 (37%) studies were positive, whereas 22 (63%) of them were negative. On study-based analysis the overall sensitivity, specificity, accuracy for PET/CT imaging were 100%, 96% and 97%, respectively. The corresponding information for CI were 46%, 87% and 74%, for CA 125 (cut off=20U/ml) measurement were 45%, 88% and 74%, and for CA 125 (cut off=35U/ml) measurement were 27%, 100% and 78%, respectively. On lesion-based analysis, PET/CT revealed only one false positive case. In none of 21 patients with negative 22 PET/CT studies, no subsequent clinical or radiological recurrences were observed with a follow-up of at least 6 months.

CONCLUSION

FDG-PET/CT is found more useful modality than CI and CA 125 in the evaluation of post-treatment endometrial carcinoma patients, for suspected recurrence.

Posttreatment surveillance and diagnosis of recurrence in women with gynecologic malignancies: Society of Gynecologic Oncologists recommendations

Although gynecologic cancers account for only 10% of all new cancer cases in women, these cancers account for 20% of all female cancer survivors. Improvements in cancer care have resulted in almost 10 million cancer survivors, and this number is expected to grow. Therefore, determining the most cost-effective clinical surveillance for detection of recurrence is critical. Unfortunately, there has been a paucity of research in what are the most cost-effective strategies for surveillance once patients have achieved a complete response. Currently, most recommendations are based on retrospective studies and expert opinion. Taking a thorough history, performing a thorough examination, and educating cancer survivors about concerning symptoms is the most effective method for the detection of most gynecologic cancer recurrences. There is very little evidence that routine cytologic procedures or imaging improves the ability to detect gynecologic cancer recurrence at a stage that will impact cure or response rates to salvage therapy. This article will review the most recent data on surveillance for gynecologic cancer recurrence in women who have had a complete response to primary cancer therapy.

Established, emerging and future applications of FDG-PET/CT in the uterine cancer

Integrated positron emission tomography/computed tomography (PET/CT) with 2-[¹⁸F]fluoro-2-deoxy-D-glucose (FDG) is a useful technique to acquire both glucose metabolic and anatomic imaging data using a single device in a single diagnostic session and has opened a new field in clinical oncologic imaging. FDG-PET/CT has been used successfully for the staging, optimization of treatment, re-staging, therapy monitoring, and prognostic prediction of uterine cervical cancer and endometrial cancer as well as various malignant tumours. The present review discusses the current role of FDG-PET/CT in the management of uterine cancer, discussing its usefulness and limitations in the imaging of these patients.

Gynecological cancers

The clinical problems raised in patients presenting with all forms of gynecological malignancy are currently addressed using conventional cross-sectional imaging, usually MRI. In general, F-18 FDG PET-CT has not been shown to have a clinical role in any of these cancers at presentation, although studies are under way to use this form of metabolic imaging to predict prognosis and the response to treatment. Although F-18 FDG PET-CT is superior to conventional imaging techniques, it is only moderately sensitive in demonstrating lymph node metastasis preoperatively, and is inadequate for local staging of patients with endometrial cancer. In ovarian cancer, F-18 FDG PET-CT provides an accurate assessment of the extent of disease, particularly in areas difficult to assess for metastases by CT and MRI such as the abdomen and pelvis, mediastinum, and supraclavicular region. F-18 FDG PET-CT is a sensitive method of detecting pelvic and para-aortic lymph nodal disease in cervical cancer, and appears to be superior to MRI and CT despite the limitations in identifying small foci of disease. In the main, as elsewhere in patients with cancer, the value of PET-CT is in identifying and defining the extent of recurrent disease, in distinguishing between posttreatment fibrosis and recurrence, and possibly in monitoring response to therapy.

PET/CT Imaging in Gynecologic Malignancies Other than Ovarian and Cervical Cancer

Fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is an imaging modality used for staging, assessing response to therapy, and diagnosis of recurrent cervical and ovarian cancer. The potential role of FDG-PET/CT in other gynecologic malignancies such as endometrial cancer, uterine sarcomas, vaginal, and vulvar cancer has not been fully explored.

Current status in the management of uterine corpus cancer in Korea

Uterine corpus cancer has increased in prevalence in Korean women over the last decade. Recently, elegant studies have been reported from many institutes. To improve treatment strategies, a review of our own data is warranted. This work will discuss the risks and prognostic factors for uterine corpus cancer, and the radiologic evaluation, prediction of lymph node metastasis, systematic lymphadenectomy, minimally invasive surgery, ovarian-saving surgery, fertility-sparing treatment, and adjuvant treatment in women with uterine cancer.

Clinical evidence on PET-CT for radiation therapy planning in cervix and endometrial cancers

PET-CT plays an increasing role in the diagnosis and treatment of gynaecological cancers. In cervix cancer, whilst MRI remains the best imaging technique for initial primary tumor staging, PET-CT has been showed to be a highly sensitive method to determine lymph node status, except in patients with early-stage cervical cancer where PET-CT cannot replace surgical exploration of pelvic lymph nodes. In patients with advanced cervical cancer, PET-CT has the potential of showing lymph node metastasis not only within the pelvis, but also outside the pelvis, more particularly in the para-aortic area. PET-CT has also been described as a useful tool in 3-D-based adaptative brachytherapy. In endometrial cancer, the issues are different, as the recent decade has seen a therapeutic decrease in early-stage disease, especially in postoperative radiation therapy, whilst more advanced disease have been approached with more aggressive treatments, integrating chemotherapy and external beam radiotherapy. Lymph node status is also an important issue and PET-Scan may replace lymph node surgical procedure particularly in obese patients.

Controversies in the management of endometrial carcinoma

Endometrial carcinoma is the most common type of female genital tract malignancy. Although endometrial carcinoma is a low grade curable malignancy, the condition of the disease can range from excellent prognosis with high curability to aggressive disease with poor outcome. During the last 10 years many researches have provided some new valuable data of optimal treatments for endometrial carcinoma. Progression in diagnostic imaging, radiation delivery systems, and systemic therapies potentially can improve outcomes while minimizing morbidity. Firstly, total hysterectomy and bilateral salphingo-oophorectomy is the primary operative procedure. Pelvic lymhadenectomy is performed in most centers on therapeutic and prognostic grounds and to individualize adjuvant treatment. Women with endometrial carcinoma can be readily segregated intraoperatively into “low-risk” and “high-risk” groups to better identify those women who will most likely benefit from thorough lymphadenectomy. Secondly, adjuvant therapies have been proposed for women with endometrial carcinoma postoperatively. Postoperative irradiation is used to reduce pelvic and vaginal recurrences in high risk cases. Chemotherapy is emerging as an important treatment modality in advanced endometrial carcinoma. Meanwhile the availability of new hormonal and biological agents presents new opportunities for therapy.

Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

PURPOSE

To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated (18)F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer.

METHODS

A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months.

RESULTS

Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT.

CONCLUSION

PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations.

Present and future of PET and PET/CT in gynaecologic malignancies

OBJECTIVES

To review the published data in literature on patients affected by gynaecological malignancies to establish the role of (18)F-FDG positron emission tomography (PET) and PET/CT in comparison to conventional imaging (CI).

MATERIALS AND METHODS

All papers specifically addressed to the role of (18)F-FDG PET and PET/CT in gynaecological malignancies published on PubMed/Medline, in abstracts from the principal international congresses, in the guidelines from national Societies that had appeared in literature until November 2009 were considered for the purpose of the present study.

RESULTS AND CONCLUSIONS

The use of (18)F-FDG PET, and even more of (18)F-FDG PET/CT, is increasing in the follow up of patients with gynaecologic malignancies and suspected recurrent disease: there is evidence in the literature that (18)F-FDG PET/CT has a higher sensitivity than CI in depicting occult metastatic spread. An interesting issue is represented by patients with ovarian cancer with an increase of the specific biomarker, CA-125, and negative/inconclusive findings at CI. The use of (18)F-FDG PET in differential diagnosis and staging is more controversial, but there is some evidence that a baseline PET examination performed before commencing therapy, for staging purpose, is also useful to evaluate the response to chemoradiation treatment. In several papers it has been suggested a relevant role of (18)F-FDG PET/CT in evaluating the entity of response to treatment and therefore to plan the subsequent therapeutic strategy.