PET/CT in the staging of patients with a pelvic mass suspicious for ovarian cancer

ACR Appropriateness Criteria® Clinically Suspected Adnexal Mass, No Acute Symptoms: 2023 Update

Asymptomatic adnexal masses are commonly encountered in daily radiology practice. Although the vast majority of these masses are benign, a small subset have a risk of malignancy, which require gynecologic oncology referral for best treatment outcomes. Ultrasound, using a combination of both transabdominal, transvaginal, and duplex Doppler technique can accurately characterize the majority of these lesions. MRI with and without contrast is a useful complementary modality that can help characterize indeterminate lesions and assess the risk of malignancy is those that are suspicious. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Diagnostic accuracy of contrast-enhanced CT versus PET/CT for advanced ovarian cancer staging: a comparative systematic review and meta-analysis

PURPOSE

Accurate staging of ovarian cancer is critical to guide optimal management pathways. North American guidelines recommend contrast-enhanced CT as the primary work-up for staging ovarian cancer. This meta-analysis aims to compare the diagnostic accuracy of contrast-enhanced CT alone to PET/CT for detecting abdominal metastases in patients with a new or suspected diagnosis of ovarian cancer.

MATERIALS AND METHODS

A systematic review of MEDLINE, EMBASE, Scopus, the Cochrane Library, and the gray literature from inception to October 2022 was performed. Studies with a minimum of 5 patients evaluating the diagnostic accuracy of contrast-enhanced CT and/or PET/CT for detecting stage 3 ovarian cancer as defined by a surgical/histopathological reference standard ± clinical follow-up were included. Study, clinical, imaging, and accuracy data for eligible studies were independently acquired by two reviewers. Primary meta-analysis was performed in studies reporting accuracy on a per-patient basis using a bivariate mixed-effects regression model. Risk of bias was evaluated using QUADAS-2.

RESULTS

From 3701 citations, 15 studies (918 patients with mean age ranging from 51 to 65 years) were included in the systematic review. Twelve studies evaluated contrast-enhanced CT (6 using a per-patient assessment and 6 using a per-region assessment) and 11 studies evaluated PET/CT (7 using a per-patient assessment and 4 using a per-region assessment). All but one reporting study used consensus reading. Respective sensitivity and specificity values on a per-patient basis were 82% (67-91%, 95% CI) and 72% (59-82%) for contrast-enhanced CT and 87% (75-94%) and 90% (82-95%) for PET/CT. There was no significant difference in sensitivities between modalities (p = 0.29), but PET/CT was significantly more specific than CT (p < 0.01). Presumed variability could not be assessed in any single category due to limited studies using per-patient assessment. Studies were almost entirely low risk for bias and applicability concerns using QUADAS-2.

CONCLUSION

Contrast-enhanced CT demonstrates non-inferior sensitivity compared to PET/CT, although PET/CT may still serve as an alternative and/or supplement to CT alone prior to and/or in lieu of diagnostic laparoscopy in patients with ovarian cancer. Future revisions to existing guidelines should consider these results to further refine the individualized pretherapeutic diagnostic pathway.

Do PET-positive supradiaphragmatic lymph nodes predict overall survival or the success of primary surgery in patients with advanced ovarian cancer?

OBJECTIVES

Compared to conventional computed tomography (CT), fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) detects higher rates of lymph node and distant metastases in patients with ovarian cancer. However, FDG-PET/CT is not routinely performed during preoperative work-up. Therefore, we investigated the prognostic value of preoperative FDG-PET/CT in advanced epithelial ovarian cancer (EOC) and its predictive value for surgical resection in patients with no residual disease. The potential significance of PET-positive supradiaphragmatic lymph nodes (SDLNs) for these parameters was evaluated.

METHODS

All patients with FIGO IIA-IVB EOC diagnosed between March 2014 and January 2021 at our certified gynaecological cancer centre, who underwent FDG PET/CT before primary surgery were retrospectively included.

RESULTS

Fifty-three consecutive patients were included in the study. Eighteen (34 %) patients had PET-positive SDLNs. We could not demonstrate a significant correlation between PET-positive SDLNs and median overall survival (OS; SDLN-positive: 58.76 months, SDLN-negative: 60.76 months; p = 0.137) or intra- or perioperative outcomes.

CONCLUSIONS

FDG PET/CT has a higher detection rate for SDLNs in patients with ovarian cancer than CT has, as described in the literature. Moreover, PET-positive SDLNs failed to predict intraoperative outcomes or overall survival.

Current and Emerging Strategies for Tubo-Ovarian Cancer Diagnostics

Tubo-ovarian cancer is the most lethal gynaecological cancer. More than 75% of patients are diagnosed at an advanced stage, which is associated with poorer overall survival. Symptoms at presentation are vague and non-specific, contributing to late diagnosis. Multimodal risk models have improved the diagnostic accuracy of adnexal mass assessment based on patient risk factors, coupled with findings on imaging and serum-based biomarker tests. Newly developed ultrasonographic assessment algorithms have standardised documentation and enable stratification of care between local hospitals and cancer centres. So far, no screening test has proven to reduce ovarian cancer mortality in the general population. This review is an update on the evidence behind ovarian cancer diagnostic strategies.

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 Positron Emission Tomography/Computed Tomography in Epithelial Ovarian Cancer

Ovarian cancer (OC) is the most lethal gynecological malignancy with majority of cases diagnosed in advanced stages and associated with high morbidity and mortality. Positron emission tomography/computed tomography (PET/CT) has emerged as an integral part of the management of several nongynecological cancers. We used PubMed search engine using MeSH words "ovarian cancer" and "PET/CT" and reviewed the current status of PET/CT in epithelial OC. Its application related to ovarian tumor including adnexal mass evaluation, baseline staging, as a triaging tool for upfront surgery or neoadjuvant chemotherapy, for response assessment and prognostication, and for relapse detection and treatment planning has been highlighted. we highlight the current guidelines and newer upcoming PET modalities and radiotracers.

Prediction of Surgical Outcome in Advanced Ovarian Cancer by Imaging and Laparoscopy: A Narrative Review

Maximal-effort upfront or interval debulking surgery is the recommended approach for advanced-stage ovarian cancer. The role of diagnostic imaging is to provide a systematic and structured report on tumour dissemination with emphasis on key sites for resectability. Imaging methods, such as pelvic and abdominal ultrasound, contrast-enhanced computed tomography, whole-body diffusion-weighted magnetic resonance imaging and positron emission tomography, yield high diagnostic performance for diagnosing bulky disease, but they are less accurate for depicting small-volume carcinomatosis, which may lead to unnecessary explorative laparotomies. Diagnostic laparoscopy, on the other hand, may directly visualize intraperitoneal involvement but has limitations in detecting tumours beyond the gastrosplenic ligament, in the lesser sac, mesenteric root or in the retroperitoneum. Laparoscopy has its place in combination with imaging in cases where ima-ging results regarding resectability are unclear. Different imaging models predicting tumour resectability have been developed as an adjunctional objective tool. Incorporating results from tumour quantitative analyses (e.g., radiomics), preoperative biopsies and biomarkers into predictive models may allow for more precise selection of patients eligible for extensive surgery. This review will discuss the ability of imaging and laparoscopy to predict non-resectable disease in patients with advanced ovarian cancer.

A Nomogram for Preoperative Prediction of the Risk of Lymph Node Metastasis in Patients with Epithelial Ovarian Cancer

Objective: To develop a nomogram for predicting lymph node metastasis (LNM) in patients with epithelial ovarian cancer (EOC). Methods: Between December 2012 and August 2022, patients with EOC who received computed tomography (CT) and serological examinations and were treated with upfront staging or debulking surgery were included. Systematic pelvic and para-aortic lymphadenectomy was performed in all patients. Univariate and multivariate analysis was used to identify significant risk factors associated with LNM. A nomogram was then constructed to assess the risk of LNM, which was evaluated with respect to its area under the receiver operating characteristic curve (AUC), calibration, and clinical usefulness. Results: Of 212 patients enrolled in this study, 78 (36.8%) had positive LNs. The nomogram integrating CT-reported LN status, child-bearing status, tumour laterality, and stage showed good calibration and discrimination with an AUC of 0.775, significantly improving performance over the CT results (0.699, p = 0.0002) with a net reclassification improvement of 0.593 (p < 0.001) and integrated discrimination improvement of 0.054 (p < 0.001). The decision curve analysis showed the nomogram was of clinical use. Conclusions: A nomogram was constructed and internally validated, which may act as a decision aid in patients with EOC being considered for systemic lymphadenectomy.

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) predictive score for complete resection in primary cytoreductive surgery

OBJECTIVE

To assess the value of preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan, combined with clinical variables, in predicting complete cytoreduction in selected patients with advanced ovarian cancer.

METHODS

We carried out a multicenter, observational, retrospective study evaluating patients who underwent primary cytoreductive surgery for advanced ovarian cancer in two Spanish centers between January 2017 and January 2022. Inclusion criteria were histological confirmation of invasive epithelial ovarian carcinoma; preoperative International Federation of Gynecology and Obstetrics (FIGO) stage III or IV; upfront cytoreductive surgery; and 18F-FDG PET/CT performed 1 month prior to surgery. A modified 18F-FDG PET/CT peritoneal cancer index score was calculated for all patients. Clinical variables and preoperative 18F-FDG PET/CT findings were analyzed and a multivariate model was constructed. A predictive score based on the odds ratio of the variables was calculated to determine patient selection.

RESULTS

A total of 45 patients underwent primary cytoreductive surgery. Complete resection was achieved in 36 (80%) patients. On multivariate analysis, two clinical variables (age ≥58 years and American Society of Anesthesiology score ≥3) and two preoperative 18F-FDG PET/CT scan findings (presence of extra-abdominal lymph node involvement and modified peritoneal cancer index value of 6 or more) were associated with gross residual disease. For this multivariate model predictive of non-complete cytoreduction, the area under the curve was 0.881. A predictive value of ≥5 was the most predictive cut-off for gross residual disease. Complete resection rate was 91.7% in patients with a score of ≤4 and 33.3% in patients with a score of ≥5 points on the predictive score.

CONCLUSIONS

In selected patients, a predictive score value ≥5 may be consider as a cut-off point for triaging patients to diagnostic laparoscopy before the primary surgery or neoadjuvant chemotherapy.

The BUMPy road of peritoneal metastases in ovarian cancer

Ovarian cancer is the most common cause of death due to gynecologic malignancies, with more than 70% of patients presenting with advanced stage disease at the time of diagnosis. The extent and distribution of tumor guide primary treatment selection and clinical management. While primary cytoreductive surgery with complete tumor resection improves survival, patients with extensive peritoneal disease may benefit from neoadjuvant chemotherapy first to reduce tumor burden followed by interval cytoreductive surgery. Imaging plays an essential role in triaging patients including selecting patients who may benefit from neoadjuvant chemotherapy before cytoreductive surgery. Interestingly, there are no universally established criteria to predict resectability and local practices depend on local guidelines and surgeon preferences. Nevertheless, certain anatomical tumor locations are known to be difficult to resect and are associated with suboptimal cytoreduction or require special surgical considerations. This review discusses the recent advances in the initial management of patients with ovarian cancer, a practical approach to the assessment and communication of peritoneal metastases locations on CT and MRI. It also explores recent advances in genomics profiling and radiomics that may influence the initial management of these patients.

Multidetector computed tomography in diagnosing peritoneal metastases in ovarian carcinoma

Multidetector computed tomography (MDCT) of the abdomen is currently the imaging examination of choice for the staging and follow-up of ovarian carcinoma (OC). Peritoneal metastases (PMs) represent the most common pathway for the metastatic spread of OC. MDCT scanners, due to several advantages-including increased volume coverage, reduced scanning time, acquisition of thin slices and creation of multiplanar reformations, and three-dimensional reconstructions-provide useful information regarding the early and accurate detection of PMs. Detailed mapping of peritoneal carcinomatosis is feasible, with improved detection of sub-centimeter peritoneal implants and thorough evaluation of curved peritoneal surfaces.

Indirect comparison of the diagnostic performance of 18F-FDG PET/CT and MRI in differentiating benign and malignant ovarian or adnexal tumors: a systematic review and meta-analysis

Objective

To compare the value of fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) and magnetic resonance imaging (MRI) in differentiating benign and malignant ovarian or adnexal tumors.

Materials and methods

English articles reporting on the diagnostic performance of MRI or ¹⁸F-FDG PET/CT in identifying benign and malignant ovarian or adnexal tumors published in PubMed and Embase between January 2000 and January 2021 were included in the meta-analysis. Two authors independently extracted the data. If the data presented in the study report could be used to construct a 2 × 2 contingency table comparing ¹⁸F-FDG PET/CT and MRI, the studies were selected for the analysis. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate the quality of the included studies. Forest plots were generated according to the sensitivity and specificity of ¹⁸F-FDG PET/CT and MRI.

Results

A total of 27 articles, including 11¹⁸F-FDG PET/CT studies and 17 MRI studies on the differentiation of benign and malignant ovarian or adnexal tumors, were included in this meta-analysis. The pooled sensitivity and specificity for ¹⁸F-FDG PET/CT in differentiating benign and malignant ovarian or adnexal tumors were 0.94 (95% CI, 0.87–0.97) and 0.86 (95% CI, 0.79–0.91), respectively, and the pooled sensitivity and specificity for MRI were 0.92 (95% CI: 0.89–0.95) and 0.85 (95% CI: 0.79–0.89), respectively.

Conclusion

While MRI and ¹⁸F-FDG PET/CT both showed to have high and similar diagnostic performance in the differential diagnosis of benign and malignant ovarian or adnexal tumors, MRI, a promising non-radiation imaging technology, may be a more suitable choice for patients with ovarian or accessory tumors. Nonetheless, prospective studies directly comparing MRI and 18F-FDG PET/CT diagnostic performance in the differentiation of benign and malignant ovarian or adnexal tumors are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08815-3.

Performance of Multiparametric Functional Imaging to Assess Peritoneal Tumor Burden in Ovarian Cancer

PURPOSE

The aim of the study was to evaluate the clinical utility of pretreatment 18F-FDG PET/CT with quantitative evaluation of peritoneal metabolic cartography in relation to staging laparoscopy for ovarian carcinomatosis.

PATIENTS AND METHODS

A retrospective review of prospectively collected data from 84 patients with FIGO (International Federation of Gynecology and Obstetrics) stage IIIC to IV ovarian cancer was carried out. All patients had a double-blinded 18F-FDG PET/CT review. Discriminant capacity of metabolic parameters to identify peritoneal carcinomatosis in the 13 abdominal regions according to the peritoneal cancer index was estimated with area under the receiver operating characteristic curve (AUC).

RESULTS

The metabolic parameter showing the best trade-off between sensitivity and specificity to predict peritoneal extension compared with peritoneal cancer index score was the metabolic tumor volume (MTV), with a Spearman ρ equal to 0.380 (P < 0.001). The AUC of MTV to diagnose peritoneal involvement in the upper abdomen (regions 1, 2, and 3) ranged from 0.740 to 0.765. MTV AUC values were lower in the small bowel regions (9-12), ranging from 0.591 to 0.681, and decreased to 0.487 in the pelvic region 6. 18F-FDG PET/CT also improved the detection of extra-abdominal disease, upstaging 35 patients (41.6%) from stage IIIC to IV compared with CT alone and leading to treatment modification in more than one third of patients.

CONCLUSIONS

18F-FDG PET/CT metrics are highly accurate to reflect peritoneal tumor burden, with variable diagnostic value depending on the anatomic region. MTV is the most representative metabolic parameter to assess peritoneal tumor extension.

Preoperative CT or PET/CT to Assess Pelvic and Para-Aortic Lymph Node Status in Epithelial Ovarian Cancer? A Systematic Review and Meta-Analysis

Background: In advanced epithelial ovarian cancer (EOC), the LION trial restricted lymphadenectomy indication to patients with suspect lymph nodes before and during surgery. Preoperative imaging is used to assess lymph node status, and particularly CT and PET/CT. The aim of this systematic review and meta-analysis was to evaluate the diagnostic accuracy of preoperative CT and PET/CT to detect lymph node metastasis (LNM) in patients with EOC; Methods: Databases were searched from January 1990 to May 2019 for studies that evaluated the diagnostic accuracy of preoperative CT and PET/CT to detect LNM in patients with EOC with histology as the gold standard. Pooled diagnostic accuracy was calculated using bivariate random-effects models and hierarchical summary receiver operating curve (HSROC). This study is registered with PROSPERO number CRD42020179214; Results: A total of five studies were included in the meta-analysis: four articles concerned preoperative CT and four articles concerned preoperative PET/CT, involving 106 and 138 patients, respectively. For preoperative CT, pooled sensitivity was 0.47 95% CI [0.20–0.76], pooled specificity was 0.99 95% CI [0.75–1.00] and area under the curve (AUC) of the HSROC was 0.91 95% CI [0.88–0.93]. For preoperative PET/CT, pooled sensitivity was 0.81 95% CI [0.61–0.92], pooled specificity was 0.96 95% CI [0.91–0.99] and AUC of the HSROC was 0.97 95% CI [0.95–0.98]; Conclusions: PET/CT has a very high diagnostic accuracy, especially for specificity, to detect LNM in EOC and should be realized systematically, additionally to CT recommended to evaluate peritoneal spread, in the preoperative staging of patients with an advanced disease.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on preoperative diagnosis of ovarian tumors

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the preoperative diagnosis of ovarian tumors, including imaging techniques, biomarkers and prediction models. ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the preoperative diagnosis of ovarian tumors and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised. Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements. This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the preoperative diagnosis of ovarian tumors and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on preoperative diagnosis of ovarian tumours

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the preoperative diagnosis of ovarian tumours, including imaging techniques, biomarkers and prediction models.

ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the preoperative diagnosis of ovarian tumours and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised.

Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when a consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements.

This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the preoperative diagnosis of ovarian tumours and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

ESGO/ISUOG/IOTA/ESGE Consensus Statement on pre-operative diagnosis of ovarian tumors

The European Society of Gynaecological Oncology (ESGO), the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), the International Ovarian Tumour Analysis (IOTA) group, and the European Society for Gynaecological Endoscopy (ESGE) jointly developed clinically relevant and evidence-based statements on the pre-operative diagnosis of ovarian tumors, including imaging techniques, biomarkers, and prediction models. ESGO/ISUOG/IOTA/ESGE nominated a multidisciplinary international group, including expert practising clinicians and researchers who have demonstrated leadership and expertise in the pre-operative diagnosis of ovarian tumors and management of patients with ovarian cancer (19 experts across Europe). A patient representative was also included in the group. To ensure that the statements were evidence-based, the current literature was reviewed and critically appraised. Preliminary statements were drafted based on the review of the relevant literature. During a conference call, the whole group discussed each preliminary statement and a first round of voting was carried out. Statements were removed when a consensus among group members was not obtained. The voters had the opportunity to provide comments/suggestions with their votes. The statements were then revised accordingly. Another round of voting was carried out according to the same rules to allow the whole group to evaluate the revised version of the statements. The group achieved consensus on 18 statements. This Consensus Statement presents these ESGO/ISUOG/IOTA/ESGE statements on the pre-operative diagnosis of ovarian tumors and the assessment of carcinomatosis, together with a summary of the evidence supporting each statement.

Diagnostic performance of PET/CT and PET/MR in the management of ovarian carcinoma-a literature review

Ovarian cancer is a challenging disease. It often presents at an advanced stage with frequent recurrence despite optimal management. Accurate staging and restaging are critical for improving treatment outcomes and determining the prognosis. Imaging is an indispensable component of ovarian cancer management. Hybrid imaging modalities, including positron emission tomography/computed tomography (PET/CT) and PET/magnetic resonance imaging (MRI), are emerging as potential non-invasive imaging tools for improved management of ovarian cancer. This review article discusses the role of PET/CT and PET/MRI in ovarian cancer.

The Value of Contrast-Enhanced CT in the Detection of Residual Disease After Neo-Adjuvant Chemotherapy in Ovarian Cancer

RATIONALE AND OBJECTIVES

To evaluate the diagnostic performance of contrast-enhanced computed tomography (CT) in predicting residual disease following neo-adjuvant chemotherapy (NACT) in stage III/IV ovarian cancer.

MATERIALS AND METHODS

This was a retrospective observational cohort study including consecutive patients with primary stage III/IV ovarian cancer who received NACT before interval debulking surgery. CT findings before interval debulking surgerywere correlated with histological/surgical findings. Diagnostic characteristics were calculated on patient-based and lesion-based analyses. False negative results on peritoneal carcinomatosis detection were correlated with lesion size and site.

RESULTS

On patient-based analysis, CT (n = 58) had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 92.16%, 57.14%, 94.00%, 50.00%, and 87.93%. On lesion-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 63.01%, 73.47%, 82.51%, 50.00%, and 66.51%. False negative results were associated with lesion size (p < 0.001). The diagnostic performance of CT on the detection of peritoneal carcinomatosis was low at the subdiaphragmatic spaces, bowel serosa and mesentery (p < 0.001).

CONCLUSION

CT had low negative predictive value in determining residual disease following NACT on both patient-based and lesion-based analyses, especially for non-measurable lesions and at the subdiaphragmatic spaces, bowel serosa and mesentery.

The Value of PET-CT in Ovarian Epithelial Carcinoma: A Population-Based Study in British Columbia, Canada

INTRODUCTION

In epithelial ovarian cancer (EOC), consensus regarding optimal use of PET/CT is lacking. Limited evidence suggests its accuracy in preoperative staging, investigating recurrence and predicting optimal secondary debulking. This study evaluated indications for PET/CT, impact of PET/CT results on EOC management, and its added value over conventional imaging.

METHODS

Patients with EOC aged 19 years and older who underwent PET/CT at BC Cancer Vancouver between January 2007 and September 2017 were eligible. Medical records were retrospectively reviewed with the following data abstracted: patient demographics, PET/CT indications and results, recent conventional imaging results, and application of PET/CT findings. Basic descriptive analysis was performed to determine most common use of PET/CT and its management impact.

RESULTS

257 PET/CTs in 216 patients were eligible. Most PET/CTs (135/257, 52.6%) were performed for suspected disease recurrence/progression. Management after PET/CT changed in 1/3 of cases with the greatest impact seen when assessing suitability in recurrent disease for focal radiotherapy or secondary surgical debulking. For 106/257 cases with recent conventional imaging available, although differences in disease extent were found in ~50%, clinical conclusions drawn were the same in ~75%.

DISCUSSION

Although PET/CT is most commonly used to investigate suspected recurrence/progression, its impact on management here is low. Greater impact is seen when considering localized therapy in EOC recurrence. When compared with recent conventional imaging, although PET/CT may detect differences in disease extent, clinical conclusions are frequently the same.

CONCLUSION

Impact of PET/CT on management is greatest in EOC recurrence when considering local therapies, beyond which clinical presentation and conventional imaging may suffice.

Performance of pre-treatment ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography for detecting metastasis in ovarian cancer: a systematic review and meta-analysis

OBJECTIVE

We describe a systematic review and meta-analysis of the performance of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) for detecting metastasis in ovarian cancer.

METHODS

MEDLINE and Embase were searched for diagnostic accuracy studies that used ¹⁸F-FDG PET or PET/CT for pre-treatment staging, using surgical findings as the reference standard. Sensitivities and specificities were pooled and plotted in a hierarchic summary receiver operating characteristic plot. Potential causes of heterogeneity were explored through sensitivity analyses.

RESULTS

Eight studies with 594 patients were included. The overall pooled sensitivity and specificity for metastasis were 0.72 (95% confidence interval [CI]=0.61-0.81) and 0.93 (95% CI=0.85-0.97), respectively. There was considerable heterogeneity in sensitivity (I²=97.57%) and specificity (I²=96.74%). In sensitivity analyses, studies that used laparotomy as the reference standard showed significantly higher sensitivity and specificity (0.77; 95% CI=0.67-0.87 and 0.96; 95% CI=0.92-0.99, respectively) than those including diagnostic laparoscopy (0.62; 95% CI=0.46-0.77 and 0.84; 95% CI=0.69-0.99, respectively). Higher specificity was shown in studies that confirmed surgical findings by pathologic evaluation (0.95; 95% CI=0.90-0.99) than in a study without pathologic confirmation (0.69; 95% CI=0.24-1.00). Studies with a lower prevalence of the FDG-avid subtype showed higher specificity (0.97; 95% CI=0.94-1.00) than those with a greater prevalence (0.89; 95% CI=0.80-0.97).

CONCLUSION

Pre-treatment ¹⁸F-FDG PET/CT shows moderate sensitivity and high specificity for detecting metastasis in ovarian cancer. With its low false-positive rate, it can help select surgical approaches or alternative treatment options.

The role of 18F-FDG PET CT in common gynaecological malignancies

[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET CT) has increasing clinical applications supplementing conventional TVUS, CT and MRI imaging in assessing ovarian, cervical and endometrial cancer. The published literature on the applications of ¹⁸F-FDG PET CT shows its use can have significant impact on patient management by improving staging of the cancers, influencing patient selection for treatment and in detecting early recurrent disease. However, the increasing clinical use of PET CT does not always align with the guidelines, recommendations or expert opinion in the use of PET CT. This article summarizes the existing evidence base for the established clinical applications and the emerging roles for ¹⁸F-FDG PET CT in the common gynaecological malignancies.

Diagnostic value of whole body diffusion-weighted MRI compared to computed tomography for pre-operative assessment of patients suspected for ovarian cancer

BACKGROUND

Despite excellent per-lesion performance for peritoneal staging, the additional clinical value of diffusion-weighted magnetic resonance imaging (DWI/MRI) compared to computed tomography (CT) remains to be established in ovarian cancer. Our purpose was to evaluate whole body (WB)-DWI/MRI for diagnosis, staging and operability assessment of patients suspected for ovarian cancer compared to CT.

METHODS

One hundred and sixty-one patients suspected for ovarian carcinoma underwent 3 T WB-DWI/MRI and contrast-enhanced CT. WB-DWI/MRI and CT were compared for confirmation of the malignant nature and primary origin of the ovarian mass, Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) staging and prediction of incomplete resection using institutional operability criteria. Interobserver agreement between two readers was determined for WB-DWI/MRI and CT.

RESULTS

WB-DWI/MRI showed a significantly higher accuracy than CT (93 versus 82%, p = 0.001) to confirm the malignant nature of the ovarian mass and correctly identified 26 of 32 (81%) cancers of non-ovarian origin compared to 10/32 (31%) for CT (p < 0.001). WB-DWI/MRI assigned more ovarian carcinoma patients to the correct FIGO stage (82/94, 87%) compared with CT (33/94, 35%). For prediction of incomplete resection, WB-DWI/MRI showed significantly higher sensitivity (94 versus 66%), specificity (97.7 versus 77.3%) and accuracy (95.7 versus 71.3%) compared to CT (p < 0.001). Interobserver agreement was almost perfect (κ = 0.90) for WB-DWI/MRI and moderate (κ = 0.52) for CT for prediction of incomplete resection.

CONCLUSIONS

WB-DWI/MRI was superior to CT for primary tumour characterisation, staging and prediction of incomplete resection in patients suspected for ovarian cancer.

Diagnostic role of 18F-FDG PET/MRI in patients with gynecological malignancies of the pelvis: A systematic review and meta-analysis

PURPOSE

The aim of this study was to assess the diagnostic performance of 18F-FDG Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) for gynecological cancers of the pelvis, based on a systematic review and meta-analysis of published data.

METHODS

We performed a comprehensive literature search of Pubmed and Embase for studies that evaluated the diagnosis of 18F-FDG PET/MRI for gynecological malignancies in the pelvis. Quality Assessment for Studies of Diagnostic Accuracy 2 (QUADAS 2) tool was used to access the quality of included studies. After testing heterogeneity of the pooled studies with I^2 and H^2 (calculated using metaan in Stata12.0) we treated the data that extracted and transformation from the studies, based on DerSimonian-Laird method(Random-effects models),then back-transformation them to percentages and plotting to get the pooled sensitivity, specificity, likelihood ratios, and constructed summary receiver operating characteristics (SROC) curve.

RESULTS

Eventually, 7 studies fulfilled our predefined inclusion criteria were included in our research. On patient-based assessment, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of 18F-FDG PET/MRI for diagnosis of gynecological malignancies were 0.95 (95%CI 0.86-0.99), 0.95 (95% CI 0.74-1.00), 7.51 (95% CI 2.29-24.59), 0.12 (95% CI 0.05-0.29) and 116.27 (95% CI 17.07-791.74), respectively. On lesion-based assessment, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and the summary DOR were 0.89 (95%CI 0.84-0.93), 0.87 (95%CI 0.74-0.95), 6.99 (95%CI 3.30-14.79), 0.12 (95%CI 0.06-0.25) and 55.82 (95%CI 20.91-149.05), respectively.

CONCLUSIONS

Our meta-analysis indicated that 18F-FDG PET/MRI, combined the advantages of MRI and PET, may be a very promising diagnostic method to assess the primary tumor and nodal staging in patients with gynecological malignancies of the pelvis.

18F-FDG PET/CT as predictor of tumour biology and prognosis in epithelial ovarian carcinoma

OBJECTIVE

To investigate the relationship between maximum standardised uptake value (SUVmax) of ovarian lesions and histopathology subtypes, and their involvement in the response and prognosis of patients with epithelial ovarian carcinoma (EOC).

MATERIAL AND METHODS

A retrospective analysis of 31 patients with EOC and ¹⁸F-FDG-PET/CT before treatment, including an assessment of the SUVmax of ovarian lesion. Histopathological diagnosis and follow-up was performed. A study was made on the relationship between the SUVmax and histological type (type I and II) and tumour stage, as well as the role of various parameters (SUVmax, histology, stage) on the patient outcomes (complete response [CR], overall survival [OS], disease-free survival [DFS], and disease-free [DF] status, at 12 and 24 months).

RESULTS

The medium SUVmax in type I lesions was lower than in type II (6.3 and 9.3, respectively; P=.03). A 7.1 cut-off was set for SUVmax in order to identify type II EOC (sensitivity: 77.8%, specificity: 69.2%; AUC=0.748; P=.02). No significant relationship was found between tumour stage and SUVmax. CR was more common in early stages; relative risk (RR) of 1.64; P=.003, as well as in type I tumours and a lower SUVmax. Tumour stage was decisive in DFS (P=.04), LE24m (0.07) and OS (P=.08). Longer DFS and a higher percentage of DF 24m were observed in type I tumours (RR: 1.32; P=.26).

CONCLUSIONS

SUVmax was related to EOC histology, so could predict the response and prognosis of these patients. No association was found between glycolytic activity of the primary tumor with the response and prognosis.

An update on the role of PET/CT and PET/MRI in ovarian cancer

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as ¹⁸F-fluorothymidine (FLT) or ¹¹C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer.

Systematic Review on the Accuracy of Positron Emission Tomography/Computed Tomography and Positron Emission Tomography/Magnetic Resonance Imaging in the Management of Ovarian Cancer: Is Functional Information Really Needed?

Ovarian cancer (OC) often presents at an advanced stage with frequent relapses despite optimal treatment; thus, accurate staging and restaging are required for improving treatment outcomes and prognostication. Conventionally, staging of OC is performed using contrast-enhanced computed tomography (CT). Nevertheless, recent advances in the field of hybrid imaging have made positron emission tomography/CT (PET/CT) and PET/magnetic resonance imaging (PET/MRI) as emerging potential noninvasive imaging tools for improved management of OC. Several studies have championed the role of PET/CT for the detection of recurrence and prognostication of OC. We provide a systematic review and meta-analysis of the latest publications regarding the role of molecular imaging in the management of OC. We retrieved 57 original research articles with one article having overlap in both diagnosis and staging; 10 articles (734 patients) regarding the role of PET/CT in diagnosis of OC; 12 articles (604 patients) regarding staging of OC; 22 studies (1429 patients) for detection of recurrence; and 13 articles for prognostication and assessment of treatment response. We calculated pooled sensitivity and specificity of PET/CT performance in various aspects of imaging of OC. We also discussed the emerging role of PET/MRI in the management of OC. We aim to give the readers and objective overview on the role of molecular imaging in the management of OC.

Nuclear medicine for imaging of epithelial ovarian cancer

Cancer is one of the leading causes of mortality worldwide. Usually, the diagnosis of cancer at an early stage is important to facilitate proper treatment and survival. Nuclear medicine has been successfully used in the diagnosis, staging, therapy and monitoring of cancers. Single-photon emission computed tomography and PET-based companion imaging agents are in development for use as a companion diagnostic tool for patients with ovarian cancer. The present review discusses the basic and clinical studies related to the use of radiopharmaceuticals in the diagnosis and management of ovarian cancer, focusing on their utility and comparing them with other imaging techniques such as computed tomography and MRI.

The Role of Completion Surgery in Ovarian Cancer

INTRODUCTION

Patients referred with inadequately staged ovarian malignancies present a clinical dilemma. We report our experience with completion surgery in ovarian cancer.

AIMS AND OBJECTIVES

To determine the benefits and risks of completion surgery in women with ovarian cancer who presented after having had inadequate primary surgery.

METHODS

A retrospective case series of 30 women with ovarian cancer and one with fallopian tube cancer who had inadequate primary surgery underwent completion surgery at gynaecologic oncology unit in a tertiary level hospital in Tamil Nadu, India. Electronic medical records of patients with ovarian cancer who underwent completion surgery between January 2011 and September 2014 for ovarian were reviewed. Forty-five patients with initial inadequate surgery were identified of whom 31 underwent completion surgery; the remaining 14 did not return to our hospital.

RESULTS

Thirty-one women with a mean age of 37 years (17-53) and median parity of 2 (0-4) with inadequately staged ovarian malignancy underwent completion surgery. Complex ovarian mass was the most common indication for initial surgery (94 %). The tumours were epithelial in 27 (87 %), germ cell in 3 (10 %) and sex cord stromal in 1 (3 %). In view of extensive disease at presentation, 19 % (6/31) were referred for neoadjuvant chemotherapy and underwent interval debulking. With regard to surgical complexity, 52 % (16/31), 38 % (12/31) and 10 % (3/31) underwent simple, intermediate and complex surgeries, respectively. Optimal cytoreduction (R0 and R1) was performed in 25 patients (81 %). Twelve (39 %) had upstaging of disease. Six patients required no further adjuvant treatment following surgical restaging. Complications included bladder injury (1), iliac vessel injury (1) and surgical site infections (2). During the study period of 45 months, 7 patients (23 %) presented with disease recurrence. There were 2 recorded deaths.

CONCLUSIONS

In inadequately staged ovarian malignancies, completion surgery should be considered based on the patients' performance status and disease assessment. Considering the low specificity of imaging and Ca 125, completion surgery provides information to plan adjuvant therapy, besides allowing optimal cytoreduction but delays initiation of adjuvant therapy.

FDG-PET/CT to predict optimal primary cytoreductive surgery in patients with advanced ovarian cancer: preliminary results

AIMS AND BACKGROUND

Primary cytoreductive surgery (CRS) has a significant impact on prognosis in epithelial ovarian cancer (EOC). Patient selection is important to recognize factors limiting optimal CRS and to avoid unnecessary aggressive surgical procedures. We evaluated the contribution of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the presurgical identification of disease sites that may preclude EOC cytoreducibility.

METHODS

Patients with suspected EOC underwent 18F-FDG-PET/CT within 20 days before debulking surgery. The PET/CT results were compared with surgical findings and postsurgery histopathology in order to assess the diagnostic value.

RESULTS

Between August 2013 and January 2014, 29 patients were evaluated. The histopathology showed 23 EOC and 6 benign tumors. The FDG-PET/CT was positive (maximum standardized uptake value [SUVmax] 11.3 ± 5.4) in 21/23 (91%) patients with EOC and provided 2 false-negatives (1 mucinous and 1 clear cell carcinoma; SUVmax ≤2.8). The FDG-PET/CT was true-negative (SUVmax 2.2 ± 1.6) in 4 out of 6 patients (67%). False-positive FDG-PET results were obtained in 2 cellular fibromas (SUVmax 4.8 and 5.6). The sensitivity, specificity, and accuracy of PET/CT to characterize ovarian masses were 91%, 67%, and 86%, respectively. Among the 21 FDG-PET/CT-positive EOC, we detected factors limiting optimal CRS in 6 cases (29%): 4 hepatic hilum infiltration and 2 root mesentery involvement, confirmed at surgical exploration. The FDG-PET did not find limiting factors in the remaining 15 patients (71%) in whom optimal CRS was obtained.

CONCLUSIONS

Fluorodeoxyglucose-PET/CT shows high sensitivity but suboptimal specificity in the characterization of ovarian masses. However, PET/CT may play a role in noninvasively selecting patients with EOC who can benefit from primary CRS.

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

PURPOSE

To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population.

MATERIAL AND METHODS

Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT).

RESULTS

Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients.

CONCLUSION

PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection.

KEY POINTS

• PET/MRI is superior to PET/CT for primary tumour delineation • PET/CT represents a reliable tool to detect extra-abdominal distant metastasis • PET/MRI might be the preferred imaging modality for staging cervical and endometrial tumours • Whole-body staging for detection and evaluation of extra-abdominal metastases is mandatory.