PET/CT in Gynecologic Malignancies

The risk of distant metastases in patients with gynecologic cancers after surgery: a population-based study

The aim of the study was to determine the risk of distant metastases in patients with gynecologic cancers after surgery, including cervical, uterine and ovarian cancers. This is a retrospective study evaluating gynecologic cancer from 2009 to 2014 using population-based administrative datasets from the Health and Welfare Data Science Center (HWDC) and from The National Health Informatics Project (NHIP). A total of 1,464 gynecologic cancer patients, including 321 cervical cancer patients, 724 uterine cancer patients and 419 ovarian cancer patients, were analyzed retrospectively from 2009 to 2014. Among the cervical cancer patients, 173 (53.89%) received surgery only and 148 (46.11%) received surgery with radiotherapy /chemotherapy. Among the uterus cancer patients, 425(58.70%) received surgery only and 299 (41.3%) received surgery with radiotherapy /chemotherapy. Among the ovarian cancer patients, 81 (19.33%) received surgery only and 338 (80.67%) received surgery with radiotherapy/chemotherapy. Among patients with brain, liver or lung metastasis, cervical cancer patients have more cumulative metastasis-free survival than those ovarian cancer (p=0.0041). In analyzing liver metastasis based on primary cancer sites, cervical cancer patients and uterine cancer cases have more cumulative metastasis- free survival than those ovarian cancer (p<0.0001). In conclusion, ovarian cancer patients have higher risk of liver metastasis than cervical or uterine cancer. There were significantly different of pathological stage for cumulative metastasis-free survival among gynecologic cancer patients with brain or liver or lung metastasis. Pathological T stage remains the main predictive for distant metastasis of gynecologic cancer.

PET Imaging for Gynecologic Malignancies

This review article summarizes the clinical applications of established and emerging PET tracers in the evaluation of the 5 most common gynecologic malignancies: endometrial, ovarian, cervical, vaginal, and vulvar cancers. Emphasis is given to 2-deoxy-2-[¹⁸F]fluoro-d-glucose as the most widely used and studied tracer, with additional clinical tracers also explored. The common imaging protocols are discussed, including standard dose ranges and uptake times, established roles, as well as the challenges and future directions of these imaging techniques. The key points are emphasized with images from selected cases.

Endometrial Cancer, the Current International Federation of Gynecology and Obstetrics Staging System, and the Role of Imaging

Imaging plays a crucial role in the diagnosis, staging, and follow-up of endometrial cancer. Endometrial cancer is staged surgically using the International Federation of Gynecology and Obstetrics (FIGO) staging system. Preoperative imaging can complement surgical staging but is not yet considered a required component in the current FIGO staging system. Preoperative imaging can help identify some tumor characteristics and tumor spread, both locally and distally. More accurate assessment of endometrial cancers optimizes management and treatment plan, including degree of surgical intervention. In this article, we review the epidemiology, FIGO staging system, and the importance of imaging in the staging of endometrial cancer.

Contemporary management of uterine clear cell carcinoma: A Society of Gynecologic Oncology (SGO) review and recommendation

Uterine clear cell cancer (UCCC) is a rare but aggressive disease. Due to its rarity, large, prospective studies focused on UCCC are exceedingly difficult therefore available data are generally from small, retrospective studies. There is also pertinent information from subsection analysis of larger studies that include UCCC and other histotypes. In 2009, the clinical practice committee of the Society of Gynecologic Oncology (SGO) published a review on UCCC aimed at guiding management. Since that publication, there have been developments which are relevant to UCCC, these include availability of data from landmark trials regarding adjuvant therapy, increasing utilization of sentinel lymph node approach and availability of immunotherapy as a treatment option. This SGO review is updated with all relevant, published information since 2009 considered clinically important for management of UCCC. In addition, it follows the new SGO's style for this type of publication which includes utilization of the question and answer format.

The Emerging Role of PET/MR Imaging in Gynecologic Cancers

This article summarizes recent advances in PET/MR imaging in gynecologic cancers and the emerging clinical value of PET/MR imaging in the management of the 3 most common gynecologic malignancies: cervical, endometrial, and ovarian cancers. PET/MR imaging offers superior soft tissue contrast, improved assessment of primary tumor involvement because of high-resolution multiplanar reformats, and functional MR techniques such as diffusion-weighted MR imaging and dynamic contrast-enhanced MR imaging. This article discusses the challenges, future directions, and technical advances of PET/MR imaging, and the emerging new multimodality, multiparametric imaging techniques for integrating morphologic, functional, and molecular imaging data.

Relationship of 18F-FDG PET/CT metabolic, clinical and pathological characteristics of primary squamous cell carcinoma of the cervix

The objectives of this retrospective study were to use preoperative ¹⁸fluoro-d-glucose (¹⁸FDG) PET/CT in patients with primary cervical squamous cell carcinoma to explore the relationship between clinical, pathological and metabolic characteristics. Eighty consecutive patients with squamous cell carcinoma of cervix received ¹⁸FDG PET/CT scan before treatment. Metabolic tumor volume (MTV), total lesion glycolysis (TLG) and the peak standardized uptake value (SUVpeak) of the cervical tumors were calculated by an iterative adaptive algorithm. The association of these metabolic markers with serum squamous cell carcinoma antigen (SCC-ag), International Federation of Gynecology and Obstetrics (FIGO) stage, maximum tumor size and depth of cervical stromal invasion of the tumor was determined by the multivariate analysis. MTV and TLG were significantly higher in subjects with serum SCC-ag levels ≥3.95, with FIGO stage 1b2 and with a maximum tumor size of ≥4 cm (p≤0.009). Higher SUVpeak levels were associated with a maximum tumor size of ≥4 cm and with a cervical stromal invasion depth of ≥1/2 (p≤0.003). Multivariate analysis indicated that MTV was independently associated with FIGO stage Ib2 (p=0.041) and depth of cervical stromal invasion (p=0.020). TLG and SUVpeak were independently associated with maximum tumor size (p≤0.004) and depth of cervical stromal invasion (p≤0.013). Significant linear correlation was found between SUVpeak and tumor size; the Pearson correlation coefficient was 0.34 (p=0.002). Metabolic parameters such as MTV, TLG and SUVpeak are able to predict clinical and pathological status in preoperative cervical cancer.

Multidetector CT detection of peritoneal metastases: evaluation of sensitivity between standard 2.5 mm axial imaging and maximum-intensity-projection (MIP) reconstructions

OBJECTIVE

Our purpose was to evaluate the sensitivity of multidetector CT for the detection of peritoneal metastases between standard 2.5 mm axial imaging and maximum-intensity-projection (MIP) reconstructions.

MATERIALS AND METHODS

The Institutional Review Board approved this retrospective study and waived the need to obtain patient consent. We retrospectively identified 36 patients with pancreatic adenocarcinoma and peritoneal metastatic disease who underwent a pancreatic protocol CT examination of the abdomen and pelvis between January 2012 and January 2014. Three independent radiologists reviewed a randomized combination of standard axial (2.5 mm reconstructed thickness, 2.5 mm interval) and axial MIP reconstructions (6, 3 mm interval) over two sessions. Each reader recorded metastasis location in PACS. Subsequent consensus review by two radiologists determined the final number and size of metastases.

RESULTS

The reviewers found 328 peritoneal implants in 36 patients. After accounting for the size, location, and number of lesions as well as multiple readers, a generalized estimating equations model showed that the statistical combination of MIP with standard technique significantly increased the odds of correctly identifying a lesion (OR 2.16; 95% CI 1.86-2.51; p value < 0.0001) compared to standard technique alone. MIP reconstruction as a standalone technique was less sensitive compared to standard technique alone (OR 0.81; 95% CI 0.65-0.99; p value = 0.0468). When compared to standard axial imaging, evaluation via MIP reconstructions resulted in the identification of an additional 50 (15%), 45 (14%), and 55 (17%) lesions by Readers 1-3, respectively.

CONCLUSION

The axial 6 mm MIP series is complimentary in the CT evaluation of peritoneal metastases. MIP reconstruction evaluation identified a significant number of additional lesions, but is not adequate as a standalone technique for peritoneal cavity assessment.

18F-FDG positron emission tomography in oncology: main indications

The development of molecular and functional imaging with new imaging techniques such as computed tomography, magnetic resonance imaging, and positron emission tomography (PET) among others, has greatly improved the detection of tumors, tumor staging, and the detection of possible recurrences. Furthermore, the combination of these different imaging modalities and the continual development of radiotracers for PET have advanced our understanding and knowledge of the different pathophysiological processes in cancer, thereby helping to make treatment more efficacious, improving patients' quality of life, and increasing survival. PET is one of the imaging techniques that has attracted the most interest in recent years for its diagnostic capabilities. Its ability to anatomically locate pathologic foci of metabolic activity has revolutionized the detection and staging of many tumors, exponentially broadening its potential indications not only in oncology but also in other fields such as cardiology, neurology, and inflammatory and infectious diseases.

Standardized Uptake Value on F-FDG PET/CT as a Prognostic Factor for Survival of Women with Malignant Uterine Tumors: A Meta-Analysis

BACKGROUND

Malignant uterine tumors are crucial in the evaluation of prognosis and the determination of therapeutic strategy.

AIM

This meta-analysis of the available literature aimed to investigate the prognostic value of standardized uptake value (SUV) on fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) in uterine malignancies before treatment.

METHODS

The PubMed, MEDLINE and EMBASE databases (1990 to February 2014) were searched to identify studies evaluating SUV on 18F-FDG PET/CT as a prognostic tool for predicting long-term survival in patients with carcinomas of the uterus. The χ2 test and the I2 index were used to estimate heterogeneity among the trials selected in the meta-analysis. The combined hazard ratio was calculated by using a fixed- or random-effects model according to heterogeneity.

RESULTS

Thirteen studies with a total of 1,196 patients were eligible for analysis. High pretreatment SUVmax was significantly associated with poorer event-free survival and overall survival, and the summarized hazard ratio was 3.33 (95% confidence interval 2.34-4.74) and 1.31 (95% confidence interval 1.03-1.67), respectively.

CONCLUSION

The present evidence indicates that SUV on 18F-FDG PET/CT seems to be a valuable prognostic indicator for survival of patients with malignant uterine tumors. Given that 18F-FDG PET/CT can provide both morphologic and functional information, we suggest utilizing PET/CT and its quantitative marker in uterine malignancies before treatment. © 2015 S. Karger AG, Basel.

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.

Imaging in endometrial carcinoma

Endometrial carcinoma (EC) is the most common gynecologic malignancy in the United States. Prognosis depends on patient age, histological grade, depth of myometrial invasion and/or cervical invasion, and the presence of lymph node metastases. Although EC is staged surgically according to the International Federation of Gynecology and Obstetrics (FIGO) system, preoperative imaging can assist in optimal treatment planning. Several imaging techniques such as transvaginal ultrasonography (TVUS), computed tomography (CT), and magnetic resonance imaging (MRI) have been used as diagnostic tools for preoperative staging of EC. Recently, positron emission tomography (PET), PET/CT, and PET/MRI have also been used in staging these patients. In this article, we review the value of imaging in diagnosis, staging, treatment planning, and detection of recurrent disease in patients with EC.

The Role of FDG-PET in the Initial Staging and Response Assessment of Anal Cancer: A Systematic Review and Meta-analysis

PURPOSE

The aim of this systematic review and meta-analysis was to compare the role of FDG-positron emission tomography (PET) or PET/computed tomography (CT) with conventional imaging in the detection of primary and nodal disease in anal cancer, and to assess the impact of PET or PET/CT on the management of anal cancer.

METHODS

A systematic review of the literature was performed. Eligible studies included those comparing PET or PET/CT with conventional imaging in the staging of histologically confirmed anal squamous cell carcinoma (SCC), or studies that performed PET or PET/CT imaging to assess response following treatment.

RESULTS

Twelve studies met the inclusion criteria. For the detection of primary disease, CT and PET had a sensitivity of 60 % (95 % confidence interval [CI] 45.5-75.2) and 99 % (95 % CI 96-100), respectively. Compared with conventional imaging, PET upstaged 15 % (95 % CI 10-21) and downstaged 15 % (95 % CI 10-20) of nodal disease. This led to a change in nodal staging in 28 % of patients (95 % CI 18-38). When only studies performing contemporary PET/CT were considered, the rate of nodal upstaging was 21 % (95 % CI 13-30) and the TNM stage was altered in 41 % of patients. Following chemoradiotherapy, 78 % (95 % CI 65-88) of patients had a complete response on PET.

CONCLUSION

Compared with conventional imaging, PET or PET/CT alters the nodal status in a sufficient number of cases to justify its routine use in the staging of patients with anal SCC.

Management of epithelial ovarian cancer from diagnosis to restaging: an overview of the role of imaging techniques with particular regard to the contribution of 18F-FDG PET/CT

Epithelial ovarian carcinoma is a major form of cancer affecting women in the western world. The silent nature of this disease results in late presentation at an advanced stage in many patients. It is therefore important to assess the role of imaging techniques in the management of these patients. This article presents a review of the literature on the role of (18)F-FDG-PET/CT in the different stages of management of epithelial ovarian cancer. Moreover, a comparison with other imaging techniques has been made and the relationship between (18)F-PET/CT and the assay of serum CA-125 levels has been discussed.

Positron emission tomography image-guided drug delivery: current status and future perspectives

Positron emission tomography (PET) is an important modality in the field of molecular imaging, which is gradually impacting patient care by providing safe, fast, and reliable techniques that help to alter the course of patient care by revealing invasive, de facto procedures to be unnecessary or rendering them obsolete. Also, PET provides a key connection between the molecular mechanisms involved in the pathophysiology of disease and the according targeted therapies. Recently, PET imaging is also gaining ground in the field of drug delivery. Current drug delivery research is focused on developing novel drug delivery systems with emphasis on precise targeting, accurate dose delivery, and minimal toxicity in order to achieve maximum therapeutic efficacy. At the intersection between PET imaging and controlled drug delivery, interest has grown in combining both these paradigms into clinically effective formulations. PET image-guided drug delivery has great potential to revolutionize patient care by in vivo assessment of drug biodistribution and accumulation at the target site and real-time monitoring of the therapeutic outcome. The expected end point of this approach is to provide fundamental support for the optimization of innovative diagnostic and therapeutic strategies that could contribute to emerging concepts in the field of “personalized medicine”. This review focuses on the recent developments in PET image-guided drug delivery and discusses intriguing opportunities for future development. The preclinical data reported to date are quite promising, and it is evident that such strategies in cancer management hold promise for clinically translatable advances that can positively impact the overall diagnostic and therapeutic processes and result in enhanced quality of life for cancer patients.

Clinical and research applications of simultaneous positron emission tomography and MRI

Evaluation of the molecular processes responsible for disease pathogenesis and progression represents the new frontier of clinical radiology. Multimodality imaging lies at the cutting edge, combining the power of MRI for tissue characterization, microstructural appraisal and functional assessment together with new positron emission tomography (PET) tracers designed to target specific metabolic processes. The recent commercial availability of an integrated clinical whole-body PET-MRI provides a hybrid platform for exploring and exploiting the synergies of multimodal imaging. First experiences on the clinical and research application of hybrid PET-MRI are emerging. This article reviews the rapidly evolving field and speculates on the potential future direction.