Additional value of 16α-[18F]fluoro-17β-oestradiol PET for differential diagnosis between uterine sarcoma and leiomyoma in patients with positive or equivocal findings on [18F]fluorodeoxyglucose PET

Molecular Imaging in Gynecology: Beyond Cancer

Gynecological pathologies account for approximately 4.5% of the overall global disease burden. Although cancers of the female reproductive system have understandably been the focus of a great deal of research, benign gynecological conditions-such as endometriosis, polycystic ovary syndrome, and uterine fibroids-have remained stubbornly understudied despite their astonishing ubiquity and grave morbidity. This historical inattention has frequently become manifested in flawed diagnostic and treatment paradigms. Molecular imaging could be instrumental in improving patient care on both fronts. In this Focus on Molecular Imaging review, we will examine recent advances in the use of PET, SPECT, MRI, and fluorescence imaging for the diagnosis and management of benign gynecological conditions, with particular emphasis on recent clinical reports, areas of need, and opportunities for growth.

Molecular Imaging of Steroid Receptors in Breast Cancer

ABSTRACT

Steroid receptors regulate gene expression for many important physiologic functions and pathologic processes. Receptors for estrogen, progesterone, and androgen have been extensively studied in breast cancer, and their expression provides prognostic information as well as targets for therapy. Noninvasive imaging utilizing positron emission tomography and radiolabeled ligands targeting these receptors can provide valuable insight into predicting treatment efficacy, staging whole-body disease burden, and identifying heterogeneity in receptor expression across different metastatic sites. This review provides an overview of steroid receptor imaging with a focus on breast cancer and radioligands for estrogen, progesterone, and androgen receptors.

Fluorine-18-Labeled Fluoroestradiol PET/CT: Current Status, Gaps in Knowledge, and Controversies-AJR Expert Panel Narrative Review

PET/CT using 16α-[18F]-fluoro-17β-estradiol (FES) noninvasively images tissues expressing estrogen receptors (ERs). FES has undergone extensive clinicopathologic validation for ER+ breast cancer and received FDA approval in 2020 for clinical use as an adjunct to biopsy in patients with recurrent or metastatic ER+ breast cancer. Clinical use of FES PET/CT is increasing, but is not widespread in the United States. This AJR Expert Panel Narrative Review explores the present status and future directions of FES PET/CT, including image interpretation, existing and emerging uses, knowledge gaps, and current controversies. Specific controversies discussed include whether both FES PET/CT and FDG PET/CT are warranted in certain scenarios, whether further workup is required after negative FES PET/CT results, whether FES PET/CT findings should inform endocrine therapy selection, and whether immunohistochemistry should remain the standalone reference standard for determining ER status for all breast cancers. Consensus opinions from the panel include agreement with the appropriate clinical uses of FES PET/CT published by a multidisciplinary expert workgroup in 2023; anticipated expanded clinical use of FES PET/CT for staging ER-positive invasive lobular carcinomas and low-grade invasive ductal carcinomas pending ongoing clinical trial results; and the need for further research regarding use of FES PET/CT for ER-expressing nonbreast malignancies.

The Application of 18F-FES PET in Clinical Cancer Care: A Systematic Review

INTRODUCTION

[18F]fluoroestradiol (FES) can be used for the noninvasive visualization and quantification of tumor estrogen receptor (ER) expression and activity and was FDA-approved as a diagnostic agent in May 2022 for detecting ER-positive lesions in patients with recurrent or metastatic breast cancer. PET imaging was also used to detect ER-positive lesions and malignancy among patients with uterine, ovarian, and other ER-positive solid tumors. We conducted a systemic review of the studies on FES PET imaging used among patients with cancer not limited to breast cancer to better understand the application of FES PET imaging.

METHODS

PubMed/MEDLINE and Cochrane Library databases were used to perform a comprehensive and systematic search and were updated until August 15, 2022. Two authors independently reviewed the titles and abstracts of the retrieved articles by using the search algorithm and selected the articles based on the inclusion and exclusion criteria. All statistical analyses were conducted using R statistical software.

RESULTS

Forty-three studies with 2352 patients were included in the qualitative synthesis, and 23 studies with 1388 patients were included in the quantitative analysis, which estimated the FES-positive detection rate. Thirty-two studies (77%) included breast cancer patients in 43 included studies. The FES SUVmean was higher in patients with endometrial cancer (3.4-5.3) than in those with breast cancer (2.05) and uterine sarcoma (1.1-2.6). The pooled detection rates of FES PET imaging were 0.80 for breast and 0.84 for ovarian cancer patients, both similar to that of 18F-FDG. The FES uptake threshold of 1.1 to 1.82 could detect 11.1% to 45% ER heterogeneity, but the threshold of FES uptake did not have consistent predictive ability for prognosis among patients with breast cancer, unlike uterine cancer. However, FES uptake can effectively predict and monitor treatment response, especially endocrine therapy such as estradiol, ER-blocking agents (fulvestrant and tamifoxen), and aromatase inhibitors (such as letrozole and Z-endoxifen).

CONCLUSIONS

[18F]fluoroestradiol PET is not only a convenient and accurate diagnostic imaging tool for detecting ER-expressing lesions in patients with breast and ovarian cancer but also among patients with uterine cancer. [18F]fluoroestradiol PET is a noninvasive predictive and monitoring tool for treatment response and prognosis.

18F-Fluoroestradiol: Current Applications and Future Directions

In the United States, breast cancer is the second leading cause of cancer death in all women and the leading cause of cancer death in Black women. The breast cancer receptor profile, assessed with immunohistochemical staining of tissue samples, allows prediction of outcomes and direction of patient treatment. Approximately 80% of newly diagnosed breast cancers are hormone receptor (HR) positive, which is defined as estrogen receptor (ER) and/or progesterone receptor (PR) positive. Patients with ER-positive disease can be treated with therapies targeting the ER; however, the assessment of ER expression with immunohistochemical staining of biopsy specimens has several limitations including sampling error, false-negative results, challenging or inaccessible biopsy sites, and the inability to synchronously and serially assess all metastatic sites to identify spatial and/or temporal ER heterogeneity. In May 2020, after decades of research, the U.S. Food and Drug Administration approved the PET radiotracer fluorine 18 (¹⁸F) fluoroestradiol (FES) for clinical use in patients with ER-positive recurrent or metastatic breast cancer as an adjunct to biopsy. FES binds to the ER in the nucleus of ER-expressing cells, enabling whole-body in vivo assessment of ER expression. This article is focused on the approved uses of FES in the United States, including identification of a target lesion for confirmatory biopsy, in vivo assessment of biopsy-proven ER-positive disease, and evaluation of spatial and temporal ER heterogeneity. FES is an example of precision medicine that has been leveraged to optimize the care of patients with breast cancer. ^© RSNA, 2023 See the invited commentary by Fowler in this issue. Quiz questions for this article are available through the Online Learning Center.

PET Imaging of Estrogen Receptors for Gynecological Tumors

ABSTRACT

In the past few decades, PET with 18F-FDG has been used for the diagnosis of gynecological malignancies and is considered to be superior to conventional imaging methods in diagnostic accuracy for detecting metastatic lesions and local recurrence and in evaluating the treatment response. On the other hand, several gynecological tumors, such as endometrial cancer and leiomyoma, and breast cancer are estrogen-dependent, in which estrogen is essential for their development and progression. 18F-FES is an 18F-labeled compound of estradiol, the most bioactive type of estrogen, and 18F-FES PET has been well-established for diagnosis, staging, and posttherapeutic follow-up in patients with estrogen receptor-positive breast cancer. Compared with in vitro assessment of tumor biopsy material, PET imaging has the advantages of being able to measure in vivo tumor behavior, characterize the entire tumor burden, and capture the heterogeneity of the tumor phenotype. In this article, we review the phenotyping of estrogen-related gynecological tumors other than breast cancer using 18F-FES PET and demonstrate the additional value of 18F-FES PET to 18F-FDG PET in their diagnosis and prognostication. Moreover, promising PET tracers other than 18F-FES and 18F-FDG for the evaluation of estrogen-related gynecological tumors are introduced.

Ultrasound-Guided Trans-Uterine Cavity Core Needle Biopsy of Uterine Myometrial Tumors to Differentiate Sarcoma from a Benign Lesion—Description of the Method and Review of the Literature

Uterine sarcomas are rare, aggressive tumors with poor prognosis that can be further negatively affected by inadequate surgical approaches such as morcellation. There are no clinical and radiologic criteria for differentiating leiomyoma from malignant uterine tumors. However, some ultrasonography and magnetic resonance imaging findings may be informative. We present a technique of ultrasound-guided trans-uterine cavity (UG-TUC) core needle biopsy for uterine lesions. As the procedure is an in-organ biopsy, there is no risk of needle canal contamination. The technique also enables the biopsy of lesions inaccessible by the transvaginal tru-cut biopsy. The core needle of the automatic biopsy system is inserted via the cervical canal into the uterine cavity and is directed and activated at the myometrial lesion under ultrasound control. The standard local treatment of localized uterine sarcomas is en bloc total hysterectomy; for fibroids, there are multiple options including conservative management or tumorectomy and tumor morcellation using minimally invasive techniques. Fragmentation of the sarcoma significantly worsens oncologic outcomes and should therefore be avoided. The UG-TUC core needle biopsy of uterine lesions can complement imaging to obtain sufficient material for histologic and molecular analyses of suspected or undetermined lesions, thus facilitating treatment planning and decreasing the risk of unsuspected sarcomas.

Uterine Sarcomas: How to Navigate an Ever-Growing List of Subtypes

Uterine sarcomas are rare mesenchymal tumors that are aggressive cancers. The rarity of these tumors, and consequently limited prospective data, has made surgical management of uterine sarcomas challenging. One major obstacle in the management of uterine sarcomas is establishing the diagnosis prior to surgery, which is crucial for appropriate intraoperative management. This paper serves to review aspects of surgical management of uterine sarcomas that remain unanswered. Distinguishing common benign myomas from rare uterine sarcomas is important for operative planning and subspecialty care because benign myomas are frequently managed with minimally invasive hysterectomy or myomectomy, whereas the mainstay of management of uterine sarcomas is hysterectomy without specimen fragmentation. Preoperative clinical presentation, serum studies, imaging, and histologic examination all have limitations in establishing a preoperative diagnosis. In addition, patients are often of reproductive age and desire fertility preservation. Although surgery remains the cornerstone for management, high-quality data guiding best practices are sparse. Morcellation should be avoided. Expert pathologic review, imaging to assess for metastatic disease, and consideration of hormone receptor testing are advisable. Recent data have further informed surgical approach and fertility preservation in early-stage disease, but controversy remains. Despite substantial advancement in the medical management of uterine sarcomas, surgical management of uterine sarcomas remain challenging. Larger studies with long-term follow-up are needed to guide fertility preservation surgery options, both local resection and ovarian preservation, further in young women. Development of novel methods to differentiate between benign and malignant uterine masses is needed.

Radionuclide-Based Imaging of Breast Cancer: State of the Art

Simple Summary

Breast cancer is one of the most commonly diagnosed malignant tumors, possessing high incidence and mortality rates that threaten women’s health. Thus, early and effective breast cancer diagnosis is crucial for enhancing the survival rate. Radionuclide molecular imaging displays its advantages for detecting breast cancer from a functional perspective. Noninvasive visualization of biological processes with radionuclide-labeled small metabolic compounds helps elucidate the metabolic state of breast cancer, while radionuclide-labeled ligands/antibodies for receptor-targeted radionuclide molecular imaging is sensitive and specific for visualization of the overexpressed molecular markers in breast cancer. This review focuses on the most recent developments of novel radiotracers as promising tools for early breast cancer diagnosis.

Abstract

Breast cancer is a malignant tumor that can affect women worldwide and endanger their health and wellbeing. Early detection of breast cancer can significantly improve the prognosis and survival rate of patients, but with traditional anatomical imagine methods, it is difficult to detect lesions before morphological changes occur. Radionuclide-based molecular imaging based on positron emission tomography (PET) and single-photon emission computed tomography (SPECT) displays its advantages for detecting breast cancer from a functional perspective. Radionuclide labeling of small metabolic compounds can be used for imaging biological processes, while radionuclide labeling of ligands/antibodies can be used for imaging receptors. Noninvasive visualization of biological processes helps elucidate the metabolic state of breast cancer, while receptor-targeted radionuclide molecular imaging is sensitive and specific for visualization of the overexpressed molecular markers in breast cancer, contributing to early diagnosis and better management of cancer patients. The rapid development of radionuclide probes aids the diagnosis of breast cancer in various aspects. These probes target metabolism, amino acid transporters, cell proliferation, hypoxia, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), gastrin-releasing peptide receptor (GRPR) and so on. This article provides an overview of the development of radionuclide molecular imaging techniques present in preclinical or clinical studies, which are used as tools for early breast cancer diagnosis.

Analysis of uterine corporeal mesenchymal tumors occurring after menopause

Objective

Because it is difficult to diagnose accurately whether uterine corporeal mesenchymal tumors are benign or malignant before surgery, an understanding of the characteristics of patients with uterine sarcomas occurring in the postmenopausal period is required.

Methods

We retrospectively reviewed the cases of women who underwent surgery for uterine mesenchymal tumors at our hospital.

Results

Among 487 operated cases, 447 tumors occurred in the premenopausal period and 40 occurred in the postmenopausal period. Uterine sarcomas were observed in 5 cases (1.1%) during the premenopausal period and in 11 cases (28%) during the postmenopausal period. Among the postmenopausal patients, age, age at menopause, body mass index (BMI), tumor size, incidence of abnormal vaginal bleeding, serum tumor marker levels (cancer antigen 125, carbohydrate antigen 19–9, and carcinoembryonic antigen), and serum lactate dehydrogenase values were not significantly different between patients with benign tumors and those with malignant tumors. On the other hand, the incidence to have abnormal signal on MRI was significantly higher in patients with malignant tumors than in patients with benign tumors.

Conclusion

In our hospital, the incidence of malignant tumors in women with uterine corporeal mesenchymal tumors was much higher in postmenopausal patients than in premenopausal patients. Because it is generally not easy to diagnose uterine sarcomas before surgery, surgery should be positively considered when uterine sarcomas cannot be ruled out for patients in the postmenopausal period.

Value of 18F-FDG PET/CT imaging in the staging, restaging, monitoring of response to therapy and surveillance of uterine leiomyosarcomas

OBJECTIVE

Leiomyosarcoma (LMS) is the most common subtype of uterine sarcomas. It is a rare and aggressive tumour. The aim of the present study was to assess the performance of fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT imaging in four clinical settings: initial staging, restaging, monitoring of response to therapy and post-therapy surveillance of uterine LMS.

PATIENTS AND METHODS

A bicentric retrospective study was carried out on a group of 21 patients with uterine LMS for whom a total of 52 PET/CT scans were available in initial staging (n=11), restaging (n=11), monitoring of response to therapy (n=17) and post-therapy surveillance (n=13). Clinical (minimum 6 months after PET/CT scan) and/or imaging follow-up and pathology were used as the reference standard.

RESULTS

In the initial staging, the sensitivity, specificity and accuracy of PET imaging were 80, 100 and 91%, respectively. In the restaging and monitoring of response to therapy, all these indices were 100%, whereas they were lower in post-therapy surveillance at 75, 100 and 85%, respectively, because of two false-negative results. False-negative lesions were an infracentimetric lung nodule in the initial staging and a peritoneal nodule that had increased in size between two PET/CT scans in post-therapy surveillance. PET-negative lesions were all identified on the computed tomography (CT) part of the PET/CT; thus, the performances of the exam improved to 100% on taking into account the CT component of the PET/CT.

CONCLUSION

PET/CT imaging has a high diagnostic yield in the initial staging and restaging of uterine LMS, but seems less sensitive in post-therapy surveillance. Evaluation of the CT part improves the sensitivity of the PET scan. Thus, PET/CT imaging should be considered in patients presenting with LMS.

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.

Presurgical Identification of Uterine Smooth Muscle Malignancies through the Characteristic FDG Uptake Pattern on PET Scans

The unidentified presence of uterine smooth muscle malignancies poses a tremendous risk in women planning surgery for presumed benign leiomyomas. We sought to investigate whether preoperative FDG PET may be useful to identify leiomyosarcomas (LMS) and smooth muscle tumors of uncertain malignant potential (STUMP). Methods. We investigated patients with rapidly growing uterine masses which were suspected of being malignant on ultrasound or MRI. Among the 21 patients who underwent FDG PET, we identified 7 LMS, 1 STUMP, and 13 leiomyomas. PET-derived parameters and FDG uptake patterns were analyzed retrospectively. Results. The SUV_max values of LMS/STUMP (range: 3.7–11.8) were significantly higher than those observed in leiomyomas (range: 2.0–9.4; P=0.003) despite a significant overlap. The metabolic tumor/necrosis ratio was significantly higher in LMS/STUMP than in leiomyomas (P < 0.001), with no significant intergroup overlaps. All LMS/STUMP revealed a characteristic pattern of FDG uptake, identifying a specific “hollow ball” sign (corresponding to areas of coagulative tumor necrosis). In contrast, this sign was invariably absent in patients with leiomyomas. Conclusion. The characteristic FDG uptake pattern instead of SUV on PET images allows identifying LMS/STUMP in patients with rapidly growing uterine masses, avoiding the deleterious consequences of regular surgery for presumed benign leiomyomas.

Efficacy of PET/CT to exclude leiomyoma in patients with lesions suspicious for uterine sarcoma on MRI

OBJECTIVE

To analyze the efficacy of positron emission tomography/computed tomography (PET/CT) for the diagnosis of uterine sarcoma.

MATERIALS AND METHODS

Thirty-four patients evaluated between January 2010 and March 2015 were retrospectively enrolled. All patients in whom uterine sarcoma was suspected based on contrast-enhanced magnetic resonance imaging (MRI) findings (heterogeneous, high signal intensity on T2-weighted images and/or high intensity on T1-weighted images) underwent PET/CT for further assessment. Patients were divided into 2 groups based on postoperative pathological findings: uterine sarcoma (n = 15) and leiomyoma (n = 19). The maximum standardized uptake value (SUVmax) of all lesions was measured using PET/CT; we calculated the optimal cutoff value for diagnosing sarcoma.

RESULTS

The median SUVmax for uterine sarcoma and leiomyoma was 12 and 4.1, respectively; these values were significantly different. An SUVmax of greater than 7.5 was able to exclude leiomyoma with 80.8% sensitivity and 100% specificity (area under the curve, 95.3%). A cutoff SUVmax of 7.5 yields 100% specificity, and a cutoff SUVmax of 4.4 yields a 100% negative predictive value (NPV). The combination of PET/CT and lactate dehydrogenase (LDH) levels had a sensitivity of 86.6%, specificity of 100%, positive predictive value of 100%, and an NPV of 90.4%. No relation between histopathology or International Federation of Gynecology and Obstetrics (FIGO) stage and 18-fluoro-2-deoxy-d-glucose uptake value on PET/CT was seen. The surgical outcome trended toward a correlation with the SUVmax, although this was not statistically significant.

CONCLUSIONS

In patients with MRI findings consistent with either uterine sarcoma or leiomyoma, PET/CT can decrease the false-positive rate by setting an optimal cutoff SUVmax of 7.5. Using this cutoff can avoid unnecessary surgery.

Non-18F-2-Fluoro-2-Deoxy-d-Glucose PET/Computed Tomography in Gynecologic Oncology: An Overview of Current Status and Future Potential

The current status and future potential targets of non-¹⁸F-2-fluoro-2-deoxy-d-glucose (FDG) PET/computed tomography (CT) in 3 major gynecologic malignancies are discussed. Estrogen receptor-based 16alpha-¹⁸F-fluoro-17beta-estradiol (¹⁸F-FES) PET/CT has been investigated in (a) Uterine malignancies (both endometrial and myometrial pathologies) and (b) ovarian carcinoma. For uterine tumors, FDG/FES standardized uptake value and/or uptake ratio showed a positive correlation with malignant transformation (ie, endometrial carcinoma and uterine sarcoma) and higher malignant grades, whereas higher ¹⁸F-FES uptake was documented in benign pathologies (ie, endometrial hyperplasia and leiomyoma). For epithelial ovarian carcinomas, ¹⁸F-FES PET/CT can predict the response to antiestrogen therapy in platinum-resistant cases.

18F-FDG/18F-FES standardized uptake value ratio determined using PET predicts prognosis in uterine sarcoma

We investigated whether 16α-[¹⁸F]-fluoro-17β-estradiol (¹⁸F-FES) and ¹⁸F-fluoro-deoxyglucose (FDG) uptake measured using positron emission tomography (PET) predicted prognosis in 18 patients with different histological subtypes of uterine sarcoma. Standardized uptake values (SUVs) and ¹⁸F-FDG/¹⁸F-FES SUV ratios were determined, and their correlations with progression-free (PFS) and overall survival (OS) were examined. Ten patients died from local recurrence or metastasis, and one more experienced recurrence, during the at least 36-month follow-up period. Patients with higher ¹⁸F-FDG SUVs (> 5.5) had worse OS (p = 0.007) and tended toward worse PFS (p = 0.11), while patients with lower 18F-FES SUVs (≤ 1.5) had worse PFS (p = 0.03) and tended toward worse OS (p = 0.19). Patients with ¹⁸F-FDG/¹⁸F-FES ratios > 2.6 had worse PFS (p = 0.009) and OS (p = 0.005). The 5-year PFS and OS rates were 75% and 88% for patients with lower ratios, but were only 10% and 20% for those with higher ratios. These results suggest that pretreatment tumor ¹⁸F-FDG/¹⁸F-FES ratio is useful for predicting the prognosis of uterine sarcoma patients.

A Novel Diagnostic Strategy Using 16α-[18F]-Fluoro-17-β-Estradiol (18F-FES) PET/MRI to Achieve Complete Resection of Intravenous Leiomyomatosis in Reproductive-Age Women

Intravenous leiomyomatosis is a life-threatening leiomyoma that grows into the extrauterine venous system. A high recurrence rate has been reported in reproductive-age women who undergo only tumor excision to preserve fertility. Precise diagnosis of tumor extension is essential to achieve complete resection. A 24-year-old woman presented with hypermenorrhea. Contrast-enhanced MRI showed an intramural myoma with worm-like extension into the right parametrium. F-FES PET/MRI accurately depicted the extension with strong FES activity into the right uterine vein, whereas F-FDG PET/MRI excluded the possibility of malignancy. These modalities can be a novel strategy to manage such cases of intractable intravenous leiomyomatosis.

Utility of 18F-fluoroestradiol (18F-FES) PET/CT imaging as a pharmacodynamic marker in patients with refractory estrogen receptor-positive solid tumors receiving Z-endoxifen therapy

BACKGROUND

Z-endoxifen is the most potent of the metabolites of tamoxifen, and has the potential to be more effective than tamoxifen because it bypasses potential drug resistance mechanisms attributable to patient variability in the expression of the hepatic microsomal enzyme CYP2D6. 18F-FES is a positron emission tomography (PET) imaging agent which selectively binds to estrogen receptor alpha (ER-α) and has been used for non-invasive in vivo assessment of ER activity in tumors. This study utilizes 18F-FES PET imaging as a pharmacodynamic biomarker in patients with ER+ tumors treated with Z-endoxifen.

METHODS

Fifteen patients were recruited from a parent therapeutic trial of Z-endoxifen and underwent imaging with 18F-FES PET at baseline. Eight had positive lesions on the baseline scan and underwent follow-up imaging with 18F-FES 1-5 days post administration of Z-endoxifen.

RESULTS

Statistically significant changes (p = 0.0078) in standard uptake value (SUV)-Max were observed between the baseline and follow-up scans as early as 1 day post drug administration.

CONCLUSION

F-FES PET imaging could serve as a pharmacodynamic biomarker for patients treated with ER-directed therapy.

Options on fibroid morcellation: a literature review

In laparoscopy, specimens have to be removed from the abdominal cavity. If the trocar opening or the vaginal outlet is insufficient to pass the specimen, the specimen needs to be reduced. The power morcellator is an instrument with a fast rotating cylindrical knife which aims to divide the tissue into smaller pieces or fragments. The Food and Drug Administration (FDA) issued a press release in April 2014 that discouraged the use of these power morcellators. This article has the objective to review the literature related to complications by power morcellation of uterine fibroids in laparoscopy and offer recommendations to laparoscopic surgeons in gynaecology. This project was initiated by the executive board of the European Society of Gynaecological Endoscopy. A steering committee on fibroid morcellation was installed and experienced ESGE members requested to chair an action group to address distinct clinical questions. Clinical questions were formulated with regards to the sarcoma risk in presumed uterine fibroids, diagnosis of sarcoma, complications of morcellation and future research. A literature review on the different subjects was conducted, systematic if appropriate and feasible. It was concluded that the true prevalence of uterine sarcoma in presumed fibroids is not known given the wide range of prevalences (0.45–0.014 %) from meta-analyses mainly based on retrospective trials. Age and certain imaging characteristics such as ‘lacunes’ suggesting necrosis and increased central vascularisation of the tumour are associated with a higher risk of uterine sarcoma, although the risks remain low. There is not enough evidence to estimate this risk in individual patients. Complications of morcellation are rare. Reported are direct morcellation injuries to vessels and bowel, the development of so-called parasitic fibroids requiring reintervention and the spread of sarcoma cells in the abdominal cavity, which may possibly or even likely upstaging the disease. Momentarily in-bag morcellation is investigated as it may possibly prevent morcellation complications. Because of lack of evidence, this literature review cannot give strong recommendations but offers only options which are condensed in a flow chart. Prospective data collection may clarify the issue on sarcoma risk in presumed fibroids and technology to extract tissue laparoscopically from the abdominal cavity should be perfected.

PET Imaging of Steroid Hormone Receptor Expression

Steroid hormone receptor (SHR) expression and changes in SHR expression compared to basal levels, whether upregulated, downregulated, or mutated, form a distinguishing feature of some breast, ovarian, and prostate cancers. These receptors act to induce tumor proliferation. In the imaging context, total expression together with modulation of expression can yield predictive and prognostic information. Currently, biopsy for histologic assessment of SHR expression is routine for breast and prostate cancer; however, the technique is not well suited to the heterogeneous tumor environment and can lead to incorrect receptor expression assignment, which precludes effective treatment. The development of positron emission tomography (PET) radioligands to image receptor expression may overcome the difficulties associated with tumor heterogeneity and facilitate the assessment of metastatic disease.

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.

Preoperative Ultrasound-Guided Needle Biopsy of 63 Uterine Tumors Having High Signal Intensity Upon T2-Weighted Magnetic Resonance Imaging

Objective

The differential diagnosis between uterine sarcoma and benign leiomyoma is difficult when made only by magnetic resonance imaging (MRI); it usually requires an additional preoperative diagnostic procedure. We report our results using ultrasound-guided needle biopsy for these types of uterine tumors.

Methods

Ultrasound-guided needle biopsy was performed on 63 patients with uterine smooth muscle tumors suspected of malignancy by MRI. We compared the results of presurgical biopsy against the postsurgical pathology of the tumor.

Results

Among 63 patients with a high signal intensity of the uterine tumor on T2-weighted MRI (1 case was undetermined), 12 cases (19.3%) were diagnosed by the needle biopsy as malignant, and 51 cases (80.6%) were benign. Among the 12 diagnosed as malignant tumors, 11 had surgery performed, and one was treated with chemotherapy. Among the 51 patients diagnosed with a benign tumor, 27 had surgery performed, and 24 were put on a wait-and-see clinical follow-up schedule. One of the 27 surgical patients with a benign tumor had a postsurgical diagnosis of a low-grade endometrial stromal sarcoma. In the 38 cases where surgery was performed, we found the sensitivity, specificity, and the positive and negative predictive values of the needle biopsy were 91.7%, 100%, 100%, and 96.2%, respectively.

Conclusions

Ultrasound-guided needle biopsy may be a reliable preoperative diagnostic procedure for uterine tumors with suspected malignancy.

Differentiation of aggressive and indolent subtypes of uterine sarcoma using maximum standardized uptake value

Objective

The aim of the study was to elucidate the differential metabolic activities in aggressive and indolent subtypes of uterine sarcomas, which may aid in managing these heterogeneous tumours.

Methods

We retrospectively analysed the PET/computed tomography scans of consecutive patients (N=18) diagnosed with uterine sarcoma at our unit. The patients were divided into indolent (N=4) and aggressive (N=14) tumour groups, and the maximum standardized uptake values (SUV_max) of all lesions (n=134) were measured. The SUV_max of the lesions were compared between the two tumour groups using the Mann–Whitney U-test. We calculated the optimal cutoff value as determined by receiver operating characteristic analysis. A P-value less than 0.05 was considered statistically significant.

Results

The mean SUV_max of aggressive (n=104) and indolent tumours (n=30) were significantly different (8.0±7.3 vs. 1.9±0.9 respectively; P<0.001). A cutoff of SUV_max greater than 4.0 was able to exclude indolent tumours, with 100% specificity and positive predictive value (sensitivity 72%, negative predictive value 50% and accuracy 78%; area under the curve 97%). By applying this same cutoff value on the most metabolic active lesion in each patient, we were able to correctly classify all but one patient into either the aggressive or indolent tumour group with 100% specificity and positive predictive value (sensitivity 93%, negative predictive value 80% and accuracy 94%).

Conclusion

Aggressive and indolent uterine sarcoma subtypes have differential metabolic activities that can be used to classify them and this can aid in patient management for preoperative surgical planning and treatment stratification.

Clinical application of diffusion-weighted imaging for preoperative differentiation between uterine leiomyoma and leiomyosarcoma

OBJECTIVE

This study investigated the clinical usefulness of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) value for preoperative differentiation between uterine leiomyoma and leiomyosarcoma.

STUDY DESIGN

This study included 10 lesions from 5 patients with pelvic leiomyosarcoma and 83 leiomyoma nodules from 76 patients, as identified by postoperative pathological examination (1 autopsy). All magnetic resonance examinations were performed with a 1.5-T superconductive magnetic resonance unit.

RESULTS

The leiomyosarcoma lesions were readily apparent via DWI, presenting as an intermediate- to high-intensity area in the uterine wall. All low-intensity areas presented as leiomyoma nodules. The mean ADC value for the 10 leiomyosarcoma lesions was 0.791 ± 0.145 (×10(-3) mm(2)/s), significantly lower than that of the leiomyoma nodules that presented with intermediate-intensity areas, 1.472 ± 0.285 (×10(-3) mm(2)/s) (n = 41) (P < .001), and high-intensity areas (1.100 ± 0.343) (n = 9) (P = .03). Additionally, in this study, the highest ADC value for a leiomyosarcoma was 1.095, with an intermediate DWI intensity. Based on these results, we classified the patients into 2 groups: low-risk group (barely any leiomyosarcoma risk) and high-risk group. Analyses comparing the 2 groups yielded the following: sensitivity, 100%; specificity, 94.0%; positive predictive value, 66.7%; negative predictive value, 100%; and accuracy, 94.6%.

CONCLUSION

We suggest that this modality using a combination of signal intensity on DWI and ADC value is very effective, simple, and easy to apply clinically for differential diagnosis of leiomyosarcoma and myoma.

Novel methods and tracers for breast cancer imaging

Although positron emission tomography (PET) using [(18)F]fluorodeoxyglucose (FDG) has an established role in breast cancer staging and monitoring response to therapy, more specifically novel targeted tracers are under investigation and hold promise toward identification of critical molecular targets of therapy. We review herein novel tracers in breast cancer including steroidal endocrine tracers, 16α-[(18)F]fluoro-17β-estradiol (FES) to measure tumor estrogen receptor density and function and 21-(18)F-fluoro-16α,17α-[(R)-(1'-α-furylmethylidene)dioxy]-19-norpregn-4-ene-3,20-dione (FFNP) to assay tumor progesterone receptor (PgR) expression, and to asses nuclear proliferation using 3'-deoxy-3'-fluorothymidine (FLT), membrane lipids using (11)C- or (18)F-labeled choline and amino acid transport using (11)C-methionine. These investigational tracers are moving closer to clinical use, and are likely to affect clinical care by aiding in characterization of breast cancer biology, which can have an important effect in the selection of targeted therapy and monitoring responsiveness to such therapy.

PET imaging of oestrogen receptors in patients with breast cancer

Oestrogen receptors are overexpressed in around 70% of all breast cancers, and are a target for endocrine therapy. These receptors can be visualised on PET with use of 16α-[(18)F]-fluoro-17β-oestradiol ((18)F-FES) as a tracer. Compared with biopsy, which enables assessment of individual sites, whole-body (18)F-FES-PET enables quantification of oestrogen-receptor expression in all metastases. In several studies, measurement of tumour protein expression in oestrogen receptors by (18)F-FES-PET, concurrent with biopsy, detected oestrogen-receptor-positive tumour lesions with a sensitivity of 84% and specificity of 98%. Roughly 45% of patients with metastatic breast cancer have discordant oestrogen-receptor expression across lesions (ie, (18)F-FES-positive and (18)F-FES-negative metastases). Low tumour (18)F-FES uptake in metastases can predict failure of hormonal therapy in patients with oestrogen-receptor-positive primary tumours. Finally, (18)F-FES-PET has shown that oestrogen-receptor binding capacity changes after intervention with hormonal drugs, but findings need to be confirmed. Factors other than oestrogen-receptor expression, including menopausal status and concomitant therapies, that can affect tumour (18)F-FES uptake must be taken into account.

18F-FES and 18F-FDG PET for differential diagnosis and quantitative evaluation of mesenchymal uterine tumors: correlation with immunohistochemical analysis

The aim of this study was to investigate the relationship between the tumor uptake of 16α-(18)F-fluoro-17β-estradiol ((18)F-FES) and (18)F-FDG using PET and expressions of sex hormone receptors, such as estrogen receptor (ER), as well as glucose transporter 1 (GLUT-1) and Ki-67 analyzed by the immunohistochemistry method in mesenchymal uterine tumors.

METHODS

Forty-seven patients with mesenchymal uterine tumors were studied with (18)F-FES and (18)F-FDG PET. Postoperative pathologic diagnosis revealed 33 uterine leiomyomas and 14 uterine sarcomas. Tissue samples were assayed for expression of ERα, ERβ, progesterone receptor (PR), PR-B, GLUT-1, and Ki-67 by an immunohistochemistry method. Standardized uptake values (SUVs) for (18)F-FES and (18)F-FDG were compared with the semiquantitative immunoreactive score (0-12) and quantitative labeling index (LI) for Ki-67 in immunohistochemistry.

RESULTS

(18)F-FES uptake was significantly lower (P < 0.001) and the (18)F-FDG uptake and SUV ratio of (18)F-FDG to (18)F-FES ((18)F-FDG/(18)F-FES ratio) (P < 0.005 and P < 0.001, respectively) were significantly higher in uterine sarcomas than in leiomyomas. Immunohistochemistry analysis showed significantly higher expressions of ERα, PR, and PR-B in uterine leiomyomas than in sarcomas. The Ki-67 LI was significantly greater in uterine sarcomas than in leiomyomas. Correlation analysis for all tumors showed positive correlations between (18)F-FES SUV and immunohistochemistry scores of ERα, PR (P < 0.001), and PR-B (P < 0.005) as well as between (18)F-FDG SUV and GLUT-1 and Ki-67 (P < 0.001). However, the (18)F-FDG/(18)F-FES ratio showed significantly negative correlations with ERα, PR (P < 0.001), and PR-B (P < 0.005) and a positive correlation with Ki-67 LI (P < 0.001). In uterine sarcomas, ERα and (18)F-FES SUV showed a positive correlation (P < 0.001) in a low SUV range, and the (18)F-FDG/(18)F-FES ratio showed positive correlations with ERβ and GLUT-1 expression (P < 0.005).

CONCLUSION

(18)F-FES and (18)F-FDG PET showed correlations between tracer uptake and expressions of sex hormone receptors, GLUT-1, and Ki-67 in mesenchymal uterine tumors. The (18)F-FDG/(18)F-FES ratio was correlated with Ki-67, GLUT-1, and ERβ in uterine sarcoma. Functional PET imaging and PET parameters would be useful noninvasive biomarkers for the assessment of tumor hormone receptor expression, glucose metabolism, and proliferation and for differential diagnosis of uterine leiomyoma and sarcoma.

18F-FLT PET performs better than 18F-FDG PET in differentiating malignant uterine corpus tumors from benign leiomyoma

PURPOSE

The aim of this study is to test the hypothesis that positron emission tomography (PET) with 3'-deoxy-3'-[(18)F]-fluorothymidine ((18)F-FLT) can differentiate malignancy from benign leiomyoma better than PET with 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG), and to evaluate whether (18)F-FLT and (18)F-FDG uptake correlate with immunohistochemical index of cell proliferation.

METHODS

The protocol of this prospective study was approved by the institutional ethics committee, and all patients gave written informed consent. Fifteen patients (aged 26-65 years, median 44 years) with uterine corpus tumor which has the possibility of being leiomyosarcoma underwent (18)F-FLT and (18)F-FDG PET scans. Maximum standard uptake value (SUV(max)) of PET scans and Ki-67 labeling index of surgical specimens were evaluated. Mann-Whitney's U test was used for comparing uptakes between benign and malignant, and linear regression analysis was used for evaluating the correlation between Ki-67 labeling index and SUV(max).

RESULTS

Five cases were diagnosed as malignant (leiomyosarcoma for 3 cases, and carcinoma for 2 cases), and the others were benign leiomyoma. Sensitivity and negative predictive value of both tracers for detecting malignancy was 100%. Specificity, positive predictive value and accuracy of (18)F-FLT PET were higher than those of (18)F-FDG PET. Difference in SUV(max) between malignant and benign was significant for (18)F-FLT PET (P < 0.01), but not for (18)F-FDG PET. While all the malignant cases showed positive uptake in both tracers, a case of leiomyosarcoma with huge necrosis showed relatively low uptake. Uptake of (18)F-FLT showed better correlation with Ki-67 labeling index compared with (18)F-FDG (R(2) = 0.91 vs. R(2) = 0.26).

CONCLUSION

Negative findings on additional (18)F-FDG or (18)F-FLT PET may rule out the possibility of malignancy for the patients with suspected leiomyosarcoma diagnosed by conventional methods. (18)F-FLT PET is superior to (18)F-FDG PET in differentiating malignant from benign leiomyoma. Moreover, (18)F-FLT uptake correlated well with the immunohistochemical index of cell proliferation.

Oestrogen-related tumour phenotype: positron emission tomography characterisation with ¹⁸F-FDG and ¹⁸F-FES

This article outlines the role of 16α-[(18)F]fluoro-17β-oestradiol ((18)F-FES) positron emission tomography (PET) combined with 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) in patients with oestrogen-related tumours for evaluating tumour phenotype. (18)F-FES-PET combined with (18)F-FDG is helpful in characterising the distinct phenotypic features of oestrogen-related tumours; that is, inter- and intrapatient tumour heterogeneity, which indicates its great potential as a determinant of individualised treatment and a prognostic predictor for patients with oestrogen-related tumours.