Whole-body positron emission tomography and tumor marker CA125 for detection of recurrence in epithelial ovarian cancer

ACR Appropriateness Criteria® Staging and Follow-Up of Ovarian Cancer

In the management of epithelial ovarian cancers, imaging is used for cancer detection and staging, both before and after initial treatment. The decision of whether to pursue initial cytoreductive surgery for ovarian cancer depends in part on accurate staging. Contrast-enhanced CT of the abdomen and pelvis (and chest where indicated) is the current imaging modality of choice for the initial staging evaluation of ovarian cancer. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT and MRI may be appropriate for problem-solving purposes, particularly when lesions are present on CT but considered indeterminate. In patients who achieve remission, clinical suspicion for relapse after treatment prompts imaging evaluation for recurrence. Contrast-enhanced CT is the modality of choice to assess the extent of recurrent disease, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT is also usually appropriate, as small metastatic foci may be identified. If imaging or clinical examination confirms a recurrence, the extent of disease and timing of disease recurrence then determines the choice of treatments, including surgery, chemotherapy, and radiation therapy. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The added value of whole-body magnetic resonance imaging in the management of patients with advanced breast cancer

This study investigates the impact of whole-body MRI (WB-MRI) in addition to CT of chest-abdomen-pelvis (CT-CAP) and 18F-FDG PET/CT (PET/CT) on systemic treatment decisions in standard clinical practice for patients with advanced breast cancer (ABC). WB-MRI examinations in ABC patients were extracted from our WB-MRI registry (2009-2017). Patients under systemic treatment who underwent WB-MRI and a control examination (CT-CAP or PET/CT) were included. Data regarding progressive disease (PD) reported either on WB-MRI or on the control examinations were collected. Data regarding eventual change in treatment after the imaging evaluation were collected. It was finally evaluated whether the detection of PD by any of the two modalities had induced a change in treatment. Among 910 WB-MRI examinations in ABC patients, 58 had a paired control examination (16 CT-CAP and 42 PET/CT) and were analysed. In 23/58 paired examinations, additional sites of disease were reported only on WB-MRI and not on the control examination. In 17/28 paired examinations, PD was reported only on WB-MRI and not on the control examination. In 14 out of the 28 pairs of examinations that were followed by a change in treatment, PD had been reported only on WBMRI (14/28; 50%), while stable disease had been reported on the control examination. In conclusion, WB-MRI disclosed PD earlier than the control examination (CT-CAP or PET/CT), and it was responsible alone for 50% of all changes in treatment.

Diagnostic value of integrated ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography in recurrent epithelial ovarian cancer: accuracy of patient selection for secondary cytoreduction in 134 patients

Objective

The aim of this study was to evaluate the diagnostic value of integrated ¹⁸F-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) for suspected recurrence of epithelial ovarian cancer (EOC) with non-disseminated lesions.

Methods

We retrospectively reviewed the medical records of recurrent EOC patients who underwent secondary cytoreduction from January 2000 to December 2013. A total of 134 patients underwent secondary cytoreduction after imaging with either ¹⁸F-FDG-PET/CT or contrast-enhanced computed tomography (CECT).

Results

In a patient-based analysis of 134 patients, 124 (92.5%) were confirmed to be positive for malignancy. Among 72 patients with suspected non-disseminated recurrence on ¹⁸F-FDG-PET/CT, 65 (89.0%) were confirmed to have recurrence, giving 98.5% sensitivity, 87.7% accuracy, and 88.9% positive predictive value (PPV). In the 65 patients with recurrence, residual tumor remained in 14 patients, giving an accuracy of patient selection for secondary cytoreduction of 69.4% (50/72) and it is higher than that of CECT (64.0%). In 169 lesions removed from patients who underwent preoperative ¹⁸F-FDG-PET/CT, 135 (79.9%) were confirmed to be positive for malignancy and 124 were accurately detected by ¹⁸F-FDG-PET/CT, giving 91.9% sensitivity, 81.1% accuracy, and 85.5% PPV. Foreign body granuloma was found in 33.3% of 21 lesions with false-positive ¹⁸F-FDG-PET/CT findings (7/21). The mean preoperative cancer antigen 125 (CA-125) level in false-positive patients was 28.8 U/mL.

Conclusion

Compared with CECT, ¹⁸F-FDG-PET/CT shows higher sensitivity in lesion-based analysis and better accuracy of patient selection for secondary cytoreduction. However, there is still a need for integration of the results of ¹⁸F-FDG-PET/CT, CECT, and CA-125 levels to aid treatment planning.

Diagnostic value of positron emission tomography (PET) and PET/computed tomography in recurrent/metastatic ovarian cancer: A meta-analysis

AIM

The study was conducted to assess and compare the overall diagnostic value of positron emission tomography (PET) alone and PET/computed tomography (CT) for the detection of recurrent/metastatic ovarian cancer.

METHODS

A systematic literature search in PubMed, EMBASE and Chinese literature databases (CNKI, VIP and Wanfang) up to August 2014 was performed to identify relevant articles. The diagnostic performance of PET alone or PET/CT was assessed in terms of the following evaluation indexes: summary sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio and area under the curve summary receiver operating characteristics.

RESULTS

Sixty-four studies with 3722 patients were included in this meta-analysis. Favorable results were obtained for both PET/CT and PET alone with similar sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio and area under the curve in diagnosing recurrent/metastatic ovarian cancer (P > 0.05). However, the sensitivity of PET/CT was significantly higher than PET alone in European patients.

CONCLUSIONS

Both PET and PET/CT have promising diagnostic value in recurrent/metastatic ovarian cancer. The diagnostic performance of PET/CT may be superior to PET alone in European patients.

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.

Predictive value of (18)F-FDG PET/CT in restaging patients affected by ovarian carcinoma: a multicentre study

PURPOSE

Ovarian cancer is the eighth most common malignancy among women and has a high mortality rate. Prognostic factors able to drive an effective therapy are essential. (18)F-Fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has been investigated in patients with epithelial ovarian cancer and showed promise in diagnosing, staging, detecting recurrent lesions and monitoring treatment response. Conversely, its prognostic role remains unclear. We aimed at assessing the prognostic value of (18)F-FDG PET/CT performed in the restaging process in a multicentre study.

METHODS

We evaluated 168 patients affected by ovarian carcinoma, who underwent a restaging (18)F-FDG PET/CT. The presence of local recurrences, lymph node involvement and distant metastasis was recorded as well as lesion dimensions, maximum and mean standardized uptake values (SUVmax and SUVmean, respectively). Progression-free survival (PFS) and overall survival (OS) at 3 and 4 years were computed by using Kaplan-Meier curves. Increased odds ratio was assessed using Cox regression analysis testing all lesion parameters measured by PET/CT.

RESULTS

PFS was significantly longer in patients with a negative than a positive restaging PET/CT study (3- and 4-year PFS 64 and 53% vs 23 and 12%, respectively; p < 0.001). Similarly, a negative study was associated with a significantly higher OS rate after 4 years of follow-up (67 vs 25% in negative and positive groups, respectively; p < 0.001). Lymph node or distant involvement were also independently associated with an increased risk of disease progression [hazard ratio (HR) 1.6 and 2.2, respectively; p = 0.003]. Moreover, PET/CT showed an incremental prognostic value compared to the International Federation of Gynecology and Obstetrics (FIGO) staging system. In the analysis of patient subsets, individuals with the same FIGO stage I-II but with negative PET had a significantly better 4-year OS than patients with low FIGO stage but positive PET. This implies that patients with the same FIGO stage can be further prognostically stratified using PET (p = 0.01). At receiver-operating characteristic (ROC) analysis, no thresholds for semiquantitative parameters were predictive of a worse outcome.

CONCLUSION

(18)F-FDG PET/CT has an important prognostic value in assessing the risk of disease progression and mortality rate. An efficacious therapy planning might therefore effectively rely on (18)F-FDG PET/CT findings. Semiquantitative data were not proven to be an effective tool to predict disease progression.

Simultaneous positron emission tomography/magnetic resonance imaging for whole-body staging in patients with recurrent gynecological malignancies of the pelvis: a comparison to whole-body magnetic resonance imaging alone

OBJECTIVES

The objective of this study was to assess the diagnostic value of integrated positron emission tomography/magnetic resonance imaging (PET/MRI) for whole-body staging of patients with recurrent gynecological pelvic malignancies, in comparison to whole-body MRI alone.

MATERIALS AND METHODS

The study was approved by the local institutional ethics committee. Written informed consent was obtained before each examination. Thirty-four consecutive patients with a suspected recurrence of cervical (n = 18) or ovarian (n = 16) cancer were prospectively enrolled for an integrated PET/MRI examination, which comprised a diagnostic, contrast-enhanced whole-body MRI protocol including dedicated sagittal dynamic imaging of the pelvis. Two radiologists separately evaluated the data sets regarding lesion count, lesion detection, lesion characterization, and diagnostic confidence. Mean and median values were calculated for each rating. Statistical analyses were performed both per-patient and per-lesion bases using a Wilcoxon signed-rank test to indicate potential significant differences among PET/MRI and MRI (alone) data sets.

RESULTS

Malignant lesions were present in 25 of the 34 patients. Positron emission tomography/magnetic resonance imaging offered correct and superior identification of all 25 patients with cancer recurrence, compared with MRI alone (23/25). A total of 118 lesions (malignant, 89; benign, 29) were detected. Positron emission tomography/magnetic resonance imaging correctly identified 88 (98.9%) of 89 malignant lesions, whereas MRI alone allowed for correct identification of 79 (88.8%) of the 89 malignant lesions. In addition, PET/MRI provided significantly higher lesion contrast and diagnostic confidence in the detection of malignant lesions (P < 0.001) compared with MRI alone.

CONCLUSIONS

These first results demonstrate the high diagnostic potential of integrated PET/MRI for the assessment of recurrence of female pelvic malignancies compared with MRI alone.

Immuno-PET of epithelial ovarian cancer: harnessing the potential of CA125 for non-invasive imaging

Background

Epithelial ovarian cancer (EOC) is characterized by the overexpression of cancer antigen 125 (CA125), a mucinous glycoprotein that serves as a tumor biomarker. Early diagnosis of EOC is plagued by its asymptomatic nature of progression and the limitations of currently used immunoassay techniques that detect CA125 as a shed antigen in serum samples. Presently, there is no technique available for the in vivo evaluation of CA125 expression in malignant tissues. Moreover, there could be an unexplored pathophysiological time window for the detection of CA125 in EOC, during which it is expressed on tumor cells prior to being shed into the bloodstream. A method for the in vivo evaluation of CA125 expression on ovarian neoplasms earlier along disease progression and/or recurrence can potentially contribute to better disease management. To this end, the present work utilizes an anti-CA125 monoclonal antibody (MAb) and a single-chain variable fragment (scFv) labeled with the positron-emitting radionuclide ⁶⁴Cu for preclinical molecular imaging of CA125 expression in vivo.

Methods

Anti-CA125 MAb and scFv were prepared and functionally characterized for target binding prior to being tested as radiotracers in a preclinical setting.

Results

Immunoblotting, immunofluorescence, and flow cytometry revealed specific binding of CA125-targeting vectors to NIH:OVCAR-3 cells and no binding to antigen-negative SKOV3 cells. ⁶⁴Cu-labeled anti-CA125 MAb and scFv were obtained in specific activities of 296 and 122 MBq/mg, respectively. Both radioimmunoconjugate vectors demonstrated highly selective binding to NIH:OVCAR-3 cells and virtually no binding to SKOV3 cells. In vivo radiopharmacological evaluation using xenograft mouse models injected with ⁶⁴Cu-labeled anti-CA125 MAb provided a standardized uptake value (SUV) of 5.76 (29.70 %ID/g) in OVCAR3 tumors 24 h post-injection (p.i.) versus 1.80 (5.91 %ID/g) in SKOV3 tumors. ⁶⁴Cu-labeled anti-CA125 scFv provided an SUV of 0.64 (3.21 %ID/g) in OVCAR3 tumors 24 h p.i. versus 0.25 (1.49 %ID/g) in SKOV3 tumors. Results from small-animal PET imaging were confirmed by ex vivo autoradiography and immunohistochemistry.

Conclusions

Radiolabeling of anti-CA125 MAb and scFv with ⁶⁴Cu did not compromise their immunoreactivity. Both radioimmunoconjugates presented specific tumor uptake and expected biological clearance profiles. This renders them as potential immuno-PET probes for targeted in vivo molecular imaging of CA125 in EOC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-014-0060-4) contains supplementary material, which is available to authorized users.

Which imaging technique should we use in the follow up of gynaecological cancer?

Follow-up routines after gynaecological cancer vary. The optimal approach is unknown, and no randomised-controlled trials comparing surveillance protocols have been published. In this chapter, we summarise the diagnostic performance of ultrasound, computed tomography, and magnetic resonance imaging in the follow up of women treated for ovarian or uterine cancers. Computed tomography is today the standard imaging method for the follow up of women treated for endometrial, cervical, or ovarian cancer. Six-monthly or annual follow-up examinations have not been shown to positively affect survival. Instead, a combination of transvaginal and transabdominal ultrasound examination with clinical examination might be a more cost-effective strategy for early detection of recurrence. Positron-emission tomography might play a role in women with clinical or serological suspicion of recurrence but without evidence of disease at conventional diagnostic imaging. To create guidelines, more studies, preferably randomised-controlled trials, on follow-up strategies are needed.

The special role of ultrasound for screening, staging and surveillance of malignant ovarian tumors: distinction from other methods of diagnostic imaging

Ovarian cancer is the most aggressive gynecologic malignancy, with a 5-year survival rate ranging around 40%. A crucial factor influencing the prognosis is early detection of a suspicious mass and referral to a gynecologic oncology center for further diagnosis, staging and debulking surgery. Here, we present the different imaging methods ultrasound (US), magnetic resonance imaging, computer tomography (CT) and 18F-fluoro-deoxyglucose positron emission tomography (PET)/CT that are used for the characterization, diagnosis, staging and surveillance of ovarian cancer. In this review, we focus on US and discuss in detail the advantages and the limitations, as well as the appropriate indications for each of the individual imaging techniques.

Long Term Prognostic Implications of Expression of Glucose Transporter-1 and Hexokinase II in Patients with Stage I Uterine Leiomyosarcoma

Many malignant epithelial tumors show increased expression of glucose transporter-1 (GLUT-1) and hexokinase II (HK-II), both of which are involved in glucose metabolism. GLUT-1 levels are often correlated with prognosis in these tumors. The current retrospective study was conducted to evaluate the importance of GLUT-1 and HK-II expression in leiomyosarcoma (LMS), a malignant uterine non-epithelial tumor with a poor prognosis. The subjects were 23 patients with stage I LMS. Expression of GLUT-1 and HK-II was evaluated immunohistochemically in samples removed surgically, and the MIB-1 index was evaluated as a measure of cell proliferation. The association of these results with prognosis was examined. Twenty samples of leiomyoma (LOM), a benign non-epithelial tumor, were used as controls. Immunohistochemical expression was defined as negative staining (–), weak to sporadic staining (1+), and strong staining (2+) per microscopic field, respectively. Malignancy was evaluated in 2000 cells and the MIB-1 index was calculated. Overall survival for LMS was estimated using the Kaplan-Meier method. Of the LMS cases, 12 were GLUT-1-positive (52.2%; 2+: 2, 1+: 10) and 15 were HK-II-positive (65.2%; 2+: 1, 1+: 14). GLUT-1 expression in LMS was significantly correlated with the MIB1 index. The 10-year survival rates were 90.9% and 58.3% in GLUT-1-negative and GLUT-1-positive cases, respectively, and 75.0% and 73.3% in HK-II-positive and HK-II-negative cases, respectively. GLUT-1 expression was significantly correlated with prognosis. Cases of stage I LMS showed a significant correlation between the expression level of GLUT-1 and the MIB-1 index, an indicator of malignancy. GLUT-1-negative cases had a better prognosis than GLUT-1-positive cases, suggesting that GLUT-1 expression is an effective prognostic marker.

Role of New Functional MRI Techniques in the Diagnosis, Staging, and Followup of Gynecological Cancer: Comparison with PET-CT

Recent developments in diagnostic imaging techniques have magnified the role and potential of both MRI and PET-CT in female pelvic imaging. This article reviews the techniques and clinical applications of new functional MRI (fMRI) including diffusion-weighted MRI (DWI), dynamic contrast-enhanced (DCE)-MRI, comparing with PET-CT. These new emerging provide not only anatomic but also functional imaging, allowing detection of small volumes of active tumor at diagnosis and early disease relapse, which may not result in detectable morphological changes at conventional imaging. This information is useful in distinguishing between recurrent/residual tumor and post-treatment changes and assessing treatment response, with a clear impact on patient management. Both PET-CT and now fMRI have proved to be very valuable tools for evaluation of gynecologic tumors. Most papers try to compare these techniques, but in our experience both are complementary in management of these patients. Meanwhile PET-CT is superior in diagnosis of ganglionar disease; fMRI presents higher accuracy in local preoperative staging. Both techniques can be used as biomarkers of tumor response and present high accuracy in diagnosis of local recurrence and peritoneal dissemination, with complementary roles depending on histological type, anatomic location and tumoral volume.

Histologic, molecular, and cytogenetic features of ovarian cancers: implications for diagnosis and treatment

Ovarian epithelial carcinoma (OEC), the most common ovarian malignancy, is a heterogeneous disease with several histologic subtypes that show characteristic cytogenetic features, molecular signatures, oncologic signaling pathways, and clinical-biologic behavior. Recent advances in histopathology and cytogenetics have provided insights into pathophysiologic features and natural history of OECs. Several studies have shown that high- or low-grade serous, endometrioid, and clear cell carcinomas are characterized by mutations involving the TP53, K-ras/BRAF, CTNNB1, and PIK3CA genes, respectively. High-grade serous carcinomas, the most common subtype, often manifest with early transcoelomic spread of disease beyond the ovaries, whereas low-grade serous and mucinous carcinomas commonly manifest with early-stage disease, with a resultant excellent prognosis. On the basis of pathogenetic mechanisms, recent findings suggest a dualistic model of ovarian carcinogenesis consisting of types I and II. Type I (low-grade serous, mucinous, and endometrioid) cancers commonly arise from well-described, genetically stable precursor lesions (usually borderline tumors); manifest as large adnexal masses with early-stage disease; and have a relatively indolent clinical course, with an overall good prognosis. In contrast, type II carcinomas (high-grade serous, endometrioid, mixed, and undifferentiated variants) originate de novo from the adnexal epithelia, often demonstrate chromosomal instability, and have aggressive biologic behavior. Better knowledge of hereditary ovarian cancer syndromes and associated cytogenetic abnormalities has led to increased interest in novel biomarkers and molecular therapeutics. Genetic changes, pathologic features, imaging findings, and natural histories of a variety of histologic subtypes of OEC are discussed in this article.

The role of FDG-PET/CT in ovarian cancer patients with high tumor markers or suspicious lesion on contrast-enhanced CT in evaluation of recurrence and/or in determination of intraabdominal metastases

OBJECTIVES

This retrospective study was designed to investigate the role of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in determination of recurrence and/or intraabdominal metastasis in patients with ovarian cancer having increased tumor markers or suspicious lesion detected by a contrast-enhanced abdominal CT (ceCT).

MATERIALS AND METHODS

A total of 34 female patients who were treated for histopathologically proven ovarian cancer, underwent PET/CT examination for restaging and suspected recurrence. Patients with pathology report, tumor marker levels, ceCT and PET/CT performed within one month were included in the study.

RESULTS

A total of 34 patients were included in the study. 25 of 34 patients had high tumor marker (CA 125) level. The remaining 9 patients had suspected recurrence on ceCT imaging with normal tumor marker levels. Recurrence was confirmed by re-operation and biopsy (n=4), clinical and imaging follow-up (n=21) in 25 patients with elevated tumor markers. Recurrent disease was not shown in 5 of 25 patients on ceCT imaging and 1 of 25 patients on PET/CT imaging with high CA125 values. Both ceCT and PET/CT revealed recurrent disease in 19 of 25 patients. PET/CT showed more lesions in 11 of 19 patients. Sensitivity, specificity and accuracy of the PET/CT were 96.1%, 100% and 97%, respectively.

CONCLUSION

PET/CT is found as a beneficial method for detection of the recurrence, in patients with increased serum CA 125 level and negative CT findings or with normal CA 125 level and recurrence detected by CT which was performed due to clinical symptoms.

The utility and cost of routine follow-up procedures in the surveillance of ovarian and primary peritoneal carcinoma: a 16-year institutional review

Background:

The purpose of this study was to evaluate the number of ovarian cancer and primary peritoneal cancer (PPC) progressive disease cases identified via routine follow-up procedures and the corresponding cost throughout a 16-year period at a single medical institution.

Methods:

Previously undiagnosed epithelial ovarian (n=241), PPC (n=23), and concurrent ovarian and uterine (n=24) cancer patients were treated and then followed via CA-125, imaging (e.g., CT scan, chest X-ray), physical examination and vaginal cytology.

Results:

In the group of 287 patients, there were 151 cases of disease progression. Serial imaging detected the highest number of progressive disease cases (66 initial and 45 confirmatory diagnoses), but the cost was rather high ($13 454 per patient recurrence), whereas CA-125 testing (74 initial and 20 corroborative diagnoses) was the least expensive ($3924) per recurrent diagnosis. The total cost of surveillance during the 16-year period was nearly $2 400 000.

Conclusion:

Ultimately, serial imaging and the CA-125 assay detected the highest number of ovarian cancer and PCC progressive disease cases in comparison to physical examination and vaginal cytology, but nevertheless, all of the procedures were conducted at a considerable financial expense.

Prevalence of positive FDG-PET findings in patients with high CEA levels

OBJECTIVE

The purpose of this study was to evaluate the prevalence of positive findings of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in patients with high serum CEA levels.

METHODS

A total of 303 patients who had undergone an FDG-PET scan in our institution with high serum CEA levels were analyzed. The prevalence of positive PET findings was evaluated with regard to a previous history of malignancy, absolute value of CEA levels, and the time course of CEA levels (an increasing or decreasing pattern, a change divided by time (DeltaCEA) and doubling time of CEA).

RESULTS

Of 303 patients, 232 were confirmed to have malignancy, and the patient-based sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PET were 87, 86, 95, 66, and 86%, respectively. There was no statistically significant difference in positive rates according to the history of previous malignancy. The prevalence of PET-positive cases was higher with an increase in absolute CEA levels, and more than 90% of the patients were positive when CEA levels were more than 20 ng/ml. The DeltaCEA was significantly higher and the doubling time was significantly shorter in patients with positive results than those with negative results.

CONCLUSIONS

A high value of serum CEA levels was correlated with a higher prevalence of positive PET findings. FDG-PET scans would be justified in patients with high serum CEA levels, regardless of whether there was or was not a previous history of malignancy.

Surveillance of patients after initial treatment of ovarian cancer

The surveillance of ovarian cancer patients after initial treatment is a challenging question in clinical practice. Serum CA 125 assay, physical examination, and imaging examinations have been employed with different time schedules for the follow-up of asymptomatic patients. Rising serum CA 125 levels may precede the clinical detection of relapse in 56-94% of cases with a median lead time of 3-5 months. An ongoing randomised phase III European trial is comparing the benefits of early administration of chemotherapy based on serum CA 125 assay alone versus delaying treatment until clinical or radiological detection of recurrent disease. Physical examination, with or without ultrasound, is very useful for the surveillance of these patients, since approximately 25-50% of relapses involve the pelvis. Additional radiological imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), are usually performed in asymptomatic patients with rising CA 125 levels as well as in patients with suspicious symptoms or signs. Integrated positron emission tomography (PET) and CT scanners (PET/CT) can identify recurrent disease in tissues that appear normal at CT imaging as well as metastatic lesions intimately associated with the bowel wall that are difficult to detect with CT or MRI, so that in most series PET/CT has a higher diagnostic reliability than that of conventional imaging techniques. Moreover, PET/CT can disclose unusual supra-diaphragmatic spreading of the disease and may be very helpful for treatment planning, especially for the selection of patients suitable for secondary surgical cytoreduction. A prospective, randomised trial of therapeutic interventions based on stratification by PET/CT disease status could elucidate the real impact of this diagnostic procedure in the management of patients with recurrent ovarian cancer.

ACR Appropriateness Criteria® on Staging and Follow-Up of Ovarian Cancer

Ovarian cancer is the most common cause of cancer death from gynecologic malignancy in women. The diagnosis and treatment of ovarian cancer are especially challenging because of the high prevalence of benign disease in the ovaries and the tendency for late presentation of ovarian cancer after it has spread. The role of diagnostic imaging is in lesion detection, lesion characterization, preoperative staging, and the prediction of disease resectability that may require chemotherapy and later debulking for improved survival.

F-18 fluorodeoxyglucose uptake in leiomyomatous uterus

Leiomyomas of uterus are common disease in gynecology. It is important to differentiate leiomyoma from leiomyosarcoma at the decision of treatment methods, especially in the case of the conservative treatment for uterine leiomyoma. But the exact diagnosis of benign leiomyoma is often difficult due to the degeneration of myoma by imaging modalities including magnetic resonance imaging. Recently, whole-body positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) has been used for a diagnosis of malignant tumors. There is a growing body of evidence for the use of FDG in differentiating malignant from benign disease. But optimal utilization in gynecology remains unclear. Our case represents increased uptake of FDG in myomatous uterus, which is pathologically confirmed benign leiomyoma by the hysterectomy. Immunohistochemical analysis of glucose transporter-1 showed positive in endometrial tissue and negative in leiomyoma. Our case indicates that myomatous uterus in premenopausal women shows the potential pitfall of a positive result of FDG-PET.

Ovarian cancer

Imaging has become an essential part of the clinical management of patients with ovarian cancer, contributing to tumor detection, characterization, staging, treatment planning, and follow-up. Imaging findings incorporated into the clinical impression assist in creating a treatment plan specific for an individual patient. Advances in cross-sectional imaging and nuclear medicine (PET) have yielded new insights into the evaluation of tumor prognostic factors. A multimodality approach can satisfy the complex imaging needs of a patient with ovarian cancer; however, the success of such an approach always depends on available resources and on the skills of the physicians involved.

Role of [18F]FDG PET/CT in the assessment of suspected recurrent ovarian cancer: correlation with clinical or histological findings

PURPOSE

To evaluate the accuracy of integrated positron emission tomography (PET) and computed tomography (CT) for depiction of suspected recurrent ovarian carcinoma after treatment, with use of clinical or histological findings as the reference standard.

METHODS

Seventy-seven women (median age, 51 years) with ovarian carcinoma treated with primary cytoreductive surgery followed by platinum-based combination chemotherapy were included, and [18F]fluorodeoxyglucose (FDG) PET/CT was performed for suspected recurrence. In all patients, imaging findings were compared with results of histological examination after surgical exploration or clinical follow-up to determine the diagnostic accuracy of PET/CT in the evaluation of disease status. Fisher's exact test was used to measure the ability of PET/CT to predict recurrent lesions.

RESULTS

Forty-five (58.4%) of the 77 patients had documented recurrence during surgical exploration or clinical follow-up, while 32 (41.6%) had no evidence of recurrent tumour. Of the 45 patients with recurrent disease, 27 (60%) were confirmed to have recurrence by surgical biopsy. A correlation was found between PET/CT and histological or clinical analyses (kappa = 0.894). The overall sensitivity, specificity, accuracy, positive predictive value and negative predictive value of PET/CT were 93.3%, 96.9%, 94.8%, 97.7% and 91.2%, respectively. PET/CT modified the diagnostic or treatment plan in 19 (24.7%) patients, by leading to the use of previously unplanned therapeutic procedures in 11 (57.9%) patients and the avoidance of previously planned diagnostic procedures in eight (42.1%) patients.

CONCLUSION

Integrated FDG PET/CT is a sensitive post-therapy surveillance modality for the detection of recurrent ovarian cancer; it aids decisions on treatment plans and may ultimately have a favourable impact on prognosis.