Diagnostic accuracy of FDG PET in the follow-up of platinum-sensitive epithelial ovarian carcinoma

Meta-analysis of the diagnostic value of 18F-FDG PET/CT in the recurrence of epithelial ovarian cancer

BACKGROUND

Ovarian cancer is the leading cause of cancer-related death among gynecologic malignancies. With much evidence suggesting that 18F-FDG PET/CT may be an excellent imaging test for the diagnosis of epithelial ovarian cancer recurrence, we conducted a systematic review and meta-analysis to summarize relevant studies and evaluate the accuracy and application value of 18F-FDG PET/CT in the diagnosis of recurrence of epithelial ovarian cancer.

MATERIALS AND METHODS

Clinical trials of 18F-FDG PET/CT for the diagnosis of recurrence of epithelial ovarian cancer were systematically searched in PubMed, Embase, Cochrane Library, Web of Science and OVID database. The relevant literature was searched until May 22, 2022. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to evaluate the quality of the included original studies, and the meta-analysis was performed using a bivariate mixed-effects model and completed in Stata 15.0.

RESULTS

A total of 17 studies on 18F-FDG PET/CT for the diagnosis of epithelial ovarian cancer recurrence were included in this systematic review, involving 639 patients with epithelial ovarian cancer. Meta-analysis showed that the sensitivity, specificity and area under the curve of 18F-FDG PET/CT for the diagnosis of epithelial ovarian cancer recurrence were 0.88 (95% CI: 0.79 - 0.93), 0.89 (95% CI: 0.72 - 0.96) and 0.94 (95% CI: 0.91- 0.96), respectively. Subgroup analysis showed higher diagnostic efficacy in prospective studies than in retrospective studies, and no significant publication bias was observed in Deeks' funnel plot, with sensitivity analysis revealing the stability of results. Meta regression shows that the heterogeneity of this study comes from study type.

CONCLUSION

18F-FDG PET/CT has good diagnostic value in the recurrence of epithelial ovarian cancer.

Role of biomarkers for early detection of ovarian cancer recurrence

Ovarian cancer is frequently diagnosed at an advanced stage and a fraction of these patients fail to respond to primary therapy and relapses in 70% of cases. On account of the high recurrence probability and the poor outcomes after recurrence, there is an urgent need to predict progression as early as possible and thus found the strategies to detect and prevent a recurrence. Considering that biomarkers have contributed to the management of ovarian cancer by distinguishing benign and malignant pelvic masses and monitoring response to treatment, in this review, we aim to discuss the latest evidence reported in the literature about the use of biomarkers to detect OC recurrence. In detail, we summarized all the evidence of the most quoted biomarkers like HE4, osteopontin, mesothelin (MSLN), Folate receptor α (FOLR1), paraneoplastic antigens, miRNA, cancer stem cells (CSCs) and a combination of them to evaluate their role as prognostic biomarkers for ovarian cancer recurrence.

[Follow-up of patients treated for an epithelial ovarian cancer, place of hormone replacement therapy and of contraception: Article drafted from the French Guidelines in oncology entitled "Initial management of patients with epithelial ovarian cancer" developed by FRANCOGYN, CNGOF, SFOG, GINECO-ARCAGY under the aegis of CNGOF and endorsed by INCa]

OBJECTIVES

To define follow-up modalities after an epithelial ovarian, tubal or primitive peritoneal cancer. To define possibilities of hormone replacement therapy (HRT) and contraceptive use after treatment.

METHODS

Systematic review of the literature in French and English langage conducted on Pubmed/Medline and the Cochrane Library.

RESULTS

After the treatment of an epithelial ovarian, tubal or primitive peritoneal cancer, symptoms evaluation for follow-up is recommended at 3 months, 6 months, 12 months, 18 months, 24 months, and then yearly (Grade B). Only patients with an initial complete surgery (CC0, without any macroscopic signs of disease), and with a good general condition (ECOG 0) should be followed with paraclinic tests, with a serum HE4 or CA125 concentration measurement, from 6 months after the end of treatments (GradeC). Systematic follow-up with CT of the chest, abdomen, and pelvis is not recommended (GradeC). Imaging test is recommended in case of an increased serum concentration of HE4 or CA125 (Grade B). An HRT should be proposed to women younger than 45 after a non-conservative treatment for a high grade serous (GradeC) or for a mucinous (GradeC) ovarian, tubal or primitive peritoneal adenocarcinoma. HRT is not contra-indicated in women older than 45 presenting a climacteric syndrome after the treatment of a high grade serous (Grade B) or of a mucinous (GradeC) ovarian, tubal or primitive peritoneal adenocarcinoma.

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.

Does serum CA125 have clinical value for follow-up monitoring of postoperative patients with epithelial ovarian cancer? Results of a 12-year study

Background

The detection of CA125 has been used in the follow up of ovarian cancer. At present, some scholars believe that serum CA125 has no clinical value for the follow-up monitoring the recurrence for postoperative patients with epithelial ovarian cancer, but in our clinical follow-up found that when the serum CA125 value is <35 U/ml, postoperative patients of epithelial ovarian carcinoma had already showed recurrent lesions in some ecological and imaging examinations or in laparotomy exploration and biopsy, and we given the patients timely treatment, the prognosis were improved.

Methods

Retrospective analysis the values of serum CA125 of 342 postoperative patients of epithelial ovarian carcinoma, consisting of 296 non-recurrent and 46 recurrent cases, as well as 3175 cases of menopausal women and 603 cases of postoperative patients of gynecological malignant tumor for the follow-up from January 2005 to December 2016.

Results

The median value of CA125 for non-recurrent patients of epithelial ovarian carcinoma is 8.9 U/ml, the median value of CA125 for non-recurrent patients of epithelial ovarian carcinoma is 29.7 U/ml; for menopausal women, 8.1 U/ml; and for postoperative patients of gynecological malignant tumor, 7.2 U/ml, whereas the mean ± standard deviation is 9.0 ± 1.9 U/ml, 31.3 ± 16.2U/ml, 8.0 ± 1.1 U/ml, and 6.8 ± 2.1 U/ml, respectively.

Conclusions

If the value of the CA125 for postoperative patients of epithelial ovarian carcinoma between 10 and 35 U/ml indicates a relative risk of recurrence. When the value of CA125 is higher than 10 U/ml and continuously increased, need to be vigilant and should be combined with imaging examination (PET-CT). This result may improve the prognosis for recurrent patients because of the early detection of recurrent lesions and early retreatment.

The clinical utility of FDG PET/CT among solid organ transplant recipients suspected of malignancy or infection

PURPOSE

Solid organ transplant (SOT) recipients are at high risk of developing infections and malignancies. 18F-FDG PET/CT may enable timely detection of these diseases and help to ensure early intervention. We aimed to describe the clinical utility of FDG PET/CT in consecutive, diagnostic unresolved SOT recipients transplanted from January 2004 to May 2015.

METHODS

Recipients with a post-transplant FDG PET/CT performed as part of diagnostic work-up were included. Detailed chart reviews were done to extract relevant clinical information and determine the final diagnosis related to the FDG PET/CT. Based on á priori defined criteria and the final diagnosis, results from each scan were classified as true or false, and diagnostic values determined.

RESULTS

Among the 1,814 recipients in the cohort, 145 had an FDG PET/CT performed; 122 under the indication of diagnostically unresolved symptoms with a suspicion of malignancy or infection. The remaining (N = 23) had an FDG PET/CT to follow-up on a known disease or to stage a known malignancy. The 122 recipients underwent a total of 133 FDG PET/CT scans performed for a suspected malignancy (66 %) or an infection (34 %). Sensitivity, specificity, and positive and negative predictive values of the FDG PET/CT in diagnosing these conditions were 97, 84, 87, and 96 %, respectively.

CONCLUSION

FDG PET/CT is an accurate diagnostic tool for the work-up of diagnostic unresolved SOT recipients suspected of malignancy or infection. The high sensitivity and NPV underlines the potential usefulness of PET/CT for excluding malignancy or focal infections in this often complex clinical situation.

Follow-up of patients who are clinically disease-free after primary treatment for fallopian tube, primary peritoneal, or epithelial ovarian cancer: a Program in Evidence-Based Care guideline adaptation

BACKGROUND

A need for follow-up recommendations for survivors of fallopian tube, primary peritoneal, or epithelial ovarian cancer after completion of primary treatment was identified by Cancer Care Ontario's Program in Evidence-Based Care.

METHODS

We searched for existing guidelines, conducted a systematic review (medline, embase, and cdsr, January 2010 to March 2015), created draft recommendations, and completed a comprehensive review process. Outcomes included overall survival, quality of life, and patient preferences.

RESULTS

The Cancer Australia guidance document Follow Up of Women with Epithelial Ovarian Cancer was adapted for the Ontario context. A key randomized controlled trial found that the overall survival rate did not differ between asymptomatic women who received early treatment based on elevated serum cancer antigen 125 (ca125) alone and women who waited for the appearance of clinical symptoms before initiating treatment (hazard ratio: 0.98; 95% confidence interval: 0.80 to 1.20; p = 0.85); in addition, patients in the delayed treatment group reported good global health scores for longer. No randomized studies were found for other types of follow-up. We recommend that survivors be made aware of the potential harms and benefits of surveillance, including a discussion of the limitations of ca125 testing. Women could be offered the option of no formal follow-up or a follow-up schedule that is agreed upon by the woman and her health care provider. Education about the most common symptoms of recurrence should be provided. Alternative models of care such as nurse-led or telephone-based follow-up (or both) could be emerging options.

CONCLUSIONS

The recommendations provided in this guidance document have a limited evidence base. Recommendations should be updated as further information becomes available.

Ovarian Cancer, the Revised FIGO Staging System, and the Role of Imaging

OBJECTIVE

It is now recognized that ovarian cancer includes a heterogeneous group of malignant epithelial tumors originating from the ovaries, fallopian tubes, or peritoneum. This development has prompted the International Federation of Gynecology and Obstetrics (FIGO) to issue a revised staging system that can provide prognostic information and guidance on personalized management of ovarian cancer.

CONCLUSION

We review the epidemiology of ovarian cancer, the new FIGO staging system, and the role of imaging in the assessment, staging, and follow-up of ovarian cancer.

Gynecologic oncologic imaging with PET/CT

FDG-PET/CT has been evaluated in a variety of gynecologic malignancies in a variety of settings and is approved by the Centers for Medicare & Medicaid Services for the initial and subsequent treatment strategies of these malignancies. Cervical cancer is typically very FDG avid, and FDG-PET/CT appears to be most valuable for initial staging, radiation therapy planning, and detection of recurrent disease. For ovarian cancer, the most value of FDG-PET/CT appears to be for detecting recurrent disease in the setting of rising CA-125 level and negative or equivocal anatomical imaging studies. Initial studies evaluating response to therapy are promising and further work in this area is needed. FDG uptake in both nonmalignant and physiological processes in the pelvis can make interpretation of FDG-PET/CT in this region challenging and knowledge of these entities and patterns can avoid misinterpretation. Some of the most common findings relate to the cyclic changes that occur as part of the menstrual cycle in premenopausal women. Mucinous tumors and low-volume or peritoneal carcinomatosis are causes of false-negative results on FDG-PET/CT studies. As new tracers are developed, comparisons with patient outcomes and standards of care (eg, FDG-PET/CT) will be needed.

Impact of FDG PET in optimizing patient selection for cytoreductive surgery in recurrent ovarian cancer

PURPOSE

To investigate the impact of PET and PET/CT scanning on decision-making in management planning and to identify the optimal setting for selecting candidates for surgery in suspicious recurrent ovarian cancer.

METHODS

A retrospective chart review was performed in patients with possible recurrent ovarian cancer after primary optimal cytoreduction and taxane/carboplatin chemotherapy who had undergone FDG PET or FDG PET/CT scans from July 2002 to August 2008 to help make treatment decisions. The analysis included 44 patients who had undergone a total of 89 PET scans. The positive PET scans were classified as follows. (1) localized (one or two localized sites of FDG uptake), (2) multiple (three or more sites of FDG uptake), (3) diffuse (extensive low-grade activity outlining serosal and peritoneal surfaces).

RESULTS

Of the 89 PET scans, 52 (58.4%) led to a change in management plan. The total number of patients in whom cytoreductive surgery was selected as the treatment of choice increased from 12 to 35. Miliary disseminated disease, which was not detected by PET scan, was found in 22.2% of those receiving surgery. Miliary disseminated disease was detected in 6 of the 12 patients with recurrent disease whose treatment-free interval (TFI) was <12 months, whereas none of those with a TFI of ≥12 months had such disease (P = 0.0031).

CONCLUSION

PET or PET/CT is useful for selecting candidates for cytoreductive surgery among patients with recurrent ovarian cancer. To avoid surgical attempts in those with miliary dissemination, patients with a TFI of ≥12 months are the best candidates for cytoreductive surgery.

Value of FDG PET/CT in patients with treated ovarian cancer and raised CA125 serum levels

PURPOSE

Patients treated for ovarian cancer are usually referred for 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) in case of increased Carcinoma Antigen 125 (CA125) but negative conventional imaging. However, there is not enough in the literature to support the value of FDG PET/CT in this context. This study aimed to assess role of FDG PET/CT in a cohort of patients with treated ovarian cancer and correlate the results with serum levels of CA125.

PROCEDURES

We retrospectively studied 175 patients, mean age 65.2 years (range 24-88 years) who had radical treatment for ovarian cancer (chemotherapy, surgery or combination). The patients had a standard FDG PET/CT and measurement of serum CA125 within a month of the scan. PET/CT was considered positive if demonstrated areas of abnormally increased metabolic activity unrelated to physiological distribution, on the basis of a visual analysis. The results of PET/CT imaging were compared to the level of CA125, and receiver operating characteristic (ROC) curves were plotted and area-under-the curve (AUC) statistics were computed. Cytologic or histologic data or clinical and imaging follow-up were taken as gold standard.

RESULTS

Patients were divided into five groups based on CA125 values. The average level of CA125 was 107.7 (range 3-867, SD 166.1). PET/CT was positive in 125/175 cases (71.4%), mean value of CA125 132.2 (SD 182.9) and negative in 50/175 (28.6%), mean value of CA125 46.4 (SD 89.3). In descriptive ROC analyses, the discriminatory power of this marker was relatively high (AUC statistics 0.77, range = 0.703-0.8). The optimal cut-off point of CA125 after treatment to reflect active disease on PET/CT was 18 U/mL achieving a detection rate of 85.6%. There was no relation between PET/CT negativity and the histological type of the tumor.

CONCLUSION

PET/CT was able to detect active disease at relatively low levels of CA125, thereby facilitating the early diagnosis of recurrence or residual disease. Also in patients with low CA125 levels (<30), PET/CT had a relatively high detection rate (53%). According to our preliminary results, the use of FDG PET/CT in this setting is justified even with low serum CA125 levels.

Autoantibodies as biomarkers for ovarian cancer

Ovarian cancer (OVCA) has the highest mortality of all gynecologic cancers. The poor survival rate is due to the lack of diagnostic screening tests and high incidence of recurrence in OVCA patients resistant to chemotherapy that leads to a more aggressive form of the disease. Therefore, a search for biomarkers holds great promise not only for early detection of OVCA at presymptomatic stage and for monitoring the course of the disease during the first-line chemotherapy treatment but also for identifying those women whose disease is likely to recur. Research efforts have sought to unravel the complexity of the tumor specific proteome by profiling immune responses generated against tumor associated antigens (TAAs) using multianalyte-based analytical discovery platforms readily adaptable to clinical diagnostic screening tests. The occurrence of tumor-specific autoantibodies directed to respective TAAs can be observed before the development of clinical symptoms. Evaluation of the level of tumor autoantibodies during the time of tumor debulking followed by first-line chemotherapy for the prediction of early recurrence as well as their correlation with other clinical parameters to evaluate their prognostic value has been conducted in various clinical studies. The anti-tumor immune response against OVCA is the ultimate key to the development of multiple immune-based therapeutic strategies that have been proposed and tested in different clinical trials that may have beneficial impact on the disease outcome in OVCA patients.

Impact of FDG-PET and -PET/CT imaging in the clinical decision-making of ovarian carcinoma: an evidence-based approach

The most definitive role of fluorodeoxyglucose (FDG)-PET/computed tomography (CT) at present is surveillance and detecting recurrence in patients who have completed primary therapy but demonstrate a rising serum tumor marker (e.g., CA-125 levels). In this scenario, PET/CT demonstrates high sensitivity and accuracy in detecting lesions that are otherwise challenging, and appears superior (with less interobserver variability) compared with CT alone. Despite the fact that peritoneal deposits may be missed by PET/CT, the overall performance is better than CT alone. FDG-PET does not play a significant additional role in the primary diagnosis of ovarian cancers; however, the role of combined PET/CT modality has recently begun to be re-explored for initial disease staging, particularly because PET/CT can pick up small unsuspected lesions and thereby provide a better disease assessment of the whole body in a single examination. The baseline PET/CT also subserves an important role for future monitoring of therapy response. Therapy monitoring by PET could help to optimize neoadjuvant therapy protocols and to avoid ineffective therapy in nonresponders early in its course, although PET/CT has cost-effectiveness issues that need further evaluation. The prognostic value of FDG-PET/CT has been investigated in the following areas: in the preoperative setting to predict optimal cytoreduction; to assess the value of a positive FDG-PET following primary surgery; and when employed as a replacement for second-look laparotomy following completion of primary surgery and chemotherapy. The data, although promising, are still sparse in all the three domains for a definite recommendation.

Metabolomic Characterization of Ovarian Epithelial Carcinomas by HRMAS-NMR Spectroscopy

Objectives. The objectives of the present study are to determine if a metabolomic study by HRMAS-NMR can (i) discriminate between different histological types of epithelial ovarian carcinomas and healthy ovarian tissue, (ii) generate statistical models capable of classifying borderline tumors and (iii) establish a potential relationship with patient's survival or response to chemotherapy. Methods. 36 human epithelial ovarian tumor biopsies and 3 healthy ovarian tissues were studied using (1)H HRMAS NMR spectroscopy and multivariate statistical analysis. Results. The results presented in this study demonstrate that the three histological types of epithelial ovarian carcinomas present an effective metabolic pattern difference. Furthermore, a metabolic signature specific of serous (N-acetyl-aspartate) and mucinous (N-acetyl-lysine) carcinomas was found. The statistical models generated in this study are able to predict borderline tumors characterized by an intermediate metabolic pattern similar to the normal ovarian tissue. Finally and importantly, the statistical model of serous carcinomas provided good predictions of both patient's survival rates and the patient's response to chemotherapy. Conclusions. Despite the small number of samples used in this study, the results indicate that metabolomic analysis of intact tissues by HRMAS-NMR is a promising technique which might be applicable to the therapeutic management of patients.

Early detection of recurrent ovarian cancer in patients with low-level increases in serum CA-125 levels by 2-[F-18]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography

PURPOSE

Serum CA-125 has been shown to be a sensitive tumor marker of recurrent ovarian cancer. The goal of this study was to evaluate the use of 2-[F-18]fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the early detection of recurrent ovarian cancer in patients with low-level increases in serum CA-125 levels.

METHODS

Patients who demonstrated a normalization of serum CA-125 levels after complete remission of ovarian cancer were recruited for this study. FDG-PET/CT was performed to evaluate serum CA-125 levels ≥ 35 U/mL (Group 1) or progressive low-level increases in the levels of serum CA-125 (Group 2). The results were analyzed based on pathology, disease progression, and/or clinical follow-up.

RESULTS

Twenty-seven (27) consecutive patients consented to the aforementioned criteria (n = 16 in Group 1 and n = 11 in Group 2). In Group 1, of the 16 patients, 15 had a proven tumor recurrence, and the remaining 1 had a second primary cancer with no evidence of recurrent ovarian lesions. In Group 2, all 11 patients had recurrent tumors. The use of FDG-PET/CT allowed the detection of recurrences in 25 patients and a second primary cancer in 1 patient, which included all of the patients in Group 1 and 10 of the 11 patients in Group 2. The detection rate of FDG-PET/CT for recurrent ovarian cancer was 100% in Group 1 and 90.9% in Group 2 (15/15 vs. 10/11, p = 0.423). FDG-PET/CT changed the intended management in 14 (53.8%) of the patients, which included 4 cases in Group 1 and 10 cases in Group 2.

CONCLUSIONS

FDG-PET/CT has the ability to detect recurrent ovarian cancer and second primary tumors in patients with increased levels of serum CA-125. FDG-PET/CT affects the clinical management by localizing recurrent lesions and creating a specific treatment plan for each patient, especially patients who demonstrate a low-level increase in serum CA-125 levels.

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.

The Roles of Fluorodeoxyglucose-PET/Computed Tomography in Ovarian Cancer: Diagnosis, Assessing Response, and Detecting Recurrence

The potential roles of fluorodeoxyglucose positron emission tomography/computed tomography imaging in ovarian cancer include noninvasive characterization of an ovarian mass, staging, and treatment planning. This article assesses these roles for predicting and monitoring response to treatment, restaging, and early diagnosis of recurrence.

Application of 18F-fluorodeoxyglucose positron emission tomography in diagnosis of malignant diseases

OBJECTIVE

To testify the efficacy of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in the diagnosis of cancer.

METHODS

A total of 170 patients with diagnosed cancer or suspicious cancer were enrolled in this study, and underwent 18F-FDG PET. The standard uptake value (SUV) and diameter for each abnormal region in PET images were analyzed. All data were analyzed by SPSS 11.5.

RESULTS

PET scan identified a primary cancer in 45.8% (11/24) patients. The sensitivity and specificity of PET scan in differentiating malignant lesions from benign ones were 78.8% (52/66) and 77.1% (27/35) respectively. Twenty-nine out of 68 (42.6%) lesions were detected earlier by PET than by computed tomography. The SUV of primary cancer was significantly higher than that of metastatic lymph nodes (5.84 +/- 3.12 vs. 3.14 +/- 2.24, P<0.001). And SUV of primary lung cancer was also significantly higher than that of metastatic lung cancer (6.30 +/- 3.01 vs. 2.86 +/- 2.37, P<0.01).

CONCLUSION

18F-FDG PET plays a very important role in cancer diagnosis.

The role of 18F-FDG PET in assessing therapy response in cancer of the cervix and ovaries

For locally advanced cervical cancer, the current literature supports the use of (18)F-FDG PET for assessing treatment response 3 mo after the completion of concurrent chemoradiation. (18)F-FDG PET can provide reliable long-term prognostic information for these patients and, in the future, may be used to guide additional therapy. Investigational areas include the use of (18)F-FDG PET for monitoring response during radiotherapy and chemotherapy in the metastatic and neoadjuvant settings. For ovarian masses, the performance of (18)F-FDG PET in the detection of borderline tumors is limited, and the presence of physiologic (18)F-FDG uptake in normal ovaries of premenopausal women poses another limitation. Preliminary data suggest that the performance of (18)F-FDG PET and (18)F-FDG PET/CT is superior to that of CT alone in initial staging, but the sensitivity of both in the detection of carcinomatosis is limited. Preliminary data also suggest that (18)F-FDG PET may be promising for early prediction of response to chemotherapy and for prediction of response after the completion of chemotherapy. (18)F-FDG PET and (18)F-FDG PET/CT are most helpful in the evaluation of patients with suspected recurrent ovarian carcinoma, especially when CA-125 levels are rising and CT findings are normal or equivocal. PET and CT are complementary, and PET/CT should be used when available. Preliminary data suggest that the addition of (18)F-FDG PET/CT to the evaluation of these patients changes management in approximately a third and reduces overall treatment costs by accurately identifying patients who will or will not benefit from surgery.

18F-FDG PET/CT evaluation of patients with ovarian carcinoma

PURPOSE

The role of F-FDG PET has been studied in ovarian carcinoma, but its sensitivity and specificity calculations are based on dedicated PET acquisition, not PET/CT in the majority of the published studies. Therefore, we were prompted to review our experience with PET/CT in the management of patients with ovarian carcinoma.

MATERIALS AND METHODS

This is a retrospective study of 43 women with ovarian carcinoma, 27-80 years old (average: 53.9+/-7.8), who had whole-body PET/CT at our institution from 1 January 2003 to 31 August 2006. We reviewed the patients' outcomes from medical records and compared them to the interpretation of the PET/CT scans. Sensitivity and specificity were calculated using a 2 x 2 table with pathology results (79.1% of the patients) or clinical follow-up (20.9% of the cases) as the 'gold standard'. Confidence interval (CI) estimations were performed using the Wilson score method.

RESULTS

All patients had advanced stage ovarian cancer and the study was requested for re-staging. A total of 60 scans were performed: 30 patients had one scan, nine patients had two scans and four patients had three scans. The administered doses of F-FDG ranged from 381.1 to 769.6 MBq (average: 569.8+/-73.3). PET/CT had a sensitivity of 88.4% (95% CI: 75.1-95.4) and a specificity of 88.2% (95% CI: 64.4-97.9) for detection of ovarian cancer. The SUV max of the detected lesions ranged from 3 to 27 (average: 9.4+/-5.9). The CA-125 tumor marker ranged from 3 to 935 kU/ml (average: 265.2) in patients with positive scans and 4-139 kU/ml (average: 17.1) in patients with negative scans. This difference was statistically significant (P value: 0.0242).

CONCLUSION

This study confirms the good results of F-FDG PET/CT for identification of residual/recurrent ovarian cancer, as well as for distant metastases localization. PET/CT should be an integral part in evaluation of patients with high-risk ovarian cancer or rising values of tumor markers (CA-125), prior to selection of the most appropriate therapy.