Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT scans for diagnosing ovarian cancer recurrence

Comprehensive literature review of oral and intravenous contrast-enhanced PET/CT: a step forward?

The integration of diagnostic CT scans into PET/CT facilitates a comprehensive single examination, presenting potential advantages for patients seeking a thorough one-shot check-up. The introduction of iodinated contrast media during PET scanning raises theoretical concerns about potential interference with uptake quantification, due to the modification of tissue density on CT. Nevertheless, this impact appears generally insignificant for clinical use, compared to the intrinsic variability of standardized uptake values. On the other hand, with the growing indications of PET, especially 18F-FDG PET, contrast enhancement increases the diagnostic performances of the exam, and provides additional information. This improvement in performance achieved through contrast-enhanced PET/CT must be carefully evaluated considering the associated risks and side-effects stemming from the administration of iodinated contrast media. Within this article, we present a comprehensive literature review of contrast enhanced PET/CT, examining the potential impact of iodinated contrast media on quantification, additional side-effects and the pivotal clinically demonstrated benefits of an all-encompassing examination for patients. In conclusion, the clinical benefits of iodinated contrast media are mainly validated by the large diffusion in PET protocols. Contrary to positive oral contrast, which does not appear to offer any major advantage in patient management, intravenous iodine contrast media provides clinical benefits without significant artifact on images or quantification. However, studies on the benefit-risk balance for patients are still lacking.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

To Enhance or Not to Enhance? The Role of Contrast Medium 18F-FDG PET/CT in Recurrent Ovarian Carcinomas

Background and Objectives: ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/X-ray computed tomography (PET/CT) represents the mainstay diagnostic procedure for suspected ovarian cancer (OC) recurrence. PET/CT can be integrated with contrast medium and in various diagnostic settings; however, the effective benefit of this procedure is still debated. We aimed to compare the diagnostic capabilities of low-dose and contrast-enhanced PET/CT (PET/ldCT and PET/ceCT) in patients with suspected ovarian cancer relapse. Materials and Methods: 122 OC patients underwent both PET/ldCT and PET/ceCT. Two groups of nuclear medicine physicians and radiologists scored the findings as positive or negative. Clinical/radiological follow-up was used as ground truth. Sensitivity, specificity, negative/positive predictive value, and accuracy were calculated at the patient and the lesion level. Results: A total of 455 and 474 lesions were identified at PET/ldCT and PET/ceCT, respectively. At the lesion level, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were not significantly different between PET/ldCT and PET/ceCT (98%, 93.3%, 97.4%, 94.9%, and 96.9% for PET/ldCT; 99%, 95.5%, 98.3%, 97%, and 98% for PET/ceCT, p = ns). At the patient level, no significant differences in these parameters were identified (e.g., p = 0.22 and p = 0.35 for accuracy, in the peritoneum and lymph nodes, respectively). Smaller peritoneal/lymph node lesions close to physiological FDG uptake sources were found in the cases of misidentification by PET/ldCT. PET/ceCT prompted a change in clinical management in four cases (3.2%) compared to PET/ldCT. Conclusions: PET/ceCT does not perform better than PET/ldCT but can occasionally clarify doubtful peritoneal findings on PET/ldCT. To avoid unnecessary dose to the patient, PET/ceCT should be excluded in selected cases.

Preoperative omental metastasis-related maximum standardized fluorine-18-fluorodeoxyglucose uptake value can predict chemosensitivity and recurrence in advanced high-grade serous ovarian cancer patients

OBJECTIVE

The aim of this study was to explore the clinical and prognostic implication of preoperative fluorine-18-fluorodeoxyglucose uptake value of omental metastasis-related in advanced high-grade serous ovarian cancer patients (HGSC).

PATIENTS AND METHODS

We retrospectively investigated HGSC patients with omental metastasis (International Federation of Gynecology and Obstetrics stage IIIB-IV) who underwent PET/CT before primary surgery in our hospital between January 2010 and January 2016. All patients were confirmed omental metastasis by postoperative pathology. None of these patients received neoadjuvant chemotherapy. PET/CT parameters, including maximum standardized uptake value of primary ovary tumor (SUVp), omental metastasis (SUVo), and omental metastasis-to-primary tumor (SUVo/p) were measured. The relationships between PET/CT parameters and clinical characteristics were analyzed by t-test. Kaplan-Meier methods and log-rank tests were used to analyze progression-free survival (PFS) in univariate analysis. For multivariate analysis, COX regression analysis was used to assess the prognostic predictive value of PET/CT-derived variables.

RESULTS

Totally 81 advanced HGSC patients with omental metastasis were enrolled in our study, and 49 (60.5%) patients experienced recurrence and disease progression. The median (range) follow-up time was 18.5 (7-72) months. Older patients showed higher level of SUVo/p (P=0.006). Chemosensitive patients had lower levels of SUVo (P=0.009) and SUVo/p (P<0.001) than those chemoresistant ones. In univariate analysis, patients with better PFS were associated with lower SUVo (P<0.001) and SUVo/p (P<0.001). Multivariate analysis found only SUVo/p was an independent factor for PFS (P=0.006).

CONCLUSION

Preoperative SUVo/p measured by fluorine-18-fluorodeoxyglucose PET/CT appeared to be an independent predictive factor for recurrence in advanced HGSC patients. Chemosensitive patients had lower omentum-related SUV values than those chemoresistant ones.

Tumor-to-background ratios of the maximum standardized uptake value could not indicate the prognosis of advanced high-grade serous ovarian cancer patients

OBJECTIVE

Our study aimed to explore the prognostic influence of tumor-to-background ratios (TBRs) of the maximum standardized uptake value (SUVmax) in advanced high-grade serous ovarian cancer (HGSC) patients.

PATIENTS AND METHODS

We retrospectively investigated 51 advanced HGSC patients who underwent PET/CT before primary surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. SUVmax of ovarian tumor (SUVmax-P) and background (SUVmax-B) were measured using a PET/CT workstation. TBR was calculated by SUVmax-P/SUVmax-B. Backgrounds included the liver, mediastinum, and muscle, and TBRs were noted as TBR-L, TBR-Me, and TBR-Mu, respectively. The χ-test was used to analyze the relationships between PET/CT parameters and several clinical features. Progression-free survival and overall survival were analyzed using the Kaplan-Meier method and log-rank tests in univariate analyses.

RESULTS

The median (range) follow-up duration was 27 (8-61) months. The median (range) PET/CT parameter values were as follows: SUVmax, 11.41 (3.24-24.14), TBR-L, 2.84 (2.08-11.93), TBL-Me, 2.09 (1.33-9.07), and TBR-Mu, 1.04 (0.56-14.02). The patients were categorized into low and high groups by the median values of these parameters above separately. A larger proportion of patients in the high TBR-Me group were chemoresistant compared with the low-value group (P=0.039). Neither the residual disease nor the ascites levels correlated with SUVmax or TBR values. There were no differences in progression-free survival and overall survival between the patients in the high and low TBR level groups.

CONCLUSION

TBRs of SUVmax were not prognostic indicators for advanced HGSC patients.

FOXM1 promotes reprogramming of glucose metabolism in epithelial ovarian cancer cells via activation of GLUT1 and HK2 transcription

Cancer cells exhibit the reprogrammed metabolism mainly via aerobic glycolysis, a phenomenon known historically as the Warburg effect; however, the underlying mechanisms remain largely unknown. In this study, we characterized the critical role of transcription factor Forkhead box protein M1 (FOXM1) in aerobic glycolysis of human epithelial ovarian cancer (EOC) and its molecular mechanisms. Our data showed that aberrant expression of FOXM1 significantly contributed to the reprogramming of glucose metabolism in EOC cells. Aerobic glycolysis and cell proliferation were down-regulated in EOC cells when FOXM1 gene expression was suppressed by RNA interference. Moreover, knockdown of FOXM1 in EOC cells significantly reduced glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) expression. FOXM1 bound directly to the GLUT1 and HK2 promoter regions and regulated the promoter activities and the expression of the genes at the transcriptional level. This reveals a novel mechanism by which glucose metabolism is regulated by FOXM1. Importantly, we further demonstrated that the expression levels of FOXM1, GLUT1 and HK2 were significantly increased in human EOC tissues relative to normal ovarian tissues, and that FOXM1 expression was positively correlated with GLUT1 and HK2 expression. Taken together, our results show that FOXM1 promotes reprogramming of glucose metabolism in EOC cells via activation of GLUT1 and HK2 transcription, suggesting that FOXM1 may be an important target in aerobic glycolysis pathway for developing novel anticancer agents.

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.

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

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

Nuclear medicine for imaging of epithelial ovarian cancer

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

The performance of contrast-enhanced FDG PET/CT for the differential diagnosis of unexpected ovarian mass lesions in patients with nongynecologic cancer

PURPOSE

This study aimed to evaluate the diagnostic accuracy of contrast-enhanced FDG PET/CT for unexpected ovarian lesions in patients with nongynecologic cancers.

PATIENTS AND METHODS

The present retrospective study was approved by the hospital institutional review board. We enrolled 72 nongynecologic cancer patients (33 colorectal cancer, 20 breast cancer, and 19 gastric cancer) who showed unexpected ovarian lesions on contrast-enhanced FDG PET/CT and subsequently underwent surgical resection of the ovarian lesions. The SUVmax values of the ovarian lesions were compared according to the histopathological results, and the accuracy of PET/CT was evaluated.

RESULTS

A total of 103 ovarian lesions were surgically resected from 72 patients (64 ovarian lesions were metastases, 21 were benign, and 18 were malignant primary ovarian cancer). SUVmax among the 3 groups were different (P < 0.0001). Using a cutoff SUVmax of 2.5, the sensitivity, specificity, and accuracy of PET/CT for detecting malignant ovarian lesions were 80.5%, 81.0%, and 80.6%, respectively. Detection rates of PET/CT for colorectal, breast, and gastric cancer metastases, as well as primary ovarian cancers were 91.4%, 83.3%, 47.8%, and 100.0%, respectively. Using contrast-enhanced CT findings with SUVmax, the sensitivity, specificity, and accuracy of contrast-enhanced FDG PET/CT were improved to 95.1%, 76.2%, and 91.3%, respectively (P = 0.003).

CONCLUSIONS

Conventional FDG PET/CT showed moderate diagnostic accuracy for the detection of malignant ovarian lesions mainly due to low detection rate in gastric cancer metastases. The PET/CT detection rate of malignant ovarian lesions can be improved using contrast-enhanced CT findings with FDG uptake measurement.

Clinical and Survival Impact of FDG PET in Patients with Suspicion of Recurrent Ovarian Cancer: A 6-Year Follow-Up

Background

The aim of this retrospective study was to evaluate the contribution of fluorine-18-fluoro-deoxyglucose (FDG) positron emission tomography (PET) to the clinical management and survival outcome of patients (pts) suspected of recurrent ovarian carcinoma, with the hypothesis that early diagnosis of recurrent ovarian cancer may improve overall survival (OS).

Methods

Fifty-three FDG PET/CT scans were retrospectively analyzed for 42 pts. CT and PET/CT findings were confirmed by imaging and clinical follow-up, and/or pathology, which were considered as the gold standard diagnosis. The treatment plan based on CT staging was compared with that based on PET/CT findings. Medical records were reviewed for pts characteristics, progression-free survival (PFS), and OS. PFS and OS were analyzed using the Cox proportional hazards regression model.

Results

The final diagnosis of recurrence was established pathologically (n = 16), or by a median clinical follow-up of 6.5 years (range 0.5-7.5) after the PET/CT (n = 37). PET/CT provided a higher detection sensitivity (92.2%, 47/51) than CT (60.8%, 31/51) (p < 0.001). Globally, PET/CT modified the treatment plan in 56.6% (30/53) and in 65.2% (15/23) when the CT was negative prior to PET/CT. In 30 cases, those benefited from a modified treatment plan, these changes led to the intensification of a previous treatment procedure in 83.3% (25/30), and to a reduction in the previous treatment procedure in 16.6% of cases (5/30). The Cox regression multivariate analysis showed that the number of lesions visualized by CT and presence of lung lesions detected by PET/CT were significantly associated with PFS (p = 0.002 and p = 0.035, respectively).

Conclusion

On account of its impact on treatment planning, and especially in predicting patient outcome, FDG PET is a valuable diagnostic tool for cases of suspected ovarian cancer recurrence.

Dose optimization in nuclear medicine

The practice of diagnostic nuclear medicine involves the use of ionizing radiation, and thus the potential risk associated with such exposure must be weighed against the benefits to the patient. This requires that the right test with the right dose be administered to the right patient at the right time. Therefore the procedure should be performed only if it is deemed most appropriate for the clinical question being asked. If appropriate, the procedure should be performed in the most optimum manner that keeps the radiation dose to the patient as low as possible while providing the patient's clinician with information that is needed to devise a plan of medical management. If this approach is followed, the benefits to the patient will far outweigh the small potential risks associate with the procedure. This article discusses these issues, particularly in the context of cardiovascular nuclear medicine and hybrid imaging including PET/CT and SPECT/CT.

Evaluation of follow-up strategies for patients with epithelial ovarian cancer following completion of primary treatment

BACKGROUND

Ovarian cancer is the sixth most common cancer and seventh commonest cause of death in women worldwide. Traditionally, many people who have been treated for cancer undergo long-term follow-up in secondary care. However, it has been suggested that the use of routine review may not be effective in improving survival, quality of life (QoL), or relieving anxiety, or both. In addition, traditional follow-up may not be cost-effective.

OBJECTIVES

To compare the potential benefits of different strategies of follow-up in patients with epithelial ovarian cancer following completion of primary treatment.

SEARCH METHODS

For this update we searched the Cochrane Gynaecological Cancer Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) Issue 7, 2013, MEDLINE and EMBASE from November 2010 to July 2013. We also searched reference lists of review articles and contacted experts in the field.

SELECTION CRITERIA

All relevant randomised controlled trials (RCTs) that evaluated follow-up strategies for women with epithelial ovarian cancer following completion of primary treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias.

MAIN RESULTS

The authors did not identify any new studies that were eligible for inclusion in this update of the review. The search for the original review identified only one RCT that met the inclusion criteria, which included 529 women. This study reported data on immediate treatment of ovarian cancer relapse following rise of serum CA125 levels versus delaying treatment until symptoms developed. All the women participating had previous confirmation of remission, with normal CA125 concentration and no radiological evidence of disease, after surgery and first-line chemotherapy for ovarian cancer.Overall survival between the immediate and delayed arms showed no difference after a median follow-up of 56.9 months (unadjusted hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.80 to 1.20; P value 0.85). Time from randomisation to first deterioration in global health score or death was shorter in the immediate treatment group than in the delayed treatment group (HR 0.71, 95% CI 0.58 to 0.88; P value < 0.01). The trial was at low risk of bias.

AUTHORS' CONCLUSIONS

Limited evidence from a single trial suggests that routine surveillance with CA125 in asymptomatic patients and treatment at CA125 relapse does not seem to offer survival advantage when compared to treatment at symptomatic relapse. RCTs are needed to compare different types of follow-up, looking at survival, QoL, cost and psychological effects as outcomes.

The role of metabolic tumor volume and total lesion glycolysis on ¹⁸F-FDG PET/CT in the prognosis of epithelial ovarian cancer

PURPOSE

This study assessed the prognostic value of pre-operative 2-[(18)F] fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) volumetric parameters, including metabolic tumor volume (MTV) and total lesion glycolysis (TLG), in patients with epithelial ovarian cancer.

METHODS

A total of 175 patients with epithelial ovarian cancer who underwent (18) F-FDG PET/CT and subsequent cytoreductive surgery were retrospectively enrolled. Maximum standardized uptake value (SUVmax) on (18)F-FDG PET/CT was measured for all patients. Because nine patients showed low tumor-to-background uptake ratios, MTV and TLG were measured in 166 patients. Univariate and multivariate analyses were performed to evaluate the prognostic significance of SUVmax, MTV, TLG, and clinicopathological factors for disease progression-free survival.

RESULTS

Disease progressed in 78 (44.6 %) of the 175 patients, and the 2-year disease progression-free survival rate was 57.5 %. Univariate analysis showed that tumor stage, histopathological type, presence of regional lymph node metastasis, residual tumor after cytoreductive surgery, pre-operative serum carbohydrate antigen 125 (CA125) level, SUVmax, MTV, and TLG were significant prognostic factors (p < 0.05). Among these variables, tumor stage (p = 0.0006) and TLG (p = 0.008) independently correlated with disease progression-free survival on multivariate analysis. The disease progression rate was only 2.3 % in stage I-II patients with low TLG (≤100.0), compared to 80.0 % in stage III-IV patients with high TLG (>100.0).

CONCLUSION

Along with tumor stage, TLG is an independent prognostic factor for disease progression after cytoreductive surgery in patients with epithelial ovarian cancer. By combining tumor stage and TLG, one can further stratify the risk of disease progression for patients undergoing cytoreductive surgery.

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.

Comparison of 80 and 120 kVp contrast-enhanced CT for attenuation correction in PET/CT, using quantitative analysis and reporter assessment of PET image quality

AIM

To determine the effect of low tube voltage on positron-emission tomography (PET) image quality, quantitative analysis, and radiation dose in a combined PET/computed tomography (CT) study in patients with normal body mass index (BMI).

MATERIALS AND METHODS

One hundred and twenty-nine examinations performed in 46 patients (mean age 57 years), who had at least two separate studies were retrospectively evaluated; at least one with 120 kVp and one with 80 kVp. Three independent readers reviewed all PET images and graded the image quality. PET signal and noise were recorded on the liver, spleen, fat, bone marrow, and aorta. CT dose index (CTDI) and the dose-length product (DLP) were used for CT radiation dose estimation. A mixed-effects model analysis was used for comparison of estimated radiation dose and PET data.

RESULTS

There was a significant decrease of 15% in the radiation dose estimates between 80 and 120 kVp (DLP 946.2 ± 189 versus 1157.0 ± 236, respectively; p < 0.001). There was an increase of 12% in PET signal in the normal liver with 80 kVp. The average score of PET image quality obtained between 80 and 120 kVp was 4.85 ± 0.42 versus 4.90 ± 0.27, respectively (p = 0.47).

CONCLUSION

PET/80 kVp CT has no statistically significant difference in the PET image quality and quantitative analysis compared to PET/120 kVp and may be used in selected patients to reduce the radiation dose.

PET scan integration in lymphoma management

SUMMARY Despite a marked improvement in lymphoma treatment outcome, current prognostic models, relying on a pretreatment set of static clinical variables, appear unable to support a risk-adapted therapeutic strategy. On the other hand, functional imaging with 18F-fluoro-2-deoxy-D-glucose (FDG)-PET proved to be a reliable tool to dynamically assess tumor FDG uptake changes during and after treatment. In this article we aim to review the prognostic value of FDG-PET in all the stages of Hodgkin’s and non-Hodgkin’s lymphoma management, without the intent to address the diagnostic value of PET or to replace available consensus guidelines. In particular we focused on two critical issues: the cost–effectiveness of PET in the overall strategy of lymphoma diagnosis and treatment; and ongoing clinical trials adopting an interim PET-based strategy to modulate treatment intensity based on PET results. Finally, new trends in multimodality imaging, as well as in new radiopharmaceutical tracers, are briefly reviewed.