The role of 18F-FDG PET/CT-based quantitative metabolic parameters in patients with ovarian clear cell carcinoma

Prognostic Value of Pretreatment 18F-FDG-PET/CT Metabolic Parameters in Advanced High-Grade Serous Ovarian Cancer

AIM

To assess the prognostic value of pretreatment 18F-FDG-PET/CT quantitative metabolic parameters in patients with advanced high-grade serous ovarian cancer (HGSOC).

METHODS

A review of 47 patients diagnosed with advanced HGSOC between 2012 and 2020 in our center was performed, evaluating pretreatment 18F-FDG-PET/CT metabolic parameters: maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG) and metabolic tumoral volume (MTV). Two experienced nuclear medicine physicians evaluated the images, thereby obtaining quantitative parameters semiautomatically classifying the volume of interest (VOI) as the target (t): VOI with the highest SUVmax normalized by lean body mass (SUVmax(lbm)), non target (nt) and total (sum of target and non-target VOIs). The disease-free survival (DFS) and overall survival (OS) were calculated. Optimal cutoff values with ROC curves/median values were used. The Correlation between metabolic parameters and DFS/OS was determined using univariate and survival-curves analysis.

RESULTS

The median DFS was 18 months (2.5-55) and the OS 33.6 months (2.5-92). The MTVtotal, MTV(t), TLGtotal and TLG(t) were significantly associated with DFS (p = 0.005, 0.01, 0.04 and 0.04, respectively). The patients with MTVtotal > 427.8 cm3 and MTVtarget > 434 cm3 had shorter DFS than the patients with lower values (18.8 versus 31 months and 15.6 versus 30, p = 0.02 and 0.01, respectively). The patients with higher TLGtotal and TLG(t) values tended to have worse DFS (p = 0.26 and 0.31, respectively). In a multivariate analysis, the MTVtotal was statistically significantly associated with DFS (p = 0.003). No correlation was found with OS.

CONCLUSIONS

Pretreatment MTVtotal and MTV(t) appear to be predictive of relapse in patients with advanced HGSOC.

The unique metabolome of clear cell ovarian carcinoma

Clear cell ovarian carcinoma (CCOC) is an aggressive malignancy affecting younger women. Despite ovarian cancer subtypes having diverse molecular and clinical characteristics, the mainstay of treatment for advanced stage disease remains cytotoxic chemotherapy. Late stage CCOC is resistant to conventional chemotherapy, which means a suboptimal outcome for patients affected. Despite detailed genomic, epigenomic, transcriptomic, and proteomic characterisation, subtype-specific treatment for CCOC has shown little progress. The unique glycogen accumulation defining CCOC suggests altered metabolic pathway activity and dependency. This study presents the first metabolomic landscape of ovarian cancer subtypes, including 42 CCOC, 20 high-grade serous and 21 endometrioid ovarian carcinomas, together comprising the three most common ovarian carcinoma subtypes. We describe a distinct metabolomic landscape of CCOC compared with other ovarian cancer subtypes, including alterations in energy utilisation and cysteine metabolism. In addition, we identify CCOC-specific alterations in metabolic pathways including serine biosynthesis and ROS-associated pathways that could serve as potential therapeutic targets. Our study provides the first in-depth study into the metabolome of ovarian cancers and a rich resource to support ongoing research efforts to identify subtype-specific therapeutic targets that could improve the dismal outcome for patients with this devastating malignancy. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Predicting epithelial ovarian cancer prognosis: correlation of posttreatment 18F-fluorodeoxyglucose positron emission tomography-computed tomography metabolic parameters, serum carbohydrate antigen, and human epididymis protein levels with overall survival

Background

Identifying reliable prognostic indicators can aid in improving patient care. The aim of this study was to establish the association of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) whole-body metabolic parameters, serum carbohydrate antigen 125 (CA125), and human epididymis protein 4 (HE4) with overall survival (OS) in patients with epithelial ovarian cancer (EOC) after surgery combined with platinum-based chemotherapy.

Methods

From May 2014 to May 2019, a total of 79 patients with EOC who underwent posttreatment 18F-FDG PET/CT in the First Affiliated Hospital of Chongqing Medical University were included. Clinical data and laboratory indicators were obtained. The whole-body maximum standardized uptake value (WBSUVmax), whole-body metabolic tumor volume (WBMTV), and whole-body total lesion glycolysis (WBTLG) were measured and calculated on 18F-FDG PET/CT. The follow-up was conducted until February 2023, and the endpoint was death from any cause. Pearson correlation analysis, Kaplan-Meier, and Cox proportional regression were used in this study.

Results

The PET-positive (PET-P) patients had significantly decreased OS based on either Kaplan-Meier survival analysis (P<0.001) or univariate Cox regression analysis [hazard ratio (HR) =40.177, 95% confidence interval (CI): 2.690-600.134; P=0.007]. "Ln" is a logarithmic transformation with a base of "e" (natural logarithm). LnWBMTV, lnWBTLG, and therapy after PET were independent predictors of OS in a cohort of 63 PET-P patients. The difference in OS between groups sorted by the median WBMTV (4.16; P<0.001) and WBTLG (14.71; P<0.001) was statistically significant. There were statistically significant differences in CA125 and HE4 levels between patients in the PET-P and PET-negative (PET-N) groups (P<0.001). In the PET-P patient cohort, serum HE4 levels were substantially correlated with WBMTV and WBTLG. Kaplan-Meier survival analysis suggested a reduction in OS after treatment in patients with EOC positive for CA125, HE4, and PET (P<0.001).

Conclusions

Post-PET/CT treatment strategy, WBMTV, and WBTLG demonstrated significant prognostic utility in predicting posttreatment OS in patients with EOC. Patients who tested positive for both tumor markers CA125 and HE4 and had a positive PET scan demonstrated a significantly poorer prognosis in terms of posttreatment OS.

Evaluation of patients with advanced epithelial ovarian cancer before primary treatment: correlation between tumour burden assessed by [18F]FDG PET/CT volumetric parameters and tumour markers HE4 and CA125

OBJECTIVES

Accurate assessment of disease extent is required to select the best primary treatment for advanced epithelial ovarian cancer patients. Estimation of tumour burden is challenging and it is usually performed by means of a surgical procedure. Imaging techniques and tumour markers can help to estimate tumour burden non-invasively. 2-[¹⁸F]FDG PET/CT allows the evaluation of the whole-body disease. This study aimed to correlate HE4 and CA125 serum concentrations with tumour burden evaluated by volumetric 2-[¹⁸F]FDG PET/CT parameters in advanced high-grade epithelial ovarian cancer.

METHODS

We included 66 patients who underwent 2-[¹⁸F]FDG PET/CT and serum tumour markers determination before primary treatment. Volumes of interest were delimited in every pathological uptake. Whole-body metabolic tumour volume (wb_MTV) and total lesion glycolysis (wb_TLG) were calculated summing up every VOI's MTV value. SUVmax thresholds were set at 40% (MTV40 and TLG40) and 50% (MTV50 and TLG50). In addition, four VOI subgroups were defined: peritoneal carcinomatosis, retroperitoneal nodes, supradiaphragmatic nodes, and distant metastases. MTV and TLG were calculated for each group by adding up the corresponding MTV values. TLG was calculated likewise.

RESULTS

wb_MTV and wb_TLG were found to be significantly correlated with serum CA125 and HE4 concentrations. The strongest correlation was observed between HE4 and wb_MTV40 (r = 0.62, p < 0.001). Pearson's correlation coefficients between peritoneal carcinomatosis MTV40 and tumour markers were 0.61 (p < 0.0001) and 0.29 (p = 0.02) for HE4 and CA125 respectively. None of these tumour markers showed a positive correlation with tumour load outside the abdominal cavity assessed by volumetric parameters.

CONCLUSION

HE4 performs better than CA125 to predict metabolic tumour burden in high-grade epithelial ovarian cancer before primary treatment. 2-[18F]FDG PET/CT volumetric parameters arise as feasible tools for the objective assessment of tumour load and its anatomical distribution. These results support the usefulness of HE4 and PET/CT to improve the stratification of these patients in clinical practice.

KEY POINTS

• In patients with high-grade advanced ovarian epithelial carcinoma, both CA125 and HE4 correlate to whole-body tumour burden assessed by PET/CT before primary treatment. • HE4 estimates peritoneal disease much better than CA125. • PET/CT volumetric parameters arise as feasible tools for the objective assessment of tumour load and its anatomical distribution.

Diagnostic performance of PET/CT and PET/MR in the management of ovarian carcinoma-a literature review

Ovarian cancer is a challenging disease. It often presents at an advanced stage with frequent recurrence despite optimal management. Accurate staging and restaging are critical for improving treatment outcomes and determining the prognosis. Imaging is an indispensable component of ovarian cancer management. Hybrid imaging modalities, including positron emission tomography/computed tomography (PET/CT) and PET/magnetic resonance imaging (MRI), are emerging as potential non-invasive imaging tools for improved management of ovarian cancer. This review article discusses the role of PET/CT and PET/MRI in ovarian cancer.