Prognostic value of metabolic parameters measured by pretreatment dual-time-point 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with intrahepatic or perihilar cholangiocarcinoma: A STROBE study

Prognostic Significance of the Bone Marrow-to-Aorta Uptake Ratio on 2-Deoxy-2-[18F]fluoro-d-glucose Positron Emission Tomography/Computed Tomography in Patients with Cholangiocarcinoma

2-Deoxy-2-[18F]fluoro-d-glucose (FDG) uptake of the reticuloendothelial system on positron emission tomography/computed tomography (PET/CT) is known to be related to systemic inflammatory response to cancer cells in patients with diverse malignancies. This retrospective study aimed to investigate whether FDG uptake by the reticuloendothelial system had a prognostic value in predicting progression-free survival (PFS) and overall survival (OS) in 138 cholangiocarcinoma patients. Quantifying FDG uptake of the aorta, bone marrow (BM), liver, and spleen from staging FDG PET/CT images, we found significant correlations between the BM-to-aorta uptake ratio (BAR), spleen-to-aorta uptake ratio, and BM-to-liver uptake ratio with tumor stage and serum inflammatory markers. In the multivariate survival analysis, BAR was an independent predictor of PFS (p = 0.016; hazard ratio, 2.308) and OS (p = 0.030; hazard ratio, 2.645). Patients with stages III-IV of the disease and a high BAR exhibited low 1-year PFS (35.8%) and OS (60.2%) rates, while those with stages I-II of the disease and low BAR showed robust rates of 90.0% and 96.7%, respectively. BAR measured on staging FDG PET/CT might be a potential imaging biomarker offering insights into the systemic inflammatory response and predicting prognosis in cholangiocarcinoma. This study highlights BAR as a promising, independent predictor with potential for personalized prognostication and treatment strategies.

Prognostic significance of 18F-Fluorodeoxyglucose positron-emission tomography parameters in patients with biliary tract cancers: a meta-analysis

BACKGROUND AND OBJECTIVE

Numerous previous studies have assessed the prognostic role of 18F-fluorodeoxyglucose positron-emission tomography (18F FDG PET) in patients with biliary tract cancer (BTC), but those results were inconsistent. The present study aims to determine the predictive value of 18F FDG PET in BTC patients via a meta-analysis.

METHODS

The underlying studies related to 18F FDG PET and BTC patients` outcomes were searched and identified in the online databases. The interested parameters include total lesion glycolysis (TLG), metabolic tumor volume (MTV), primary tumor and metastatic lymph node (LN) maximum standardized uptake value (SUVmax), as well as change of SUVmax (ΔSUVmax) during treatment. Overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were considered as the primary endpoints. Hazard ratio (HR) and corresponding 95% confidence intervals (CIs) were defined as the effective measure and calculated by a pooled analysis. Publication bias was assessed by funnel plot, Bagg's and Egger's tests.

RESULTS

Totally, 23 studies involving 1478 patients were included in the present meta-analysis. After a pooled analysis, it revealed that a high SUVmax was significantly associated with a poor OS (HR:2.07, 95%CI: 1.74-2.46, P = 0.000) and DFS (HR: 2.28, 95%CI: 1.53-3.41, P = 0.000). In addition, an increased TLG level contributed to a shorter OS (HR:1.91, 95%CI: 1.26-2.90, P = 0.002) and DFS (HR: 4.34, 95%CI: 1.42-13.27, P = 0.01). Moreover, we confirmed that an elevated MTV was significantly associated with increased mortality (HR:2.04, 95%CI:1.26-3.31, P = 0.004) and disease relapse (HR: 3.88, 95%CI:1.25-12.09, P = 0.019) risks. Besides, the present study uncovered that increased ΔSUVmax could predict poor OS (HR:1.26, 95%CI:1.06-1.50, P = 0.008) instead of PFS (HR: 1.96, 95%CI: 0.82-4.72, P = 0.280). Lastly, we found that LN SUVmax did not link to OS (HR: 1.49, 95%CI: 0.83-2.68, P = 0.178). No obvious publication bias was detected in the present study.

CONCLUSION

18F FDG PET parameters, including SUVmax, TLG, MTV, and ΔSUVmax, could be applied as convenient and reliable factors for predicting BTC patients` outcomes.

Metabolic reprogramming and its clinical implication for liver cancer

Cancer cells often encounter hypoxic and hypo-nutrient conditions, which force them to make adaptive changes to meet their high demands for energy and various biomaterials for biomass synthesis. As a result, enhanced catabolism (breakdown of macromolecules for energy production) and anabolism (macromolecule synthesis from bio-precursors) are induced in cancer. This phenomenon is called "metabolic reprogramming," a cancer hallmark contributing to cancer development, metastasis, and drug resistance. HCC and cholangiocarcinoma (CCA) are 2 different liver cancers with high intertumoral heterogeneity in terms of etiologies, mutational landscapes, transcriptomes, and histological representations. In agreement, metabolism in HCC or CCA is remarkably heterogeneous, although changes in the glycolytic pathways and an increase in the generation of lactate (the Warburg effect) have been frequently detected in those tumors. For example, HCC tumors with activated β-catenin are addicted to fatty acid catabolism, whereas HCC tumors derived from fatty liver avoid using fatty acids. In this review, we describe common metabolic alterations in HCC and CCA as well as metabolic features unique for their subsets. We discuss metabolism of NAFLD as well, because NAFLD will likely become a leading etiology of liver cancer in the coming years due to the obesity epidemic in the Western world. Furthermore, we outline the clinical implication of liver cancer metabolism and highlight the computation and systems biology approaches, such as genome-wide metabolic models, as a valuable tool allowing us to identify therapeutic targets and develop personalized treatments for liver cancer patients.

Dual-phase FDG PET/CT for predicting prognosis in operable breast cancer

Purpose

We aimed to investigate the role of dual-phase FDG PET/CT in predicting the prognosis of patients with operable breast cancer.

Methods

We retrospectively reviewed the data of 998 patients who underwent radical treatment for breast cancer. Before treatment, PET/CT scans were performed 1 and 2 h after FDG administration. The maximum standardized uptake value (SUVmax) at both time points (SUVmax1 and SUVmax2) in the primary tumor and the retention index (RI) were calculated. PET recurrence risk (PET-RR) was determined based on the SUVmax1 and RI, and disease-free survival (DFS) and overall survival (OS) were evaluated according to the metabolic parameters. Propensity score matching was performed to adjust for biological characteristics.

Results

The cut-off values for SUVmax1 and RI were 3 and 5%, respectively. The 5-year DFS was 94.9% and 86.1% (P < 0.001), and the 5-year OS was 97.6% and 92.7% (P < 0.001) in the low and high PET-RR groups, respectively. In multivariate analysis, high T status, nodal metastasis, the triple-negative subtype, and high PET-RR were independent factors of poor DFS. Propensity score matching revealed similar findings (5-year DFS 91.8% vs. 88.6%, P = 0.041 and 5-year OS 97.1% vs. 94.2%, P = 0.240, respectively).

Conclusion

The combined parameters of SUVmax1 and RI on dual-phase FDG PET/CT were useful for predicting prognosis of patients with breast cancer. Patients with a high SUVmax1 and a negative time course of FDG uptake had a favorable prognosis.

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SUVmax and retention index on FDG PET/CT are related with breast cancer prognosis.

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Breast cancer with high SUVmax but no increase over time has a favorable prognosis.

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Dual-phase FDG PET/CT is useful to predict the prognosis in operable breast cancer.

Metabolic reprogramming in cholangiocarcinoma

Metabolic reprogramming is a hallmark of cancer and allows tumour cells to meet the increased energy demands required for rapid proliferation, invasion, and metastasis. Indeed, many tumour cells acquire distinctive metabolic and bioenergetic features that enable them to survive in resource-limited conditions, mainly by harnessing alternative nutrients. Several recent studies have explored the metabolic plasticity of cancer cells with the aim of identifying new druggable targets, while therapeutic strategies to limit the access to nutrients have been successfully applied to the treatment of some tumours. Cholangiocarcinoma (CCA), a highly heterogeneous tumour, is the second most common form of primary liver cancer. It is characterised by resistance to chemotherapy and poor prognosis, with 5-year survival rates of below 20%. Deregulation of metabolic pathways have been described during the onset and progression of CCA. Increased aerobic glycolysis and glutamine anaplerosis provide CCA cells with the ability to generate biosynthetic intermediates. Other metabolic alterations involving carbohydrates, amino acids and lipids have been shown to sustain cancer cell growth and dissemination. In this review, we discuss the complex metabolic rewiring that occurs during CCA development and leads to unique nutrient addiction. The possible role of therapeutic interventions based on metabolic changes is also thoroughly discussed.

Normal values for 18F-FDG uptake in organs and tissues measured by dynamic whole body multiparametric FDG PET in 126 patients

BACKGROUND

Dynamic whole-body (D-WB) FDG PET/CT is a recently developed technique that allows direct reconstruction of multiparametric images of metabolic rate of FDG uptake (MR_FDG) and "free" FDG (DV_FDG). Multiparametric images have a markedly different appearance than the conventional SUV images obtained by static PET imaging, and normal values of MR_FDG and DV_FDG in frequently used reference tissues and organs are lacking. The aim of this study was therefore to: (1) provide an overview of normal MR_FDG and DV_FDG values and range of variation in organs and tissues; (2) analyse organ time-activity curves (TACs); (3) validate the accuracy of directly reconstructed MR_FDG tissue values versus manually calculated K_i (and MR_FDG) values; and (4) explore correlations between demographics, blood glucose levels and MR_FDG values. D-WB data from 126 prospectively recruited patients (100 without diabetes and 26 with diabetes) were retrospectively analysed. Participants were scanned using a 70-min multiparametric PET acquisition protocol on a Siemens Biograph Vision 600 PET/CT scanner. 13 regions (bone, brain grey and white matter, colon, heart, kidney, liver, lung, skeletal muscle of the back and thigh, pancreas, spleen, and stomach) as well as representative pathological findings were manually delineated, and values of static PET (SUV), D-WB PET (K_i, MR_FDG and DV_FDG) and individual TACs were extracted. Multiparametric values were compared with manual TAC-based calculations of K_i and MR_FDG, and correlations with blood glucose, age, weight, BMI, and injected tracer dose were explored.

RESULTS

Tissue and organ MR_FDG values showed little variation, comparable to corresponding SUV variation. All regional TACs were in line with previously published FDG kinetics, and the multiparametric metrics correlated well with manual TAC-based calculations (r² = 0.97, p < 0.0001). No correlations were observed between glucose levels and MR_FDG in tissues known not to be substrate driven, while tissues with substrate driven glucose uptake had significantly correlated glucose levels and MR_FDG values.

CONCLUSION

The multiparametric D-WB PET scan protocol provides normal MR_FDG values with little inter-subject variation and in agreement with manual TAC-based calculations and literature values. The technique therefore facilitates both accurate clinical reports and simpler acquisition of quantitative estimates of whole-body tissue glucose metabolism.

Dynamic whole-body FDG-PET imaging for oncology studies

Introduction

Recent PET/CT systems have improved sensitivity and spatial resolution by smaller PET detectors and improved reconstruction software. In addition, continuous-bed-motion mode is now available in some PET systems for whole-body PET imaging. In this review, we describe the advantages of dynamic whole-body FDG-PET in oncology studies.

Methods

PET–CT imaging was obtained at 60 min after FDG administration. Dynamic whole-body imaging with continuous bed motion in 3 min each with flow motion was obtained over 400 oncology cases. For routine image analysis, these dynamic phases (usually four phases) were summed as early FDG imaging. The image quality of each serial dynamic imaging was visually evaluated. In addition, changes in FDG uptake were analyzed in consecutive dynamic imaging and also in early delayed (90 min after FDG administration) time point imaging (dual-time-point imaging; DTPI). Image interpretation was performed by consensus of two nuclear medicine physicians.

Result

All consecutive dynamic whole-body PET images of 3 min duration had acceptable image quality. Many of the areas with physiologically high FDG uptake had altered uptake on serial images. On the other hand, most of the benign and malignant lesions did not show visual changes on serial images. In the study of 60 patients with suspected colorectal cancer, unchanged uptake was noted in almost all regions with pathologically proved FDG uptake, indicating high sensitivity with high negative predictive value on both serial dynamic imaging and on DTPI. We proposed another application of serial dynamic imaging for minimizing motion artifacts for patients who may be likely to move during PET studies.

Discussion

Dynamic whole-body imaging has several advantages over the static imaging. Serial assessment of changes in FDG uptake over a short period of time is useful for distinguishing pathological from physiological uptake, especially in the abdominal regions. These dynamic PET studies may minimize the need for DPTI. In addition, continuous dynamic imaging has the potential to reduce motion artifacts in patients who are likely to move during PET imaging. Furthermore, kinetic analysis of the FDG distribution in tumor areas has a potential for precise tissue characterization.

Conclusion

Dynamic whole-body FDG-PET imaging permits assessment of serial FDG uptake change which is particularly useful for differentiation of pathological uptake from physiological uptake with high diagnostic accuracy. This imaging can be applied for minimizing motion artifacts. Wide clinical applications of such serial, dynamic whole-body PET imaging is expected in oncological studies in the near future.