Metabolic Activity by 18F-FDG-PET/CT Is Prognostic for Stage I and II Pancreatic Cancer

Prognostic Significance of 18 F-FDG PET/CT Radiomics in Patients With Resectable Pancreatic Ductal Adenocarcinoma Undergoing Curative Surgery

PURPOSE

This study aimed to investigate the prognostic significance of PET/CT radiomics to predict overall survival (OS) in patients with resectable pancreatic ductal adenocarcinoma (PDAC).

METHODS

We enrolled 627 patients with resectable PDAC who underwent preoperative 18 F-FDG PET/CT and subsequent curative surgery. Radiomics analysis of the PET/CT images for the primary tumor was performed using the Chang-Gung Image Texture Analysis toolbox. Radiomics features were subjected to least absolute shrinkage and selection operator (LASSO) regression to select the most valuable imaging features of OS. The prognostic significance was evaluated by Cox proportional hazards regression analysis. Conventional PET parameters and LASSO score were assessed as predictive factors for OS by time-dependent receiver operating characteristic curve analysis.

RESULTS

During a mean follow-up of 28.8 months, 378 patients (60.3%) died. In the multivariable Cox regression analysis, tumor differentiation, resection margin status, tumor stage, and LASSO score were independent prognostic factors for OS (HR, 1.753, 1.669, 2.655, and 2.946; all P < 0.001, respectively). The time-dependent receiver operating characteristic curve analysis showed that the LASSO score had better predictive performance for OS than conventional PET parameters.

CONCLUSIONS

The LASSO score using the 18 F-FDG PET/CT radiomics of the primary tumor was the independent prognostic factor for predicting OS in patients with resectable PDAC and may be helpful in determining therapeutic and follow-up plans for these patients.

Advances in pre-treatment evaluation of pancreatic ductal adenocarcinoma: a narrative review

BACKGROUND AND OBJECTIVE

Despite advances in the multidisciplinary management of pancreatic cancer, overall prognosis remains poor, due to early progression of the disease. There is a need to also take action in staging, to make it increasingly accurate and complete, to define the setting of the therapeutic strategy. This review was planned to update the current status of pre-treatment evaluation for pancreatic cancer.

METHODS

We conducted an extensive review, including relevant articles dealing with traditional imaging, functional imaging and minimally invasive surgical procedures before treatment for pancreatic cancer. We searched articles written in English only. Data in the PubMed database, published in the period between January 2000 and January 2022, were retrieved. Prospective observational studies, retrospective analyses and meta-analyses were reviewed and analysed.

KEY CONTENT AND FINDINGS

Each imaging modality (endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, computed tomography, positron emission tomography/computed tomography, staging laparoscopy) has its own diagnostic advantages and limitations. The sensitivity, specificity and accuracy for each image set are reported. Data that support the increasing role of neoadjuvant therapy (radiotherapy and chemotherapy) and the meaning of a patient-tailored treatment selection, based on tumour staging, are also discussed.

CONCLUSIONS

A multimodal pre-treatment workup should be searched as it improves staging accuracy, orienting patients with resectable tumors towards surgery, optimizing patient selection with locally advanced tumors to neoadjuvant or definite therapy and avoiding surgical resection or curative radiotherapy in those with metastatic disease.

18-Fluoride fluorodeoxyglucose positron emission tomography is impactful in newly diagnosed pancreatic adenocarcinoma

BACKGROUND

Adenocarcinoma of the pancreas has a dismal prognosis. Surgical resection increases survival but is reliant on accurate detection and staging of disease. In overseas studies, ¹⁸ F-FDG positron emission tomography (PET) has been shown to have high diagnostic accuracy and staging utility, but local data remain sparse, in part because the technique has hitherto been unfunded via the Medicare benefits schedule. Although Commonwealth funding for rare tumours (including of the pancreas) has been recently approved to commence in late 2022, the proposed item descriptor wording implies that PET should lead to a significant change in management. Accordingly, the aims of this study are to characterize PET findings in newly diagnosed pancreatic adenocarcinoma using standard parameters, such as the SUV_max , and assess the proportion of cases in which PET altered initial management planning.

METHODS

We analysed the PET findings of these cancers (presence and degree of metabolic activity in the primary lesion, as well as within malignant nodal and metastatic lesions) and compared the pre- and post-PET management plans of the referring specialists.

RESULTS

Of 51 patients we found that (a) increasing SUV_max of the primary lesion correlated with an increase in disease stage (r-value = 0.335; P-value = 0.016), and (b) PET contributed to a significant change in management in 35% of patients.

CONCLUSION

In newly diagnosed pancreatic adenocarcinoma, parameters in PET correlate with disease stage and the overall findings contribute to a significant management change in about 35% of patients.

18F-FDG-PET/CT Imaging for Gastrointestinal Malignancies

Gastrointestinal malignancies encompass a variety of primary tumor sites, each with different staging criteria and treatment approaches. In this review we discuss technical aspects of 18F-FDG-PET/CT scanning to optimize information from both the PET and computed tomography components. Specific applications for 18F-FDG-PET/CT are summarized for initial staging and follow-up of the major disease sites, including esophagus, stomach, hepatobiliary system, pancreas, colon, rectum, and anus.

Pancreatic Ductal Adenocarcinoma: The Dawn of the Era of Nuclear Medicine?

Pancreatic ductal adenocarcinoma (PDAC), accounting for 90-95% of all pancreatic tumors, is a highly devastating disease associated with poor prognosis. The lack of accurate diagnostic tests and failure of conventional therapies contribute to this pejorative issue. Over the last decade, the advent of theranostics in nuclear medicine has opened great opportunities for the diagnosis and treatment of several solid tumors. Several radiotracers dedicated to PDAC imaging or internal vectorized radiotherapy have been developed and some of them are currently under clinical consideration. The functional information provided by Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) could indeed provide an additive diagnostic value and thus help in the selection of patients for targeted therapies. Moreover, the therapeutic potential of β-- and α-emitter-radiolabeled agents could also overcome the resistance to conventional therapies. This review summarizes the current knowledge concerning the recent developments in the nuclear medicine field for the management of PDAC patients.

Can Spectral Power Be Used as a Candidate Seizure Marker of the Periodic Discharges Pattern?

Introduction: It remains controversial whether the periodic discharges (PDs) pattern is an ictal or interictal phenomenon. The aims of the study are to apply time-frequency and power spectrum analysis to study the PDs pattern and prediction of seizures.

Methods: We retrospectively searched continuous electroencephalography (cEEG) recordings to identify patients exhibiting the PDs pattern. Artifact-free cEEG segments demonstrating the PDs pattern with stable baselines were chosen for time-frequency and power spectrum analysis.

Results: In total, 72 patients (1.3%) exhibited the PDs pattern, with a mean age 36.0 ± 20.7 years (range, 8–76 years). The median spectral power of PDs with a length of 60 s was 70.94 μV² and that of PDs with a length of 20 s was 195.80 μV². During follow-up, patients with spectral power of PDs of length 60 and 20 s lower than 28.65 and 36.09 μV², respectively, exhibited no seizure. For predicting seizures, when the spectral power for PDs of 60 and 20 s equaled to 17.26 and 21.40 μV², respectively, the diagnostic sensitivity was 100% and specificity was 86%. The locations of maximal spectral power of PDs, crude seizure onset zone (SOZ) judged from scalp EEG, and the most prominent regions of hyper- or hypo-metabolism on FDG-PET were congruent.

Conclusions: Spectral power might be a candidate seizure marker of the PDs pattern. High spectral power predicted a high risk of seizures, and low spectral power was associated with a low risk of seizures.

A Novel Validated Recurrence Stratification System Based on 18F-FDG PET/CT Radiomics to Guide Surveillance After Resection of Pancreatic Cancer

objective

Despite the heterogeneous biology of pancreatic cancer, similar surveillance schemas have been used. Identifying the high recurrence risk population and conducting prompt intervention may improve prognosis and prolong overall survival.

Methods

One hundred fifty-six resectable pancreatic cancer patients who had undergone ¹⁸F-FDG PET/CT from January 2013 to December 2018 were retrospectively reviewed. The patients were categorized into a training cohort (n = 109) and a validation cohort (n = 47). LIFEx software was used to extract radiomic features from PET/CT. The risk stratification system was based on predictive factors for recurrence, and the index of prediction accuracy was used to reflect both the discrimination and calibration.

Results

Overall, seven risk factors comprising the rad-score and clinical variables that were significantly correlated with relapse were incorporated into the final risk stratification system. The 1-year recurrence-free survival differed significantly among the low-, intermediate-, and high-risk groups (85.5, 24.0, and 9.1%, respectively; p < 0.0001). The C-index of the risk stratification system in the development cohort was 0.890 (95% CI, 0.835-0.945).

Conclusion

The ¹⁸F-FDG PET/CT-based radiomic features and clinicopathological factors demonstrated good performance in predicting recurrence after pancreatectomy in pancreatic cancer patients, providing a strong recommendation for an adequate adjuvant therapy course in all patients. The high-risk recurrence population should proceed with closer follow-up in a clinical setting.

Venous thromboembolism detected by FDG-PET/CT in cancer patients: a common, yet life-threatening observation

Cancer patients are at markedly increased risk for venous thromboembolism (VTE). Early detection of VTE may decrease morbidity and mortality in this population. We conducted this study to evaluate the ability of FDG-PET/CT to detect thrombosis in cancer patients. This retrospective study included 131 cancer patients with a history of deep vein thrombosis (DVT) or pulmonary embolism (PE) referred for 2-deoxy-2-[¹⁸F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). All subjects underwent PET/CT imaging 60 minutes after FDG injection. Images were visually assessed for increased FDG uptake within the venous lumen. For positive cases, clinical follow-up and Doppler ultrasonography and/or contrast-enhanced CT scans were reviewed. FDG-PET/CT revealed abnormal uptake in the venous system of 26 (19.8%) patients. Eighteen (69.2%) had a history of DVT, and 13 (50%) had a history of PE. The most common site of thrombosis was the inferior vena cava (IVC) (n=14, 53.8%), followed by lower extremities veins (n=9, 34.6%), jugular veins (n=2, 7.7%), and superior vena cava (n=1, 3.8%). The presence of thrombi was confirmed by reviewing clinical follow-up in 6 (23.1%) patients. Among this group, thrombosis was detected in lower extremity veins (n=4, 15.8%), jugular veins (n=1, 3.8%), and IVC (n=1, 3.8%). Our study demonstrates that thrombi prior to their clinical manifestation can be detected by FDG-PET/CT in cancer patients. Moving forward, physicians must carefully consider the venous system when reporting FDG-PET/CT for cancer patients.

Prognostic value of FDG-PET radiomics with machine learning in pancreatic cancer

Patients with pancreatic cancer have a poor prognosis, therefore identifying particular tumor characteristics associated with prognosis is important. This study aims to investigate the utility of radiomics with machine learning using 18F-fluorodeoxyglucose (FDG)-PET in patients with pancreatic cancer. We enrolled 161 patients with pancreatic cancer underwent pretreatment FDG-PET/CT. The area of the primary tumor was semi-automatically contoured with a threshold of 40% of the maximum standardized uptake value, and 42 PET features were extracted. To identify relevant PET parameters for predicting 1-year survival, Gini index was measured using random forest (RF) classifier. Twenty-three patients were censored within 1 year of follow-up, and the remaining 138 patients were used for the analysis. Among the PET parameters, 10 features showed statistical significance for predicting overall survival. Multivariate analysis using Cox HR regression revealed gray-level zone length matrix (GLZLM) gray-level non-uniformity (GLNU) as the only PET parameter showing statistical significance. In RF model, GLZLM GLNU was the most relevant factor for predicting 1-year survival, followed by total lesion glycolysis (TLG). The combination of GLZLM GLNU and TLG stratified patients into three groups according to risk of poor prognosis. Radiomics with machine learning using FDG-PET in patients with pancreatic cancer provided useful prognostic information.

[18F]FDG Uptake in Adipose Tissue Is Not Related to Inflammation in Type 2 Diabetes Mellitus

Purpose

2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG) uptake is a marker of metabolic activity and is therefore used to measure the inflammatory state of several tissues. This radionuclide marker is transported through the cell membrane via glucose transport proteins (GLUTs). The aim of this study is to investigate whether insulin resistance (IR) or inflammation plays a role in [¹⁸F]FDG uptake in adipose tissue (AT).

Procedures

This study consisted of an in vivo clinical part and an ex vivo mechanistic part. In the clinical part, [¹⁸F]FDG uptake in abdominal visceral AT (VAT) and subcutaneous AT (SAT) was determined using PET/CT imaging in 44 patients with early type 2 diabetes mellitus (T2DM) (age 63 [54–66] years, HbA1c [6.3 ± 0.4 %], HOMA-IR 5.1[3.1–8.5]). Plasma levels were measured with ELISA. In the mechanistic part, AT biopsies obtained from 8 patients were ex vivo incubated with [¹⁸F]FDG followed by autoradiography. Next, a qRT-PCR analysis was performed to determine GLUT and cytokine mRNA expression levels. Immunohistochemistry was performed to determine CD68⁺ macrophage infiltration and GLUT4 protein expression in AT.

Results

In vivo VAT [¹⁸F]FDG uptake in patients with T2DM was inversely correlated with HOMA-IR (r = − 0.32, p = 0.034), and positively related to adiponectin plasma levels (r = 0.43, p = 0.003). Ex vivo [¹⁸F]FDG uptake in VAT was not related to CD68⁺ macrophage infiltration, and IL-1ß and IL-6 mRNA expression levels. Ex vivo VAT [¹⁸F]FDG uptake was positively related to GLUT4 (r = 0.83, p = 0.042), inversely to GLUT3 (r = − 0.83, p = 0.042) and not related to GLUT1 mRNA expression levels.

Conclusions

In vivo [¹⁸F]FDG uptake in VAT from patients with T2DM is positively correlated with adiponectin levels and inversely with IR. Ex vivo [¹⁸F]FDG uptake in AT is associated with GLUT4 expression but not with pro-inflammatory markers. The effect of IR should be taken into account when interpreting data of [¹⁸F]FDG uptake as a marker for AT inflammation.

Electronic supplementary material

The online version of this article (10.1007/s11307-020-01538-0) contains supplementary material, which is available to authorized users.

Value of Pretreatment 18F-fluorodeoxyglucose Positron Emission Tomography in Patients With Localized Pancreatic Cancer Treated With Neoadjuvant Therapy

Background:¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging is not routine in patients with localized pancreatic cancer (PC). We evaluated the prognostic value of PET/CT in patients who received neoadjuvant therapy.

Methods: Patients with localized PC underwent pretreatment PET/CT with or without posttreatment (preop) PET/CT. Maximum standardized uptake values (SUV) were classified as high or low based on a cut point of 7.5 at diagnosis (SUV_dx) and 3.5 after neoadjuvant therapy (preoperative; SUV_preop). Preop carbohydrate antigen 19-9 (CA19-9) was classified as normal ( ≤ 35 U/mL) or elevated.

Results: Pretreatment PET/CT imaging was performed on 201 consecutive patients; SUV_dx was high in 98 (49%) and low in 103 (51%). Preop PET/CT was available in 104 (52%) of the 201 patients; SUV_preop was high in 60 (58%) and low in 44 (42%). Following neoadjuvant therapy, preop CA19-9 was normal in 90 (45%) patients and elevated in 111 (55%). Median overall survival (OS) of all patients was 27 months; 33 months for the 103 patients with a low SUV_dx and 22 months for the 98 patients with a high SUV_dx (p = 0.03). Median OS for patients with low SUV_dx/normal preop CA19-9, high SUV_dx/normal preop CA19-9, low SUV_dx/elevated preop CA19-9, and high SUV_dx/elevated preop CA19-9 were 66, 34, 23, and 17 months, respectively (p < 0.0001). OS was 44 months for the 148 (74%) patients who completed all intended neoadjuvant therapy and surgery and 13 months for the 53 (26%) who did not undergo surgery (p < 0.001).

Conclusion: Pretreatment PET/CT avidity and preop CA19-9 are clinically significant prognostic markers in patients with PC.

Early variation of 18-fluorine-labelled fluorodeoxyglucose PET-derived parameters after chemoradiotherapy as predictors of survival in locally advanced pancreatic carcinoma patients

OBJECTIVE

To investigate if early variation of PET-derived parameters after concomitant chemoradiotherapy (CRT) predicts overall survival (OS), local relapse free survival (LRFS), distant relapse free survival (DRFS) and progression free survival (PFS) in locally advanced pancreatic cancer (LAPC) patients.

METHODS

Fifty-two LAPC patients (median age: 61 years; range: 35-85) with available FDG PET/CT before and after RT (2-6 months, median: 2) were enrolled from May 2005 to June 2015. The predictive value of the percentage variation of mean/maximum standard uptake value (ΔSUVmean/max), metabolic tumour volume (ΔMTV) and total lesion glycolysis (ΔTLG), estimated considering different uptake thresholds (40-50-60%), was investigated between pre- and post-RT PET. The percentage difference between gastrointestinal cancer-associated antigen (ΔGICA) levels measured at the time of PET was also considered. Log-rank test and Cox regression analysis were performed to assess the prognostic value of considered PET-derived parameters on survival outcomes.

RESULTS

The median follow-up was 13 months (range: 4-130). At univariate analysis, ΔTLG50 showed borderline significance in predicting OS (P = 0.05) and was the most significant parameter correlated to LRFS and PFS (P = 0.001). Median LRFS was 4 and 33 months if ΔTLG50 was below or above 35% respectively (P = 0.0003); similarly, median PFS was 3 vs 6 months (P = 0.0009). No significant correlation was found between PET-derived parameters and DRFS, while the ΔGICA was the only borderline significant prognostic value for this endpoint (P = 0.05).

CONCLUSION

PET-derived parameters predict survival in LAPC patients; in particular, ΔTLG50 is the strongest predictor. The combination of these biochemical and imaging biomarkers is promising in identifying patients at higher risk of earlier relapse.

18F-FDG PET/CT in pancreatic adenocarcinoma: A role at initial imaging staging?

Pancreatic ductal adenocarcinoma represents 90% of all pancreatic tumors. The only hope for prolonged survival in patients with this condition still remains surgery with complete R0 resection. Initial imaging has a pivotal role to identify patients who are eligible to curative surgery and those who may benefit of neoadjuvant chemotherapy. This review provides an analysis of the recent literature on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in pancreatic adenocarcinoma. Performances of FDG PET in the detection of lymph node involvement and metastatic spread at initial staging and those in the assessment of response to treatment are described.

Different biological behaviors in left-sided pancreatic cancer according to Yonsei criteria: Proposal of a modified Yonsei criteria score

BACKGROUND/OBJECTIVES

Our institutional experience has demonstrated that bloodless and margin-negative resection is the most potent prognostic factor in treating left-sided pancreatic cancer and we developed selection guideline. The Yonsei criteria (YC) is selection criteria for oncologically safe and effective resection of left-sided pancreatic cancer by a minimally invasive approach. In this study, we investigated whether left-sided pancreatic cancer with YC can be more individualized to predict long-term survival by using clinically and pathologically detectable parameters.

METHODS

From January 2000 to December 2015, 105 patients underwent distal pancreatectomy for left-sided pancreatic cancer. The medical records of the patients were retrospectively reviewed.

RESULTS

Among clinically and pathologically detectable parameters to predict tumor conditions, radiologically determined tumor size (p = 0.080) and SUV_max (p = 0.086) were identified as predictors of early tumor recurrence with marginal significance. Among them, 20% of the patients with YC were identified as having the most favoring tumor condition, with an modified YC score of 3. The patient group with the lowest mYC score was found to have a very long disease-free survival time, with a mean of 108 months, which was statistically different from those with other mYC scores (mYC score = 4, mean 47.1 months [95% CI: 27.8-69.5] vs. mYC score = 5, mean 36.7 months [95% CI: 12.7-60.7], vs. mYC score = 6, mean 10.7 months [95% CI: 3.9-17.4]).

CONCLUSIONS

Modified Yonsei criteria score can predict long-term survival in resected left-sided pancreatic cancer. And patients within YC with a mYC score = 3 could have a favorable survival outcome.

Clinical significance of defining borderline resectable pancreatic cancer

Since the introduction of the concept of borderline resectable pancreatic cancer (BRPC), various definitions of this disease entity have been suggested. However, there are several obstacles in defining this disease category. The current diagnostic criteria of BRPC mainly focuses on its expanded 'technical resectability'; however, they are difficult to interpret because of their ambiguity using potential subjective or arbitrary terminology, In addition, limitations in current imaging technology and a lack of evidence in radiological-pathological-clinical correlation make it difficult to refine the criteria. On the other hand, neoadjuvant treatment is usually applied to increase the R0 resection rate of BRPC focusing on the 'oncological curability'. However, evidence is needed concerning the effect of neoadjuvant treatment by quality-controlled prospective randomized clinical trials based on a standardized radiologic and pathologic reporting system. In conclusion, there are two aspects in the current concept of BRPC, which are technical resectability and oncological curability. Although the recent evolution of surgical techniques is expanding the scope of technical resectability, it should not be overlooked that the disease entity must be defined based on the evidence of oncological curability.

18-Fluorodeoxyglucose Positron Emission Tomography Predicts Recurrence in Resected Pancreatic Ductal Adenocarcinoma

BACKGROUND

We aimed to determine whether treatment should be stratified according to 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) maximum standardized uptake values (SUV_max) in pancreatic ductal adenocarcinoma.

METHODS

Patients who underwent preoperative 18F-FDG PET/CT between 2006 and 2014 (n = 138) were stratified into high (≥ 4.85) and low (< 4.85) PET groups. The clinicopathological characteristics and prognostic outcomes were analyzed retrospectively.

RESULTS

The primary tumor SUV_max was positively correlated with preoperative CA19-9 levels (P < 0.001). The high PET group failed to achieve postoperative CA19-9 normalization (P = 0.014). Disease-specific (P < 0.001), recurrence-free (P < 0.001), liver recurrence-free (P < 0.001), and peritoneal recurrence-free (P = 0.020) survivals were significantly shorter in the high PET group. The primary tumor SUV_max was an independent predictive risk factor for liver metastasis (hazard ratio 3.46, 95% confidence interval 1.61-7.87; P = 0.001) and peritoneal recurrence (hazard ratio 3.36, 95% confidence interval 1.18-10.89; P = 0.023).

CONCLUSIONS

Surgical resection failed to achieve CA19-9 normalization in the high PET group and distant recurrence was frequent. This suggests the potential for residual cancer at distant sites, even after curative resection. Stronger preoperative systemic chemotherapy is preferred for the high PET group patients.

The Role of 18F-FDG PET/CT and PET/MRI in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a difficult disease to treat and continues to portend a poor prognosis, as most patients are unresectable at diagnosis. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) combined with CT (PET/CT) has been a cornerstone in oncological imaging of different cancers; however, the role of PET/CT in PDAC is continually evolving and currently not well established. Studies have shown the potential of PET/CT in guiding the management of patients with PDAC, with possible added benefit over anatomic imaging with CT or MRI in certain scenarios. PET/CT may be useful in diagnosis, initial staging, treatment response assessment, differentiation of recurrent tumor from post-treatment fibrosis, and radiotherapy planning. Additionally, PET/CT may be a cost-effective modality due to upstaging of patients originally deemed as surgical candidates. Recently, the advent of simultaneous PET/MRI represents an exciting advancement in hybrid functional imaging with potential applications in the imaging of PDAC. The advantages of PET/MRI include simultaneous acquisition to improve registration of fusion images, lower radiation dose, superior soft tissue contrast, and availability of multiparametric imaging. Studies are underway to evaluate the utility of PET/MRI in PDAC, including in initial staging and treatment response assessment and to determine the subgroup of patients that will benefit from PET/MRI. Further studies are warranted in both PET/CR and PET/MRI to better understand the role of these modalities in PDAC.

18F-fluorodeoxyglucose uptake of hepatocellular carcinoma as a prognostic predictor in patients with sorafenib treatment

PURPOSE

Sorafenib, an oral multikinase inhibitor, is a recommended treatment option available for patients with Barcelona Clinic Liver Cancer (BCLC)-C stage hepatocellular carcinoma (HCC). This study aimed to evaluate the performance of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) for predicting tumour progression during sorafenib treatment.

METHODS

We formed a retrospective cohort comprising patients treated with sorafenib for at least 30 days and undergoing ¹⁸F-FDG PET/CT within 1 month before treatment. For statistical analyses, the tumour-to-liver standardised uptake value (SUV) ratio (TLR) of the most hypermetabolic lesion was measured.

RESULTS

Among a total of 35 patients, two obtained partial remission, and 11 showed stable disease after the first response evaluation. Patients with a TLR ≥ 2.9 (n = 17) had a median overall survival (OS) of 3.7 months after sorafenib treatment, whereas patients with a TLR < 2.9 (n = 18) had median OS of 12.2 months (P < 0.001), although the disease control rate was not significantly different between the two groups. Pretreatment TLR ≥ 2.9 (hazard ratio [HR] = 6.318, P = 0.002) and Child-Pugh class B (HR = 4.316, P = 0.044) were poor prognostic factors for OS, and a TLR ≥ 2.9 (HR = 2.911, P = 0.024) was the only poor prognostic factor for progression-free survival in a multivariate analysis.

CONCLUSION

Pretreatment tumour metabolic activity assessed by ¹⁸F-FDG PET is an independent prognostic factor for survival in patients with BCLC-C stage HCC receiving sorafenib monotherapy, although it may not predict tumour response to the treatment.

Prognostic value of 18F-FDG-PET/CT parameters in patients with pancreatic carcinoma: A systematic review and meta-analysis

BACKGROUND

The identification of pancreatic carcinoma (PC) patients with poor prognosis is a priority in clinical oncology because of their high 5-year mortality. However, the prognostic value of pretreatment F-fluorodeoxyglucose (F-FDG)- positron emission tomography (PET)/computed tomography (CT) parameters in PC patients is controversial and no consensus exists as to its predictive capability. This meta-analysis was performed to comprehensively explore the prognostic significance of F-FDG-PET/CT parameters in patients with pancreatic carcinoma.

METHODS

Extensive literature searches of the PubMed, Embase, Web of Science, and Cochrane Library databases were conducted to identify literature published until March 5, 2017. Comparative analyses of the pooled hazard ratios (HRs) for event-free survival (EFS) and overall survival (OS) were performed to assess their correlations with pretreatment maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Either the fixed- or the random-effects model was adopted, depending on the heterogeneity observed across studies. Subgroup and sensitivity analyses were performed to assess the robustness of the results.

RESULTS

Sixteen studies including 1146 patients were identified. The pooled HRs for the probability of EFS were 1.90 (95% confidential interval (CI): 1.48-2.45) for SUVmax, 1.76 (95% CI: 1.20-2.58) for MTV, and 1.81 (95% CI: 1.27-2.58) for TLG. The pooled HRs for the probability of OS were 1.21 (95% CI: 1.12-1.31) for SUVmax, 1.56 (95% CI: 1.13-2.16) for MTV, and 1.70 (95% CI: 1.25-2.30) for TLG. A slight publication bias was detected using Begg test. After adjustment using the trim and fill procedure, the corrected HRs were not significantly different. The results of the subgroup analyses by SUVmax, MTV, and TLG showed that these factors may have similar prognostic significance.

CONCLUSION

F-FDG-PET/CT parameters, such as SUVmax, MTV, and TLG, may be significant prognostic factors in patients with pancreatic carcinoma. F-FDG-PET/CT imaging could be a promising tool to provide prognostic information for these patients.

Novel Diagnostic and Predictive Biomarkers in Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease for a multitude of reasons including very late diagnosis. This in part is due to the lack of understanding of the biological behavior of PDAC and the ineffective screening for this disease. Significant efforts have been dedicated to finding the appropriate serum and imaging biomarkers to help early detection and predict response to treatment of PDAC. Carbohydrate antigen 19-9 (CA 19-9) has been the most validated serum marker and has the highest positive predictive value as a stand-alone marker. When combined with carcinoembryonic antigen (CEA) and carbohydrate antigen 125 (CA 125), CA 19-9 can help predict the outcome of patients to surgery and chemotherapy. A slew of novel serum markers including multimarker panels as well as genetic and epigenetic materials have potential for early detection of pancreatic cancer, although these remain to be validated in larger trials. Imaging studies may not correlate with elevated serum markers. Critical features for determining PDAC include the presence of a mass, dilated pancreatic duct, and a duct cut-off sign. Features that are indicative of early metastasis includes neurovascular bundle involvement, duodenal invasion, and greater post contrast enhancement. 18-F-fluorodeoxyglucose (18-FDG) radiotracer uptake and changes following treatment may predict patient overall survival following treatment. Similarly, pretreatment apparent diffusion coefficient (ADC) values may predict prognosis with lower ADC lesions having worse outcome. Although these markers have provided significant improvement in the care of pancreatic cancer patients, further advancements can be made with perhaps better combination of markers or discovery of unique marker(s) to pancreatic cancer.

Qualification of National Cancer Institute-Designated Cancer Centers for Quantitative PET/CT Imaging in Clinical Trials

The National Cancer Institute developed the Centers for Quantitative Imaging Excellence (CQIE) initiative in 2010 to prequalify imaging facilities at all of the National Cancer Institute-designated comprehensive and clinical cancer centers for oncology trials using advanced imaging techniques, including PET. Here we review the CQIE PET/CT scanner qualification process and results in detail. Methods: Over a period of approximately 5 y, sites were requested to submit a variety of phantoms, including uniform and American College of Radiology-approved phantoms, PET/CT images, and examples of clinical images. Submissions were divided into 3 distinct time periods: initial submission (T0) and 2 requalification submissions (T1 and T2). Images were analyzed using standardized procedures, and scanners received a pass or fail designation. Sites had the opportunity to submit new data for scanners that failed. Quantitative results were compared across scanners within a given time period and across time periods for a given scanner. Results: Data from 65 unique PET/CT scanners across 56 sites were submitted for CQIE T0 qualification; 64 scanners passed the qualification. Data from 44 (68%) of those 65 scanners were submitted for T2. From T0 to T2, the percentage of scanners passing the CQIE qualification on the first attempt rose from 38% for T1 to 67% for T2. The most common reasons for failure were SUV outside specifications, incomplete submission, and uniformity issues. Uniform phantom and American College of Radiology-approved phantom results between scanner manufacturers were similar. Conclusion: The results of the CQIE process showed that periodic requalification may decrease the frequency of deficient data submissions. The CQIE project also highlighted the concern within imaging facilities about the burden of maintaining different qualifications and accreditations. Finally, for quantitative imaging-based trials, further evaluation of the relationships between the level of the qualification (e.g., bias or precision) and the quality of the image data, accrual rates, and study power is needed.