18-Fluorodeoxyglucose positron emission tomography in predicting survival of patients with pancreatic carcinoma

Clinical Outcomes of Proton Beam Therapy for Unresectable Locally Advanced Pancreatic Cancer: A Single-Center Retrospective Study

Purpose

We retrospectively researched the treatment outcome of proton beam therapy (PBT) and assessed its efficacy for inoperable locally advanced pancreatic cancer (LAPC) at our institution.

Methods and Materials

Fifty-four patients (28 men and 26 women, median age 67 years ranging from 40-88 years) were diagnosed with unresectable stage III LAPC and administered PBT from April 2009 to March 2020. Patients who could not complete PBT, had new distant metastases during the treatment, or did not have enough follow-up time were excluded from this study. All patients were clinically staged based on the International Union of Cancer TNM staging system (eighth edition) using computed tomography, magnetic resonance imaging, and positron emission tomography and were diagnosed as stage III (histologic type: 18 patients with adenocarcinoma and 36 clinically diagnosed patients). PBT was performed using the passive method, with a median total dose of 67.5 GyE (range, 50-77 GyE/25-35 fractions).Chemotherapy was used in combination during PBT in 46 patients (85.2%). Overall survival (OS), local progression-free survival (LPFS), progression-free survival, and median OS time were analyzed by Kaplan-Meier and log-rank tests. Univariate and multivariate analyses were performed for the following factors: maximum standardized uptake value (SUVmax), Eastern Cooperative Group performance status (PS), tumor site, total irradiation dose, concurrent chemotherapy, and primary tumor site. Cutoff values for SUVmax and tumor diameter were estimated using receiver operating characteristic curves and the area under the curve based on OS. Multivariate analysis was evaluated using the Cox proportional hazards models. Adverse events were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.

Results

The median observation period was 17.4 months, ranging from 4.0 to 89.7 months. The median tumor diameter was 36.5 mm, ranging from 15 to 90 mm, the median SUVmax was 5.85 (range, 2.1-27.6), and their cutoff values were estimated to be 37 mm and 4.8 mm, respectively. The 1- and 2-year OS was 77.8% and 35.2%, respectively, with a median OS time of 18.2 months, and only one patient survived >5 years. Twelve patients (22.2%) developed local recurrence, and 1- and 2-year LPFS rates were 89.7% and 74.5%, respectively; progression-free survival at 1 year was 58.8%. The PS score, tumor site, and irradiation dose were the prognostic factors related to OS that showed a significant difference. On the other hand, there was a significant difference in factors involved in LPFS, at 96.7%/77.9% in the first year and 86.6%/54.4% in the second year in the groups with tumor dose ≥67.5 GyE and <67.5 GyE, respectively (P = .015). Treatment-related acute toxicities were neutropenia (grade 1/2/3 at 3.7%/11.1%/31.5%, respectively), leukopenia (grade 1/2/3 at 1.8%/7.4%/20.4%, respectively), and thrombocytopenia (grade 1/2 at 1.8%/7.4%, respectively), whereas the late effects including peptic ulcer were captured only grade 2+. The late adverse events of grade 3 or higher were not observed.

Conclusions

PBT achieving 67.5 Gy combined with standard chemotherapy showed excellent local control for unresectable LAPC. Total irradiation dose, tumor site, and PS score at an initial diagnosis could be important prognostic factors. In this study, the dose-effect relationship was found, so an increase in dose should be considered to improve prognosis.

Prognostic Strength of CA 19-9, Demographic Parameters, and Maximum Standardized Uptake Value of Baseline 18F-FDG PET/CT in Treatment-naïve Patients with Pancreatic Carcinoma

Aim and Background

The aim of this study was to evaluate the prognostic value of imaging-based variables and tumor marker in predicting the progression-free survival (PFS) in treatment-naïve pancreatic cancer (PC) using baseline 18-fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT).

Materials and Methods

This retro-prospective study was conducted at PET/CT imaging facility of JCIA health-care facility of Pakistan. Total 68 patients with PCs were retrospectively included who had 18FDG PET/CT for staging from March 2017 to December 2020. Thirty-two patients had unresectable Stage IV disease on baseline imaging while the remaining 36 underwent Whipple's procedure and both categories were followed by chemotherapy with/without immunotherapy. These patients were followed for a median period of 18 months (1-62 months) for PFS. Logistic regression analysis and receiver operating characteristic (ROC) analysis were used for independent predictors of patients' demographics, tumor characteristics, CA 19-9, and maximum standardized uptake value (SUVmax) in PFS. Kaplan-Meier's survival curves were analyzed to measure PFS using ROC-derived significant cutoff values of CA 19-9 and SUVmax.

Results

Median PFS was 18 months (11-45) with 60% (41/68) patients were either died or labelled having metabolic progressive disease (MPD. Using logistic regression analysis, significant correlations were found for Stage IV disease and pancreatic body/tail tumor with disease progression (odd ratio: 7.535 and 4.803, respectively; P < 0.05). Gender, obesity, histological tumor type, and 18FDG-avid regional nodes did not show a significant impact on PFS. On ROC analysis, SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS (area under the curve: 0.827 and 0.911, respectively; P < 0.0001) and no association of age and primary tumor size in PFS. Significantly, shorter PFS was found using ROC-derived cutoff values of SUVmax >5.3 versus ≤5.3 of primary tumor (mean and 95% confidence interval [CI]: 16.7 vs. 48.5 and 10-23 vs. 41-56; log-rank = 25.014; P < 0.0001) and baseline CA 19-9 >197 versus ≤197 U/ml (mean and 95% CI: 11.8 vs. 46.9 and 7-16 vs. 39-55; log-rank = 38.217; P < 0.0001).

Conclusion

SUVmax >5.3 of primary tumor and baseline CA 19-9 >197 U/ml were found to have a significant negative correlation with PFS in treatment-naïve PC patients. Among demographics, only Stage IV disease and pancreatic tail and body tumors were found to have a negative association with disease progression.

High SUVmax on routine pre-operative FDG-PET predicts early recurrence in pancreatic and peri-ampullary cancer

BACKGROUND

SUVmax of a primary pancreatic tumour on FDG-PET/CT (SUVmax-p) may predict early post-operative recurrence. This has not been tested in the context of routine pre-operative FDG-PET/CT. It is also unknown whether this association exists independent of local residual tumour.

METHODS

FDG-PET/CT was performed routinely prior to resection of pancreatic or peri-ampullary adenocarcinoma between 2008 and 2012 as part of a previous prospective study. We compared SUVmax-p according to whether recurrence was diagnosed within 6 months of resection. We also determined the odds ratio for recurrence within 6 months for multiple cut-points of SUVmax-p. This analysis was repeated exclusively for patients who had resection with clear surgical margins (R0).

RESULTS

Of 56 patients from the initial study 23 underwent resection and were eligible. Recurrence within 6 months was associated with higher median SUVmax-p (5.9 vs 3.5; p = 0.04). This was also observed in 12 patients who underwent R0 resection (6.5 vs 2.2; p = 0.05). The cut-point with the highest odds for recurrence within 6 months for both groups was SUVmax-p ≥ 5.5 (OR = 10.8, CI = 1.56-109; OR[R0] = 24.0, CI = 1.64-1020).

CONCLUSION

SUVmax-p on routine FDG-PET/CT is useful for identifying patients likely to benefit from additional pre-operative staging or neoadjuvant therapy, even where clear margins can confidently be achieved.

The Significance of FDG PET/CT-Derived Parameters in Determining Prognosis of Cases with Pancreatic Adenocarcinoma: A Prospective Study

Background and objectives: Pancreatic adenocarcinoma represents one of the common malignancies with a relatively poor prognosis. However, early detection of this type of cancer may prove to be curable. Recent advancements in the radiological techniques might represent a hope for the early diagnosis and prediction of prognosis of pancreatic adenocarcinoma. This study aimed to assess the prognostic value of the primary tumor volumetric parameters obtained from FDG PET/CT first stage for the overall survival (OS) and progression-free survival (PFS) of patients with pancreatic adenocarcinoma and to explore the possible correlation between serum matrix metalloproteinase-2 (MMP-2) and the patients’ characteristics. Methods: Fifty patients with pancreatic adenocarcinoma were subjected to FDG PET/CT scan. The SUVpeak, SUVmax, and the metabolic tumor volume (MTV) were determined, as well as the SUVmean of the liver. Moreover, serum levels of MMP-2 were assessed. Follow-up of the patients was carried out for sixty months with determination of PFS and OS. Results: Peak SUV ≥ 3.9 was significantly correlated with the primary pancreatic lesions’ mean total glycolytic activity of >92 g, and MTV and was directly correlated with mortality. There was a positive correlation between peak SUV ≥ 3.9 and 50% SUVmax threshold > 82. Moreover, there was significant correlation between the total glycolytic activity and the studied clinicopathologic factors, except the age and sex of the patients and ECOG performance status. In addition, FDG uptake and the tumor glycolytic activity were substantially linked with a shorter PFS. Similarly, a strong correlation was found between MTV and PFS. Serum MMP-2 levels showed a significant relationship with the performance status, tumor stage, SUVmax threshold, and the glycolytic activity. Conclusions: Peak SUV, main lesion SUVmax, serum MMP-2, and the tumor glycolytic activity are good predictors of PFS of patients with pancreatic adenocarcinoma.

Nomogram Predicts Risk and Prognostic Factors for Bone Metastasis of Pancreatic Cancer: A Population-Based Analysis

BACKGROUND

The overall survival (OS) of pancreatic cancer (PC) patients with bone metastasis (BM) is extremely low, and it is pretty hard to treat bone metastasis. However, there are currently no effective nomograms to predict the diagnosis and prognosis of pancreatic cancer with bone metastasis (PCBM). Therefore, it is of great significance to establish effective predictive models to guide clinical practice.

METHODS

We screened patients from Surveillance Epidemiology and End Results (SEER) database between 2010 and 2016. The independent risk factors of PCBM were identified from univariable and multivariable logistic regression analyses, and univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors affecting the prognosis of PCBM. In addition, two nomograms were constructed to predict the risk and prognosis of PCBM. We used the area under the curve (AUC), C-index and calibration curve to determine the predictive accuracy and discriminability of nomograms. The decision curve analysis (DCA) and Kaplan-Meier(K-M) survival curves were employed to further confirm the clinical effectiveness of the nomogram.

RESULTS

Multivariable logistic regression analyses revealed that risk factors of PCBM included age, primary site, histological subtype, N stage, radiotherapy, surgery, brain metastasis, lung metastasis, and liver metastasis. Using Cox regression analyses, we found that independent prognostic factors of PCBM were age, race, grade, histological subtype, surgery, chemotherapy, and lung metastasis. We utilized nomograms to visually express data analysis results. The C-index of training cohort was 0.795 (95%CI: 0.758-0.832), whereas that of internal validation cohort was 0.800 (95%CI: 0.739-0.862), and the external validation cohort was 0.787 (95%CI: 0.746-0.828). Based on AUC of receiver operating characteristic (ROC) analysis, calibration plots, and decision curve analysis (DCA), we concluded that the risk and prognosis model of PCBM exhibits excellent performance.

CONCLUSION

Nomogram is sufficiently accurate to predict the risk and prognostic factors of PCBM, allowing for individualized clinical decisions for future clinical work.

Borderline Resectable and Locally Advanced Pancreatic Cancer: FDG PET/MRI and CT Tumor Metrics for Assessment of Pathologic Response to Neoadjuvant Therapy and Prediction of Survival

BACKGROUND. Imaging biomarkers of response to neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDA) are needed to optimize treatment decisions and long-term outcomes. OBJECTIVE. The purpose of this study was to investigate metrics from PET/MRI and CT to assess pathologic response of PDA to NAT and to predict overall survival (OS). METHODS. This retrospective study included 44 patients with ¹⁸F-FDG-avid borderline resectable or locally advanced PDA on pretreatment PET/MRI who also underwent post-NAT PET/MRI before surgery between August 2016 and February 2019. Carbohydrate antigen 19-9 (CA 19-9) level, metabolic metrics from PET/MRI, and morphologic metrics from CT (n = 34) were compared between pathologic responders (College of American Pathologists scores 0 and 1) and nonresponders (scores 2 and 3). AUCs were measured for metrics significantly associated with pathologic response. Relation to OS was evaluated with Cox proportional hazards models. RESULTS. Among 44 patients (22 men, 22 women; mean age, 62 ± 11.6 years), 19 (43%) were responders, and 25 (57%) were nonresponders. Median OS was 24 months (range, 6-42 months). Before treatment, responders and nonresponders did not differ in CA 19-9 level, metabolic metrics, or CT metrics (p > .05). After treatment, responders and nonresponders differed in complete metabolic response (CMR) (responders, 89% [17/19]; nonresponders, 40% [10/25]; p = .04], mean change in SUV_max (ΔSUV_max; responders, -70% ± 13%; nonresponders, -37% ± 42%; p < .001), mean change in SUV_max corrected to serum glucose level (ΔSUV_gluc) (responders, -74% ± 12%; nonresponders, -30% ± 58%; p < .001), RECIST response on CT (responders, 93% [13/14]; nonresponders, 50% [10/20]; p = .02)], and mean change in tumor volume on CT (ΔTvol) (responders, -85% ± 21%; nonresponders, 57% ± 400%; p < .001). The AUC of CMR for pathologic response was 0.75; ΔSUV_max, 0.83; ΔSUV_gluc, 0.87; RECIST, 0.71; and ΔTvol 0.86. The AUCs of bivariable PET/MRI and CT models were 0.83 (CMR and ΔSUV_max), 0.87 (CMR and ΔSUV_gluc), and 0.87 (RECIST and ΔTvol). OS was associated with CMR (p = .03), ΔSUV_max (p = .003), ΔSUV_gluc (p = .003), and RECIST (p = .046). CONCLUSION. Unlike CA 19-9 level, changes in metabolic metrics from PET/MRI and morphologic metrics from CT after NAT were associated with pathologic response and OS in patients with PDA, warranting prospective validation. CLINICAL IMPACT. Imaging metrics associated with pathologic response and OS in PDA could help guide clinical management and outcomes for patients with PDA who undergo emergency therapeutic interventions.

Incidental anal 18fluorodeoxyglucose uptake: Should we further examine the patient?

BACKGROUND

There are no studies on incidental anal ¹⁸F-fluorodeoxyglucose (¹⁸FDG) uptake.

AIM

To assess the rate and aetiologies of incidental anal ¹⁸FDG uptake and to evaluate the correlation between ¹⁸FDG positron-emission tomography/computed tomography (PET/CT) parameters and the diagnosis of an anorectal disease.

METHODS

The data from patients with incidental anal ¹⁸FDG uptake were retrospectively analysed. Patients who underwent anorectal examinations were identified and compared to those who did not undergo examinations. Patients who were offered treatment were then identified and compared to those who did not receive treatment.

RESULTS

Among the 43020 ¹⁸FDG PET/CT scans performed, 197 ¹⁸FDG PET/CT scans of 146 patients (0.45%) reported incidental anal uptake. Among the 134 patients included, 48 (35.8%) patients underwent anorectal examinations, and anorectal diseases were diagnosed in 33 (69.0%) of these patients and treated in 18/48 (37.5%) patients. Among the examined patients, those with a pathology requiring treatment had significantly smaller metabolic volumes (MV) 30 and MV41 values and higher maximal and mean standardized uptake value measurements than those who did not require treatment.

CONCLUSION

Incidental anal ¹⁸FDG uptake is rare, but a reliable anorectal diagnosis is commonly obtained when an anorectal examination is performed. The diagnosis of an anorectal disease induces treatment in more than one-third of the patients. These data should encourage practitioners to explore incidental anal ¹⁸FDG uptake systematically.

Prognostic value of 18FDG PET/CT volumetric parameters in the survival prediction of patients with pancreatic cancer

PURPOSE

To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of overall survival (OS) in patients with pancreatic cancer and also, assess their independence relative to well-established clinico-pathological variables.

METHODS

We conducted a retrospective analysis of patients with a confirmed diagnosis of pancreatic cancer who underwent 18 FDG PET/CT. The tumour maximum standardised uptake value (SUVmax) in addition to SUVmean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated. The prognostic value of 18 FDG PET/CT and clinico-pathological parameters for OS were assessed using univariate and multivariable analyses.

RESULTS

A sum of 89 patients were analysed in this study. Median survival for patients categorised as having high TLG (≥55) and low TLG (<55) was 18 vs 5 months (p < 0.001). Similarly, the respective high vs low SUVmean, MTV and SUVmax were 18 vs 6 months (p = 0.001), 16 vs 6 months (p = 0.002) and 18 vs 6 months (p = 0.001). Univariate analysis showed SUVmax, SUVmean, MTV, TLG, tumour size, tumour differentiation and presence of distant metastasis as prognostic factors for OS. On multivariable analysis, TLG (HR 2.0, 95% CI 1.26-3.18, p = 0.004) and the presence of distant metastasis (HR 3.37, 95% CI 1.97-5.77, p < 0.001) emerged as independent prognostic factors. Subgroup analysis identified TLG as the only significant PET metric after adjusting for the presence of distant metastasis.

CONCLUSIONS

18 FDG PET/CT is a useful tool in the preoperative evaluation of patients with pancreatic cancer. Tumour TLG offer an independent prognostic value in both potentially operable and metastatic disease settings.

Prognostic Implications of 18-FDG Positron Emission Tomography/Computed Tomography in Resectable Pancreatic Cancer

There are currently no known preoperative factors for determining the prognosis in pancreatic cancer. The aim of this study was to examine the role of 18-fluorodeoxyglucose (18-FDG) positron emission tomography/computed tomography (18-FDG-PET/CT) as a prognostic factor for patients with resectable pancreatic cancer. Data were obtained from a retrospective analysis of patients who had a preoperative PET scan and then underwent pancreatic resection from January 2007 to December 2015. The maximum standardized uptake value (SUVmax) of 18-FDG-PET/CT was calculated. Patients were divided into high (>3.65) and low (≤3.65) SUVmax groups, and compared in terms of their TNM classification (Union for International Cancer Contro classification), pathological grade, surgical treatment, state of resection margins, lymph node involvement, age, sex, diabetes and serum Carbohydrate Antigen 19-9 (CA 19-9) levels. The study involved 144 patients, 82 with high SUVmax pancreatic cancer and 62 with low SUVmax disease. The two groups’ disease-free and overall survival rates were significantly influenced by tumor stage, lymph node involvement, pathological grade, resection margins and SUVmax. Patients with an SUVmax ≤ 3.65 had a significantly better survival than those with SUVmax > 3.65 (p < 0.001). The same variables were independent predictors of survival on multivariate analysis. The SUVmax calculated with 18-FDG-PET/CT is an important prognostic factor for patients with pancreatic cancer, and may be useful in decisions concerning patients’ therapeutic management.

Standardized thresholds of volume-based PET/CT parameters predicting survival of patients with pancreatic head cancer treated with stereotactic body radiation therapy

OBJECTIVE

To explore standardized relative thresholds of volume-based parameters on FDG PET/CT, and define the optimal prognosticator among the relative thresholds for patients with locally advanced pancreatic head cancer (LAPHC) treated by stereotactic body radiation therapy (SBRT).

METHODS

Thirty-five patients with LAPHC were enrolled, and all underwent SBRT and baseline FDG PET/CT scan. Maximum standardized uptake value (SUVmax) was measured, and metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated under the relative (30%, 40%, and 50%) thresholds of SUVmax. Survival analysis was performed via univariate and multivariate analyses, and independent prognostic factors were determined by Cox proportional hazard models and corresponding survival curves and scatter diagram were drawn.

RESULTS

The median overall survival (OS) and progression-free survival (PFS) were 13.8 and 9.8 months, respectively. On univariate analysis, MTV(40%) < 5.6 cm³, accumulated dose (AD) ≥ 36 Gy and the absence of pancreatic duct (PD) stents were significantly correlated with both superior OS and PFS, TLG (40%) < 29.9 was related to better OS and biological effective dose (BED₁₀) ≥ 57.6 Gy was related to better PFS (all with p < 0.05). Further, multivariate analysis demonstrated both MTV (40%) and AD were independent prognosticators for OS and PFS, and BED₁₀ was an independent predictor for PFS (all with p < 0.05). Scatter diagram showed BED₁₀ to be a stronger clinical prognosis predictor for PFS than AD.

CONCLUSIONS

MTV (40%) was the optimal prognosticator among the relative thresholds of SUVmax for tumor delineation on PET/CT for LAPHC patients receiving SBRT. AD was also favorable indicators for OS and PFS of patients, and BED₁₀ was more sensitive than AD in predicting the PFS of patients.

The Role of PET/CT in the Imaging of Pancreatic Neoplasms

Pancreas cancer is a complex disease and its prognosis is related to the origin of the tumor cell as well as the stage of disease at the time of diagnosis. Pancreatic adenocarcinomas derive from the exocrine pancreas and are the fourth leading cause of cancer-related deaths in the United States, while well-differentiated pancreatic neuroendocrine tumors (pNETs) derived from the endocrine part of the pancreas are rare and characterized by a slow growth and good life expectancy. Surgery is the only curative treatment approach, and an accurate assessment of resectability is of paramount importance in order to avoid futile procedures. The role of molecular imaging with positron emission tomography and computed tomography ranges from indispensable for pNETs to controversial for certain scenarios in pancreatic adenocarcinomas. This review article aims to overview molecular pancreatic imaging.

Prognostic indicators in pancreatic cancer patients undergoing total pancreatectomy

PURPOSE

To evaluate the long-term outcomes of total pancreatectomy in a modern cohort of pancreatic cancer patients and to establish whether any factors identified prior to pancreatic resection were related to poor survival.

METHODS

We analyzed, retrospectively, patients who underwent total pancreatectomy for pancreatic cancer between 2007 and 2016. The short- and long-term outcomes were investigated and Cox regression analysis was used to evaluate the prognostic factors identified before resection.

RESULTS

The subjects were 49 patients with a mean age of 65 years, who underwent total pancreatectomy in our hospital during the study period. Peritoneal washing cytology was performed in 48 patients, with positive results in 4 (8.3%). There was no 30-day mortality. The median overall survival was 22.5 months, with a 5-year survival rate of 28.5%. Univariate analyses of the pre-resection variables revealed that overall survival was associated with tumor location, resectability classification, maximum standardized uptake value of positron emission tomography, the preoperative carbohydrate antigen 19-9 level, and peritoneal washing cytology status. Multivariate analysis revealed that positive peritoneal washing cytology status and the maximum standardized uptake value were independent predictors of poor survival.

CONCLUSION

Total pancreatectomy for pancreatic cancer is appropriate for selected patients, but peritoneal washing cytology and positron emission tomography should be performed preoperatively.

Optimal respiratory-gated [18F]FDG PET/CT significantly impacts the quantification of metabolic parameters and their correlation with overall survival in patients with pancreatic ductal adenocarcinoma

PURPOSE

Metabolic parameters are increasingly being used to characterize tumors. Motion artifacts due to patient respiration introduce uncertainties in quantification of metabolic parameters during positron emission tomography (PET) image acquisition. The present study investigates the impact of amplitude-based optimal respiratory gating (ORG) on quantification of PET-derived image features in patients with pancreatic ductal adenocarcinoma (PDAC), in correlation with overall survival (OS).

METHODS

Sixty-nine patients with histologically proven primary PDAC underwent 2'-deoxy-2'-[¹⁸F]fluoroglucose ([¹⁸F]FDG) PET/CT imaging during diagnostic work-up. Standard image acquisition and reconstruction was performed in accordance with the EANM guidelines and ORG images were reconstructed with a duty cycle of 35%. PET-derived image features, including standard parameters, first- and second-order texture features, were calculated from the standard and corresponding ORG images, and correlation with OS was assessed.

RESULTS

ORG significantly impacts the quantification of nearly all features; values of single-voxel parameters (e.g., SUV_max) showed a wider range, volume-based parameters (e.g., SUV_mean) were reduced, and texture features were significantly changed. After correction for motion artifacts using ORG, some features that describe intra-tumoral heterogeneity were more strongly correlated to OS.

CONCLUSIONS

Correction for respiratory motion artifacts using ORG impacts the quantification of metabolic parameters in PDAC lesions. The correlation of metabolic parameters with OS was significantly affected, in particular parameters that describe intra-tumor heterogeneity. Therefore, interpretation of single-voxel or average metabolic parameters in relation to clinical outcome should be done cautiously. Furthermore, ORG is a valuable tool to improve quantification of intra-tumoral heterogeneity in PDAC.

Detecting tumour response and predicting resectability after neoadjuvant therapy for borderline resectable and locally advanced pancreatic cancer

BACKGROUND

This systematic review aimed to determine the accuracy of imaging modalities to predict resectability and R0 resection for borderline resectable (BRPC) or locally advanced pancreatic cancer (LAPC) after neoadjuvant therapy (NAT).

METHODS

A systematic search of major databases was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Fifteen studies identified 995 patients of which 683 had BRPC and 312 LAPC. Computed tomography (CT) scan was the most common modality for re-staging (n = 14), followed by positron emission tomography (PET)-CT (n = 3) and endosonography (EUS) (n = 2). Stable disease on RECIST criteria was found in 67% of patients (range 53-80%) with 20% demonstrating reduction in tumour size. A total of 60% of patients underwent surgery post-NAT (range 31-85%) with a R0 rate of 88% (range 57-100%). Accuracy for predicting R0 resectability and T-stage on CT scan was 71 and 49%. A reduction in SUV_max on PET-CT and reduction of tumour stiffness on EUS elastography positively correlated with resectability.

CONCLUSIONS

More than half the patients undergo resection post-NAT for LAPC and BRPC. Stable, or reduction of, tumour disease may predict resectability. Reduction in tumour SUV_max on PET-CT and decreased tumour stiffness on EUS elastography may be potential markers of NAT response and resectability.

Clinical impact of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in patients with resectable pancreatic cancer: diagnosing lymph node metastasis and predicting survival

PURPOSE

To evaluate the diagnostic accuracy of fluorine-18-fluorodeoxyglucose PET/computed tomography (F-FDG PET/CT) for lymph node (LN) metastasis and the prognostic significance of F-FDG PET/CT LN parameters in patients with resectable pancreatic cancer.

PATIENTS AND METHODS

Patients with resectable pancreatic cancer who underwent staging F-FDG PET/CT between May 2007 and September 2016 were retrospectively enrolled and analyzed through medical record and image re-evaluation. The diagnostic accuracy of F-FDG PET/CT in predicting LN metastasis was evaluated and compared with that of contrast-enhanced abdominal computed tomography (CECT). Prognostic variables, including LN parameters assessed by F-FDG PET/CT [standardized uptake value (SUV)LN and LN/tumor SUV ratio], that affect disease-free survival (DFS) and overall survival (OS) were evaluated by regression analysis.

RESULTS

When predicting LN metastasis, F-FDG PET/CT showed greater sensitivity, positive predictive value, negative predictive value, and accuracy than CECT. Among prognostic factors affecting DFS, PET-positive LN (P=0.008), and LN/tumor SUV ratio (P=0.003) were found to be significant by regression analysis. Among the variables affecting OS, lymphovascular invasion (P=0.018) and the LN/tumor SUV ratio (P=0.046) were found to be significant.

CONCLUSION

F-FDG PET/CT showed higher diagnostic accuracy in predicting LN metastasis than CECT in patients with resectable pancreatic cancer. Only the LN/tumor SUV ratio of F-FDG PET/CT was an independent prognostic variable in both DFS and OS.

18 F-Fluorodeoxyglucose positron emission tomography can be used to determine the indication for endoscopic resection of superficial esophageal cancer

¹⁸F‐Fluorodeoxyglucose positron emission tomography (FDG‐PET) is a useful imaging modality that reflects the tumor activity. However, FDG‐PET is mainly used for advanced cancer, not superficial cancer. In this study, we investigated the relationship between the superficial tumor depth of esophageal cancer and the FDG uptake to determine the indications for endoscopic resection (ER). From 2009 to 2017, 444 patients with esophageal cancer underwent esophagectomy or endoscopic submucosal dissection (ESD), and 195 patients were pathologically diagnosed with superficial cancer. Among them, 146 patients were examined by FDG‐PET before esophagectomy or ESD. In these 146 patients, the relationship between the pathological tumor depth and FDG uptake was analyzed. The mean maximum standardized uptake value in pT1a‐EP/LPM tumors was 1.362 ± 0.890, that in pT1a‐MM/pT1b‐SM1 tumors was 2.453 ± 1.872, and that in pT1b‐SM2/SM3 tumors was 4.265 ± 3.233 (P < .0001). Among 51 pT1a‐EP/LPM tumors, 10 (19.6%) showed positive detection of FDG. For pT1a‐MM/pT1b‐SM1 and pT1b‐SM2/SM3 tumors, the detection rate was 52.9% (18/34) and 82.0% (50/61), respectively. The detection rate of pT1a‐EP/LPM was significantly lower than in the other two groups (P < .0001). Among 10 FDG‐PET‐positive lesions, only 1 had no apparent reason for PET positivity; however, 9 of 10 had a suitable reason for detectability by PET and inadequacy for ER. Negative detection of superficial esophageal squamous cell carcinoma by FDG‐PET is useful to determine the indication for ER when the tumor depth cannot be diagnosed even after performing magnifying endoscopy with narrow band imaging and endoscopic ultrasonography. When FDG uptake is recognized, a therapeutic modality other than ER should be considered.

SUVmax after (18)fluoro-deoxyglucose positron emission tomography/computed tomography: A tool to define treatment strategies in pancreatic cancer

BACKGROUND

(18)fluoro-deoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) might be a useful tool in the management of pancreatic ductal adenocarcinoma (PDAC).

AIMS

The aim of this study was to analyze maximum standard uptake value (SUVmax) after 18FDG-PET/CT as predictor of survival outcomes and method to determine treatment strategies.

METHODS

A consecutive series of patients who underwent preoperative 18FDG-PET/CT and subsequent resection for PDAC were retrospectively reviewed. Patients who underwent neoadjuvant chemotherapy were excluded.

RESULTS

46 patients were included in the analysis. Median follow-up was 27 months (4-67). Patients who recurred within 12 months showed a significantly higher preoperative median SUVmax (8.1 vs 6.1, p=0.039). Receiver operating characteristics (ROC) curves for disease-free survival (DFS) and disease-specific survival (DSS) identified SUVmax of 6.0 as optimal cut-off. Multivariate analysis showed that SUVmax ≥ 6.0 was an independent predictor of poor DFS (HR 2.288, p=0.024) and DSS (HR 4.875, p<0.001). The combination of SUVmax ≥6.0 with CA19.9 ≥200U/ml was significantly associated with survival outcomes in comparison to patients without concordantly elevated values.

CONCLUSION

SUVmax ≥6.0 is an independent predictor of DFS and DSS in resected PDAC. 18FDG-PET/CT might be considered in the preoperative evaluation of patients with pancreatic cancer.

Can 18F-FDG PET/CT predict recurrence in patients with cutaneous malignant melanoma?

The aim of this study was to evaluate the prognostic significance of maximum standardized uptake value (SUVmax) of primary cutaneous malignant melanoma (CMM) lesions by 18F-FDG positron emission tomography/ computerized tomography (PET/ CT) in terms of recurrence. Patients, methods: 37 CMM patients (17 men, mean age: 61.7 ± 13.6 years) that underwent PET/CT at presentation were enrolled in this study. Recurrence was determined by histological confirmation or by radiological and clinical follow- up for at least 8 months after curative surgery. Clinical variables such as age, sex, clinical stage, and primary lesion location, thickness, and ulceration, and SUVmax values were analyzed with respect to their usefulness for predicting recurrence. Results: SUVmax was found to be significantly higher in patients with ulceration of primary lesion of CMM (p = 0.004) and in patients with a stage ≥ III (p < 0.000). Patients that experience recurrence had a significantly higher mean SUVmax value (4.9 ± 2.9) than patients who did not (2.1 ± 1.5, p = 0.024). ROC analysis showed that a SUVmax cut-off value 2.2 had high sensitivity (88.9%) and specificity (67.9%) for predicting recurrence. Kaplan-Meier analysis identified ulceration of primary lesion (p = 0.034), stage ≥ III (p = 0.019) and SUVmax ≥ 2.2 (p = 0.002) as predictors of recurrence. However, Cox proportional-hazards analysis showed that only SUVmax (p = 0.025, relative risk 11.063) significantly predicted recurrence. Conclusion: Preoperative SUVmax of primary lesion was found to be the most potent predictor of recurrence in CMM patient. Patients with high SUV max of primary lesion should be followed meticulously for recurrence.

Predictive prognostic value of local and distant recurrence of F-fluorodeoxyglucose positron emission tomography for pancreatic neuroendocrine tumors with reference to World Health Organization classifications (2004, 2010). Case series study

BACKGROUND

F-flurodeoxyglucose positron emission tomography (FDG-PET) have been claimed to be an important prognostic tool in different malignancies. However, its predictive prognostic value on pancreatic neuroendocrine tumors (PNETs) is still under investigation.

AIM

We study the prognostic impact of FDG-PET scan in neuroendocrine pancreatic tumors.

METHODOLOGY

Between 2007 and 2012, 26 patients with no metastastatic histologically confirmed PNETs (mean age: 57 years) were examined with FDG-PET. We studied its captation in relation with the well established hystopathological prognostic markers assessed in the tumoral resected specimen according to the WHO 2004 and ENETS/WHO 2010 classification.

RESULTS

FDG-PET captation was positive in 17 cases (65.4%). The median follow-up period was 34.4 months and recurrences occurred in 4 cases (15.4%). We found a significant correlation between this captation and Ki 67 index (p = 0.032), mitotic index (p = 0.002), tumor grade (p = 0.017) and tumor size (p = 0.01).

CONCLUSIONS

FDG-PET provides a good prognostic value for PNETs. Present results must be further validated with larger sample studies.

18F-FLT PET imaging of cellular proliferation in pancreatic cancer

Pancreatic ductal adenocarcinoma is known for its poor prognosis. Since the development of computerized tomography, magnetic resonance and endoscopic ultrasound, novel imaging techniques have struggled to get established in the management of patients diagnosed with pancreatic adenocarcinoma for several reasons. Thus, imaging assessment of pancreatic cancer remains a field with scope for further improvement. In contrast to cross-sectional anatomical imaging methods, molecular imaging modalities such as positron emission tomography (PET) can provide information on tumour function. Particularly, tumour proliferation may be assessed by measurement of intracellular thymidine kinase 1 (TK1) activity level using thymidine analogues radiolabelled with a positron emitter for use with PET. This approach, has been widely explored with [(18)F]-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT) PET. This manuscript reviews the rationale and physiology behind (18)F-FLT PET imaging, with special focus on pancreatic cancer and other gastrointestinal malignancies. Potential benefit and challenges of this imaging technique for diagnosis, staging and assessment of treatment response in abdominal malignancies are discussed.

Effect of Diabetes Mellitus on Survival in Patients with Pancreatic Cancer: A Systematic Review and Meta-analysis

Concurrent diabetes has been linked with an increased risk of death in many cancers, but findings in pancreatic cancer have been inconsistent. We performed a systematic review and meta-analysis to assess the effect of diabetes on survival in patients with pancreatic cancer. Of 4, 463 original articles, 41 were included in the review; 29 studies with 33 risk estimates were included in the meta-analysis. In the overall comparison of patients with pancreatic cancer and diabetes with their nondiabetic counterparts, the former had significantly higher all-cause mortality (pooled HR: 1.13; 95% CI: 1.04-1.22). Subgroup analyses showed that diabetes was associated with poor survival in patients with resectable disease (HR: 1.37; 95% CI: 1.15-1.63) but not in those with unresectable disease (HR: 1.07; 95% CI: 0.89-1.29). The HR (95% CI) was 1.52 (1.20-1.93) for patients with new-onset diabetes (≤ 2 years of diabetes duration) and 1.22 (0.83-1.80) for those with longstanding diabetes (> 2 years). Diabetes was associated with higher mortality overall in patients with pancreatic cancer. The effect of diabetes on overall survival was associated with the stages of tumor and the duration of diabetes.

Standardized uptake value on positron emission tomography/computed tomography predicts prognosis in patients with locally advanced pancreatic cancer

BACKGROUND

The aim of the present study was to investigate the use and value of maximum standardized uptake value (SUV max) on positron emission tomography/computed tomography (PET/CT) images as a prognostic marker for patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

The medical records of all consecutive patients who underwent PET/CT examination in our institution were retrospectively reviewed. Inclusion criteria were histologically or cytologically proven LAPC. Patients with distant metastasis were excluded. For statistical analysis, the SUV max of primary pancreatic cancer was measured. Survival rates were calculated using the Kaplan-Meier method, and multivariable analysis was performed to determine the association of SUV max with overall survival (OS) and progression-free survival (PFS) using a Cox proportional hazards model.

RESULTS

Between July 2006 and June 2013, 69 patients were enrolled in the present study. OS and PFS were 14.9 months [95% confidence interval (CI) 13.1-16.7] and 8.3 months (95% CI 7.1-9.5), respectively. A high SUV max (>5.5) was observed in 35 patients, who had significantly worse OS and PFS than the remaining patients with a low SUV max (P = 0.025 and P = 0.003). Univariate analysis showed that SUV max and tumor size were prognostic factors for OS, with a hazard ratio of 1.90 and 1.81, respectively. A high SUV max was an independent prognostic factor, with a hazard ratio of 1.89 (95% CI 1.015-3.519, P = 0.045).

CONCLUSION

The present study suggests that increased SUV max is a predictor of poor prognosis in patients with LAPC.

Prognostic Value of FDG PET/CT-Derived Parameters in Pancreatic Adenocarcinoma at Initial PET/CT Staging

OBJECTIVE

The purpose of this study is to evaluate the performance of PET-derived parameters as prognostic markers for overall survival (OS) and progression-free survival (PFS) outcome in patients with pancreatic adenocarcinoma.

MATERIALS AND METHODS

We conducted a retrospective study of 106 patients (62 men and 44 women) with histologically proven pancreatic adenocarcinoma who underwent initial staging FDG PET/CT before treatment. Peak standardized uptake value (SUV), maximum SUV (SUVmax), metabolic tumor volume, and tumor glycolytic activity of the primary pancreatic tumor were measured. Two segmentation methods were performed to obtain the metabolic tumor volume and tumor glycolytic activity for all tumors: a gradient-based segmentation model (metabolic tumor volume and tumor glycolytic activity by gradient edge detection) and a fixed-threshold model with a threshold of 50% of the lesion's SUVmax and peak SUV. Univariate and multivariate Cox regression models were developed including clinical and imaging parameters for OS and PFS.

RESULTS

Multivariate Cox regression analysis showed a statistically significant association between PFS and age, SUVmax, peak SUV, and tumor glycolytic activity by gradient edge detection. There was a statistically significant difference in PFS for patients with values above and below the median cutoff points for SUVmax (hazard ratio [HR], 1.12; p < 0.01), peak SUV (HR, 1.25; p < 0.02), and tumor glycolytic activity measured by gradient edge detection (HR, 1.00; p < 0.02) of the primary tumor. However, multivariate Cox regression analysis showed a statistically significant association only between tumor glycolytic activity by gradient edge detection and OS (p = 0.04), and there was a statistically significant difference in OS between patients with values above and below the median cutoff point for the tumor glycolytic activity by gradient edge detection of the primary tumor (HR, 1.42; p = 0.05).

CONCLUSION

Age, SUVmax, peak SUV, and total lesion glycolysis (i.e., tumor glycolytic activity) of the primary tumor are associated with PFS, and tumor glycolytic activity is associated with OS in patients with pancreatic adenocarcinoma.

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

18F-fluoro-2-deoxy-D-glucose retention index as a prognostic parameter in patients with pancreatic cancer

OBJECTIVES

The objective of this study was to determine the most effective way to use dual-phase F-fluoro-2-deoxy-D-glucose (F-FDG) PET/computed tomography (CT) semiquantitative indices to predict prognosis in patients with pancreatic cancer and to guide treatment.

STUDY DESIGN

Prognostic parameters were retrospectively analyzed in 40 patients with histologically proven pancreatic cancer who received F-FDG PET/CT at Ruijin Hospital. Maximum standardized uptake values (SUVs) were determined at 1 h (SUV1) and 2 h (SUV2) after F-FDG injection. The retention index (RI) was defined as the percentage change between SUV1 and SUV2.

RESULTS

RI less than 17% was explored as having a significant independent correlation with prolonged patient survival (P<0.05). Patients with tumor resection and RI less than 17% survived significantly longer than those with or without tumor resection and RI of 17% or higher (P<0.05). Neither SUV1, nor SUV2 showed any prognostic significance, but they did show a positive correlation with tumor diameter (P1<0.01; P2<0.05); RI had a strong positive correlation with tumor, node, and metastasis stage (P<0.01). Two factors were found to be associated with RI, including pancreatitis (P<0.05) and diabetes (P<0.01).

CONCLUSION

RI served as the most accurate parameter to predict disease prognosis in pancreatic cancer and to identify patients who could benefit from surgery. However, pancreatitis and diabetes had a potential impact on RI, reflecting the influence of tumor pathophysiological changes on the metabolism of glucose in pancreatic tumor cells. Therefore, further comprehensive analyses are required.

Utility of PET/CT in diagnosis, staging, assessment of resectability and metabolic response of pancreatic cancer

Pancreatic cancer is one of the most common gastrointestinal tumors, with its incidence staying at a high level in both the United States and China. However, the overall 5-year survival rate of pancreatic cancer is still extremely low. Surgery remains the only potential chance for long-term survival. Early diagnosis and precise staging are crucial to make proper clinical decision for surgery candidates. Despite advances in diagnostic technology such as computed tomography (CT) and endoscopic ultrasound, diagnosis, staging and monitoring of the metabolic response remain a challenge for this devastating disease. Positron emission tomography/CT (PET/CT), a relatively novel modality, combines metabolic detection with anatomic information. It has been widely used in oncology and achieves good results in breast cancer, lung cancer and lymphoma. Its utilization in pancreatic cancer has also been widely accepted. However, the value of PET/CT in pancreatic disease is still controversial. Will PET/CT change the treatment strategy for potential surgery candidates? What kind of patients benefits most from this exam? In this review, we focus on the utility of PET/CT in diagnosis, staging, and assessment of resectability of pancreatic cancer. In addition, its ability to monitor metabolic response and recurrence after treatment will be emphasis of discussion. We hope to provide answers to the questions above, which clinicians care most about.

Preoperative FDG-PET predicts early recurrence and a poor prognosis after resection of pancreatic adenocarcinoma

OBJECTIVE

The aim of this study was to evaluate the clinical utility of preoperative 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) as a prognostic predictor of resectable pancreatic adenocarcinoma.

METHODS

A total of 128 patients with resected pancreatic adenocarcinoma who preoperatively underwent FDG-PET examinations were studied. The maximum standard uptake value (SUVmax) was calculated for each primary lesion. A receiver operating characteristics (ROC) curve was constructed to estimate the optimal cutoff value of the SUVmax. In order to determine which outcomes of interest were appropriately demonstrated, ROC curve analyses were conducted for six outcomes: 6-, 12-, and 24-month disease-free survival (DFS), and 6-, 12-, and 24-month overall survival (OS). A multivariate analysis was conducted to identify prognostic factors.

RESULTS

The ROC curves revealed that the SUVmax predicted the 6-month DFS most optimally (area under the curve 0.757), with a cutoff value of 6.0. Of the 69 patients with an SUVmax ≥ 6.0, 34 (49 %) developed recurrence within 6 months. In contrast, only 3 of 59 (5 %) patients with an SUVmax < 6.0 exhibited early recurrence (p < 0.001). The median OS time was 37 months in patients with an SUVmax < 6.0 and 18 months in patients with an SUVmax ≥ 6.0 (p < 0.001). The multivariate analysis revealed lymph node metastasis (hazard ratio [HR] 2.31; p = 0.001) and an SUVmax ≥ 6.0 (HR 2.05; p = 0.002) to be significantly correlated with a poor survival.

CONCLUSIONS

An SUVmax ≥ 6.0 was a significant predictor of early postoperative recurrence and subsequent poor survival following resection of pancreatic adenocarcinoma.

Predictive value of maximum standardized uptake value (SUVmax) on 18F-FDG PET/CT in patients with locally advanced or metastatic pancreatic cancer

PURPOSE

We investigated the prognostic role of 18F-FDG PET/CT in the prediction of progression-free survival (PFS) and chemotherapeutic response in patients with locally advanced or metastatic pancreatic cancer.

METHODS

We enrolled 21 newly diagnosed patients with locally advanced or metastatic pancreatic cancer who underwent 18F-FDG PET/CT scanning before palliative gemcitabine-based chemotherapy between 2006 and 2012. Maximum standardized uptake value (SUVmax) of the primary tumor was measured by 18F-FDG PET/CT. Chemotherapeutic response was evaluated according to the Response Evaluation Criteria in Solid Tumors. Survival analysis was performed for time to progression using the Kaplan-Meier method. Cox proportional hazard models were used to determine independent prognostic factors.

RESULTS

All pancreatic tumors showed detectable FDG uptake (mean SUVmax = 6.8 ± 3.0, range 2-12) The mean SUVmax values among response groups showed no significant difference (P = 0.853) and chemotherapeutic response was not different according to SUVmax level (P = 0.807). PFS was significantly shorter in the high SUVmax (≥6.8) group than in the low SUVmax (<6.8) group (2.9 vs. 6 months, P = 0.012). Multivariate analysis revealed that SUVmax was an independent prognostic factor for predicting PFS (P = 0.046).

CONCLUSIONS

Higher SUVmax of primary pancreatic tumor is associated with poor PFS and pretreatment SUVmax is an independent prognostic factor for predicting PFS in patients with locally advanced or metastatic pancreatic cancer who received gemcitabine-based palliative chemotherapy. However, pretreatment SUVmax is not associated with chemotherapeutic response.

Usefulness of F-18-fluorodeoxyglucose positron emission tomography to confirm suspected pancreatic cancer: a meta-analysis

INTRODUCTION

Pancreatic cancer is among the five most lethal malignancies in the world. Unfortunately, many malignant tumors go undetected by the current primary diagnostic tools. (18)FDG-PET and (18)FDG-PET/CT might be useful to confirm suspected pancreatic cancer.

METHODS

A meta-analysis was performed using all major search engines. Methodological quality of included studies was assessed as well as quality of the PET-protocol. The following pooled estimates served as primary outcome measures: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy.

RESULTS

Thirty-five studies were included. Pooled estimates for (18)FDG-PET were: sensitivity 90%, specificity 76%, PPV 90%, NPV 76% and accuracy 86%. Pooled estimates for (18)FDG-PET/CT were: sensitivity 90%, specificity 76%, PPV 89%, NPV 78% and accuracy 86%. The pooled sensitivity and specificity for (18)FDG-PET to differentiate between pancreatic cancer and chronic pancreatitis were 90% and 84%, respectively.

CONCLUSION

Both (18)FDG-PET and (18)FDG-PET/CT offer no benefit over the current primary diagnostic tools in diagnosing pancreatic cancer. However, the (18)FDG-PET/CT systems are still improving. We should investigate the sensitivity and specificity of these new systems while reevaluating the tradeoff between false positive and false negative results. Yet, (18)FDG-PET/CT may have a role in the staging of pancreatic cancer, in survival prediction, and may add to other diagnostic information, like histology.

Role of ¹⁸F-FDG PET CT as an independent prognostic indicator in patients with hepatocellular carcinoma

OBJECTIVES

The aim of the study was to evaluate the role of F-fluorodeoxyglucose PET computed tomography (F-FDG PET CT) as an independent prognostic indicator in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

PET contrast-enhanced CT scans of 100 consecutive patients with HCC were reviewed retrospectively. Patients were asked to fast for 6 h before the study and blood glucose levels were monitored and ensured to be less than 200 mg/dl before injection of F-FDG. After administering the F-FDG injection (370-550 MBq) patients were instructed to rest comfortably for 45-60 min. All images were acquired using a dedicated GE Discovery PET/CT scanner. The PET CT scans of all the patients were reported separately by two nuclear medicine physicians. A stage-wise analysis of the compiled data was carried out. Lesions that showed standardized uptake values greater than background activity (activity in adjacent normal liver tissue) were defined as having increased F-FDG uptake. Pearson's χ -test or the Kruskal-Wallis test was used to assess statistical significance. A P value less than 0.05 was taken as significant.

RESULTS

In this retrospective study of 100 HCC patients, a radiologically higher-stage disease was found more commonly in patients with F-FDG-avid primary tumors (P<0.001), whereas a lower-stage disease was found in patients with non-F-FDG-avid primary tumors. The non-F-FDG-avid tumors also showed lower incidence of metastatic disease and portal vein thrombosis (P<0.001). The histopathological findings of the patients who underwent liver transplantation demonstrated that a higher-grade tumor was more common in the F-FDG-avid tumor group than in the non-F-FDG-avid tumor group (P<0.05).

CONCLUSION

An F-FDG PET CT scan can be used not only for staging but also as a tool for preoperative prediction of cellular differentiation in patients with HCC. The F-FDG uptake seen on a PET scan can serve as a molecular signature for management decisions and can be used as an independent and significant prognostic factor in patients with HCC.

Impact of preoperative diabetes on long-term survival after curative resection of pancreatic adenocarcinoma: a systematic review and meta-analysis

BACKGROUND

Diabetes mellitus (DM) is coupled to the risk and symptomatic onset of pancreatic ductal adenocarcinoma (PDAC). The important question whether DM influences the prognosis of resected PDAC has not been systematically evaluated in the literature. We therefore performed a systematic review and meta-analysis evaluating the impact of preoperative DM on survival after curative surgery.

METHODS

The databases Medline, Embase, Web of Science, and the Cochrane Library were searched for studies reporting on the impact of preoperative DM on survival after PDAC resection. Hazard ratios and 95 % confidence intervals (CI) were extracted. The meta-analysis was calculated using the random-effects model.

RESULTS

The data search identified 4,365 abstracts that were screened for relevant articles. Ten retrospective studies with a cumulative sample size of 4,471 patients were included in the qualitative review. The mean prevalence of preoperative DM was 26.7 % (1,067 patients), and all types of pancreatic resections were considered. The meta-analysis included 8 studies and demonstrated that preoperative DM is associated with a worse overall survival after curative resection of PDAC (hazard ratio 1.32, 95 % CI 1.46-1.60, P = 0.004). Only 2 studies reported separate data for new-onset and long-standing DM.

CONCLUSIONS

To our knowledge, this is the first meta-analysis evaluating long-term survival after PDAC resection in normoglycemic and diabetic patients, demonstrating a significantly worse outcome in the latter group. The mechanism behind this observation and the question whether different antidiabetic medications or early control of DM can improve survival in PDAC should be evaluated in further studies.

Role of SUV(max) obtained by 18F-FDG PET/CT in patients with a solitary pancreatic lesion: predicting malignant potential and proliferation

OBJECTIVES

Maximum standardized uptake value (SUV(max)) is a marker of tumor glucose metabolism detected by [(18)F]-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (PET/CT) and reflects tumor aggressiveness. The aim of the study was to evaluate the value of SUV(max) in differentiating benign from malignant solitary pancreatic lesions and explore the correlation between SUV(max) and tumor proliferative activity.

MATERIALS AND METHODS

F-FDG PET/CT scans were performed in 80 patients with solitary pancreatic lesions who were scheduled for resective surgery. The relationships between SUV(max) and postoperative pathologic diagnosis, histologic grade, and Ki-67 proliferation index (PI) were analyzed.

RESULTS

Of these 80 patients, 54 had malignant lesions. The SUV(max) of malignant tumors (6.3 ± 2.4) was significantly greater than that of benign lesions (2.9 ± 2.0) (P<0.001). Receiver-operating characteristic curve analysis showed that the SUV(max) cutoff value of 3.5 had a high sensitivity (92.6%) and specificity (76.9%) for the diagnosis of malignancies. Among pancreatic cancers with low (Ki-67<5%), moderate (5% ≤ Ki-67<50%), and high (Ki-67 ≥ 50%) PI, SUV(max) increased significantly from 4.2 ± 1.2, through 6.0 ± 1.7, to 8.6 ± 2.5 (P<0.001). The SUV(max) had a positive correlation with Ki-67 PI (P<0.001, r=0.60).

CONCLUSION

The SUV(max) of F-FDG PET/CT can be used in the differential diagnosis of solitary pancreatic lesions and can also aid in the prediction of proliferative activity of pancreatic cancer.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography in patients with resectable pancreatic cancer

PURPOSE

We evaluated the prognostic value of (18)F-2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) in patients with resectable pancreatic cancer.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of pancreatic cancer patients who underwent curative resection, which included 64 consecutive patients who had preoperative FDG PET scans. For statistical analysis, the maximal standardized uptake value (SUVmax) of primary pancreatic cancer was measured. Survival time was estimated by the Kaplan-Meier method, and Cox's proportional hazard model was used to determine whether SUVmax added new predictive information concerning survival together with known prognostic factors. p<0.05 indicated statistical significance.

RESULTS

Overall survival (OS) and disease- free survival (DFS) were respectively 42.9 months (27.6-58.2; 95% CI) and 14.9 months (10.1-19.7; 95% CI). When subjects were divided into two groups according to SUVmax with a cutoff value of 3.5, the high SUVmax group (n=32; SUVmax >3.5) showed significantly shorter OS and DFS than the low SUVmax group. Multivariate analysis of OS and DFS showed that both high SUVmax and poor tumor differentiation were independent poor prognostic factors.

CONCLUSION

Our study showed that degree of FDG uptake was an independent prognostic factor in pancreatic cancer patients who underwent curative resection.

FDG-PET in diagnosis, staging and prognosis of pancreatic carcinoma: A meta-analysis

AIM: To investigate the potential role of positron emission tomography (PET) in the diagnosis, staging and prognosis predicting of pancreatic carcinoma (PC).

METHODS: A systematic review of relevant literatures in PubMed, Embase and Cochrane Library was performed. The sensitivity and specificity of diagnostic and staging studies, and HRs for prognosis predicting studies were pooled. The bivariate model was used for diagnostic studies and the random-effect model for prognostic studies. Heterogeneity between included studies was tested using χ² test, and subgroup analysis was performed to explain the heterogeneities. All of the calculations were performed using Stata version 11.0.

RESULTS: A total of 39 studies were included. The pooled sensitivity of PET in diagnosing PC (30 studies, 1582 patients), evaluating N stating (4 studies, 101 patients) and liver metastasis (7 studies, 316 patients) were 0.91 (95%CI: 0.88-0.93), 0.64 (95%CI: 0.50-0.76), and 0.67 (95%CI: 0.52-0.79), respectively; and the corresponding specificity was 0.81 (95%CI: 0.75-0.85), 0.81 (95%CI: 0.25-0.85), and 0.96 (95%CI: 0.89-0.98), respectively. In prognosis analysis (6 studies, 198 patients), significant difference of overall survival was observed between high and low standardized uptake value groups (HR = 2.39, 95%CI: 1.57-3.63). Subgroup analysis showed that PET/CT was more sensitive than PET alone in evaluating liver metastasis of PC, 0.82 (95%CI: 0.48-0.98) and 0.67 (95%CI: 0.52-0.79), respectively.

CONCLUSION: PET can be used as a valuable diagnostic and predictive tool for PC, but its effect in the staging of PC remains indeterminate.

Prognostic value of SUVmax measured by Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography with Computed Tomography in Patients with Pancreatic Cancer

PURPOSE

Recent studies have been conducted on the relationship between fluorodeoxyglucose (FDG) uptake in F-18 FDG PET/CT and prognosis in patients with pancreatic cancer, but these studies have been carried out in small numbers of patients. The aim of this retrospective study was to determine in a large number of patients whether glucose metabolism as assessed by F-18 FDG PET/CT provides prognostic information independent of established prognostic factors in patients with pancreatic cancer.

METHODS

We reviewed retrospectively the medical records of 165 patients (men 105, women 60, mean age 67 ± 10 years) with a diagnosis of pancreatic cancer that had undergone F-18 FDG PET/CT as part of a pretreatment workup from January 2004 to December 2009. Subsequently, all patients underwent surgery, cyberknife, radiotherapy, and/or chemotherapy. For the analysis, patients were classified by age, demographic data, maximum standardized uptake value (SUVmax), size, location, serum level of CA19-9, type of treatment, and AJCC stage. The relationship between FDG uptake and survival was analyzed using the Kaplan-Meier with log-Rank test and Cox's proportional-hazard regression methods.

RESULTS

Median survival for all 165 study subjects was 290 days and median SUV by PET/CT was 5.8 (range: 0-25.1). Patients were allocated to high (> 4.1) and low (≤4.1) SUV groups, and median survivals of these patients were 229 days and 610 days, respectively, which were significantly different (p < 0.0001). Furthermore, SUVmax was found to be significantly related to survival in each stage, i.e., there were 1267 days in stage I, 440 days in stage II, 299 days in stage III, and 143 days in stage IV (p < 0.0001). The median survival was also found to be significantly related to tumor size (p = 0.001), site (p = 0.0298), serum level of CA19-9 (p = 0.0017), distant metastasis (p < 0.0001), and type of treatment (p < 0.0001). Multivariate analysis study revealed that the patients with a low SUV (p = 0.0298), a lower serum level of CA19-9 (p = 0.0071), a lower stage (p = 0.0017), and no distant metastasis (p < 0.0001) had longer survivals. In addition, SUVmax values were found to have a similar hazard ratio of distant metastasis; it was well known predictor. Furthermore, SUVmax values showed a higher hazard ratio than that of other clinicopathologic predictors.

CONCLUSION

The present study shows that SUVmax on F-18 FDG PET/CT can provide a prognostic information in patients with pancreatic cancer.

Role of (18F) 2-fluoro-2-deoxyglucose positron emission tomography in upper gastrointestinal malignancies

The role of whole-body FDG [(¹⁸F) 2-fluoro-2-deoxyglucose] positron emission tomography (PET) scanning as an imaging modality in the management of patients with malignancy has evolved enormously over the past two decades. FDG-PET has demonstrated significant efficacy in the staging, prognostication and detection of occult metastatic disease in malignancies of the gastrointestinal tract, in addition to assessment of the response to cytotoxic chemotherapy in a more timely manner than has traditionally been possible by more conventional imaging tools. The sensitivity and specificity of FDG-PET for the detection and staging of malignancy depend not only on the site and size of the primary tumor and metastases, but also on histological cell type, reflecting underlying disparities in glucose metabolism. The metabolic response to neo-adjuvant chemotherapy or to chemo-radiotherapy in cancers of the gastro-esophageal junction or stomach has been demonstrated in several prospective studies to correlate significantly with both the histological tumor response to treatment and with consequent improvements in overall survival. This may offer a future paradigm of personalized treatment based on the PET response to chemotherapy. FDG-PET has been less successful in efforts to screen for and detect recurrent upper gastrointestinal malignancies, and in the detection of low volume metastatic peritoneal disease. Efforts to improve the accuracy of PET include the use of novel radiotracers such as (¹⁸F) FLT (3-deoxy-3-fluorothymidine) or ¹¹C-choline, or fusion PET-CT with concurrent high-resolution computed tomography. This review focuses on the role of FDG-PET scanning in staging and response assessment in malignancies of the upper gastrointestinal tract, specifically gastric, esophageal and pancreas carcinoma.

Use of S-100B to evaluate therapy effects during bevacizumab induction treatment in AJCC stage III melanoma

AIM

To investigate the feasibility of using bevacizumab to improve the survival of American Joint Committee on Cancer (AJCC) stage III melanoma patients, we investigated how a single bevacizumab treatment affected nodal disease and a panel of biomarkers in clinically fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT)-staged, stage III melanoma patients, prior to therapeutic lymph node dissection (TLND).

METHODS

Four weeks before TLND, nine patients (median age 50, range 28.8-62.1 years; two male, seven female) with palpable lymph node metastases received 7.5 mg/kg bevacizumab. Before and after this treatment, all patients were assessed by measurements of the maximum standardized uptake value (SUVmax) by FDG-PET scan, and serum S-100B and lactate dehydrogenase (LDH). After TLND, the dissection specimen was analyzed for number of removed lymph nodes, number of metastatic lymph nodes, and tumor necrosis.

RESULTS

Median follow-up was 15.5 (2.2-32.9) months. Histopathological analysis revealed tumor necrosis in six patients, of whom five had an S-100B decline and one had an unchanged S-100B level after bevacizumab. The other three patients showed an S-100B increase and no necrosis. Tumor necrosis was correlated with S-100B decrease (P = 0.048). No association was found between necrosis and the markers SUVmax and LDH. No wound healing disturbances were encountered.

CONCLUSION

Tumor necrosis in dissection specimens was associated with declining S-100B levels, while elevated S-100B was only found in cases with no necrosis. Bevacizumab might be useful in treating AJCC stage III melanoma patients prior to TLND, and S100-B appears to be a useful marker for assessment of treatment effects.

Usefulness of positron emission tomography with fluorine-18-fluorodeoxyglucose in predicting treatment response in unresectable hepatocellular carcinoma patients treated with external beam radiotherapy

PURPOSE

To assess the significance of the ratio between standardized uptake values (SUV) of tumor and normal liver tissue obtained from positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) in predicting the response of hepatocellular carcinoma (HCC) patients treated with external beam radiotherapy (EBRT).

METHODS AND MATERIALS

We retrospectively analyzed 35 HCC patients who were treated with EBRT between January 2004 and June 2007. All patients underwent FDG-PET in which SUV values were obtained from tumor and normal liver tissues and were used to calculate the ratios (SUV(Tumor)/SUV(Liver)). After FDG-PET, patients received liver treatment including concurrent chemoradiation, transarterial chemoembolization plus RT, or intraarterial chemotherapy plus RT. Using three-dimensional conformal RT, median dose of 45 Gy was delivered in conventional fractions. Patients underwent abdominal/pelvic CT 1 month after RT, and treatment responses were evaluated according to the Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Patients were divided into high-SUV ratio group (n = 20) and low-SUV ratio group (n = 15) according to SUV ratio at a cutoff value of 2.5. Objective responses consisting of either complete response (CR) or partial response (PR) were observed in 16 and 6 patients (46% vs. 17%, p = 0.015), respectively; median survivals after RT were 8 months and 5 months (p = 0.41) for the high-SUV ratio group and the low-SUV ratio group, respectively. Rates of intrahepatic metastases (9% vs. 11%, p = 0.39) and distant metastases (32% vs. 32%, p = 0.27) showed no significant difference between two groups.

CONCLUSIONS

External beam RT for HCC patients with higher SUV ratios resulted in higher response rates than for patients with lower SUV ratios. Treatment of HCC with higher SUV ratios did not result in increased survival; high rates of intrahepatic and distant metastases in both SUV groups may have affected patient survival. SUV ratios from pre-RT FDG-PET may be beneficial for selecting patients who are likely to respond to EBRT for unresectable HCC.

Standardized FDG uptake as a prognostic variable and as a predictor of incomplete cytoreduction in primary advanced ovarian cancer

INTRODUCTION

In patients with advanced ovarian cancer undergoing preoperative PET/CT, we investigated the prognostic value of SUV in the primary tumor and we evaluated the value of SUV for predicting incomplete primary cytoreduction (macroscopic residual tumor).

MATERIAL AND METHODS

From September 2004 to August 2007, 201 consecutive patients with a pelvic tumor and a Risk of Malignancy Index (RMI) > 150 based on serum CA-125, ultrasound examinations and menopausal state, underwent PET/CT within two weeks prior to standard surgery/debulking of a pelvic tumor. At two-year follow-up (August 15, 2009) the association between SUV and overall survival/cytoreductive result were analyzed in 60 ovarian cancer patients (58 stage III and two stage IV).

RESULTS

At inclusion median age was 62 years (range 35-85 years); 97% (58/60) had a performance status ≤2; 42% (25/60) underwent complete debulking (no macroscopic residual tumor); median SUV(max) was 13.5 (range 2.5-39.0). Median follow-up was 30.2 months. At follow-up 57% (34/60) were alive and 43% (26/60) had died from ovarian cancer. SUV(max) in patients alive was not statistically different from SUV(max) in dead patients (p=0.69), and SUV(max) was not correlated with the amount of residual tumor after surgery (p=0.19). Using univariate Cox regression analysis, residual tumor was a significant prognostic variable (p=0.001); SUV(max) was not a statistically significant prognostic variable (p=0.86).

DISCUSSION

FDG uptake (SUV(max)) in the primary tumor of patients with advanced ovarian cancer was not a prognostic variable and the FDG uptake did not predict complete cytoreduction after primary surgery. Future prospective clinical trials will need to clarify if other PET tracers can serve as prognostic variables in ovarian cancer.

GLUT-1 expression in pancreatic neoplasia: implications in pathogenesis, diagnosis, and prognosis

OBJECTIVES

GLUT-1 has been found to have an important role in the upregulation of various cellular pathways and implicated in neoplastic transformation correlating with biological behavior in malignancies. However, literature regarding the significance of GLUT-1 expression in pancreatic neoplasia has been limited and controversial.

METHODS

Immunohistochemical expression of GLUT-1 was tested in a variety of pancreatic neoplasia including ductal adenocarcinomas (DAs), pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and serous cystadenomas.

RESULTS

There was a progressive increase in the expression of GLUT-1 from low- to higher-grade dysplastic lesions: All higher-grade PanINs/IPMNs (the ones with moderate/high-grade dysplasia) revealed noticeable GLUT-1 expression. Among the 94 DAs analyzed, there were minimal/moderate expression in 46 and significant expression in 24 DAs. However, all 4 clear-cell variants of DAs revealed significant GLUT-1 immunolabeling, as did areas of clear-cell change seen in other DAs. Moreover, all 12 serous cystadenomas expressed significant GLUT-1. GLUT-1 expression was also directly correlated with DA histological grade (P = 0.016) and tumor size (P = 0.03).

CONCLUSIONS

GLUT-1 may give rise to the distinctive clear-cell appearance of these tumors by inducing the accumulation of glycogen in the cytoplasm. Additionally, because GLUT-1 expression was related to histological grade and tumor size of DA, further studies are warranted to investigate the association of GLUT-1 with prognosis and tumor progression.