Role of FDG-PET/CT in diagnosis, staging, response to treatment, and prognosis of pancreatic cancer. Am J Clin Oncol. 2011;34:111-114. [PMID: 21483236 DOI: 10.1097/coc.0b013e3181d275a0]

The Impact of Metabolic 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters on the Prognosis of Resectable Pancreatic Adenocarcinoma

Objectives

¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) is a useful staging method in pancreatic cancer. The prognosis of pancreatic adenocarcinoma is affected by the tumor stage and resectable state. Maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary tumors are related to prognostic parameters in pancreatic cancer. This study compared ¹⁸F-FDG PET/CT findings with prognostic factors and overall survival of patients with pancreatic cancer.

Methods

Patients with pancreatic adenocarcinoma, referred to our department between 2015 and 2022 for staging, were retrospectively evaluated. Head-to mid-thigh PET/CT images were obtained 1 h after ¹⁸F-FDG injection. Demographic data, survival, and clinical and pathological findings of 39 patients, who underwent surgery after PET/CT imaging, were collected. All primary tumor MTV, SUV_max, background SUV_max, and TLG data have were measured.

Results

The images of 39 patients (24 women and 15 men) with a mean age of 66.62±9.60 years were evaluated. The mean SUV_max, MTV 40%, and TLG of the primary tumors in the pancreatic tissue were 6.28±2.33, 19.33±9.77, and 66.56±45.99, respectively. The average survival after disease diagnosis was 18.97±11.47 (2-55) months. MTV and TLG were significantly higher in patients who died during our study. SUV_max has a significant effect on mortality.

Conclusion

¹⁸F-FDG PET/CT metabolic parameters of SUV_max, MTV, and TLG could help predicting the prognosis of pancreatic cancer preoperatively and follow-up in patients with resectable tumors. Additionally, in our study group tumor grade and perineural invasion significantly affected overall survival.

FDG-PET/CT Variants and Pitfalls in Haematological Malignancies

Hematologic malignancies represent a vast group of hematopoietic and lymphoid cancers that typically involve the blood, the bone marrow, and the lymphatic organs. Due to extensive research and well defined and standardized response criteria, the role of [¹⁸F]FDG-PET/CT is well defined in these malignancies. Never the less, the reliability of visual and quantitative interpretation of PET/CT may be impaired by several factors including inconsistent scanning protocols and image reconstruction methods. Furthermore, the uptake of [¹⁸F]FDG not only reflects tissue glucose consumption by malignant lesions, but also in other situations such as in inflammatory lesions, local and systemic infections, benign tumors, reactive thymic hyperplasia, histiocytic infiltration, among others; or following granulocyte colony stimulating factors therapy, radiation therapy, chemotherapy or surgical interventions, all of which are a potential source of false-positive or negative interpretations. Therefore it is of paramount importance for the Nuclear Medicine Physician to be familiar with, not only the normal distribution of [¹⁸F]FDG in the body, but also with the most frequent findings that may hamper a correct interpretation of the scan, which could ultimately alter the patients management. In this review, we describe these myriad of situations so the interpreting physician can be familiar with them, providing tools for their correct identification and interpretation when possible.

Preoperative maximum standardized uptake value and carbohydrate antigen 19-9 were independent predictors of pathological stages and overall survival in Chinese patients with pancreatic duct adenocarcinoma

Background

Purpose of this study was to analyze whether preoperative maximum standardized uptake value (SUVmax) and carbohydrate antigen 19–9 (CA19–9) levels might provide prognostic information in Chinese patients with pancreatic duct adenocarcinoma (PDAC) after pancreaticoduodenectomy (PD).

Methods

Standard PD was performed on 109 patients with PDAC by the same operative team, and all patients received preoperative positron emission tomography/computed tomography examination and blood test.

Results

Patients had a mean age of 59 ± 9.35 years. Females accounted for 38.5%. Mean levels of SUVmax, carcino-embryonic antigen (CEA) and CA19–9 were 5.70 ± 2.76, 3.95 ± 4.16ng/mL and 321.62 ± 780.71kU/L. In univariate Logistic regression analysis, preoperative SUVmax, CEA and CA19–9 levels (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly related to AJCC stages. Multivariate Logistic regression analysis showed that preoperative SUVmax and CA19–9 levels (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly associated with AJCC stages. Mean overall survival (OS) was 21 ± 14.50 months. In univariate Cox regression analysis, age, SUVmax, CEA and CA19–9 levels before operation (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly related to OS. Multivariate Cox regression analysis showed that age, SUVmax and CA19–9 levels before operation (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly associated with OS.

Conclusions

This study demonstrated that preoperative SUVmax and CA19–9 levels independently predicted pathological stages and OS of patients with PDAC after PD. These preoperative variables might have significant prognostic implication in patients with PDAC after PD. Patients with abnormal SUVmax and CA19–9 levels should be paid special attention to in operative strategy and perioperative management.

PET-based Treatment Response Assessment for Neoadjuvant Chemoradiation in Pancreatic Adenocarcinoma: An Exploratory Study

PURPOSE: Performance of anatomical metrics of Response Evaluation Criteria in Solid Tumors (RECIST1.1) versus Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST1.0) for neoadjuvant chemoradiation (nCR) of pancreatic adenocarcinoma was evaluated based on the pathological treatment response (PTR) data. METHODS AND MATERIALS: The pre- and post-nCR CT and PET data for 14 patients with resectable or borderline resectable pancreatic head adenocarcinoma treated with nCR followed by surgery were retrospectively analyzed. These data were compared with the PTR which were graded according to tumor cell destruction (cellularity), with Grade 0, 1, 2 or 3 (G0, G1, G2 or G3) for complete, moderate, minimal and poor responses, respectively. Maximum standardized uptake value (SUVmax) was defined using body-weight (SUVbw). PERCIST1.0 was defined using lean-body mass normalized SUV (SUVlb or SUL). RECIST1.1 was defined by contouring the whole pancreas head on the CT image. Pre- and post-SUL-peak and SUVmax, RECIST1.1 and PETRECIST1.0 were correlated with PTR using Pearson’s correlation coefficient test. RESULTS: The average mean and SD in SUL-peak for all patients analyzed were lower in post-nCR (3.63±1.06) compared to those at pre-nCR (4.29±0.89). Using PERCIST1.0, 62% of patients showed stable metabolic disease (SMD), 23% partial metabolic response (PMR), and 15% progressive metabolic disease (PMD). Using RECIST1.1, 85% of patients showed stable disease (SD), 8% partial response (PR), and 7% progressive diseases (PD). A poor insignificant correlation was established between PRT and PERECIST1.0 (r=0.121), whereas no correlation was seen with RECIST1.1. CONCLUSIONS: PERCIST1.0 appears to increase the chance of detecting patients with progressive disease compared to the conventional anatomical-based assessment of RECIST1.1. The integration of these additional radiographic metrics in assessing treatment response to nCR for pancreatic adenocarcinoma may provide a promising strategy to better select patients that are most suitable for therapeutic intensification.

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.

Role of PET/CT in the Clinical Management of Locally Advanced Pancreatic Cancer

Aim

To evaluate the role of 18F-fluorodeoxyglucose (FDG) PET/CT in: a) the selection of patients with locally advanced pancreatic cancer for helical tomotherapy with concurrent chemotherapy (HTT-ChT); b) monitoring HTT-ChT treatment efficacy in comparison with contrast-enhanced CT (c.e.CT).

Methods

Forty-two consecutive patients with unresectable locally advanced pancreatic cancer referred for HTT-ChT were enrolled in the study. All patients were pretreated with induction ChT. Before the beginning of HTT-ChT treatment patients underwent diagnostic c.e.CT (CT0) and FDG PET/CT (PET/CT0) for staging. After staging, patients received HTT-ChT. Three months after the end of HTT-ChT a control c.e.CT (CT1) was done. FDG PET/CT (PET/CT1) was repeated only in patients with positive PET/CT0. PET/CT1 and CT1 were compared with baseline imaging results to assess treatment efficacy.

Results

In 31/42 cases (74%) PET/CT0 documented pathological uptake in pancreatic lesions, while in the remaining 11/42 cases it showed no uptake. In 7/42 (17%) patients, PET/CT0 also detected distant metastases, prompting a change in the therapeutic approach. Compared to PET/CT0, PET/CT1 (n = 18) documented 3 complete metabolic responses, 9 partial metabolic responses, 2 instances of stable metabolic disease, and 4 instances of progressive metabolic disease. In the same group of 18 patients, CT1 showed 0 complete responses, 3 partial responses, 8 instances of stable disease, and 7 instances of progressive disease compared to CT0. Concordance between PET/CT and CT response was seen in 33% of cases. In 50% of cases, PET/CT1 documented a response to therapy that was not evident on CT.

Conclusions

PET/CT influenced the treatment strategy by detecting distant metastases not documented by CT, thus accurately selecting patients for HTT-ChT after induction ChT. In monitoring treatment efficacy, PET/CT can detect a metabolic response to treatment not identified by CT.

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.

A pilot study of the diagnostic and prognostic values of FLT-PET/CT for pancreatic cancer: comparison with FDG-PET/CT

PURPOSE

The purpose of the study was to examine the diagnostic and prognostic values of ¹⁸F-fluorothymidine (FLT)-PET/CT for pancreatic cancer by comparing with ¹⁸F-fluorodeoxyglucose (FDG)-PET/CT.

METHODS

Fifteen patients with newly diagnosed pancreatic cancer underwent both FLT and FDG-PET/CT scans before treatment. The sensitivity, specificity, and accuracy in detecting nodal and distant metastases were compared between both scans using McNemar exact or χ ² test. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier method. Prognostic significance was assessed by Cox proportional hazards analysis.

RESULTS

Both scans visualized all primary cancers. The sensitivity, specificity, and accuracy per patient basis for detecting nodal metastasis were equal and 63.6% (7/11), 100% (4/4), and 73.3% (11/15) for both scans, and for detecting distant metastasis were 100% (6/6), 88.9% (8/9), and 93.3% (14/15) for FDG-PET/CT, and 50.0% (3/6), 100% (9/9), and 80.0% (12/15) for FLT-PET/CT, respectively, without significant difference in each of them between both scans (p > 0.05). However, of 4 patients with multiple liver metastases, FDG-PET/CT was positive in all, but FLT-PET/CT was negative in three patients. At univariate analysis, only FLT-SUV_max correlated with PFS (hazard ratio, 1.306, p = 0.048), and FDG total lesion glycolysis (TLG), FLT-SUV_max, and FLT-total lesion proliferation (TLP) correlated with OS (p = 0.021, p = 0.005, and p = 0.022, respectively). At bivariate analysis, FLT-SUV_max was superior to FDG-TLG or FLT-TLP for prediction of OS [HR (adjusted for FDG-TLG), 1.491, p = 0.034, HR (adjusted for FLT-TLP), 1.542, p = 0.023].

CONCLUSION

FLT-PET/CT may have a potential equivalent to FDG-PET/CT for detecting primary and metastatic cancers except liver metastasis. FLT-SUV_max can provide the most significant prognostic information.

Preoperative Volume-Based PET Parameter, MTV2.5, as a Potential Surrogate Marker for Tumor Biology and Recurrence in Resected Pancreatic Cancer

This study aims to evaluate the role of volume-based positron emission tomography parameters as potential surrogate markers for tumor recurrence in resected pancreatic cancer. Between January 2008 and October 2012, medical records of patients who underwent surgical resection for pancreatic ductal adenocarcinoma and completed ¹⁸F-fluorodeoxyglucose positron emission tomography/CT as a part of preoperative staging work-up were retrospectively reviewed. Not only clinicopathologic variables but also positron emission tomography parameters such as SUVmax, MTV2.5 (metabolic tumor volume), and TLG (total lesion glycolysis) were obtained. Twenty-six patients were women and 31 were men with a mean age of 62.9 ± 9.1 years. All patients were preoperatively determined to resectable pancreatic cancer except 1 case with borderline resectability. R0 resection was achieved in all patients and 45 patients (78.9%) received postoperative adjuvant chemotherapy with or without radiation therapy. Median overall disease-free survival was 12.8 months with a median overall disease-specific survival of 25.1 months. SUVmax did not correlate with radiologic tumor size (P = 0.501); however, MTV2.5 (P = 0.001) and TLG (P = 0.009) were significantly associated with radiologic tumor size. In addition, MTV2.5 (P < 0.001) and TLG (P < 0.001) were significantly correlated with a tumor differentiation. There were no significant differences in TLG and SUVmax according to lymph node ratio; only MTV2.5 was related to lymph node ratio with marginal significance (P = 0.055). In multivariate analysis, lymph node ratio (Exp [β] = 2.425, P = 0.025) and MTV2.5 (Exp[β] = 2.273, P = 0.034) were identified as independent predictors of tumor recurrence following margin-negative resection. Even after tumor size-matched analysis, MTV2.5 was still identified as significant prognostic factor in resected pancreatic cancer (P < 0.05). However, preoperative neoadjuvant treatment attenuated adverse oncologic impact of high preoperative MTV2.5 (P = 0.210). Preoperatively determined volume-based PET parameter, MTV2.5, can potentially be used as a surrogate marker to estimate tumor biology and tumor recurrence. Individual treatment strategies for pancreatic cancer can be suggested based on patients' preoperative MTV2.5.

Functional imaging of interstitial brachytherapy in pancreatic carcinoma xenografts using spectral CT: how does iodine concentration correlate with standardized uptake value of (18)FDG-PET-CT?

OBJECTIVE

This study aimed to investigate the correlation between iodine concentration (IC) for the quantitative analysis of spectral CT and maximum standardized uptake value (SUVmax) of 18 fludeoxyglucose positron emission tomography-CT ((18)FDG PET-CT) as an indicator of therapeutic response to interstitial brachytherapy in transplanted human pancreatic carcinomas in BALB/c-nu mice.

METHODS

Xenograft models were created by subcutaneous injection of SW1990 human pancreatic cancer cell suspensions into immunodeficient BALB/c-nu mice. 30 mice bearing SW1990 human pancreatic cancer cell xenografts were randomly separated into two groups: experimental (n = 15; 1.0 mCi) and control (n = 15, 0 mCi). After 2 weeks of treatment, spectral CT and (18)FDG micro-PET-CT scan were performed. IC values and SUVmax in the lesions were measured. IC normalized to the muscle tissue is indicated as nIC. The relationships between the nIC and SUVmax of the transplantation tumours were analysed.

RESULTS

2 weeks after treatment, the nIC in three-phase scans and SUVmax of the experimental group were significantly lower than those of the control group. The nIC values of the three-phase scans have certain positive correlation with the SUVmax values (r = 0.69, p < 0.05; r = 0.73 and p < 0.05; r = 0.80, p < 0.05 in the 10-, 25- and 60-s phase, respectively).

CONCLUSION

Spectral CT could serve as a valuable imaging modality, as our results suggest that nIC correlates with SUVmax of (18)FDG PET-CT for evaluating the therapeutic effect of (125)I interstitial brachytherapy in a pancreatic carcinoma xenograft.

ADVANCES IN KNOWLEDGE

Spectral CT offers opportunities to assess the therapeutic response of pancreatic cancer. This study supports the conclusion that nIC values in spectral CT could also serve as a valuable functional imaging parameter for early monitoring and evaluation of the therapeutic response of (125)I interstitial brachytherapy mouse models because the nIC correlates with the SUVmax of (18)FDG PET-CT.

Correlation between apparent diffusion coefficients on diffusion-weighted MRI and standardized uptake value on FDG-PET/CT in pancreatic adenocarcinoma

BACKGROUND

Diffusion-weighted magnetic resonance imaging (DW-MRI) and 2-deoxy-2-[18F]fluoro-D-glucose-positron emission tomography/computed tomography (PET/CT) is increasingly recognized as important for assessing tumor malignancy in oncology. Apparent diffusion coefficient (ADC) and standardized uptake value (SUV) are negatively correlated in some types of cancer based on tumor aggressiveness.

PURPOSE

To evaluate relationships between ADC of magnetic resonance imaging and SUV of PET/CT in pancreatic adenocarcinomas.

MATERIAL AND METHODS

Twenty-nine patients histopathologically diagnosed with pancreatic adenocarcinomas were evaluated. ADC maps were generated from 3 T-MRI using b values (b = 0, 800 s/mm(2)). PET/CT was performed 60 min after intravenous injection of FDG (3.7 MBq/kg). The margins of tumors on DW-MRI and PET/CT were assessed to measure ADC and SUV of tumor appropriately. For tumors considered well-marginated, minimal and mean ADC as well as maximal and mean SUV were measured. The correlation of ADC and SUV were statistically evaluated and survival period stratified on ADC and SUV also evaluated.

RESULTS

Twenty-two tumors on DW-MRI and 25 on PET/CT were deemed well-marginated. Minimal ADC was significantly and negatively correlated with maximal and mean SUV (r = -0.61, P = 0.0040; r = -0.66, P = 0.0015), and mean ADC also showed significantly and negatively correlation with maximal and mean SUV (r = -0.50, P = 0.024; r = -0.54, P = 0.012). There was no significant difference on overall survival stratified on ADC and SUV.

CONCLUSION

ADC and SUV were significantly correlated in pancreatic adenocarcinomas, although no significant findings were observed in overall survival.

Impact of Plasma Glucose Level at the Time of Fluorodeoxyglucose Administration on the Accuracy of FDG-PET/CT in the Diagnosis of Pancreatic Lesions

BACKGROUND

High fasting plasma glucose (FPG) levels before fluorodeoxyglucose (FDG) administration for positron emission tomography/computed tomography (PET/CT) might affect the accuracy of 18-fluoro-deoxy-glucose-positron emission tomography-computed tomography (FDG-PET/CT) in diagnosis of pancreatic lesions. Current guidelines require FPG levels of < 200 mg/dL before FDG administration; however, the literature on the effect of FPG levels of < 200 mg/dL on the accuracy of FDG-PET/CT is scarce.

OBJECTIVES

The aim of this study was to evaluate the effect of FPG levels of < 200 mg/dL on the accuracy of FDG-PET/CT in diagnosis of pancreatic lesions.

PATIENTS AND METHODS

In this retrospective study, 161 patients who had FDG-PET/CT for initial diagnosis of pancreatic lesions were included. Fasting plasma glucose levels before FDG administration were recorded. Accuracy of FDG-PET/CT in diagnosis of pancreatic lesions was compared between patients who were non diabetic (FPG < 126 mg/dL) and hyperglycemic (126 ≤ FPG < 200 mg/dL).

RESULTS

Thirty-four patients were hyperglycemic and 127 non diabetic. Sensitivity, specificity, positive predictive value and negative predictive value of FDG-PET/CT were 90%, 88%, 87% and 91% in non diabetic and 82%, 92%, 95% and 73% in hyperglycemic patients, respectively. Overall, the accuracy was higher in non diabetic than hyperglycemic patients (89% vs. 85%).

CONCLUSIONS

Accuracy of FDG-PET/CT for primary diagnosis of pancreatic lesions is higher in patients with FPG levels < 126 mg/dL than in patients with FPG levels between 126 and 200 mg/dL.

Prognostic significance of SUVmax and serum carbohydrate antigen 19-9 in pancreatic cancer

AIM: To investigate the prognostic significance of pretreatment standardized maximum uptake value (SUVmax) and serum carbohydrate antigen (CA)19-9 in pancreatic cancer.

METHODS: From January 2007 to October 2011, 80 consecutive patients with pancreatic cancer who received positron emission/computed tomography before any treatment were enrolled in this study. The pretreatment SUVmax and CA19-9 level of the primary pancreatic tumor were obtained and compared with clinicopathological and prognostic factors. Student’s t test for unpaired data was used to analyze the differences between two groups. Univariate analysis and Cox proportional hazards regression were used to examine the independent effects of each significant variable. Survival was analyzed by the Kaplan-Meier method.

RESULTS: There was a significant correlation between both the SUVmax and serum CA19-9 of pancreatic cancer and R0 surgical resection (P = 0.043 and P = 0.007). Lymph node metastasis was associated with SUVmax (P = 0.017), but not serum CA19-9 (P = 0.172). On the contrary, the tumor stage was significantly related to serum CA19-9 (P = 0.035), but not SUVmax (P = 0.110). The univariate analysis showed that survival time was significantly related to tumor stage (P < 0.001), lymph node metastasis (P = 0.043), R0 surgical resection (P < 0.001), serum CA19-9 (P = 0.001), SUVmax (P < 0.001) and SUVmax plus CA19-9 (P = 0.002). Multivariate analysis clearly showed that only tumor stage (hazard ratio = 0.452; P = 0.020) was an independent prognostic factor for overall survival in pancreatic cancer. Higher SUVmax or CA19-9 showed worse prognosis. We found that high serum CA19-9 plus SUVmax was the most significant variable.

CONCLUSION: Higher pretreatment SUVmax and serum CA19-9 indicates poor prognosis. SUVmax plus serum CA19-9 is the most significant variable in predicting survival.

Prognostic Value of Metabolic Tumor Volume and Total Lesion Glycolysis on Preoperative ¹⁸F-FDG PET/CT in Patients with Pancreatic Cancer

In this study, we aimed to assess the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured on (18)F-FDG PET/CT in pancreatic cancer patients who underwent resection with curative intent.

METHODS

Eighty-seven patients with pancreatic ductal adenocarcinoma who underwent (18)F-FDG PET/CT and subsequent surgical resection with curative intent with (30 patients) or without (57 patients) neoadjuvant therapy were retrospectively enrolled. The maximum standardized uptake value (SUVmax), MTV, and TLG were measured on (18)F-FDG PET/CT in all patients. The prognostic significances of PET/CT parameters and tumor factors for recurrence-free survival (RFS) and overall survival (OS) were evaluated by univariate and multivariate analyses.

RESULTS

Of the 87 patients, 57 (64%) experienced recurrence during the follow-up period. The tumor size, pathologic T (pT) stage, SUVmax, MTV, and TLG were significant prognostic factors for both RFS and OS (P < 0.05) on univariate analyses, and the presence of lymph node metastasis showed significance only for predicting RFS (P < 0.05). On multivariate analyses, the tumor size, MTV, and TLG were independent prognostic factors for RFS, and pT stage, MTV, and TLG were independent prognostic factors for OS. For the 57 patients who did not undergo neoadjuvant treatment, MTV and TLG remained significant predictive factors for tumor recurrence, along with tumor size and SUVmax.

CONCLUSION

MTV and TLG are independent prognostic factors for predicting RFS and OS in patients with pancreatic cancer. Thus, (18)F-FDG PET/CT can provide useful prognostic information for patients undergoing resection of pancreatic cancer with curative intent irrespective of neoadjuvant treatment.

The role of 18F-fluorodeoxyglucose positron emission tomography in the management of patients with pancreatic adenocarcinoma

Pancreatic cancer continues to have a grim prognosis with 5-year survival rates at less than 5 %. It is a particularly challenging health problem given these poor survival outcomes, aggressive tumor biology, and late onset of symptoms. Most patients present with advanced unresectable cancer however, margin-negative resection provides a rare chance for cure for patients with resectable disease. The standard imaging modality for the diagnosis and management of pancreatic cancer is contrast-enhanced multidetector computed tomography. Remarkable advances in CT technology have led to improvements in the ability to detect small tumors and intricate vasculature involvement by the tumor, yet CT is still restricted to providing a morphological portrait of the tumor. Diagnosis can be challenging due to similar appearance of certain benign and malignant disease. Distant metastatic disease can be silent on CT leading to improper staging, and thus management, of certain patients. Furthermore, radiation-induced fibrosis and necrosis complicate assessment of treatment response by CT alone. F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) is becoming a prevalent tool employed by physicians to improve accuracy in these clinical scenarios. Malignant transformation causes a high metabolic activity of cancer cells. 18F-FDG-PET captures this functional activity of malignancies by capturing areas with high glucose utilization rates. Imaging function rather than morphological appearance, 18F-FDG-PET has a unique role in the management of oncology patients with the ability to detect regions of tumor involvement that may be silent on conventional imaging. Literature on the sensitivity and specificity of 18F-FDG-PET fails to reach a consensus, and improvements resulting in hybridization of 18F-FDG-PET and CT imaging techniques are preliminary. Here we review the potential role of 18F-FDG-PET and PET/CT in improving accuracy in the initial evaluation and subsequent steps in the management of pancreatic cancer patients.

Multimodality imaging of pancreatic cancer-computed tomography, magnetic resonance imaging, and positron emission tomography

Pancreatic adenocarcinoma continues to have a dismal prognosis, with curative surgery (resection with negative margins) possible in only a small percentage of patients. Not only does radiological imaging play a major role in diagnosing the primary lesion at presentation, but it is also crucial for staging of locoregional disease and distant metastases, both of which are critical for selecting appropriate candidates for surgery. Over the last 2 decades, computed tomography has become the dominant imaging modality for both the diagnosis and staging of pancreatic cancer, with advances in multidetector computed tomography technology improving the ability to identify small tumors and demonstrate subtle degrees of vascular involvement by tumor. However, magnetic resonance imaging and positron emission tomography are now playing an increasing role in pancreatic cancer imaging. These 3 imaging modalities each have specific strengths and benefits and should be used in a complementary fashion.

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.

Detection of hypoxia with 18F-fluoromisonidazole (18F-FMISO) PET/CT in suspected or proven pancreatic cancer

PURPOSE OF THE REPORT

Pancreatic carcinoma is known to demonstrate molecular features of hypoxia. The aim of this prospective pilot study is to analyze the hypoxia agent fluoromisonidazole (FMISO) using PET/CT in pancreatic carcinoma and to compare FMISO activity with glucose metabolism reflected by FDG.

PATIENTS AND METHODS

Ten patients with pancreatic carcinoma underwent FMISO and FDG PET scans. FMISO and FDG PET/CT scans were analyzed by 2 PET physicians. Regions of interest drawn on the FDG images were transposed to the FMISO images after study coregistration. The FDG SUVmax was used to quantify metabolic activity and FMISO SUVmax and tumor-to-background (muscle) ratio to quantify hypoxia.

RESULTS

Seven patients were diagnosed with pancreatic adenocarcinoma. The remaining patients had a neuroendocrine tumor, poorly differentiated/sarcomatoid carcinoma, and mucinous neoplasm. Visual analysis demonstrated increased FMISO activity in 2 pancreatic adenocarcinomas. All patients, however, had increased FDG activity at the tumor site. Mean FDG SUVmax was 6 (range: 3.8 to 9.5) compared to 2.3 for FMISO (range: 1 to 3.4). The 2 positive studies on visual analysis of FMISO did not correspond to the largest tumors, the studies with the highest FMISO or FDG SUVmax. There was no significant correlation between FMISO and FDG SUVmax values.

CONCLUSIONS

The hypoxia imaging agent, FMISO, demonstrates minimal activity in pancreatic tumors. If FMISO PET/CT is to be included in clinical trial protocols of hypoxia in pancreatic cancer, it would require correlation with other imaging modalities to localize the tumor and allow semiquantitative analysis.

Evaluation of the Metabolic Response to Cyclopamine Therapy in Pancreatic Cancer Xenografts Using a Clinical PET-CT System

OBJECTIVES

We analyzed the effects of anti-hedgehog signaling on the (18)F-FDG uptake of pancreatic cancer xenografts (PCXs) using a clinically implemented positron emission tomography (PET)-computer tomography (CT) scanner with high-resolution reconstruction.

METHODS

PCXs from two pancreatic cancer cell lines were developed subcutaneously in nude mice and injected intraperitoneally with a low dose of cyclopamine for 1 week. (18)F-FDG PET-CT was performed using a new-generation clinical PET-CT scanner with minor modifications of the scanning protocol to adapt for small-animal imaging. The data set was reconstructed and quantified using a three-dimensional workstation.

RESULTS

MiaPaCa-2 cells, which respond to cyclopamine, showed decreased (18)F-FDG uptake without a change in tumor size. For hip tumors, the maximum standardized uptake value (SUV(max)) was reduced by -24.5 ± 9.2%, the average SUV (SUV(avg)) by -33.5 ± 7.0%, and the minimum SUV (SUV(min)) by -54.4 ± 11.5% (P < .05). For shoulder tumors, SUV(max) was reduced by -14.7 ± 7.5%, SUV(avg) by -12.6 ± 6.3, and SUV(min) by -30.3 ± 16.7% (P < .05). Capan-1 cells, which do not respond to cyclopamine, did not show significant SUV changes.

CONCLUSIONS

The new generations of clinically implemented PET-CT scanners with high-resolution reconstruction detect a minimal response of PCX to low-dose short-term cyclopamine therapy without changes in tumor size and offer potential for preclinical translational imaging.