18F-fluorodeoxyglucose positron emission tomography in the diagnosis of small pancreatic cancer

[99mTc]Tc-labeled cyc-DX600-HYNIC as a SPECT probe for ACE2-specific pancreatic cancer imaging

As a regulator in renin-angiotensin-aldosterone system, angiotensin-converting enzyme 2 (ACE2) closely correlated with tumor progression of pancreatic cancer, meantime, was easily affected by a variety of factors. [99mTc]Tc-cyc-DX600 SPECT was established as an ACE2-specific imaging protocol to figure out the ACE2 status in pancreatic tumor. BALB/C-NU mice were used to prepare the subcutaneous cell derived xenograft (CDX) models with HEK-293T or HEK-293T/hACE2 cells to validate ACE2 specificity of [99mTc]Tc-cyc-DX600 SPECT and establish SPECT imaging protocol. On the basis of [99mTc]Tc-cyc-DX600 SPECT and [18F]F-FDG PET/CT, ACE2-dependence on tumor size and tumor metabolism were further verified on orthotopic pancreatic cancer model with KPC cells. Immunohistochemical analysis was used to demonstrate the findings on ACE2 SPECT. [99mTc]Tc-cyc-DX600 was of superior tumor uptake in HEK-293T/hACE2 CDX than wild type (6.74 ± 0.31 %ID/mL vs 1.83 ± 0.26 %ID/mL at 1.5 h post injection (p.i.); 3.14 ± 0.31 %ID/mL vs 1.16 ± 0.15 %ID/mL at 4.5 h p.i.). For the CDX models with PANC-1 cells, a significant negative correlation between the slope of tumor volume and tumor uptake was observed (r = -0.382 for the 1-4th day; r = -0.146 for the 1-5th day; r = -0.114 for the 1-6th day; r = -0.152 for the 1-7th day; but P > 0.05 for all). For orthotopic pancreatic cancer model, the linear correlation between FDG PET and ACE2 SPECT of the pancreatic lesions was negative (r = -0.878), the quantitative values of ACE2 SPCET was positively correlated with the volume of primary lesions (r = 0.752) and also positively correlated with the quantitative values of ACE2 immunohistochemical analysis (r = 0.991). Conclusively, [99mTc]Tc-cyc-DX600 SPECT is an ACE2-specific imaging protocol with clinical translational potential, adding multidimensional information on the disease progression of pancreatic cancer.

The Value of Circulating Tumor Cells in the Prognosis and Treatment of Pancreatic Cancer

In the past few decades, tumor diagnosis and treatment theory have developed in a variety of directions. The number of people dying from pancreatic cancer increases while the mortality rate of other common tumors decreases. Traditional imaging methods show the boundaries of pancreatic tumor, but they are not sufficient to judge early micrometastasis. Although carcinoembryonic antigen (CEA) and carbohydrate antigen19-9 (CA19-9) have the obvious advantages of simplicity and minimal invasiveness, these biomarkers obviously lack sensitivity and specificity. Circulating tumor cells (CTCs) have attracted attention as a non-invasive, dynamic, and real-time liquid biopsy technique for analyzing tumor characteristics. With the continuous development of new CTCs enrichment technologies, substantial progress has been made in the basic research of CTCs clinical application prospects. In many metastatic cancers, CTCs have been studied as an independent prognostic factor. This article reviews the research progress of CTCs in the treatment and prognosis of pancreatic cancer.

Recent development of a magneto-optical nanoplatform for multimodality imaging of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. Given its inconspicuous and atypical early symptoms and hidden location, most patients have already reached the terminal stage before diagnosis. At present, the diagnosis of PDAC mainly depends on serological and imaging examinations. However, serum tests cannot identify specific tumor locations and each imaging technology has its own defects, bringing great challenges to the early diagnosis of PDAC. Therefore, it is of great significance to find new strategies for the early and accurate diagnosis of PDAC. In recent years, a magneto-optical nanoplatform integrating near infrared fluorescence, photoacoustic, magnetic resonance imaging, etc. has attracted widespread attention, giving full play to the complementary advantages of each imaging modality. Herein, we summarize the recent advances of imaging modalities in the diagnosis of pancreatic cancer, and then discuss in detail the construction and modification of magneto or/and optical probes for multimodal imaging, and advances in early diagnosis using the combination of various imaging modalities, which can provide potential tools for the early diagnosis or even intraoperative navigation and post-treatment follow-up of PDAC patients.

Conversion Therapy for Advanced Pancreatic Cancer: The Case Series and Literature Review

Background

Pancreatic cancer has a high incidence and mortality. Most patients are in an advanced stage at the time of initial diagnosis and cannot be cured by a single surgery. The ASCO clinical practice guideline emphasized the overall management and multidisciplinary comprehensive treatment which put forward the concept of conversion therapy. In this paper, the real-world observation and study were carried out to explore the conversion effect of chemotherapy in patients with advanced pancreatic cancer and their long-term survival.

Methods

The subjects of this study are advanced pancreatic cancer patients who visited the oncology department of Zhejiang Provincial People’s Hospital from 2015 to 2019. Collected and summarized the cases, and selected 5 representative patients for analysis, all of them received standard treatment (FOLFIRINOX, AS, AG, or GS). The progress, clinical evaluation, adverse reactions, and prognosis of these patients after conversion therapy were analyzed and discussed in conjunction with relevant literature.

Results

Five patients with advanced pancreatic cancer received conversion therapy with an average survival time of 29.8 months, two of them received surgical treatment, and postoperative evaluations were pathological complete response (pCR). The tolerance of chemotherapy was good in five patients, and no serious adverse reactions of grade 3 or 4 occurred.

Conclusion

Conversion therapy for patients with advanced pancreatic cancer strives for surgical opportunities of radical resection, prolongs survival and improves quality of life.

Usefulness of 18 F-FDG-PET/CT in the diagnosis and prediction of recurrence of pancreatic neuroendocrine neoplasms

BACKGROUND

Although ¹⁸ F-FDG-PET/CT is a widely used diagnostic tool for several malignancies, its efficacy in diagnosing pancreatic neuroendocrine tumors is reported to be controversial because of the short-term follow-up.

METHODS

We retrospectively compared demographics and pathological features between ¹⁸ F-FDG-positive and -negative diseases. Additionally, we evaluated whether the avidity of ¹⁸ F-FDG-PET/CT affected earlier recurrence after curative treatment of non-functioning tumors. The median duration of observation was 65.6 months.

RESULTS

Seventy-two patients were enrolled. ¹⁸ F-FDG-positive diseases were pathologically advanced and significantly associated with metastatic behavior. In a multivariate analysis, metastatic behavior and WHO tumor grade was independently associated with ¹⁸ F-FDG accumulation. Only 25% of functional tumors (4/16) and 8% of insulinomas (1/12) were ¹⁸ F-FDG-positive. In a Kaplan-Meier analysis in patients with non-functioning tumors (n = 56), ¹⁸ F-FDG-positivity was significantly correlated with poorer recurrence-free survival (RFS) but had no correlation with overall survival. In univariate analysis of factors associated with shorter RFS, male gender, prevalence of nodal metastasis, WHO tumor grade ≥G2, or ¹⁸ F-FDG-positive disease were significantly higher in patients with shorter RFS, whereas only ¹⁸ F-FDG-positivity was associated with shorter RFS in multivariate analyses.

CONCLUSIONS

The avidity of ¹⁸ F-FDG-PET/CT was associated with metastatic behavior of pancreatic neuroendocrine tumors and recurrence after treatment of non-functioning tumors.

Imaging diagnosis and staging of pancreatic ductal adenocarcinoma: a comprehensive review

Pancreatic ductal adenocarcinoma (PDAC) has continued to have a poor prognosis for the last few decades in spite of recent advances in different imaging modalities mainly due to difficulty in early diagnosis and aggressive biological behavior. Early PDAC can be missed on CT due to similar attenuation relative to the normal pancreas, small size, or hidden location in the uncinate process. Tumor resectability and its contingency on the vascular invasion most commonly assessed with multi-phasic thin-slice CT is a continuously changing concept, particularly in the era of frequent neoadjuvant therapy. Coexistent celiac artery stenosis may affect the surgical plan in patients undergoing pancreaticoduodenectomy. In this review, we discuss the challenges related to the imaging of PDAC. These include radiological and clinical subtleties of the tumor, evolving imaging criteria for tumor resectability, preoperative diagnosis of accompanying celiac artery stenosis, and post-neoadjuvant therapy imaging. For each category, the key imaging features and potential pitfalls on cross-sectional imaging will be discussed. Also, we will describe the imaging discriminators of potential mimickers of PDAC.

Natural History of Pancreatic Ductal Adenocarcinoma Diagnosed During Observation of Other Organ Cancers

BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is a rapidly progressive malignancy that exhibits an extremely poor prognosis, with most cases diagnosed at an advanced stage. To date, few reports have explored the natural history of PDAC, and the period leading up to the detection of PDAC as a tumor with contrast-enhanced computed tomography (CECT) remains unclear. Here, we report 3 PDAC cases diagnosed incidentally by repeating imaging examinations during observation of other organ cancers. CASE REPORT Two patients were undergoing postoperative follow-up for colorectal cancer; owing to the elevation of serum CA19-9 or dilatation of the main pancreatic duct, both cases were finally diagnosed with PDAC. Another patient was administered neoadjuvant chemotherapy for a gastrointestinal stromal tumor; the fluorodeoxyglucose uptake in the pancreas with fluorodeoxyglucose positron emission tomography for the treatment assessment led to the diagnosis of PDAC. All patients underwent frequent CECT for assessment of other diseases, and PDAC became visible with CECT within 3-4 months of the appearance of indirect findings of PDAC. CONCLUSIONS The period leading up to the detection of PDAC as a tumor with CECT was approximately 3-4 months. These cases suggest that additional imaging examinations should be performed when the indirect findings of PDAC are noted. This report adds value to the literature by elucidating the natural course of PDAC.

Staging of pancreatic cancer: resectable, borderline resectable, and unresectable disease

Pancreatic ductal adenocarcinoma (PDAC) is a relatively common malignancy that carries an overall poor prognosis, with five-year survival below 10%. Despite ongoing research, surgical resection remains the only potentially curative treatment. Therefore, accurate identification of those patients who would benefit from surgical resection is of paramount importance. High-quality imaging and image interpretation is central to this process. Radiology helps in the determination of whether patients are resectable, borderline resectable, or unresectable and guides treatment planning.

Diagnostic and therapeutic recommendations in pancreatic ductal adenocarcinoma. Recommendations of the Working Group of the Polish Pancreatic Club

These recommendations refer to the current management in pancreatic ductal adenocarcinoma (PDAC), a neoplasia characterised by an aggressive course and extremely poor prognosis. The recommendations regard diagnosis, surgical, adjuvant and palliative treatment, with consideration given to endoscopic and surgical methods. A vast majority of the statements are based on data obtained in clinical studies and experts' recommendations on PDAC management, including the following guidelines: International Association of Pancreatology/European Pancreatic Club (IAP/EPC), American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), National Comprehensive Cancer Network (NCCN) and Polish Society of Gastroenterology (PSG) and The National Institute for Health and Care Excellence (NICE). All recommendations were voted on by members of the Working Group of the Polish Pancreatic Club. Results of the voting and brief comments are provided with each recommendation.

PET/MR Imaging of the Pancreas

PET/MR imaging has the potential to markedly alter pancreatic care in both the malignant, and premalignant states with the ability to perform robust, high-resolution, quantitative molecular imaging. The ability of PET/MR imaging to monitor disease processes, potentially correct for motion in the upper abdomen, and provide novel biomarkers that may be a combination of MR imaging and PET biomarkers, offers a unique, precise interrogation of the pancreatic milieu going forward.

18F-fluorodeoxyglucose positron emission tomography to indicate conversion surgery in patients with initially unresectable locally advanced pancreatic cancer

Objective

Advances in chemotherapy and chemoradiotherapy have enabled conversion of initially unresectable locally advanced (UR-LA) pancreatic adenocarcinoma (PDAC) to a resectable disease. However, definitive criteria for conversion surgery have not been established. We evaluated the potential of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to indicate conversion surgery in patients with primary UR-LA PDAC.

Methods

Twenty consecutive patients with UR-LA PDAC underwent chemoradiation or chemotherapy followed by assessment with FDG-PET. We defined PET responders (standardized uptake value <3.0) with marked reduction (>80%) of carbohydrate antigen 19-9 as potential candidates for conversion surgery. Outcomes were compared with those of the patients with resectable (R; n = 94) and borderline resectable (BR; n = 37) PDAC.

Results

Eight of the 20 patients (40%) were considered PET responders with marked reduction of CA19-9 and received conversion surgery (UR-LAR) 3-9 months (median, 5 months) after the initiation of therapy. Complete resection (R0) was achieved in 7 of 8 patients (87.5%) with UR-LAR. There was no significant difference in R0 rates, morbidity, or mortality among the UR-LAR, R and BR groups. The overall survival (OS) curve was better in the UR-LAR group than in the group that did not receive surgery. There was no significant difference in OS between the UR-LAR and the R or BR groups.

Conclusions

FDG-PET could be a potential indicator for conversion surgery in patients with primary UR-LA PDAC and may help in selecting patients who qualify for complete surgical resection and have a promising prognosis.

Challenges in diagnosis of pancreatic cancer

Pancreatic cancer is a growing source of cancer related death, yet has poor survival rates which have not improved in the last few decades. Its high mortality rate is attributed to pancreatic cancer biology, difficulty in early diagnosis and the lack of standardised international guidelines in assessing suspicious pancreatic masses. This review aims to provide an update in the current state of play in pancreatic cancer diagnosis and to evaluate the benefits and limitations of available diagnostic technology. The main modalities discussed are imaging with computed tomography, magnetic resonance imaging, endoscopic ultrasound and positron emission tomography and tissue acquisition with fine needle aspiration. We also review the improvements in the techniques used for tissue acquisition and the opportunity for personalised cancer medicine. Screening of high risk individuals, promising biomarkers and common mimickers of pancreatic cancer are also explored, as well as suggestions for future research directions to allow for earlier detection of pancreatic cancer. Timely and accurate diagnosis of pancreatic cancer can lead to improvements in the current poor outcome of this disease.

Early Diagnosis to Improve the Poor Prognosis of Pancreatic Cancer

Pancreatic cancer (PC) has a poor prognosis due to delayed diagnosis. Early diagnosis is the most important factor for improving prognosis. For early diagnosis of PC, patients with clinical manifestations suggestive of PC and high risk for developing PC need to be selected for examinations for PC. Signs suggestive of PC (e.g., symptoms, diabetes mellitus, acute pancreatitis, or abnormal results of blood examinations) should not be missed, and the details of risks for PC (e.g., familial history of PC, intraductal mucin producing neoplasm, chronic pancreatitis, hereditary pancreatitis, or life habit) should be understood. Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) can be performed for diagnosing PC, but the diagnostic ability of these examinations for PC is limited. Endoscopic diagnostic procedures, such as endoscopic ultrasonography, including fine-needle aspiration, and endoscopic retrograde pancreatocholangiography, including Serial Pancreatic-juice Aspiration Cytologic Examination (SPACE), could be recommended for a detailed examination to diagnose pancreatic carcinoma earlier.

Effective screening for early diagnosis of pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.

Hybrid imaging for pancreatic malignancy: clinical applications, merits, limitations, and pitfalls

The role of PET/CT in pancreatic malignancy is evolving with new scientific evidence emerging continuously. PET/CT applications in imaging the pancreas and its organ-specific merits, limitations, and potential pitfalls are still evolving. This article provides an overview of the state-of-the-art applications of PET/CT imaging in evaluating pancreatic malignancy, comparing with conventional imaging modalities, such as contrast-enhanced CT and MRI. Current PET/MRI is also reviewed, along with brief discussion on cost-benefit analysis.

Transcriptomic and Immunohistochemical Profiling of SLC6A14 in Pancreatic Ductal Adenocarcinoma

We used a target-centric strategy to identify transporter proteins upregulated in pancreatic ductal adenocarcinoma (PDAC) as potential targets for a functional imaging probe to complement existing anatomical imaging approaches. We performed transcriptomic profiling (microarray and RNASeq) on histologically confirmed primary PDAC tumors and normal pancreas tissue from 33 patients, including five patients whose tumors were not visible on computed tomography. Target expression was confirmed with immunohistochemistry on tissue microarrays from 94 PDAC patients. The best imaging target identified was SLC6A14 (a neutral and basic amino acid transporter). SLC6A14 was overexpressed at the transcriptional level in all patients and expressed at the protein level in 95% of PDAC tumors. Very little is known about the role of SLC6A14 in PDAC and our results demonstrate that this target merits further investigation as a candidate transporter for functional imaging of PDAC.

Dual-phase 18F-FDG PET/CT imaging in the characterization of pancreatic lesions: does it offer prognostic information?

OBJECTIVE

The primary aim of our prospective study was to evaluate the usefulness of dual-phase F-fluoro-deoxy-glucose PET/computed tomography (F-FDG PET/CT) in the characterization of pancreatic masses. The secondary aim was to assess whether delayed imaging revealed any prognostic information.

MATERIALS AND METHODS

Fifty patients with periampullary or pancreatic masses on conventional imaging were included in this study. Early and delayed PET/CT was performed, followed by pathological examination in all patients. PET/CT parameters including uptake pattern, SUVearly, SUVdelayed, lesion to background ratio (L/B), and retention index (RI) were assessed for their ability to differentiate benign from malignant lesions. Patients with malignant lesions were followed up for a median duration of 26 months. The association of 11 variables with survival was analyzed by univariate and multivariate methods.

RESULTS

Thirty-one patients had malignant lesions and 19 had benign lesions. The mean SUVearly, L/B, SUVdelayed, and RI between the malignant and benign lesions were statistically significant. The F-FDG uptake pattern of the lesions had higher sensitivity (93.5%) and specificity (100%) compared with RI (cutoff 25.7%) (84 and 37%, respectively) for diagnosing malignancy (P<0.05). In univariate analysis both RI (>18.7%) and tumor size (>2.6 cm) predicted significantly poor survival, whereas in multivariate analysis RI (P=0.04) was the only predictor of poor survival.

CONCLUSION

Dual-phase F-FDG PET/CT is not useful in characterizing pancreatic masses as it cannot differentiate benign from malignant lesions, and focal uptake on early PET imaging is the best indicator of malignancy. A possible benefit in performing a delayed scan is that a high RI (>18.7) can predict poor survival and hence may be useful in treatment planning.

Usefulness of dual-phase 18F-FDG PET/CT for diagnosing small pancreatic tumors

OBJECTIVES

The usefulness of dual-phase F-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) for pancreatic tumors was investigated including numerous small tumors.

METHODS

Consecutive 116 patients with solid pancreatic tumors were subjected. Maximum standard uptake values (SUVmax) at 1 and 2 hours after FDG injection were defined as early and delayed SUVmax, respectively. Receiver operating characteristic curve was used to determine the optimal cutoff value of early SUVmax. Diagnostic accuracy of dual-phase FDG PET/CT was compared with that of single phase.

RESULTS

The mean ± SD tumor size was 25 ±12 mm in diameter. The level of early SUVmax and proportion of elevated SUVmax in delayed phase were significantly higher in malignancy than those in benignancy for less than 25 mm tumors (4.1 ± 2.6 vs 1.9 ± 0.5, P < 0.001; 89% vs 17%, P < 0.0001) although they did not reach statistical significance for greater than or equal to 25 mm tumors. When diagnostic criteria of dual-phase FDG PET/CT for less than 25 mm tumors were determined as (1) early SUVmax greater than or equal to 2.1 and/or (2) delayed SUVmax greater than early SUVmax, sensitivity, specificity, and over all accuracy of dual-phase FDG PET/CT were better than that of single phase for less than 25 mm tumor (93%, 83%, and 91% vs 79%, 83%, and 80%, respectively).

CONCLUSIONS

Dual-phase FDG PET/CT might be useful for diagnosing small pancreatic tumors.

Cross-modality PET/CT and contrast-enhanced CT imaging for pancreatic cancer

AIM: To explore the diagnostic value of the cross-modality fusion images provided by positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT (CECT) for pancreatic cancer (PC).

METHODS: Data from 70 patients with pancreatic lesions who underwent CECT and PET/CT examinations at our hospital from August 2010 to October 2012 were analyzed. PET/CECT for the cross-modality image fusion was obtained using TureD software. The diagnostic efficiencies of PET/CT, CECT and PET/CECT were calculated and compared with each other using a χ² test. P < 0.05 was considered to indicate statistical significance.

RESULTS: Of the total 70 patients, 50 had PC and 20 had benign lesions. The differences in the sensitivity, negative predictive value (NPV), and accuracy between CECT and PET/CECT in detecting PC were statistically significant (P < 0.05 for each). In 15 of the 31 patients with PC who underwent a surgical operation, peripancreatic vessel invasion was verified. The differences in the sensitivity, positive predictive value, NPV, and accuracy of CECT vs PET/CT and PET/CECT vs PET/CT in diagnosing peripancreatic vessel invasion were statistically significant (P < 0.05 for each). In 19 of the 31 patients with PC who underwent a surgical operation, regional lymph node metastasis was verified by postsurgical histology. There was no statistically significant difference among the three methods in detecting regional lymph node metastasis (P > 0.05 for each). In 17 of the 50 patients with PC confirmed by histology or clinical follow-up, distant metastasis was confirmed. The differences in the sensitivity and NPV between CECT and PET/CECT in detecting distant metastasis were statistically significant (P < 0.05 for each).

CONCLUSION: Cross-modality image fusion of PET/CT and CECT is a convenient and effective method that can be used to diagnose and stage PC, compensating for the defects of PET/CT and CECT when they are conducted individually.

Diagnostic strategies for early pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery is the approach with the potential to significantly improve long-term patient outcome. Recently, some reports showed that patients with pancreatic tumors smaller than 10 mm showed a favorable prognosis. However, the rate of tumor detection on computed tomography in patients with small pancreatic tumors is low. For the diagnoses of PC with tumors smaller than 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on computed tomography or other modalities, and histologic diagnosis using EUS-guided fine-needle aspiration was helpful in confirming the diagnosis. For the diagnosis of PC in situ, EUS and magnetic resonance cholangiopancreatography may play important roles in detecting the local irregular stenosis of the pancreatic duct. Endoscopic retrograde pancreatography and sequential cytodiagnosis using pancreatic juice obtained by endoscopic nasopancreatic drainage multiple times was useful in the final diagnosis of PC in situ. At present, improving survival lies in identifying those individuals with high-risk factors or precursor lesions through an effective screening method. For example, these should include ultrasonography, various biological markers, or national familial pancreatic cancer registration. Additionally, the relationship between specialists in PC from medical centers and practicing physicians plays an important role in the early diagnosis of PC.

Strategies for early detection of resectable pancreatic cancer

Pancreatic cancer is difficult to diagnose at an early stage and generally has a poor prognosis. Surgical resection is the only potentially curative treatment for pancreatic carcinoma. To improve the prognosis of this disease, it is essential to detect tumors at early stages, when they are resectable. The optimal approach to screening for early pancreatic neoplasia has not been established. The International Cancer of the Pancreas Screening Consortium has recently finalized several recommendations regarding the management of patients who are at an increased risk of familial pancreatic cancer. In addition, there have been notable advances in research on serum markers, tissue markers, gene signatures, and genomic targets of pancreatic cancer. To date, however, no biomarkers have been established in the clinical setting. Advancements in imaging modalities touch all aspects of the clinical management of pancreatic diseases, including the early detection of pancreatic masses, their characterization, and evaluations of tumor resectability. This article reviews strategies for screening high-risk groups, biomarkers, and current advances in imaging modalities for the early detection of resectable pancreatic cancer.

Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis and management of pancreatic cancer; comparison with multidetector row computed tomography, magnetic resonance imaging and endoscopic ultrasonography

OBJECTIVES

We aimed to analyze the contribution of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging to the diagnosis and management of pancreatic cancer compared with multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS).

MATERIAL AND METHODS

We retrospectively scanned the data of 52 patients who were referred for FDG PET/CT imaging for evaluation of pancreatic lesions greater than 10mm. The diagnostic performances of 4 imaging methods and the impact of PET/CT on the management of pancreatic cancer were defined.

RESULTS

Pancreatic adenocarcinoma was diagnosed in 33 of 52 patients (63%), 15 patients had benign diseases of pancreas (29%), and 4 patients were normal (8%). Sensitivity and NPV of EUS and PET/CT were equal (100%) and higher than MDCT and MRI. Specificity, PPV and NPV of PET/CT were significantly higher than MDCT. However, sensitivities of two imaging methods were not significantly different. There was no significant difference between PET/CT and MRI and EUS for these values. When the cut-off value of SUVmax was 3.2, the most effective sensitivity and specificity values were obtained. PET/CT contributed to the management of pancreatic cancer in 30% of patients.

CONCLUSION

FDG PET/CT is a valuable imaging method for the diagnosis and management of pancreatic cancer, especially when applied along with EUS as first line diagnostic tools.

Immunohistochemically detected expression of 3 major genes (CDKN2A/p16, TP53, and SMAD4/DPC4) strongly predicts survival in patients with resectable pancreatic cancer

OBJECTIVE

The goal of this retrospective study was to clarify the clinical implications of the status of the 3 major genes (CDKN2A/p16, TP53, and SMAD4/DPC4).

BACKGROUND

Recent whole-exome sequencing had shown that the landscape of the pancreatic ductal adenocarcinoma (PDAC) genome is notable for 4 frequently mutated genes (KRAS, TP53, CDKN2A/p16, and SMAD4/DPC4).

METHODS

We determined immunohistochemically the status of TP53, CDKN2A/p16, and SMAD4/DPC4 among the 4 genes because the KRAS gene is mutated in virtually all PDAC patients, and analyzed relationships with clinicopathological findings, including survival and patterns of disease progression, in 106 patients with PDAC undergoing radical surgery.

RESULTS

Abnormal immunolabeling of p53 was detected in 81.1% of PDACs and was significantly associated with tumor dedifferentiation (P = 0.022) and the presence of locoregional recurrence (P = 0.020). Loss of p16 and Smad4/Dpc4 immunolabeling was identified in 67.0% and 60.4%, respectively. Loss of p16 immunolabeling was associated with lymphatic invasion (P = 0.012) and postoperative widespread metastases (P < 0.001). A significant correlation was found between Smad4/Dpc4 immunolabeling and tumor size (P = 0.006), lymphatic invasion (P = 0.033), and lymph node metastasis (P = 0.006). Interestingly, all of the 6 patients demonstrating 5-year survival had intact SMAD4/DPC4. Kaplan-Meier survival analysis showed that lymph node metastasis (P = 0.001), lymphatic invasion (P = 0.008), the tumor (T) factor (T3 vs. T1/T2, P = 0.004), loss of p16 immunolabeling (P = 0.029), and loss of Smad4/Dpc4 immunolabeling (P < 0.001) were significantly associated with shorter overall survival. Multivariate analysis revealed that loss of Smad4/Dpc4 immunolabeling was an independent and significant poor prognostic factor for overall and disease-free survival. On analysis of combinations of the status of these 3 genes, increasing number of alterations reflected poorer survival.

CONCLUSIONS

Genetic alterations of these 3 genes and their accumulation are strongly associated with malignant behavior of PDAC. Their immunohistochemical assessment at the time of diagnosis may provide a new prognostic tool, assisting in deciding optimal therapeutic strategies for patients.

The usefulness of (18)F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with (18)F-FDG PET/CT

PURPOSE

This study aimed at demonstrating the feasibility of retrospectively fused (18)F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image.

METHODS

We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion.

RESULTS

FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT.

CONCLUSIONS

In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.

Positron emission tomography in malignancies of the liver, pancreas and biliary tract - indications and potential pitfalls

Abstract Malignancies of the hepato-pancreatico-biliary (HPB) system are relatively common and generally characterized by a dismal prognosis. Positron emission tomography (PET) is a functional imaging technique that has emerged as an important modality in oncological decision-making. The principal radiopharmaceutical in PET imaging is the glucose analog (18)F-fluorodeoxyglucose, which is able to detect altered glucose metabolism in malignant tissue. PET is typically used in conjunction with computed tomography (CT), and previous studies have supported several uses of PET/CT in HPB malignancies, including staging, differential diagnostics and monitoring of treatment response and progress of disease. A review of PET/CT in the context of HPB malignancies will be presented, including indications and potential pitfalls.

Use of F-18 fluorodeoxyglucose positron emission tomography with dual-phase imaging to identify intraductal papillary mucinous neoplasm

BACKGROUND & AIMS

We investigated the usefulness of dual-phase F-18 fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) to differentiate benign from malignant intraductal papillary mucinous neoplasms (IPMNs) and to evaluate branch-duct IPMNs.

METHODS

We used FDG-PET/CT to evaluate IPMNs in 48 consecutive patients who underwent surgical resection from May 2004 to March 2012. IPMNs were classified as benign (n = 16) or malignant (n = 32) on the basis of histology analysis. The ability of FDG-PET/CT to identify branch-duct IPMNs was compared with that of the International Consensus Guidelines.

RESULTS

The maximum standardized uptake value (SUVmax) was higher for early-phase malignant IPMNs than that for benign IPMNs (3.5 ± 2.2 vs 1.5 ± 0.4, P < .001). When the SUVmax cutoff value was set at 2.0, early-phase malignant IPMNs were identified with 88% sensitivity, specificity, and accuracy. The retention index values for malignant and benign IPMNs were 19.6 ± 17.8 and -2.6 ± 12.9, respectively. When the SUVmax cutoff was set to 2.0 and the retention index value to -10.0, early-phase malignant IPMNs were identified with 88% sensitivity, 94% specificity, and 90% accuracy. In identification of branch-duct IPMNs, when the SUVmax cutoff was set to 2.0, the sensitivity, specificity, and accuracy values were 79%, 92%, and 84%, respectively. By using a maximum main pancreatic duct diameter ≥7 mm, the Guidelines identified branch-duct IPMNs with greater specificity than FDG-PET/CT. The Guidelines criteria of maximum cyst size ≥30 mm and the presence of intramural nodules identified branch-duct IPMNs with almost equal sensitivity to FDG-PET/CT.

CONCLUSIONS

Dual-phase FDG-PET/CT is useful for preoperative identification of malignant IPMN and for evaluating branch-duct IPMN.

Effects of a non thermal plasma treatment alone or in combination with gemcitabine in a MIA PaCa2-luc orthotopic pancreatic carcinoma model

Pancreatic tumors are the gastrointestinal cancer with the worst prognosis in humans and with a survival rate of 5% at 5 years. Nowadays, no chemotherapy has demonstrated efficacy in terms of survival for this cancer. Previous study focused on the development of a new therapy by non thermal plasma showed significant effects on tumor growth for colorectal carcinoma and glioblastoma. To allow targeted treatment, a fibered plasma (Plasma Gun) was developed and its evaluation was performed on an orthotopic mouse model of human pancreatic carcinoma using a MIA PaCa2-luc bioluminescent cell line. The aim of this study was to characterize this pancreatic carcinoma model and to determine the effects of Plasma Gun alone or in combination with gemcitabine. During a 36 days period, quantitative BLI could be used to follow the tumor progression and we demonstrated that plasma gun induced an inhibition of MIA PaCa2-luc cells proliferation in vitro and in vivo and that this effect could be improved by association with gemcitabine possibly thanks to its radiosensitizing properties.

State-of-the-art PET/CT of the pancreas: current role and emerging indications

Fused positron emission tomography (PET)/computed tomography (CT) is a recently developed technology that couples the functional information of PET with the anatomic details of CT. Integrated PET/CT scanners produce both PET and contrast material-enhanced CT images of the entire body in one setting. Typically, the amount of fluorine 18 (18F) fluorodeoxyglucose (FDG) uptake in normal pancreatic parenchyma is insignificant compared with that of the liver. However, both malignant (eg, adenocarcinoma) and benign (eg, acute pancreatitis) pancreatic conditions may demonstrate intense FDG uptake. PET/CT provides an opportunity to depict pancreatic tumors and distant metastases, perform preoperative staging, and monitor response to treatment, and it has proved useful in distinguishing postoperative fibrosis from recurrence. In selected cases, PET/CT findings may be used to help diagnose autoimmune pancreatitis mimicking a mass by depicting systemic involvement. PET/CT may also be used to direct biopsy to sites more likely to yield representative tumor tissue. Novel radiolabeled molecules, such as sigma-receptor ligands and 18F-3'-fluoro-3'-deoxy-l-thymidine (FLT), may play an even greater role in distinguishing tumor recurrence from postoperative fibrosis or inflammation.

In vivo SPECT imaging with 111In-DOTA-c(RGDfK) to detect early pancreatic cancer in a hamster pancreatic carcinogenesis model

Early detection of pancreatic cancer is key to overcoming its poor prognosis. α(v)β(3)-integrin is often overexpressed in pancreatic tumor cells, whereas it is scarcely expressed in normal pancreatic cells. In this study, we investigated the usefulness of SPECT imaging with (111)In-1,4,7,10-tetraazacylododecane-N,N',N″,N'''-tetraacetic acid-cyclo-(Arg-Gly-Asp-d-Phe-Lys) [(111)In-DOTA-c(RGDfK)], an imaging probe of α(v)β(3)-integrin, for the early detection of pancreatic cancer in a hamster pancreatic carcinogenesis model.

METHODS

Hamsters were subcutaneously injected with the pancreatic duct carcinogen N-nitrosobis(2-oxopropyl)amine to induce pancreatic cancer. N-nitrosobis(2-oxopropyl)amine-treated hamsters underwent in vivo SPECT with (111)In-DOTA-c(RGDfK). After imaging, the tumor-to-normal pancreatic tissue radioactivity ratios in excised pancreatic samples were measured with autoradiography (ARG) and compared with the immunopathologic findings for α(v)β(3)-integrin. In a mouse model in which inflammation was induced with turpentine, the uptake of (111)In-DOTA-c(RGDfK) in inflammatory regions was evaluated with ARG and compared with that of (18)F-FDG.

RESULTS

(111)In-DOTA-c(RGDfK) was clearly visualized in pancreatic cancer lesions as small as 3 mm in diameter. ARG analysis revealed high tumor-to-normal pancreatic tissue radioactivity ratios (4.6 ± 1.0 [mean ± SD] in adenocarcinoma and 3.3 ± 1.4 in atypical hyperplasia). The uptake of (111)In-DOTA-c(RGDfK) strongly correlated with α(v)β(3)-integrin expression. In the inflammatory model, inflammation-to-muscle ratios for (18)F-FDG and (111)In-DOTA-c(RGDfK) were 8.37 ± 4.37 and 1.98 ± 0.60, respectively. These results imply that (111)In-DOTA-c(RGDfK) has a lower rate of false-positive tumor detection than (18)F-FDG.

CONCLUSION

Our findings suggest that SPECT with (111)In-DOTA-c(RGDfK) has great potential for the early and accurate detection of pancreatic cancer.

Pancreatic cancer: translational research aspects and clinical implications

Despite improvements in surgical techniques and adjuvant chemotherapy, the overall mortality rates in pancreatic cancer have generally remained relatively unchanged and the 5-year survival rate is actually below 2%. This paper will address the importance of achieving an early diagnosis and identifying markers for prognosis and response to therapy such as genes, proteins, microRNAs or epigenetic modifications. However, there are still major hurdles when translating investigational biomarkers into routine clinical practice. Furthermore, novel ways of secondary screening in high-risk individuals, such as artificial neural networks and modern imaging, will be discussed. Drug resistance is ubiquitous in pancreatic cancer. Several mechanisms of drug resistance have already been revealed, including human equilibrative nucleoside transporter-1 status, multidrug resistance proteins, aberrant signaling pathways, microRNAs, stromal influence, epithelial-mesenchymal transition-type cells and recently the presence of cancer stem cells/cancer-initiating cells. These factors must be considered when developing more customized types of intervention ("personalized medicine"). In the future, multifunctional nanoparticles that combine a specific targeting agent, an imaging probe, a cell-penetrating agent, a biocompatible polymer and an anti-cancer drug may become valuable for the management of patients with pancreatic cancer.