Adjunctive role of preoperative liver magnetic resonance imaging for potentially resectable pancreatic cancer

Deep learning CT reconstruction improves liver metastases detection

OBJECTIVES

Detection of liver metastases is crucial for guiding oncological management. Computed tomography through iterative reconstructions is widely used in this indication but has certain limitations. Deep learning image reconstructions (DLIR) use deep neural networks to achieve a significant noise reduction compared to iterative reconstructions. While reports have demonstrated improvements in image quality, their impact on liver metastases detection remains unclear. Our main objective was to determine whether DLIR affects the number of detected liver metastasis. Our secondary objective was to compare metastases conspicuity between the two reconstruction methods.

METHODS

CT images of 121 patients with liver metastases were reconstructed using a 50% adaptive statistical iterative reconstruction (50%-ASiR-V), and three levels of DLIR (DLIR-low, DLIR-medium, and DLIR-high). For each reconstruction, two double-blinded radiologists counted up to a maximum of ten metastases. Visibility and contour definitions were also assessed. Comparisons between methods for continuous parameters were performed using mixed models.

RESULTS

A higher number of metastases was detected by one reader with DLIR-high: 7 (2-10) (median (Q₁-Q₃); total 733) versus 5 (2-10), respectively for DLIR-medium, DLIR-low, and ASiR-V (p < 0.001). Ten patents were detected with more metastases with DLIR-high simultaneously by both readers and a third reader for confirmation. Metastases visibility and contour definition were better with DLIR than ASiR-V.

CONCLUSION

DLIR-high enhanced the detection and visibility of liver metastases compared to ASiR-V, and also increased the number of liver metastases detected.

CRITICAL RELEVANCE STATEMENT

Deep learning-based reconstruction at high strength allowed an increase in liver metastases detection compared to hybrid iterative reconstruction and can be used in clinical oncology imaging to help overcome the limitations of CT.

KEY POINTS

Detection of liver metastases is crucial but limited with standard CT reconstructions. More liver metastases were detected with deep-learning CT reconstruction compared to iterative reconstruction. Deep learning reconstructions are suitable for hepatic metastases staging and follow-up.

MRI with DWI improves detection of liver metastasis and selection of surgical candidates with pancreatic cancer: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis to evaluate if magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI) adds value compared to contrast-enhanced computed tomography (CECT) alone in the preoperative evaluation of pancreatic cancer.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for relevant published studies through October 2022. Studies met eligibility criteria if they evaluated the per-patient diagnostic performance of MRI with DWI in the preoperative evaluation of newly diagnosed pancreatic cancer compared to CECT. Our primary outcome was the number needed to treat (NNT) to prevent one futile surgery using MRI with DWI, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis (i.e., surgical intervention in metastatic disease missed by CECT). The secondary outcomes were to determine the diagnostic performance and the NNT of MRI with DWI to change management in pancreatic cancer.

RESULTS

Nine studies met the inclusion criteria with a total of 1121 patients, of whom 172 had liver metastasis (15.3%). The proportion of futile surgeries reduced by MRI with DWI was 6.0% (95% CI, 3.0-11.6%), yielding an NNT of 16.6. The proportion of cases that MRI with DWI changed management was 18.1% (95% CI, 9.9-30.7), corresponding to an NNT of 5.5. The per-patient sensitivity and specificity of MRI were 92.4% (95% CI, 87.4-95.6%) and 97.3% (95% CI, 96.0-98.1).

CONCLUSION

MRI with DWI may prevent futile surgeries in pancreatic cancer by improving the detection of occult liver metastasis on preoperative CECT with an NNT of 16.6.

CLINICAL RELEVANCE STATEMENT

MRI with DWI complements the standard preoperative CECT evaluation for liver metastasis in pancreatic cancer, improving the selection of surgical candidates and preventing unnecessary surgeries.

KEY POINTS

• The NNT of MRI with DWI to prevent potential futile surgeries due to occult liver metastasis on CECT, defined as those in which CECT was negative and MRI with DWI was positive for liver metastasis, in patients with pancreatic cancer was 16.6. • The higher performance of MRI with DWI to detect liver metastasis occult on CECT can be attributed to an increased detection of subcentimeter liver metastasis.

Flexible array transducer for photoacoustic-guided interventions: phantom and ex vivo demonstrations

Photoacoustic imaging has demonstrated recent promise for surgical guidance, enabling visualization of tool tips during surgical and non-surgical interventions. To receive photoacoustic signals, most conventional transducers are rigid, while a flexible array is able to deform and provide complete contact on surfaces with different geometries. In this work, we present photoacoustic images acquired with a flexible array transducer in multiple concave shapes in phantom and ex vivo bovine liver experiments targeted toward interventional photoacoustic applications. We validate our image reconstruction equations for known sensor geometries with simulated data, and we provide empirical elevation field-of-view, target position, and image quality measurements. The elevation field-of-view was 6.08 mm at a depth of 4 cm and greater than 13 mm at a depth of 5 cm. The target depth agreement with ground truth ranged 98.35-99.69%. The mean lateral and axial target sizes when imaging 600 μm-core-diameter optical fibers inserted within the phantoms ranged 0.98-2.14 mm and 1.61-2.24 mm, respectively. The mean ± one standard deviation of lateral and axial target sizes when surrounded by liver tissue were 1.80±0.48 mm and 2.17±0.24 mm, respectively. Contrast, signal-to-noise, and generalized contrast-to-noise ratios ranged 6.92-24.42 dB, 46.50-67.51 dB, and 0.76-1, respectively, within the elevational field-of-view. Results establish the feasibility of implementing photoacoustic-guided surgery with a flexible array transducer.

Pancreatic Adenocarcinoma: Diagnostic Errors, Contributing Factors and Solutions

The purpose of this article is to review diagnostic errors in preoperative and post-operative imaging for pancreatic ductal adenocarcinoma (PDAC), discuss contributing factors, and provide solutions that minimize errors. Accurate radiological staging and restaging of PDAC dictates surgical management and errors can have significant negative effects on patient care, such as missed vessel involvement or metastatic disease that would preclude surgery. Familiarity with these errors and their contributing factors improves diagnostic accuracy and ultimately leads to improved patient outcomes.

Highly Sensitive Exosome Detection for Early Diagnosis of Pancreatic Cancer Using Immunoassay Based on Hierarchical Surface-Enhanced Raman Scattering Substrate

Exosomes have emerged as potential biomarkers for pancreatic cancer (PaC). However, it is still challenging to get quantitative detection of exosomes with the specific surface receptors. In this study, a highly sensitive detection system is first constructed for the direct quantitation of specific exosomes in real samples using hierarchical surface-enhanced Raman scattering substrate (H-SERS substrate) and rapid enrichment strategy magnetic beads @ exosomes @ SERS detection probes (MEDP). It is found that the detection system (MEDP @ H-SERS substrate) could provide a 3.5 times higher SERS intensity compared with MEDP sandwich immunocomplex only. Moreover, LRG1-positive exosomes (LRG1-Exos) and GPC1-positive exosomes (GPC1-Exos) are chosen to distinguish PaC through exosome proteomics and database screening. The lower limit of detection (LOD) is 15 particles µL-1 using the MEDP @ H-SERS substrate. Significantly, the detection in clinical samples shows that the innovative combination of LRG1-Exos and GPC1-Exos could improve the diagnostic efficiency of PaC, with an area under the operating characteristic curve (AUC) of 0.95. Even for the early-stage PaC, the diagnostic accuracy is still high (AUC = 0.95). Collectively, the findings indicate that the MEDP @ H-SERS substrate has great potential for the early diagnosis of PaC.

Imaging Assessment of Pancreatic Cancer Resectability After Neoadjuvant Therapy: AJR Expert Panel Narrative Review

Despite important innovations in the treatment of pancreatic ductal adenocarcinoma (PDAC), PDAC remains a disease with poor prognosis and high mortality. A key area for potential improvement in the management of PDAC, aside from earlier detection in patients with treatable disease, is the improved ability of imaging techniques to differentiate treatment response after neoadjuvant therapy (NAT) from worsening disease. It is well established that current imaging techniques cannot reliably make this distinction. This narrative review provides an update on the imaging assessment of pancreatic cancer resectability after NAT. Current definitions of borderline resectable PDAC, as well as implications for determining likely patient benefit from NAT, are described. Challenges associated with PDAC pathologic evaluation and surgical decision making that are of relevance to radiologists are discussed. Also explored are the specific limitations of imaging in differentiating the response after NAT from stable or worsening disease, including issues relating to protocol optimization, tumor size assessment, vascular assessment, and liver metastasis detection. The roles of MRI as well as PET and/or hybrid imaging are considered. Finally, a short PDAC reporting template is provided for use after NAT. The highlighted methods seek to improve radiologists' assessment of PDAC treatment response after NAT.

Korean clinical practice guideline for pancreatic cancer 2021: A summary of evidence-based, multi-disciplinary diagnostic and therapeutic approaches

Pancreatic cancer is the eighth most common cancer and the fifth most common cause of cancer-related death in Korea. To enable standardization of management and facilitate improvements in outcome, a total of 53 multi-disciplinary experts in gastroenterology, surgery, medical oncology, radiation oncology, radiology, nuclear medicine, and pathology in Korea developed new recommendations that integrate the most up-to-date, evidence-based research findings and expert opinions. Recommendations were made on imaging diagnosis, endoscopic management, surgery, radiotherapy, palliative chemotherapy, and specific management procedures, including neoadjuvant treatment or adjuvant treatment for patients with resectable, borderline resectable, and locally advanced unresectable pancreatic cancer. This is the English version of the Korean clinical practice guideline for pancreatic cancer 2021. This guideline includes 20 clinical questions and 32 statements. This guideline represents the most standard guideline for the diagnosis and treatment of patients with pancreatic ductal adenocarcinoma in adults at this time in Korea. The authors believe that this guideline will provide useful and informative advice.

The utility of Multi-Detector Computed Tomography criteria after neoadjuvant therapy in Borderline Resectable Pancreatic cancer: Prospective, bi-institutional study

OBJECTIVES

To evaluate the utility of MDCT criteria for the determination of resectability and tumor response in borderline resectable pancreatic cancer (BRPC) following neoadjuvant therapy (NAT).

METHODS

This prospective study includes 90 consecutive BRPC patients who underwent surgery following NAT. Two radiologists assessed baseline and pre-surgical CTs for (largest tumor axis, size, attenuation, and vascular criteria). Logistic regression was used to determine which CT criteria independently associated with R0 resection and pathologic major response (pMR). Median survival and overall survival (OS) were calculated.

RESULTS

Seventy-three/90 (81.1 %) patients had R0 resection, and 11/90 (12.2 %) had pMR. After NAT, there were significant interval changes in the largest tumor axis, size, attenuation, and venous burden index (VBI) (P < 0.02). On the multivariable analysis, regression of the VBI and low VBI at the pre-surgical CT were independently associated with an increased likelihood of R0 resection (OR 1.82; 95 % CI 1.44-5.33) (OR 1.91; 95 % CI 1.83-6.14). The assessment of VBI at the pre-surgical CT showed moderate reproducibility (k-value, 0.56 - 0.60). On the multivariable analysis, partial response (PR) was found to be independently associated with an increased likelihood of pMR (OR 1.71; 95 % CI 1.31-3.45). The median survival was longer in patients who had R0 (P = 0.01). The overall survival was longer in patients who had pMR compared to those who did not (P = 0.02).

CONCLUSION

Surgical exploration could be indicated in patients who had regression of the VBI and low VBI at the pre-surgical CT. PR response is associated with pMR.

[Radiologic Evaluation for Resectability of Pancreatic Adenocarcinoma]

Imaging studies play an important role in the detection, diagnosis, assessment of resectability, staging, and determination of patient-tailored treatment options for pancreatic adenocarcinoma. Recently, for patients diagnosed with borderline resectable or locally advanced pancreatic cancers, it is recommended to consider curative-intent surgery following neoadjuvant or palliative therapy, if possible. This review covers how to interpret imaging tests and what to consider when assessing resectability, diagnosing distant metastasis, and re-assessing the resectability of pancreatic cancer after neoadjuvant or palliative therapy.

Survival equivalence in patients treated for borderline resectable and unresectable locally advanced pancreatic ductal adenocarcinoma: a systematic review and network meta-analysis

BACKGROUND

The clinical relevance of subdivision of non-metastatic pancreatic ductal adenocarcinoma (PDAC) into locally advanced borderline resectable (LA-BR) and locally advanced unresectable (LA-UR) has been questioned. We assessed equivalence of overall survival (OS) in patients with LA-BR and LA-UR PDAC.

METHODS

A systematic review was performed of studies published January 1, 2009 to August 21, 2019, reporting OS for LA-BR and LA-UR patients treated with or without neoadjuvant therapy (NAT), with or without surgical resection. A frequentist network meta-analysis was used to assess the primary outcome (hazard ratio for OS) and secondary outcomes (OS in LA-BR, LA-UR, and upfront resectable (UFR) PDAC).

RESULTS

Thirty-nine studies, comprising 14,065 patients in a network of eight unique treatment subgroups were analysed. Overall survival was better for LA-BR than LA-UR patients following surgery both with and without NAT. Neoadjuvant therapy prior to surgery was associated with longer OS for UFR, LA-BR, and LA-UR tumours, compared to upfront surgery.

CONCLUSION

Survival between the LA-BR and LA-UR subgroups was not equivalent. This subdivision is useful for prognostication, but likely unhelpful in treatment decision making. Our data supports NAT regardless of initial disease extent. Individual patient data assessment is needed to accurately estimate the benefit of NAT.

Editorial for "MRI vs. CT for the Detection of Liver Metastases in Patients With Pancreatic Carcinoma: A Comparative Diagnostic Test Accuracy Systematic Review and Meta-Analysis"

Level of Evidence

5

Technical Efficacy Stage

3

MRI vs. CT for the Detection of Liver Metastases in Patients With Pancreatic Carcinoma: A Comparative Diagnostic Test Accuracy Systematic Review and Meta-Analysis

BACKGROUND

The detection of liver metastases is important for pancreatic cancer curative treatment eligibility. The data suggest that magnetic resonance imaging (MRI) is more sensitive than computed tomography (CT) for the diagnosis of pancreatic cancer liver metastases. However, MRI is not currently recommended in multiple published guidelines.

PURPOSE

To perform a comparative diagnostic test accuracy systematic review and meta-analysis comparing CT and MRI for pancreatic cancer liver metastases detection.

STUDY TYPE

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scopus, and multiple radiology society meeting archives were searched until November 2018. Comparative design studies reporting on liver CT and MRI accuracy for detection of pancreatic cancer liver metastases in the same cohort were included.

FIELD STRENGTH

1.5T or 3.0T.

ASSESSMENT

Demographic, methodologic, and diagnostic test accuracy data were extracted. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool.

STATISTICAL TESTS

Accuracy metrics were obtained using bivariate random-effects meta-analysis. The impact of different covariates on accuracy estimates was assessed using a meta-regression model. Covariates included modality, study design, tumor characteristics, risk of bias, and imaging protocols.

RESULTS

Fourteen studies including 987 patients with pancreatic cancer (205 with liver metastases) were included. Sensitivity for CT and MRI was 45% (confidence intervals [95% CI] 21-71%) and 83% (95% CI 74-88%), respectively. Specificity for CT and MRI was 94% (95% CI 84-98%) and 96% (95% CI 93-97%), respectively. The greater observed sensitivity of MRI was preserved in the meta-regression model (P = 0.01), while no difference in specificity was detected (P = 0.16). CT sensitivity was highest for triphasic and quadriphasic examinations compared to single phase or biphasic protocols (P = 0.03). Most studies were at high risk of bias.

DATA CONCLUSION

MRI is more sensitive than CT for pancreatic cancer liver metastases detection, accounting for confounding variables. Consideration of this finding in clinical practice guidelines is recommended.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 3.

Preoperative CT staging of borderline pancreatic cancer patients after neoadjuvant treatment: accuracy in the prediction of vascular invasion and resectability

OBJECTIVES

To assess the utility of MDCT tumor-vascular interface criteria for predicting vascular invasion and resectability in borderline pancreatic cancer (BRPC) patients after neoadjuvant therapy (NAT).

METHODS

This prospective study included 90 patients with BRPC who finished NAT, showed no progression in preoperative CTs and underwent surgery. Two radiologists independently assessed preoperative vessel-tumor interface criteria. The area under the ROC curve (AUC) was used to evaluate the diagnostic performance for predicting vascular invasions and resectability using surgical and pathological results as the gold standard. Inter-reader agreement was assessed using the κ coefficient.

RESULTS

Pathologic vascular invasion was confirmed in 47 (54.7%) veins and 14 (16.3%) arteries. R0 resection was achieved in (82.6%71/86) pancreatic resection. Using criteria of circumferential interface ≥ 180 degrees with contour deformity ≥ grade 3 and/or length of tumor contact > 2 cm to predict vascular invasion, the AUCs for the two readers were 0.85-0.88 for arterial invasion and 0.92-0.87 for venous invasion. Using criteria of circumferential interface ≤ 180° with contour deformity ≤ grade 2 and/or length of tumor contact < 2 cm to predict R0 resection, the AUCs was 0.85-0.86 for the two readers. The overall inter-reader agreement was good (κ = 0.75-0.80). The κ values for venous invasion, arterial invasion and R0 resection were 0.76, 0.78, and 0.80.

CONCLUSION

Tumor-vessel criteria demonstrated good diagnostic performance and reproducibility in the prediction of vascular invasion after NAT in BRPC. These criteria could be helpful in the prediction of R0 resection in cases with only venous involvement.

Therapeutic response assessment in pancreatic ductal adenocarcinoma: society of abdominal radiology review paper on the role of morphological and functional imaging techniques

Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related death in the United States and is projected to be the second by 2030. Systemic combination chemotherapy is considered an essential first-line treatment for the majority of patients with PDA, in both the neoadjuvant and palliative settings. In addition, a number of novel therapies are being tested in clinical trials for patients with advanced PDA. In all cases, accurate and timely assessment of treatment response is critical to guide therapy, reduce drug toxicities and cost from a failing therapy, and aid adaptive clinical trials. Conventional morphological imaging has significant limitations, especially in the context of determining primary tumor response and resectability following neoadjuvant therapies. In this article, we provide an overview of current therapy options for PDA, highlight several morphological imaging findings that may be helpful to reduce over-staging following neoadjuvant therapy, and discuss a number of emerging imaging, and non-imaging, tools that have shown promise in providing a more precise quantification of disease burden and treatment response in PDA.

Adjuvant chemotherapy in pancreatic cancer: state of the art and future perspectives

PURPOSE OF REVIEW

The modalities of management of resectable pancreatic ductal adenocarcinoma (PDAC) have evolved in recent years with new practice guidelines on adjuvant chemotherapy and results of randomized phase III trials. The aim of this review is to describe the state of the art in this setting and to highlight future possible perspectives.

RECENT FINDINGS

Resectable PDAC is the tumor without vascular contact or a limited venous contact without vein irregularity. Several pathologic and biologic robust prognostic factors such as an R0 resection defined by a margin at least 1 mm have been validated. In phase III trials, the doublet gemcitabine-capecitabine provided a statistically significant, albeit modest overall survival benefit, but failed to show an improvement in relapse-free survival. Similarly, gemcitabine plus nab-paclitaxel did not increase disease-free survival. Modified FOLFIRINOX led to improved disease-free survival, overall survival, and metastasis-free survival, with acceptable toxicity. In the future, prognostic and/or predictive biomarkers could lead the optimization of therapeutic strategies and neoadjuvant treatment could become a standard of care in PDAC.

SUMMARY

After curative intent resection, modified FOLFIRINOX is the standard of care in adjuvant in fit patients with PDAC. Others regimens (monotherapy or gemcitabine-based) are an option in unfit patients.

Elevated CEA and CA19-9 serum levels independently predict advanced pancreatic cancer at diagnosis

Purpose: It is suggested that tumour markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) could be used to predict the stage of pancreatic cancer. However, optimal cut-off values for CEA and CA19-9 are disputable. This study aimed to assess the value of CEA and CA19-9 serum levels at diagnosis of pancreatic ductal adenocarcinoma (PDAC) as predictors for the advanced stage of PDAC in patients discussed at pancreatic multidisciplinary team (MDT) meetings.Methods: Patients with suspected PDAC discussed at MDT meetings from 2013 to 2017 were reviewed, in order to determine optimal cut-off values of both CEA and CA19-9.Results: In total, 375 patients were included. Optimal cut-off values for predicting advanced PDAC were 7.0 ng/ml for CEA and 305.0 U/ml for CA19-9, resulting in positive predictive values of 83.3%, 73.6%, and 91.4% for CEA, CA19-9 and combined, respectively. Both tumour markers were independent predictors of advanced PDAC, demonstrated by an odds ratio of 4.21 (95% CI:1.85-9.56; p = 0.001) for CEA and 2.58 for CA19-9 (95% CI:1.30-5.14; p = 0.007).Conclusions: CEA appears to be a more robust predictor of advanced PDAC than CA19-9. Implementing CEA and CA19-9 serum levels during MDT meetings as an additional tool for establishing tumour resectability is worthwhile for tailored diagnostics.

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

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

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios inversely correlate to clinical and pathologic stage in patients with resectable pancreatic ductal adenocarcinoma

Background

Post-surgical pathology (SP) staging correlates with long-term survival. Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have been shown to predict prognosis and extent of tumor in patients with metastatic pancreatic ductal adenocarcinoma (PDAC). This study aimed to correlate NLR and PLR to radiological clinical staging (CS), carbohydrate antigen (CA) 19-9 tumor marker and SP staging in patients with resectable-PDAC (R-PDAC); and to investigate NLR and PLR as potential markers to guide neoadjuvant therapy.

Methods

Data were collected retrospectively from R-PDAC patients who received upfront surgery from November 2011 to December 2016. NLR and PLR values on the day of diagnosis and surgery were collected. SP, tumor size, location, resected margins (RM), lymphovascular/perineural invasion (LVI/PNI), lymph node involvement, and AJCC/TNM 8th Edition staging were obtained. Associations were assessed using linear, ordinal logistic, and poison regressions or Kruskal Willis Rank Sum Test per the nature of outcome variables, with statistical significance at p-value <0.05.

Results

Fifty-five patients were identified with resectable stage I (61%) and II (38%). They had a mean age of 66 years (48-87 years) and were 47.2% male, 83.6% white, 90.9% non-Hispanic and 89% with ECOG 0-1. NLR/PLR at diagnosis for R0, R1 and R2 were 6.7/241, 4.8/224, and 2.9/147 (P=0.01/0.002), respectively. NLR/PLR for N0 and N1 were 5.1/212 and 2.7/138.3 (P=0.03/0.009) at diagnosis. No other significant association was detected.

Conclusions

These findings suggest that NLR/PLR inversely correlates with RM and lymph node status in patients with R-PDAC, but require prospective evaluation in clinically defined scenarios.

Improving preoperative detection of synchronous liver metastases in pancreatic cancer with combined contrast-enhanced and diffusion-weighted MRI

PURPOSE

To explore the value of gadolinium-enhanced MRI combined with diffusion-weighted MRI (Gd-enhanced MRI with DWI) in addition to contrast-enhanced CT (CECT) for detection of synchronous liver metastases for potentially resectable pancreatic cancer.

METHODS

By means of a retrospective cohort study we included patients with potentially resectable pancreatic cancer on CECT, who underwent Gd-enhanced MRI with DWI between January 2012 and December 2016. A single observer evaluated MRI and CT and was blinded to imaging, pathology, and surgery reports. Liver lesions were scored in both modalities, using a 3-point scale: 1-benign, 2-indeterminate, 3- malignant (i.e., metastasis). The primary outcome parameters were the presence of liver metastases on Gd-enhanced MRI with DWI and the sensitivity of Gd-enhanced MRI with DWI for synchronous liver metastases.

RESULTS

We included 66 patients (42 men, 24 women; median age 65 years, range 36-82 years). In 19 patients, liver metastases were present, which were confirmed by histopathology (n = 12), ¹⁸FDG-PET (n = 6), or surgical inspection (n = 1). Gd-enhanced MRI with DWI showed metastases in 16/19 patients (24%), which resulted in a sensitivity of 84% (95% CI 60-97%). Contrast-enhanced MRI showed 156 and DWI 397 metastases (p = 0.051), and 339 were particularly small (< 5 mm).

CONCLUSIONS

In this study, Gd-enhanced MRI with DWI detected synchronous liver metastases in 24% of patients with potentially resectable pancreatic cancer on CECT with a sensitivity of 84%. Diffusion-weighted MRI showed a greater number of metastases than any other sequence, particularly small metastases (< 5 mm).

Prognostic value of preoperative fluorodeoxyglucose positron emission tomography/computed tomography in patients with potentially resectable pancreatic cancer

PURPOSE

To evaluate the prognostic value of preoperative 18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with potentially resectable pancreatic cancer.

METHODS

The study included 103 consecutive patients with potentially resectable pancreatic cancer who underwent preoperative FDG-PET/CT. Age, sex, blood glucose level, tumor marker levels (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9)), PET-related parameters (maximum standardized uptake value (SUVmax)), and contrast-enhanced CT-related factors (tumor size, location, enhancement pattern, and CT-based T and N factors by tumor nodes metastasis (TNM) classification) were assessed for their ability to independently predict postoperative tumor recurrence using Cox proportional hazards model.

RESULTS

Median follow-up was 23.1 months. Univariate analyses revealed that SUVmax (P = 0.0004), tumor size (P = 0.0002), T factor (P = 0.0102), N factor (P = 0.0049), and CA19-9 levels (P = 0.0059) were significantly associated with disease-free survival (DFS). In multivariate analysis, SUVmax (P = 0.0163) and CA19-9 levels (P = 0.0364) independently predicted DFS. Kaplan-Meier analysis revealed that patients with low (< 2.5) SUVmax had a significantly better prognosis than those with higher SUVmax (P = 0.0006). The DFS in patients with SUVmax < 2.5 (n = 23) and SUVmax ≥ 2.5 (n = 80) was 61.9% and 9.7%, respectively, 3 years postoperatively.

CONCLUSIONS

SUVmax can predict DFS in patients with resectable pancreatic cancer. A SUVmax < 2.5 heralds a better prognosis.

Routine MRI With DWI Sequences to Detect Liver Metastases in Patients With Potentially Resectable Pancreatic Ductal Carcinoma and Normal Liver CT: A Prospective Multicenter Study

OBJECTIVE

The purpose of this study was to evaluate the performance of systematic MRI with DWI for the detection of liver metastases (LM) in patients with potentially resectable pancreatic ductal carcinoma and normal liver findings at CT.

SUBJECTS AND METHODS

Patients with potentially resectable pancreatic ductal carcinoma and a normal liver at CT were enrolled in a prospective multicenter study between March 2011 and July 2013 and underwent preoperative MRI. The reference standard was pathologic analysis of detected hepatic lesions.

RESULTS

A total of 118 patients were enrolled. MRI depicted liver lesions that were not visible at CT in 16 patients. All lesions were visualized both with and without DWI. Lesions were LM in 12 (10.2%) patients and were confirmed in seven patients by preoperative biopsy, four by intraoperative frozen section, and one at 6-month follow-up evaluation after pancreatic resection. All but one liver metastatic lesion diagnosed with MRI were smaller than 10 mm. Four of 118 (3.4%) patients had a false-positive diagnosis of LM at MRI and remained LM free after a follow-up period of 24 months or longer. Three of 102 (2.9%) patients with normal MRI findings had subcapsular LM that were diagnosed intraoperatively. At follow-up, 99 of 118 (83.9%) patients were LM free after a mean of 24 months. The patient-based sensitivity of MRI for the detection of LM was 80.0% (95% CI, 51.9-95.7%); specificity, 96.1% (95% CI, 90.4-98.9%); positive predictive value, 75.0% (95% CI, 47.6-92.7%); and negative predictive value, 97.1% (95% CI, 91.6-99.4%).

CONCLUSION

Compared with CT, preoperative MRI improves the detection of LM in patients with potentially resectable pancreatic ductal carcinoma and may change management and the rate of unnecessary laparotomy and pancreatectomy for 10% of patients.

Staging laparoscopy with ultrasound and near-infrared fluorescence imaging to detect occult metastases of pancreatic and periampullary cancer

Introduction

Up to 38% of pancreatic and periampullary cancer patients undergoing curative intended surgery turn out to have incurable disease. Therefore, staging laparoscopy (SL) prior to laparotomy is advised to spare patients the morbidity, inconvenience and expense of futile major surgery. The aim of this study was to assess the added value of SL with laparoscopic ultrasonography (LUS) and laparoscopic near-infrared fluorescence imaging (LFI).

Methods

All patients undergoing curative intended surgery of pancreatic or periampullary cancer were included prospectively in this single arm study. Patients received an intravenous infusion of 10 mg indocyanine green (ICG) one or two days prior to surgery to allow LFI. Suspect lesions were analyzed via biopsy or resection. Follow-up visits after surgery occurred every three months.

Results

A total of 25 patients were included. Suspect lesions were identified in 7 patients: liver metastases (n = 2; identified by inspection, LUS, and LFI), peritoneal metastases (n = 1; identified by inspection only), and benign lesions (n = 4; identified by inspection or LUS). Quality of LFI was good in 67% (10/15) of patients dosed one day and 89% (8/9) dosed two days prior to surgery. A futile laparotomy was averted in 3 patients (12%). Following SL the primary tumor was resected in 20 patients. Two patients (10%) developed metastases within 3 months after resection.

Conclusions

Despite current preoperative imaging modalities metastases are still identified during surgery. This study shows limited added value of LUS during SL in patients with pancreatic or periampullary cancer. LFI was of added value due to its high negative predictive value in case of suspect hepatic lesions identified by inspection.

Incidence and risk factors for abdominal occult metastatic disease in patients with pancreatic adenocarcinoma

BACKGROUND

The incidence of occult metastatic disease (OMD) in pancreatic ductal adenocarcinoma (PDAC) and associated risk factors are largely unknown.

METHODS

We identified all patients with PDAC, who had an aborted oncologic operation due to OMD within a 10-year period. The cases were matched to a cohort of resected PDAC patients on a 1:3 ratio, based on age and sex, for comparison of preoperative clinical characteristics and potential risk factors for OMD.

RESULTS

In the studied period, 117 patients with OMD were identified in 1423 pancreatectomies performed for PDAC (8%). Liver metastases were the most common finding (79%) followed by peritoneal implants (16%). When compared with non-OMD cases, patients with OMD presented more often with abdominal pain (P < 0.001), and higher preoperative carbohydrate antigen 19-9 (CA 19-9) values ( P = 0.007). Additionally, indeterminate liver lesions on preoperative computed tomography (CT) were identified in 40% of OMD versus 17% of non-OMD patients ( P < 0.001). Multivariable analysis distinguished four independent predictors for OMD: indeterminate lesions on preoperative CT, tumor size > 30 mm, abdominal pain, and preoperative CA 19-9 > 192 U/mL.

CONCLUSIONS

Occurrence of OMD in PDAC accounts for 8% of cases. Preoperative CA 19-9 > 192 U/mL, primary tumor size > 30 mm, and identification of indeterminate lesions in preoperative CT may indicate the need for diagnostic laparoscopy.

Resectable pancreatic adenocarcinoma neo-adjuvant FOLF(IRIN)OX-based chemotherapy - a multicenter, non-comparative, randomized, phase II trial (PANACHE01-PRODIGE48 study)

BACKGROUND

At time of diagnosis, less than 10% of patients with pancreatic adenocarcinomas (PDAC) are considered to be immediately operable (i.e. resectable). Considering their poor overall survival (OS), only tumours without vascular invasion (NCCN 2017) should be considered for resection, i.e. those for which resection with disease-free margins (R0) is theoretically possible in absence of presurgery treatment. With regard to high R1 rates and undetectable locoregional and/or metastatic spreading prior to surgery explain (at least in part) the observed 1-year relapse and mortality rates of 50 and 25%, respectively. Today, upfront surgery followed by adjuvant chemotherapy is the reference treatment in Europe. The main limitation of the adjuvant approach is the low rate of completion of the full therapeutic sequence. Indeed, only 47 to 60% patients received any adjuvant therapy after resection compared to more than 75% for neoadjuvant therapy. No previous prospective study has compared this approach to a neoadjuvant FOLFIRINOX or FOLFOX chemotherapy for resectable PDAC.

METHODS

PANACHE01-PRODIGE48 is a prospective multicentre controlled randomized non comparative Phase II trial, evaluating the safety and efficacy of two regimens of neo-adjuvant chemotherapy (4 cycles of mFOLFIRINOX or FOLFOX) relative to the current reference treatment (surgery and then adjuvant chemotherapy) in patients with resectable PDAC. The main co-primary endpoints are OS rate at 12 months and the rate of patients undergoing the full therapeutic sequence.

DISCUSSION

The "ideal" cancer treatment for resectable PDAC would have the following characteristics: administration to the highest possible proportion of patients, ability to identify fast-progressing patients (i.e. poor candidates for surgery), a low rate of R1 resections (through optimisation of local disease control), and an acceptable toxicity profile. The neoadjuvant approach may meet all these criteria. With respect to published data on the efficacy of FOLFOX and mFOLFIRINOX, these two regimens are potential candidates for neoadjuvant use in the aim to optimising oncological outcomes in resectable PDAC.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02959879 . Trial registration date: November 9, 2016.

Diagnosis and Detection of Pancreatic Cancer

Computed tomography is the first-line imaging modality for suspected pancreatic cancer. Magnetic resonance cholangiopancreatography is a second-line modality for suspected pancreatic cancer and is usually reserved for equivocal cases. Both computed tomography and MR are highly sensitive in the detection of pancreatic cancer, with up to 96% and 93.5% sensitivity, respectively. Computed tomography is superior to MR in the assessment of tumor resectability, with accuracy rates of up to 86.8% and 78.9%, respectively. Close attention to secondary signs of pancreatic cancer, such as pancreatic duct dilatation, abrupt pancreatic duct caliber change, and parenchymal atrophy, are critical in the diagnosis of pancreatic cancer. Emerging techniques such as radiomics and molecular imaging have the potential of identifying malignant precursors and lead to earlier disease diagnosis. The results of these promising techniques need to be validated in larger clinical studies.

Pancreatic Adenocarcinoma Staging in the Era of Preoperative Chemotherapy and Radiation Therapy

Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy. ^©RSNA, 2018.

Preoperative CT in patients with surgically resectable pancreatic adenocarcinoma: does the time interval between CT and surgery affect survival?

PURPOSE

The preoperative imaging-to-surgery time interval (ISI) influences the risk of unexpected progression (UP) found at surgery for pancreatic adenocarcinoma. We aimed to assess whether ISI influences disease recurrence and/or survival.

METHODS AND MATERIALS

A single-institution, ethics board-approved retrospective analysis of all patients who underwent attempted resection of pancreatic (PDAC) or periampullary adenocarcinoma (AmpAC) between 1st January 2010 and 31st December 2015 was performed. All patients underwent preoperative abdominal computed tomography (CT). Exclusion criteria were borderline resectable disease and neoadjuvant chemo/radiotherapy. Patients were followed up until 30th June 2016. The population was divided into ISI ≥/<25 days. Kaplan-Meier and Cox regression survival analyses were performed.

RESULTS

239 patients underwent surgical exploration. UP was found in 29 (12.1%) and these patients had longer ISI (median 46 vs. 29 days, p < 0.05). When intention-to-treat analysis was performed, there was no difference in overall survival (OS) between patients with ISI ≥/<25. In those who underwent resection, ISI did not influence disease-free survival (DFS) or OS for PDAC (n = 174). For AmpAC (n = 36), ISI ≥ 25 days was associated with longer OS (p < 0.05) but did not influence DFS. Longer ISI was independently associated with improved OS on regression analysis for AmpAC.

CONCLUSION

Performing surgery for resectable pancreatic adenocarcinoma within 25 days of abdominal CT reduces the chance of UP but does not confer a survival benefit. For those who undergo resection of AmpAC, a longer ISI was associated with longer OS. This probably represents a more biologically indolent disease in this cohort.