Modified National Comprehensive Cancer Network Criteria for Assessing Resectability of Pancreatic Ductal Adenocarcinoma

Computed tomography and guidelines-based human-machine fusion model for predicting resectability of the pancreatic cancer

BACKGROUND AND AIM

The study aims to develop a hybrid machine learning model for predicting resectability of the pancreatic cancer, which is based on computed tomography (CT) and National Comprehensive Cancer Network (NCCN) guidelines.

METHOD

We retrospectively studied 349 patients. One hundred seventy-one cases from Center 1 and 92 cases from Center 2 were used as the primary training cohort, and 66 cases from Center 3 and 20 cases from Center 4 were used as the independent test dataset. Semi-automatic module of ITK-SNAP software was used to assist CT image segmentation to obtain three-dimensional (3D) imaging region of interest (ROI). There were 788 handcrafted features extracted for 3D ROI using PyRadiomics. The optimal feature subset consists of three features screened by three feature selection methods as the input of the SVM to construct the conventional radiomics-based predictive model (cRad). 3D ROI was used to unify the resolution by 3D spline interpolation method for constructing the 3D tumor imaging tensor. Using 3D tumor image tensor as input, 3D kernelled support tensor machine-based predictive model (KSTM), and 3D ResNet-based deep learning predictive model (ResNet) were constructed. Multi-classifier fusion ML model is constructed by fusing cRad, KSTM, and ResNet using multi-classifier fusion strategy. Two experts with more than 10 years of clinical experience were invited to reevaluate each patient based on their CECT following the NCCN guidelines to obtain resectable, unresectable, and borderline resectable diagnoses. The three results were converted into probability values of 0.25, 0.75, and 0.50, respectively, according to the traditional empirical method. Then it is used as an independent classifier and integrated with multi-classifier fusion machine learning (ML) model to obtain the human-machine fusion ML model (HMfML).

RESULTS

Multi-classifier fusion ML model's area under receiver operating characteristic curve (AUC; 0.8610), predictive accuracy (ACC: 80.23%), sensitivity (SEN: 78.95%), and specificity (SPE: 80.60%) is better than cRad, KSTM, and ResNet-based single-classifier models and their two-classifier fusion models. This means that three different models have mined complementary CECT feature expression from different perspectives and can be integrated through CFS-ER, so that the fusion model has better performance. HMfML's AUC (0.8845), ACC (82.56%), SEN (84.21%), SPE (82.09%). This means that ML models might learn extra information from CECT that experts cannot distinguish, thus complementing expert experience and improving the performance of hybrid ML models.

CONCLUSION

HMfML can predict PC resectability with high accuracy.

Total laparoscopic radical antegrade modular pancreato-splenectomy with left-posterior superior mesenteric artery first-approach for distal pancreatic cancer: step-by-step technique with a surgical case report (with video)

INTRODUCTION

Left-sided pancreatic cancers are uncommon but seem more aggressive than tumors of pancreatic head. Radical antegrade modular pancreato-splenectomy (RAMPS) was proved to have safe and effective advantages while comparing with standard retrograde pancreato-splenectomy (SRPS) in recent systematic literature reviews and meta-analyses. Laparoscopic SMA first-approach RAMPS was recently proceeded with optimistic perioperative outcomes.

CASE PRESENTATION

Our patient is a 67-year-old female with a medical history of diabetes and hypertension, recruited because of upper left quadrant abdominal pain. She was referred for pancreato-splenectomy because of a 3-cm-sized mass in distal pancreas. We use 5 trocars and the patient placed in a Trendelenburg position. The retroperitoneum is opened at the left-posterior side of the meso-pancreato-duodenum along to the inframesocolic space, so that the anterior surface of the aorta (AO), inferior vena cave (IVC), left renal vein (LRV), left adrenal grand (LAG), and kidney are completely exposed. The inferior border of the pancreas had been dissected and separated from the superior mesenteric vein (SMV) below the pancreatic isthmus, removed the lymph nodes (LNs) groups 14v and 17. Then, dissect of LNs groups 7,8,9,11p,12 en bloc at the superior side of the pancreas. Dissection of LNs group 14p, d or SMA LNs after transecting the pancreas. The operation time was 240 min, the estimated blood loss was 200 ml. With no postoperative complications as well as no diarrhea, the patient was discharged on the POD10 uneventfully. Pathological result: pancreatic ductal adenocarcinoma with T2N1 staging and negative margin (R0).

CONCLUSIONS

This technique was safe and effective to perform precise and complete lymphadenectomy and negative posterior resection in total laparoscopic left-posterior SMA first-approach RAMPS for distal pancreatic cancer.

Real-world staging computed tomography scanning technique and important reporting discrepancies in pancreatic ductal adenocarcinoma

BACKGROUND

Computed tomography (CT) is the first-line staging imaging modality for pancreatic ductal adenocarcinoma (PDAC) which determines resectability and treatment pathways.

METHODS

Between January 2016 and December 2019, prospectively collated data from two Australian cancer centres was extracted from the PURPLE Pancreatic Cancer registry. Real-world staging CTs and corresponding reports were blindly reviewed by a sub-specialist radiologist and compared to initial reports.

RESULTS

Of 131 patients assessed, 117 (89.3%) presented with symptoms, 74 (56.5%) CTs included slices ≤3 mm thickness and CT pancreas protocol was applied in 69 (52.7%) patients. Initial reports lacked synoptic reporting in 131 (100%), tumour identification in 2 (1.6%) and tumour measurement in 13 (9.9%) cases. Tumour-vascular relationship reporting was missing in 69-109 (52.7-83.2%) for regarding the key arterial and venous structures that is required to assess resectability. Initial reports had no comment on venous thrombus or venous collaterals in 80 (61.1%) and 109 (83.2%) and lacked locoregional lymphadenopathy interpretation in 13 (9.9%) cases. Complete initial staging report was present in 72 (55.0%) patients. Sub-specialist radiological review resulted in down-staging in 16 (22.2%) and up-staging in 1 (1.4%) patient. Staging discrepancies were mainly regarding metastatic disease (12, 70.6%) and tumour-vascular relationship (5, 29.4%).

CONCLUSION

Real-world staging imaging in PDAC patients show low proportion of dedicated CT pancreas protocol, high proportion of incomplete staging reports and no synoptic reporting. The most common discrepancy between initial and sub-specialist reporting was regarding metastases and tumour-vascular relationship assessment resulting in sub-specialist down-staging in almost every fifth case.

Hemodynamic, Surgical and Oncological Outcomes of 40 Distal Pancreatectomies with Celiac and Left Gastric Arteries Resection (DP CAR) without Arterial Reconstructions and Preoperative Embolization

DPCAR’s short- and long-term outcomes are highly diverse, while the causes and prevention of ischemic complications are unclear. To assess oncological, surgical, and hemodynamic outcomes of 40 consecutive DPCARs for pancreatic (n37) and gastric tumors (n3) (2009−2021), retrospective analyses of mortality, morbidity, survival, and hemodynamic consequences after DPCAR were undertaken using case history data, IOUS, and pre- and postoperative CT measurements. In postoperative complications (42.5%), the pancreatic fistula was the most frequent event (27%), 90-day mortality was 7.5. With 27 months median follow-up, median overall (OS) and progression-free survival (PFS) for PDAC were 29 and 18 months, respectively; with 1-, 3-, and 5-years, the OS were 90, 60, and 28%, with an R0-resection rate of 92.5%. Liver and gastric ischemia developed in 0 and 5 (12.5%) cases. Comparison of clinical and vascular geometry data revealed fast adaptation of collateral circulation, insignificant changes in proper hepatic artery diameter, and high risk of ischemic gastropathy if the preoperative diameter of pancreaticoduodenal artery was <2 mm. DP CAR can be performed with acceptable morbidity and survival. OS and RFS in this super-selective cohort were compared to those for resectable cancer. The changes in the postoperative arterial geometry could explain the causes of ischemic complications and determine directions for their prevention.

Arterial involvement and resectability scoring system to predict R0 resection in patients with pancreatic ductal adenocarcinoma treated with neoadjuvant chemoradiation therapy

OBJECTIVES

To derive a CT-based scoring system incorporating arterial involvement and resectability status to predict R0 resection in patients with pancreatic ductal adenocarcinoma (PDAC) undergoing neoadjuvant chemoradiation therapy (CRT).

METHODS

This retrospective study included 112 patients with PDAC who underwent dynamic contrast-enhanced CT before and after neoadjuvant CRT. A 5-point score was used to determine arterial involvement (A score; 1 = no involvement, 2 = haziness, 3 = abutment, 4 = encasement, 5 = deformity) and 4-point score evaluating resectability status (R score; 1 = resectable, 2 = borderline resectable [BR] with venous involvement, 3 = BR with arterial involvement, 4 = locally advanced [LA]). A score before and after CRT were summed with R score before and after CRT to compute the AR score (AR_total). The associations between AR_total, R0 resection, overall survival (OS), and disease-free survival (DFS) were assessed.

RESULTS

The AR_total was associated with R0 resection (p < .001) and showed area under the ROC curve of 0.79 for differentiating R0 and R1 resections. Median OS was significantly lower for patients with AR_total  > 9 (median: 35.2 months) compared to patients with AR_total ≤ 9 (median: not estimable) (p < .001). Similar results were observed for DFS (median, 16.8 months in > 9 vs median, not estimable in ≤ 9; p < .001).

CONCLUSIONS

A composite score which incorporates degree of arterial involvement and resectability status before and after neoadjuvant CRT is associated with R0 resection and discriminates between R0 and R1 resections in PDAC.

KEY POINTS

• A scoring system incorporating arterial involvement and resectability status was associated with R0 resection. • AR_total >  9 could predict patients' overall and disease-free survival.

[Distal pancreatectomy with resection of the celiac trunk, right or left hepatic artery without arterial reconstruction (extended DP-CAR)]

OBJECTIVE

To evaluate safety and postoperative outcomes of DP-CAR with resection of one of the lobar hepatic arteries without arterial reconstruction (extended DP-CAR).

MATERIAL AND METHODS

Perioperative data and survival after 7 extended DP-CARs R0 were retrospectively analyzed. Arterial blood flow in the liver was assessed using intraoperative ultrasound and postoperative CT angiography.

RESULTS

Among 40 DP-CARs, resection of left or right hepatic artery was performed in 7 cases of aberrant anatomy including 1 case of portal vein resection. Mortality and ischemic complications were not observed. The main source of blood supply to the «devascularized» liver lobe was interlobar communicating artery or the arcade of the lesser curvature of the stomach. Incidence of pancreatic fistula was 44%, mean blood loss - 230 (100-650) ml, surgery time - 259 (195-310) min, mean hospital-stay - 14 (9-26) days. Median survival of patients with pancreatic ductal adenocarcinoma was 25 months after combined treatment. Three patients died after 26, 28 and 77 months. Other patients are alive without progression for 109, 24, 23 and 12 months after therapy onset.

CONCLUSION

Extended DP-CAR is advisable and safe procedure if reliable intraoperative control of liver and stomach blood supply is ensured.

Radiomics-Assisted Presurgical Prediction for Surgical Portal Vein-Superior Mesenteric Vein Invasion in Pancreatic Ductal Adenocarcinoma

Objectives

To develop a radiomics signature for predicting surgical portal vein-superior mesenteric vein (PV-SMV) in patients with pancreatic ductal adenocarcinoma (PDAC) and measure the effect of providing the predictions of radiomics signature to radiologists with different diagnostic experiences during imaging interpretation.

Methods

Between February 2008 and June 2020, 146 patients with PDAC in pancreatic head or uncinate process from two institutions were retrospectively included and randomly split into a training (n = 88) and a validation (n =58) cohort. Intraoperative vascular exploration findings were used to identify surgical PV-SMV invasion. Radiomics features were extracted from the portal venous phase CT images. Radiomics signature was built with a linear elastic-net regression model. Area under receiver operating characteristic curve (AUC) of the radiomics signature was calculated. A senior and a junior radiologist independently review CT scans and made the diagnosis for PV-SMV invasion both with and without radiomics score (Radscore) assistance. A 2-sided Pearson's chi-squared test was conducted to evaluate whether there was a difference in sensitivity, specificity, and accuracy between the radiomics signature and the unassisted radiologists. To assess the incremental value of providing Radscore predictions to the radiologists, we compared the performance between unassisted evaluation and Radscore-assisted evaluation by using the McNemar test.

Results

Numbers of patients identified as presence of surgical PV-SMV invasion were 33 (37.5%) and 19 (32.8%) in the training and validation cohort, respectively. The radiomics signature achieved an AUC of 0.848 (95% confidence interval, 0.724-0.971) in the validation cohort and had a comparable sensitivity, specificity, and accuracy as the senior radiologist in predicting PV-SMV invasion (all p-values > 0.05). Providing predictions of radiomics signature increased both radiologists' sensitivity in identifying PV-SMV invasion, while only the increase of the junior radiologist was significant (63.2 vs 89.5%, p-value = 0.025) instead of the senior radiologist (73.7 vs 89.5%, p-value = 0.08). Both radiologists' accuracy had no significant increase when provided radiomics signature assistance (both p-values > 0.05).

Conclusions

The radiomics signature can predict surgical PV-SMV invasion in patients with PDAC and may have incremental value to the diagnostic performance of radiologists during imaging interpretation.

Performance of CT-based radiomics in diagnosis of superior mesenteric vein resection margin in patients with pancreatic head cancer

OBJECTIVES

To accurately identify the relationship between a portal radiomics score (rad-score) and pathologic superior mesenteric vein (SMV) resection margin and to evaluate the diagnostic performance in patients with pancreatic head cancer.

MATERIALS AND METHODS

A total of 181 patients with postoperatively and pathologically confirmed pancreatic head cancer who underwent multislice computed tomography within one month of resection between January 2016 and December 2018 were retrospectively investigated. For each patient, 1029 radiomics features of the portal phase were extracted, which were reduced using the least absolute shrinkage and selection operator (LASSO) logistic regression algorithm. Multivariate logistic regression models were used to analyze the association between the portal rad-score and SMV resection margin.

RESULTS

Patients with negative (R0) and positive (R1) margins accounted for 70.17% (127) and 29.83% (54) of the cohort, respectively. The rad-score was significantly associated with the SMV resection margin status (p < 0.05). Multivariate analyses confirmed a significant and independent association between the portal rad-score and SMV resection margin (OR 4.62; 95% CI 2.19-9.76; p < 0.0001). The portal rad-score had high accuracy (area under the curve = 0.750). The best cut point based on maximizing the sum of sensitivity and specificity was - 0.741 (sensitivity = 64.8%; specificity = 74.0%; accuracy = 71.3%). Decision curve analysis indicated the clinical usefulness of radiomics score.

CONCLUSIONS

The portal rad-score is significantly associated with the pathologic SMV resection margin, and it can accurately and noninvasively predict the SMV resection margin in patients with pancreatic cancer.

Evaluation of the feasibility of intrapancreatic delivery of drug-loaded microparticles via EUS-guided fine needle injection using a swine model

Background and study aims  Patients with pancreatic cancer often have locally advanced or metastatic disease and are not candidates for curative surgery. Polymer-based microparticles (MPs) represent a drug delivery system that offers sustained release of a chemotherapeutic drug after intralesional injection for local tumor management. The aim of this study was to determine the feasibility of endoscopic ultrasound-guided fine-needle injection (EUS-FNI) of drug-loaded MPs tagged with a fluorophore and fiducial markers for locating the injection site. Secondary aims were to determine the tissue-specific effects of MPs. Methods  Five pigs underwent EUS with selection of an injection site within the pancreas that was marked by placing fiducial markers prior to the MPs injection. EUS-FNI of either blank microparticles (BMPs), containing no drug, or gemcitabine-loaded microparticles (GMPs) was performed. A saline flush containing Spot Endoscopic Marker was used to expel any residual MPs in the needle shaft and tattoo the injection site. Results  A green fluorescent protein flashlight was used to successfully identify the site of MP injection sites in the dissected pancreas. Frozen sections of pig pancreas demonstrated a defined deposit, confirming the delivery of the MPs. Finally, fluorescence microscopy showed activation of caspase-mediated cell death in pancreases of animals that received injections of GMPs. Conclusions  This pilot study demonstrated that fiducial marker placement and pancreatic EUS-FNI of MPs was successful in all pigs with no animals demonstrating pancreatitis. Further studies are needed to determine the role for intralesional injection of drug-loaded MPs in borderline resectable or unresectable pancreatic cancer.

Prognostic evaluation of pancreatic ductal adenocarcinoma: Associations between molecular biomarkers and CT imaging findings

OBJECTIVES

To investigate association between molecular biomarkers and computed tomography (CT) imaging findings in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Fifty-three consecutive patients with PDAC (34 men and 19 women; mean age, 70.6 ± 8.1 years; range, 56-86 years) who underwent dynamic contrast-enhanced CT prior to pancreatectomy were included. The Ki-67 index and expressions of E-cadherin, Vimentin, and TWIST were immunohistochemically evaluated. Qualitative image analysis and histogram analysis of CT numbers were conducted. Clinical and molecular biomarkers were tested as possible prognostic factors for overall survival (OS) using Kaplan-Meier method and Cox proportional hazards regression. In addition, associations between CT imaging findings and significant molecular biomarkers were investigated.

RESULTS

The TNM stage (P = 0.018) and E-cadherin expression status (P = 0.018) were independently associated with OS. E-cadherin-negative PDACs had a worse prognosis than E-cadherin-positive PDACs (hazard ratio: 2.21). Irregular tumor margin was observed more frequently in E-cadherin-negative PDACs (54.7%) than in E-cadherin-positive PDACs (45.3%) (P = 0.00054). The kurtosis of CT number during the pancreatic parenchymal phase was significantly higher in E-cadherin-negative PDACs than in E-cadherin-positive PDACs (P = 0.035).

CONCLUSIONS

E-cadherin suppression was found to be a prognostic factor for OS in patients with PDAC, and irregular tumor margin and kurtosis of CT numbers during the pancreatic parenchymal phase could be indicators for E-cadherin suppression.