Prediction and clinical implications of portal vein/superior mesenteric vein invasion in patients with resected pancreatic head cancer: the significance of preoperative CT parameters

Predicting postoperative prognosis of pancreatic cancer using a computed tomography-based radio-clinical model: exploring biologic functions

Computed tomography (CT) imaging has the potential to assist in predicting the prognosis and treatment strategies for pancreatic cancer (PC). This study aimed to develop and validate a radio-clinical model based on preoperative multiphase CT assessments to predict the overall survival (OS) of PC and identify differentially expressed genes associated with OS.

METHODS

Patients with PC who had undergone radical pancreatectomy (R0 resection) were divided into development and external validation sets. Independent predictors of OS were identified using Cox regression analyses and included in the nomogram, which was externally validated. The area under the curve was used to measure the model's accuracy in estimating OS probability. RNA sequencing data from The Cancer Genome Atlas were used for gene expression analysis.

RESULTS

In the development and external validation sets, survival was estimated respectively for 132 and 27 patients. Multivariate Cox regression analysis identified 5 independent OS predictors: age (P = .049), sex (P = .001), bilirubin level (P = .005), tumor size (P = .020), and venous invasion (P = .041). These variables were incorporated into the nomogram. Patients were divided into high- and low-risk groups for OS and survival curves showed that all patients in the low-risk group had better OS than that of those in the high-risk group (P < .001). Differentially expressed genes in patients with a poor prognosis were involved in neuroactive ligand-receptor interaction.

CONCLUSION

The radio-clinical model may be clinically useful for successfully predicting PC prognosis.

Management of Sinistral Portal Hypertension after Pancreaticoduodenectomy

BACKGROUND

Sinistral, or left-sided, portal hypertension (SPH) is a rare cause of upper gastrointestinal (GI) hemorrhage resulting from obstruction of the splenic vein. Venous drainage from the spleen via collaterals can result in venous hemorrhage into both the retroperitoneal and intra-abdominal spaces due to increased venous blood pressure in peripancreatic and gastroduodenal vasculature. SPH can occur secondary to pancreatitis with thrombosis of the splenic vein. Another possible cause is the surgical ligation of the splenic vein as part of pancreaticoduodenectomy (PD). Although splenectomy has been traditionally considered as the treatment of choice to relieve venous hypertension, individual concepts for each patient have to be developed. Considering the venous collateral drainage pathways, a comprehensive approach involving surgical, endoscopic, and interventional radiology interventions may be necessary to address the underlying cause of variceal bleeding. Among these approaches, splenic artery embolization (SAE) has demonstrated efficacy in mitigating the adverse effects associated with elevated venous outflow pressure.

SUMMARY

This review summarizes key imaging findings in SPH patients after PD and highlights the potential of minimally invasive embolization for curative treatment of variceal hemorrhage.

KEY MESSAGES

(i) SPH is a potential consequence after major pancreas surgery. (ii) Collateral flow can lead to life-threatening abdominal bleeding. (iii) Depending on the origin and localization of the bleeding, a dedicated management is required, frequently involving interventional radiology techniques.

Pancreatic Ductal Adenocarcinoma: Update of CT-Based Radiomics Applications in the Pre-Surgical Prediction of the Risk of Post-Operative Fistula, Resectability Status and Prognosis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the seventh leading cause of cancer-related deaths worldwide. Surgical resection is the main driver to improving survival in resectable tumors, while neoadjuvant treatment based on chemotherapy (and radiotherapy) is the best option-treatment for a non-primally resectable disease. CT-based imaging has a central role in detecting, staging, and managing PDAC. As several authors have proposed radiomics for risk stratification in patients undergoing surgery for PADC, in this narrative review, we have explored the actual fields of interest of radiomics tools in PDAC built on pre-surgical imaging and clinical variables, to obtain more objective and reliable predictors.

METHODS

The PubMed database was searched for papers published in the English language no earlier than January 2018.

RESULTS

We found 301 studies, and 11 satisfied our research criteria. Of those included, four were on resectability status prediction, three on preoperative pancreatic fistula (POPF) prediction, and four on survival prediction. Most of the studies were retrospective.

CONCLUSIONS

It is possible to conclude that many performing models have been developed to get predictive information in pre-surgical evaluation. However, all the studies were retrospective, lacking further external validation in prospective and multicentric cohorts. Furthermore, the radiomics models and the expression of results should be standardized and automatized to be applicable in clinical practice.

Impact of Portal Vein Resection (PVR) in Patients Who Underwent Curative Intended Pancreatic Head Resection

The oncological impact of portal vein resection (PVR) in pancreatic cancer surgery remains contradictory. Different variables might have an impact on the outcome. The aim of the present study is the retrospective assessment of the frequency of PVR, histological confirmation of tumor infiltration, and comparison of oncological outcomes in PVR patients. We retrieved n = 90 patients from a prospectively collected data bank who underwent pancreas surgery between 2012 and 2019 at the University Medical Centre Göttingen (Germany) and showed a histologically confirmed pancreatic ductal adenocarcinoma (PDAC). While 50 patients (55.6%) underwent pancreatic resection combined with PVR, 40 patients (44.4%) received standard pancreatic surgery. Patients with distal pancreatectomy or a tumor other than PDAC were excluded. PVR was performed either as local excision or circular resection of the portal vein. Clinical/patient data and follow-ups were retrieved. The median follow-up period was 20.5 months. Regarding the oncological outcome, a statistically poorer CSS (p = 0.04) was observed in PVR patients. There was no difference (p = 0.18) in patients' outcomes between tangential and complete PVR, while n = 21 (42% of PVR patients) showed portal vein infiltration. The correlation between performed PVR and resection status was statistically significant: 48.6% of PVR patients achieved R0 resections compared to 75% in non-PVR patients (p = 0.03). Patients who underwent PDAC surgery with PVR show a significantly poorer outcome regardless of PVR type. Tumor size and R-status remain two important variables significantly associated with outcome. Since there is a lack of standardization for the indication of PVR, it remains unknown if the need for resection of vein structures during pancreatic resection represents the biological aggressiveness of the tumor or is biased by the experience of the surgeon.

Utility of Diffusion-Weighted MRI for Detection of Locally Recurrent Pancreatic Cancer After Surgical Resection

BACKGROUND. Overlapping imaging findings between local tumor recurrence and postsurgical fibrosis represent a major clinical challenge after pancreatic ductal adeno-carcinoma (PDAC) resection. OBJECTIVE. The purpose of this study was to compare the diagnostic performance of MRI with and without DWI for differentiating locally recurrent tumor and postsurgical fibrosis after PDAC resection. METHODS. This retrospective study included 66 patients (35 men, 31 women; mean age, 60.5 years) who underwent PDAC resection between January 2009 and March 2016, postoperative surveillance CT showing a soft-tissue lesion at the operative site or at the site of peripancreatic vessels, and subsequent MRI with DWI for further evaluation. CT at least 6 months after MRI served as the reference standard, with increase in size of the soft tissue by 5 mm or more differentiating locally recurrent tumor (n = 26) and postsurgical fibrosis (n = 40). Two observers in consensus evaluated MRI characteristics of the soft-tissue lesions. Two additional observers independently reviewed MRI examinations in two separate sessions (conventional MRI alone vs MRI with DWI), recording likelihood of recurrent tumor using a 1-5 scale. ROC analysis was performed, considering scores of 4 or 5 as positive. RESULTS. Subjective diffusion restriction was more common in locally recurrent tumor than postsurgical fibrosis (88.5% vs 25.0%, p = .01). Median ADC was lower for locally recurrent tumor than postsurgical fibrosis (1.3 vs 1.7 × 10-3 mm2/s, p < .001). For both observers, MRI with DWI in comparison with conventional MRI alone showed higher AUC for diagnosis of locally recurrent tumor (observer 1: 0.805 vs 0.707, p = .048; observer 2: 0.898 vs 0.637, p < .001) and higher sensitivity (observer 1: 88.5% vs 61.5%, p = .008; observer 2: 84.6% vs 42.3%, p = .001) but no difference in specificity (observer 1: 72.5% vs 80.0%, p = .08; observer 2, 95.0% vs 85.0%, p = .10). Interobserver agreement was moderate for conventional MRI (κ = 0.41) and good for conventional MRI with DWI (κ = 0.62). CONCLUSION. The addition of DWI to conventional MRI improves the differentiation of locally recurrent tumor and postsurgical fibrosis after PDAC resection, primarily because of improved sensitivity for recurrence. CLINICAL IMPACT. The findings indicate a potential role for MRI with DWI in surveillance protocols after PDAC resection.

Should the Splenic Vein Be Preserved-Fate of Sinistral Portal Hypertension after Pancreatoduodenectomy with Vascular Re-Section for Pancreatic Cancer

Background: This study aims to evaluate sinistral portal hypertension (SPH) development and its clinical impact on the long-term outcomes of patients with pancreatic cancer who underwent surgical resection with splenic vein (SV) ligation. Methods: Data from 94 consecutive patients who underwent pancreatoduodenectomy (PD) with vascular resection for pancreatic cancer from 2008 to 2019 were retrospectively collected. The patients were divided into two groups according to whether the SV was preserved or ligated during the surgery. Their computed tomography images were serially reviewed (preoperative, 6-, 12-, and 24-months postoperative) with clinical parameters. The degree of variceal formation (variceal score) and splenomegaly were assessed, and the oncologic outcomes were compared between the two groups. Variceal score in the SV ligation group was significantly higher than that in the SV saving group at the same postoperative periods (SV saving vs. ligation: 12 months, 0.9 ± 1.3 vs. 3.5 ± 2.2, p < 0.001; 24 months, 1.4 ± 1.8 vs. 4.0 ± 3.4, p = 0.009). Clinically relevant variceal bleeding was noted in one patient from the SV ligation group (SV saving vs. ligation: 0.0% vs. 3.1%, p = 0.953). In survival analysis, there was no significant difference between the two groups (DFS; SV saving vs. ligation: 13.0 (11.1−14.9) months vs. 13.0 (10.4−15.6) months, p = 0.969, OS; SV saving vs. ligation: 35.0 (19.9−50.1) months vs. 27.0 (11.6−42.4) months, p = 0.417). Although SV ligation induced SPH during PD for pancreatic cancer, it did not lead to clinically significant long-term complications. In addition, it did not impact the long-term survival of patients with resected pancreatic head cancer.

Prediction of residual tumor and overall survival after first-line surgery in patients with pancreatic ductal adenocarcinoma using preoperative magnetic resonance imaging findings

BACKGROUND

Complete resection is the only potentially curative treatment in patients with pancreatic ductal adenocarcinoma (PDA) and is associated with a longer overall survival (OS) than incomplete resection of tumor. Hence, prediction of the resection status after surgery would help predict the prognosis of patients with PDA.

PURPOSE

To predict residual tumor (R) classification and OS in patients who underwent first-line surgery for PDA using preoperative magnetic resonance imaging (MRI).

MATERIAL AND METHODS

In this study, 210 patients with PDA who underwent MRI and first-line surgery were randomly categorized into a test group (n=150) and a validation group (n=60). The R classification was divided into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). Preoperative MRI findings associated with R classification and OS were assessed by using logistic regression and Cox proportional hazard models. In addition, the prediction models for the R classification and OS were validated using calibration plots and C statistics.

RESULTS

On preoperative MRI, portal vein encasement (odds ratio 4.755) was an independent predictor for R1/R2 resection (P=0.040). Tumor size measured on MRI (hazard ratio [HR] per centimeter 1.539) was a predictor of OS, along with pathologic N1 and N2 stage (HR 1.944 and 3.243, respectively), R1/R2 resection (HR 3.273), and adjuvant chemoradiation therapy (HR 0.250) (P<0.050). Calibration plots demonstrated satisfactory predictive performance.

CONCLUSION

Preoperative MRI was valuable for predicting R1/R2 resection using portal vein encasement. Tumor size measured on MRI was useful for the prediction of OS after first-line surgery for PDA.

CA19-9 Level to Serum γ-Glutamyltransferase as a Potential Prognostic Biomarker in Patients with Pancreatic Head Carcinoma

Background

The aim of this study was to reduce the influence of biliary obstruction on carbohydrate antigen 19-9 level (CA19-9) by introducing the CA19-9 level to serum γ-glutamyltransferase (GGT) ratio as an indicator, and ultimately to reveal the correlation between CA19-9/GGT and the prognosis of patients with pancreatic head carcinoma (PHC).

Methods

A total of 339 enrolled patients who underwent pancreatoduodenectomy for PHC in Beijing ChaoYang Hospital from January 2010 to December 2019 were analyzed retrospectively. The optimal cut-off value, according to which patients were divided into a low-ratio group (Group 1, n=179) and a high-ratio group (Group 2, n=160), was determined by the ROC curve obtained from preoperative CA19-9/GGT and 1-year survival. Through univariate and multivariate analyses, risk factors for postoperative tumor recurrence and long-term survival were screened out among PHC patients.

Results

The best cut-off value of CA19-9/GGT was 2.07 (area under the curve=0.567, 95% CI 0.498-0.636). Compared with Group 2, Group 1 had lower CA19-9, and higher GGT, total bilirubin (TB) and lymph-node metastasis rate (P<0.05). The 1-, 2- and 3-year disease-free survival rates of patients in Groups 1 and 2 were 68.2%, 42.5% and 28.2%, and 42.2%, 19.3% and 18.3%, respectively (P=0.000), and the 1-, 2- and 3-year overall survival rates were 79.1%, 50.7% and 29.1%, and 56.7%, 22.2% and 17.2%, respectively (P=0.000). Multivariate analysis showed that CA19-9/GGT, portal system invasion and lymph-node metastasis were independent risk factors for postoperative tumor recurrence and long-term survival among patients with PHC.

Conclusion

Compared with CA19-9 level alone, CA19-9/GGT plays a more precise role in the evaluation of postoperative tumor recurrence and the long-term prognosis of PHC patients. The lower the ratio, the better the long-term prognosis. The CA19-9/GGT ratio may prove to be a useful biomarker for identifying PHC patients at high risk of early recurrence and unfavorable prognosis.

CT texture analysis for the presurgical prediction of superior mesenteric-portal vein invasion in pancreatic ductal adenocarcinoma: comparison with CT imaging features

AIM

To investigate the value of computed tomography (CT) texture analysis (TA) and imaging features for evaluating suspected surgical superior mesenteric-portal vein (SMPV) invasion in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Fifty-four patients with PDAC in the pancreatic head or uncinate process with suspected SMPV involvement were analysed retrospectively. SMPV invasion status was identified by surgical exploration. For each patient, 396 texture features were extracted on pretreatment CT. Non-parametric tests and minimum redundancy maximum relevance were used for feature selection. A CTTA model was constructed using multivariate logistic regression, and the area under the receiver operating characteristic (AUROC) of the model was calculated. Two reviewers evaluated qualitative imaging features independently for SMPV invasion and interobserver agreement was investigated. The diagnostic performance of the imaging features and the CTTA model for SMPV invasion was compared using the McNemar test.

RESULTS

Of the 54 patients with PDAC, SMPV invasion was detected in 23 (42.6%). The CTTA model yielded an AUROC of 0.88 (95% confidence interval, 0.76-0.97) and achieved significantly higher specificity (0.90) than the two reviewers (0.61 and 0.65; p=0.027 and 0.043). Interobserver agreement was moderate between the two reviewers (κ = 0.517). Of the 13 cases with disagreement between the two reviewers, 11 cases were predicted accurately by the CTTA model.

CONCLUSION

CTTA can predict suspected SMPV invasion in PDAC and may be a beneficial addition for qualitative imaging evaluation.

Preoperative imaging characteristics predict poor survival and inadequate resection for left-sided pancreatic adenocarcinoma: a multi-institutional analysis

BACKGROUND

Optimal treatment of pancreatic ductal adenocarcinoma of the neck, body and tail (PDAC-NBT) necessitates R0 surgical resection. Preoperative radiographic identification of patients likely to achieve successful oncologic resection remains difficult. This study seeks to identify preoperative imaging characteristics predictive of non-R0 resections or impaired survival for PDAC-NBT.

METHODS

Patients at five high-volume centers who underwent resection for PDAC-NBT were retrospectively analyzed. The most immediate preoperative cross-sectional scan was assessed along with outcome measures of overall survival and margin status.

RESULTS

330 patients were treated between 2001 and 2016. Margin status included 247 R0 (78.2%), 67 R1 (21.2%), and 2 R2 (0.6%). A non-R0 resection predicted worse survival (p = 0.0002). On preoperative imaging, patients with tumors greater than 20 mm, tumor attenuation greater than 70 Hounsfield units, or who demonstrated pancreatic atrophy and/or calcifications also had worse survival (p = 0.010, p = 0.036, p = 0.025 respectively). Patients with tumors interfacing with the splenic artery or vein or extending posteriorly achieved fewer R0 resections (p = 0.0006, p = 0.0004, p = 0.001, respectively).

CONCLUSION

Preoperative cross-sectional imaging can identify tumor characteristics associated with poor survival and non-R0 resection. Further investigation is needed to identify the appropriate surgical and treatment modifications necessary to clinically benefit this subset of patients.

Radiographic portal or superior mesenteric vein invasion is an independent prognostic factor in non-metastatic pancreatic ductal adenocarcinoma: A missing block of clinical T staging?

BACKGROUND

Venous invasion is not included in the pancreatic ductal adenocarcinoma (PDAC) staging, and its correlation with prognosis remains unclear. We evaluated the prognostic impact of radiographic portal/superior mesenteric vein (PV/SMV) invasion, and its possibility of complementing T staging.

METHODS

We identified patients with non-metastatic PDAC using our institutional cohort, and divided them according to PV/SMV invasion at imaging, defined as >180-degree tumor-vessel interface or contour deformity. We conducted Cox proportional hazard regression, and compared survival in the original and 1:1 propensity score matched datasets.

RESULTS

We identified 454 patients [PV/SMV(+): 172; PV/SMV(-): 282]. In the multivariate analysis, PV/SMV invasion, age (≥70 years), performance status, tumor size (2-4, >4 cm), lymph nodes >4, and arterial invasion was correlated with prognosis. The PV/SMV(+) group had a shorter overall survival (OS) than the PV/SMV(-) group in the original (14.4 vs. 20.9 months; P < 0.001) and matched datasets (14.3 vs. 17.2 months; P = 0.009). Among patients without arterial invasion (cT1-cT3), the PV/SMV(+) group had a shorter OS (15.9 vs. 21.2 months; P = 0.002). Moreover, their OS did not differ from that of patients with arterial invasion (cT4) (15.9 vs. 14.4 months; P = 0.907). Patients with vessel (artery/vein) invasion had a shorter OS than those without vessel invasion (14.5 vs. 21.2 months; P < 0.001).

CONCLUSIONS

Radiographic PV/SMV invasion in non-metastatic PDAC was correlated with a poor prognosis. It could identify a group with shorter OS among patients without arterial invasion (cT1-cT3). It is suggested that inclusion of PV/SMV invasion in clinical T4 criteria should be considered.

MDCT findings predicting post-operative residual tumor and survival in patients with pancreatic cancer

OBJECTIVES

To predict residual tumor (R) classification and overall survival (OS) on preoperative MDCT in patients who underwent first-line surgery for pancreatic ductal adenocarcinoma (PDA).

METHODS

Three hundred sixteen patients with PDA who underwent MDCT and first-line surgery were included. Patients were divided into a test (n = 216) and a validation group (n = 100). The R classification was categorized into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). We assessed the correlation between the MDCT findings and the R classification. For survival analysis, we used the Kaplan-Meier estimation and Cox proportional hazard model to determine the prognostic factors for OS. Validation of the prediction models for the R classification and OS was performed using C statistics and calibration plot.

RESULTS

Peritumoral fat stranding (odds ratio (OR) 3.826), suspicious distant metastasis (OR 2.916), portal vein involvement (OR 2.795), and tumor size (OR 1.045) were independent predictors for residual tumor (p < .05). On survival analysis, common hepatic artery involvement (hazard ratio (HR) 5.656), R1/R2 stage (HR 2.476), and N1 stage (HR 1.745) were predictors of poor OS (p < .05). C statistics for prediction models for R classification and OS were 0.816 and 0.662, respectively. Calibration plots showed good predictive performance in a high probability of the R1/R2 stage or poor OS.

CONCLUSION

Preoperative MDCT is useful for predicting the R classification using the tumor size, peritumoral fat stranding, portal vein involvement, and suspicious distant metastasis, as well as for anticipating poor OS using the N1 stage, common hepatic artery involvement, and R1/R2 stage in patients with PDA.

KEY POINTS

• Thorough assessment of the involvement of common hepatic artery or portal vein and peritumoral fat stranding is warranted for predicting prognosis in patients with pancreatic ductal adenocarcinoma. • Not only encasement but also abutment of common hepatic artery or portal vein by tumor predicts poor prognosis after upfront surgery. • If residual tumor or poor overall survival is anticipated on preoperative MDCT, neoadjuvant treatment can be performed.

Borderline-resectable pancreatic adenocarcinoma: Contour irregularity of the venous confluence in pre-operative computed tomography predicts histopathological infiltration

PURPOSE

The purpose of the current study was to compare CT-signs of portal venous confluence infiltration for actual histopathological infiltration of the vein or the tumor/vein interface (TVI) in borderline resectable pancreatic ductal adenocarcinoma (PDAC).

METHODS AND MATERIALS

101 patients with therapy-naïve, primarily resected PDAC of the pancreatic head without arterial involvement were evaluated. The portal venous confluence was assessed for contour irregularity (defined as infiltration) and degree of contact. The sensitivity and specificity of contour irregularity versus tumor to vein contact >180° as well as the combination of the signs for tumor cell infiltration of the vessel wall or TVI was calculated. Overall survival (OS) was compared between groups.

RESULTS

Sensitivity and specificity of contour irregularity for identification of tumor infiltration of the portal venous confluence or the TVI was higher compared to tumor to vessel contact >180° for tumor cell infiltration (96%/79% vs. 91%/38% respectively, p<0.001). The combination of the signs increased specificity to 92% (sensitivity 88%). Patients with contour irregularity/ tumor to vein contact >180°/ both signs had significantly worse overall survival (16.2 vs. 26.5 months/ 17.9 vs. 37.4 months/ 18.5 vs. 26.5 months respectively, all p<0.05).

CONCLUSION

Portal venous confluence contour irregularity is a strong predictor of actual tumor cell infiltration of the vessel wall or the TVI and should be noted as such in radiological reports.

Pancreatoduodenectomy without Vascular Resection in Patients with Primary Resectable Adenocarcinoma and Unilateral Venous Contact: A Matched Case Study

PURPOSE

To investigate the oncological outcome and survival of patients following a conservative approach on the portal-mesenteric axis, in an intraoperative ultrasound-selected group of pancreatoduodenectomy (PD), performed on patients with primary resectable with vascular contact (prVC) pancreatic ductal adenocarcinoma (PDAC).

METHODS

A consecutive series of patients who underwent PD for PDAC at our tertiary care center, between 2008 and 2017, were reviewed. A total of 156 PDs and 88 total pancreatectomies were performed during the study period, including 35 vascular resections. We identified a group of 40 (25.6%) patients with prVC-PDAC in whom after checking the feasibility with intraoperative ultrasound, we were able to perform PD by separation of the tumor from the portomesenteric axis avoiding vascular resection, without residual macroscopic disease (no vascular resection, nvrPD), and compared this group, using case-matched methodology, with the standard PD (sPD) group of primary resectable without vascular contact- (prwVC-) PDAC.

RESULTS

The median follow-up was 28.5 ± 23.2 months in the sPD group and 23.8 ± 20.8 months in the nvrPD group (p = 0.35). Isolated local recurrence rate was 2/40 (5%) in both groups. Additionally, there were no statistical differences in the systemic progression of the disease (42.5% sPD vs. 45% nvrPD, p = 0.82) or local plus synchronous systemic disease rates (2.5% sPD vs. 7.5% nvrPD, p = 0.30). The median survival was 22 months for the sPD group and 23 months for the nvrPD group, p = 0.86. The overall survival was similar in the two groups (1 y: 76.3% sPD vs. 70.0% nvrPD; 3 y: 35.6% vs. 31.6%; and 5 y: 28.5% vs. 25.3%; p = 0.80). Conclusions. PD without vascular resection can be considered safe and oncologically acceptable in selected patients with preoperative diagnosis of prVC-PDAC. The poor prognosis of PDAC is related to the aggressive biology and systemic spread of the tumor, rather than the local control of the disease.