Preoperative MDCT Assessment of Resectability in Borderline Resectable Pancreatic Cancer: Effect of Neoadjuvant Chemoradiation Therapy

Computed tomography-based vascular burden index as a predictor of vascular resection and pathological vascular invasion in pancreatic cancer with neo-adjuvant chemotherapy

BACKGROUND

Determination of vessel resection in patients with pancreatectomy after neo-adjuvant chemotherapy remains controversial. The recently introduced computed tomography-based vascular burden index presents a potential solution to this challenge. This study aimed to evaluate the model performance for the prediction of vascular resection and pathological invasion.

METHODS

Patients who underwent surgery after neo-adjuvant chemotherapy were included. Two independent reviewers measured the vascular tumour burden index around the adjacent artery (AVBI), and vein (VVBI). The area under the curve was compared to assess the predictive capacity of vascular burden index values and their changes for vascular resection and pathological vascular invasion.

RESULTS

Among 252 patients, 179 and 73 had borderline resectable and locally advanced pancreatic cancer, respectively. Concurrent vessel resection and pathological vascular invasion were observed in 121 (48.0 %) and 42 (16.6 %) patients, respectively. In all patients, the VVBI (area under the curve: 0.872) and AVBI (0.911) after neo-adjuvant therapy significantly predicted vessel resection. In patients with vascular resection, the VVBI after neo-adjuvant chemotherapy (0.752) and delta value of the AVBI (0.706) demonstrated better performance for predicting pathological invasion of the resected vein. The regression of the AVBI and VVBI was an independent prognostic factor for survival (hazard ratio: 0.54, 95 % confidence interval: 0.34-0.85; P = 0.009) CONCLUSIONS: Regressed VVBI on serial computed tomography scans is useful for predicting vein resection and pathological venous invasion before surgery. The delta value of the AVBI may therefore be helpful for predicting pathological arterial invasion after neo-adjuvant chemotherapy.

Staging Computed Tomography Parameters Predict the Need for Vein Resection during Pancreaticoduodenectomy in Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND

Surgery-first approach is the current standard of care for resectable pancreatic ductal adenocarcinoma (PDAC), and a proportion of these cases will require venous resection. This study aimed to identify parameters on staging computed tomography (CT) that predict the need for venous resection during pancreaticoduodenectomy (PD) for resectable PDAC.

METHODS

We conducted a retrospective analysis of prospectively collected data on patients who underwent PD for resectable staged PDAC (as per NCCN criteria) between 2011 and 2020. Staging CTs were independently reviewed by two specialist radiologists blinded to the clinical outcomes. Univariate and multivariate risk analyses were performed.

RESULTS

In total, 296 PDs were included. Venous resection was performed in 62 (21%) cases. There was a higher rate of resection margin positivity in the vein resection group (72.6% vs. 48.7%, p = 0.001). Tumour at the neck of the pancreas, superior mesenteric vein involvement of ≥10 mm and pancreatic duct dilatation were identified as independent predictors for venous resection.

DISCUSSION

Staging CT parameters can predict the need for venous resection during PD for resectable cases of PDAC. This may assist in surgical planning, patient selection and counselling. Future efforts should concentrate on validating these results or identifying additional predictors in a multicentre and prospective setting.

Determination of "borderline resectable" pancreatic cancer - A global assessment of 30 shades of grey

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a poor prognosis. Accurate preoperative assessment using computed tomography (CT) to determine resectability is crucial in ensuring patients are offered the most appropriate therapeutic strategy. Despite the use of classification guidelines, any interobserver variability between reviewing surgeons and radiologists may confound decisions influencing patient treatment pathways.

METHODS

In this multicentre observational study, an international group of 96 clinicians (42 hepatopancreatobiliary surgeons and 54 radiologists) were surveyed and asked to report 30 pancreatic CT scans of pancreatic cancer deemed borderline at respective multidisciplinary meetings (MDM). The degree of interobserver agreement in resectability among radiologists and surgeons was assessed and subgroup regression analysis was performed.

RESULTS

Interobserver variability between reviewers was high with no unanimous agreement. Overall interobserver agreement was fair with a kappa value of 0.32 with a higher rate of agreement among radiologists over surgeons.

CONCLUSION

Interobserver variability among radiologists and surgeons globally is high, calling into question the consistency of clinical decision making for patients with PDAC and suggesting that central review may be required for studies of neoadjuvant or adjuvant approaches in future as well as ongoing quality control initiatives, even amongst experts in the field.

Post-neoadjuvant treatment pancreatic cancer resectability and outcome prediction using CT, 18F-FDG PET/MRI and CA 19-9

BACKGROUND

CT prediction of resectability and prognosis following neoadjuvant treatment (NAT) in patients with pancreatic ductal adenocarcinoma (PDAC) remains challenging. This study aims to determine whether addition of ¹⁸F-fluorodeoxyglucose (FDG) postiron emission tomography (PET)/MRI and carbohydrate antigen (CA) 19-9 to contrast-enhanced CT (CECT) can improve accuracy of predicting resectability compared to CECT alone and predict prognosis in PDAC patients after NAT.

METHODS

In this retrospective study, 120 PDAC patients (65 women; mean age, 66.7 years [standard deviation, 8.4]) underwent CECT, PET/MRI, and CA 19-9 examinations after NAT between January 2013 and June 2021. Three board-certified radiologists independently rated the overall resectability on a 5-point scale (score 5, definitely resectable) in three sessions (session 1, CECT; 2, CECT plus PET/MRI─no FDG avidity and no diffusion restriction at tumor-vessel contact indicated modification of CECT scores to ≥ 3; 3, CECT plus PET plus CA 19-9─no FDG avidity at tumor-vessel contact and normalized CA 19-9 indicated modification of CECT scores to ≥ 3). Jackknife free-response receiver operating characteristic method and generalized estimating equations were used to compare pooled area under the curve (AUC), sensitivity, and specificity of three sessions. Predictors for recurrence-free survival (RFS) were assessed using Cox regression analyses.

RESULTS

Each session showed different pooled AUC (session 1 vs. 2 vs. 3, 0.853 vs. 0.873 vs. 0.874, p = 0.026), sensitivity (66.2% [137/207] vs. 86.0% [178/207] vs. 84.5% [175/207], p < 0.001) and specificity (67.3% [103/153] vs. 58.8% [90/153] vs. 60.1% [92/153], p = 0.048). According to pairwise comparison, specificity of CECT plus PET/MRI was lower than that of CECT alone (adjusted p = 0.042), while there was no significant difference in specificity between CECT alone and CECT plus PET plus CA 19-9 (adjusted p = 0.081). Twenty-eight of 69 patients (40.6%) with R0 resection experienced tumor recurrence (mean follow-up, 18.0 months). FDG avidity at tumor-vessel contact on post-NAT PET (HR = 4.37, p = 0.033) and pathologically confirmed vascular invasion (HR = 5.36, p = 0.004) predicted RFS.

CONCLUSION

Combination of CECT, PET and CA 19-9 increased area under the curve and sensitivity for determining resectability, compared to CECT alone, without compromising the specificity. Furthermore, ¹⁸F-FDG avidity at tumor-vessel contact on post-NAT PET predicted RFS.

Is neoadjuvant chemoradiotherapy for pancreatic cancer beneficial: A systematic review and meta-analysis

To examine the potential benefits and adverse events of neoadjuvant Chemoradiotherapy (CRT) versus upfront surgery in pancreatic cancer (PC) patients. Extensive librarian-led literature searches were conducted on PubMed, Web-of-Science, Scopus, Google Scholar, the Cochrane Central Library and Embase. The primary outcomes were resectability, adverse events, pathological and survival outcomes. Five studies, including 437 participants, were analyzed. Upfront surgery had a significantly higher resectability among PC patients than neoadjuvant CRT group (Odds ratio = -0.11, 95% CI = -0.19-0.02, P = 0.01). The neoadjuvant CRT group had a comparatively higher Ro resection rate (OR = 3.38, 95% CI = 2.03-5.62, P < 0.01), fewer severe adverse events(OR = 0.56, 95% CI = 0.34-0.92, P = 0.02), lower positive LN rate(OR = 0.18, 95% CI = 0.11-0.31, P < 0.01) and higher 2-year OS(OR = 1.60, 95% CI = 1.02-2.52, P = 0.04) among PC patients than control group. There was no significant difference between neoadjuvant CRT and upfront surgery among PC patients on postoperative complications(OR = 1.49, 95% CI = 0.86-2.57, P = 0.16), metastasis rate(OR = 1.32, 95% CI = 0.42-4.18, P = 0.64) and 1-year OS(OR = 1.30, 95% CI = 0.85-1.98, P = 0.22). This systematic review confirmed the status of neoadjuvant CRT in the PC treatment. The neoadjuvant CRT could increase the R0 resection rate, which was important to the survival and life quality of patients. The specific choice of various neoadjuvant CRT therapy needs to be further studied. Individualized neoadjuvant therapy should be suitable for each patient, and patients with PC are best managed by a multidisciplinary team.

Tumor resectability and response on CT following neoadjuvant therapy for pancreatic cancer: inter-observer agreement study

OBJECTIVES

First, to measure inter-observer agreement regarding tumor resectability and response, and second, to measure diagnostic performance in predicting negative resection margin, on re-staging CTs of patients who received neoadjuvant therapy for pancreatic cancer.

METHODS

This retrospective study included patients who received neoadjuvant therapy for borderline resectable pancreatic cancer from 2017 to 2020. Six readers independently evaluated initial staging and re-staging CT images. They categorized the resectability on re-staging CT based on the NCCN guideline, and evaluated tumor response to neoadjuvant therapy according to our proposed criteria on a 5-grade scale. For inter-observer agreement, Gwet's agreement coefficients were used. A crossed random effect model was used to pool the sensitivity and specificity of six readers in predicting negative resection margin.

RESULTS

Seventy-seven patients with the median age of 66 (59-70) were included. The pooled agreement for tumor resectability was 0.64 (95% CI, 0.56-0.71) for differentiating the three categories, and 0.84 (0.77-0.91) for differentiating resectable or borderline resectable cancer vs. unresectable cancer. Agreement for tumor response grade was 0.89 (0.85-0.92). The pooled sensitivity and specificity for predicting negative resection margin were 48% (43-52%) and 61% (57-64%), respectively, when only "resectable" on re-staging CT was considered as index test positive. When either "resectable"' or "borderline resectable" was considered as positive, the pooled sensitivity and specificity were 91% (89-94%) and 5% (4-6%), respectively.

CONCLUSION

CT can be used reliably with a high inter-observer agreement in selecting candidates for surgery after neoadjuvant therapy of pancreatic cancer.

KEY POINTS

• On CT following neoadjuvant therapy of pancreatic cancer, six readers showed high agreement in differentiating resectable or borderline resectable vs. unresectable cancer (Gwet's coefficient, 0.84). • Inter-observer agreement was also high for our proposed tumor response grade (Gwet's coefficient, 0.89). • Specificity was very low (5%) while sensitivity was high (91%) when either resectable or borderline resectable cancer on re-staging CT was considered as predictive of negative resection margin status.

Can a simplified CT response criteria for vascular involvement in pancreatic adenocarcinoma after neoadjuvant therapy predict survival in patients who achieved subsequent R0 resection?

PURPOSE

To investigate if a simplified image based scoring system assessing treatment response after neoadjuvant therapy (NAT) can predict survival in patients with pancreatic ductal adenocarcinoma (PDAC) who achieved subsequent R0 resection.

METHODS

Retrospective analysis of 57 PDAC patients (male = 29, 51%) with mean age of 64 at diagnosis (range 42-79) who received NAT and R0 resection. Post-NAT overall, arterial and venous imaging response was characterized as improved, similar, or worse by 2 readers independently followed by consensus review. Kaplan-Meier Analysis was performed to compare overall survival (OS) with post-NAT overall imaging response. A Multivariable Cox proportional hazards analysis was performed to evaluate the association of the following variables with OS: overall, arterial and venous radiology response, clinical staging, postoperative CA19-9, and patient age.

RESULTS

At study conclusion, 30/57 patients were deceased (53%), 26/57 (46%) alive, and 1 patient unknown. Post-NAT, 39/57 (68.4%) had overall improved disease and 18/57 (31.6%) had similar disease. The median OS was 55.7 months (95% CI 33.4-not reached, NR) for those with improved disease vs. 53.9 months (95% CI 14.3-NR) with similar disease (p = 0.859) after NAT. Among all clinical parameters, only post-operative CA 19-9 level was associated with OS (p = 0.002) and PFS (p = 0.005), respectively.

CONCLUSION

Pancreatic cancer patients who underwent R0 resection showed no difference in survival when comparing those with similar vs improved disease on post-NAT imaging.

Systematic review and meta-analysis of diagnostic performance of CT imaging for assessing resectability of pancreatic ductal adenocarcinoma after neoadjuvant therapy: importance of CT criteria

PURPOSE

To assess the CT diagnostic performance for evaluating resectability of pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant therapy and identify the factor(s) that affect(s) diagnostic performance.

METHODS

Databases were searched to identify studies published from January 1, 2000, to November 5, 2019 that evaluated the CT diagnostic performance for assessing resectability of post-neoadjuvant PDAC. Two reviewers independently extracted data and assessed the study quality. A meta-analysis was performed to obtain summary sensitivity and specificity values using a bivariate random-effects model, and heterogeneity across studies was assessed. Univariable meta-regression analysis was performed with eight variables, including the different CT criteria for resectability, conventional National Comprehensive Cancer Network (NCCN) criteria for upfront surgery, and modified criteria for post-neoadjuvant surgery.

RESULTS

Ten studies were included and analyzed. The summary sensitivity and specificity for resectability were 78% (95% CI 68-86%) and 60% (95% CI 44-74%), respectively. No significant heterogeneity was identified (bivariate correlation coefficient ρ = - 1, p-value for hierarchical summary receiver operating characteristics model β = 0.667). The two different CT criteria showed different diagnostic performance (p < 0.01), with higher sensitivity (81% [95% CI 73-90%] vs. 28% [95% CI 15-42%], p < 0.01) and lower specificity (57% [95% CI 41-73%] vs. 90% [95% CI 80-100%], p < 0.01) for the modified criteria. No other variables affected the diagnostic performance.

CONCLUSION

CT criteria were the factors that affected the diagnostic performance. Modification of the conventional criteria improved sensitivity but lowered specificity. Further modifications are required to improve specificity and uniformity.

The Role of Positron Emission Tomography/Computed Tomography (PET/CT) for Staging and Disease Response Assessment in Localized and Locally Advanced Pancreatic Cancer

Pancreatic Cancer (PC) has a poor prognosis, with a 5-year survival rate of only 9%. Even after radical surgical procedures, PC patients have poor survival rates, with a high chance of relapse (70-80%). Imaging is involved in all aspects of the clinical management of PC, including detection and characterization of primary tumors and their resectability, assessment of vascular, perineural and lymphatic invasion and detection of distant metastases. The role of Positron Emission Tomography/Computed Tomography (PET/CT) in detecting PC is still controversial, with the international guidelines not recommending its routine use. However, in resectable PC, PET/CT may play a role in assessing PC stage and grade and potential resectability after neoadjuvant treatment. Quantitative image analysis (radiomics) and new PET/CT radiotracers account for future developments in metabolic imaging and may further improve the relevance of this technique in several aspects of PC. In the present review, the current state of the art and future directions of PET/CT in resectable PC are presented.

CT-diagnosed extra-pancreatic extension of pancreatic ductal adenocarcinoma is a more reliable prognostic factor for survival than pathology-diagnosed extension

OBJECTIVES

To determine the correlation between CT-diagnosed extra-pancreatic extension of pancreatic ductal adenocarcinoma (PDAC), pathology-diagnosed extra-pancreatic extension, and survival in patients with PDAC.

METHODS

This retrospective study included 87 patients with resected PDAC. Two radiologists evaluated negative ((i) tumours surrounded by the pancreatic parenchyma and (ii) tumours contacting the pancreatic surface) or positive ((iii) tumours with peri-pancreatic strand appearances and/or with expansive growth) CT-diagnosed extra-pancreatic extension. Clinical, pathological, and CT imaging characteristics predicting disease-free survival (DFS) and overall survival (OS) were assessed using Cox proportional-hazards models. Diagnostic accuracy for pathology-diagnosed extra-pancreatic extension was also assessed.

RESULTS

CT-diagnosed extra-pancreatic extension (42/87 tumours, 48.3%; κ = 0.82) had a higher hazard ratio (HR) for the DFS (HR, 5.30; p < 0.01) and OS (HR, 5.31; p < 0.01) rates than pathology-diagnosed extension in univariable analyses. It was also an independent prognostic factor for the DFS (HR, 4.22; p < 0.01) and OS (HR, 4.38; p < 0.01) rates in multivariable analyses. Of 45 tumours without CT-diagnosed extra-pancreatic extension, pathology-diagnosed extra-pancreatic extension was observed in 2/8 (25.0%) and 32/37 (86.5%) tumours with CT categories (i) and (ii), respectively. However, the differences in the survival rates between patients with CT categories (i) and (ii) were insignificant, although those in the latter category had significantly better survival rates than those with CT-diagnosed extra-pancreatic extension (category (iii)).

CONCLUSIONS

CT-diagnosed extra-pancreatic extension was a better prognostic factor than pathology-diagnosed extension and considered an independent factor for the postoperative DFS and OS rates with reasonable frequency and high reproducibility, despite the low diagnostic accuracy for predicting pathology-diagnosed extra-pancreatic extension.

KEY POINTS

• A CT-diagnosed extra-pancreatic extension had a higher hazard ratio for both disease-free survival and overall survival compared to pathology-diagnosed extension in univariable survival analyses. • A CT-diagnosed extra-pancreatic extension was a significant independent predictor of both disease-free survival and overall survival, as observed in multivariable survival analyses. • Patients with tumours contacting with the pancreatic surface on CT images (CT category (ii)) showed similar survival rates to those whose tumours were surrounded by the pancreatic parenchyma (CT category (i)), although many tumours with CT category (ii) extended pathologically beyond the pancreas.

How to approach pancreatic cancer after neoadjuvant treatment: assessment of resectability using multidetector CT and tumor markers

OBJECTIVES

To investigate clinical and CT factors associated with local resectability in patients with nonmetastatic pancreatic cancers after neoadjuvant chemotherapy ± radiation therapy (CRT).

METHODS

This retrospective study included consecutive patients with nonmetastatic pancreatic cancers who underwent neoadjuvant CRT between June 2009 and June 2019. Tumor size, tumor-vascular contact with artery/vein, and local resectability categories (resectable, borderline resectable, or locally advanced) were assessed at baseline and post-CRT CT. Baseline and post-CRT carbohydrate antigen (CA) 19-9 levels were also assessed. Clinical or imaging features related to R0 resection were determined using logistic regression analysis.

RESULTS

A total of 179 patients (mean age, 62.4 ± 9.3 years; 92 men) were included. After neoadjuvant CRT, 105 (58.7%) patients received R0 resection, while 74 (41.3%) did not. R0 resection rates were significantly different according to post-CRT CT resectability categories (p < 0.001): 82.8% (48/58), 70.1% (47/67), and 18.5% (10/54) for resectable, borderline resectable, and locally advanced disease, respectively. For post-CRT borderline resectable disease, ≥ 50% decrease in CA 19-9 was significantly associated with R0 resection (odds ratio (OR), 3.160; p = 0.02). For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm (OR, 9.668; p = 0.026) and decreased tumor-arterial contact (OR, 24.213; p = 0.022) were significantly associated with R0 resection.

CONCLUSION

Post-CRT CT resectability categorization may be useful for the assessment of R0 resectability in patients with pancreatic cancer following neoadjuvant CRT. Additionally, ≥ 50% decrease in CA 19-9 was associated with R0 resection in post-CRT borderline resectable disease, while small post-CRT tumor size and decreased tumor-arterial contact were with locally advanced disease.

KEY POINTS

• R0 resection rates following neoadjuvant chemotherapy ± radiation therapy (CRT) were 82.8%, 70.1%, and 18.5% in resectable, borderline resectable, and locally advanced disease, respectively, at post-CRT CT (p < 0.001). • For post-CRT borderline resectable disease, ≥ 50% decrease in carbohydrate antigen (CA) 19-9 was significantly associated with R0 resection. • For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm and decreased tumor-arterial contact were significantly associated with R0 resection.

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.

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.

CT in the prediction of margin-negative resection in pancreatic cancer following neoadjuvant treatment: a systematic review and meta-analysis

OBJECTIVES

We aimed to systematically evaluate the diagnostic accuracy of CT-determined resectability following neoadjuvant treatment for predicting margin-negative resection (R0 resection) in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Original studies with sufficient details to obtain the sensitivity and specificity of CT-determined resectability following neoadjuvant treatment, with a reference on the pathological margin status, were identified in PubMed, EMBASE, and Cochrane databases until February 24, 2020. The identified studies were divided into two groups based on the criteria of R0 resectable tumor (ordinary criterion: resectable PDAC alone; extended criterion: resectable and borderline resectable PDAC). The meta-analytic summary of the sensitivity and specificity for each criterion was estimated separately using a bivariate random-effect model. Summary results of the two criteria were compared using a joint-model bivariate meta-regression.

RESULTS

Of 739 studies initially searched, 6 studies (6 with ordinary criterion and 5 with extended criterion) were included for analysis. The meta-analytic summary of sensitivity and specificity was 45% (95% confidence interval [CI], 19-73%; I² = 88.3%) and 85% (95% CI, 65-94%; I² = 60.5%) for the ordinary criterion, and 81% (95% CI, 71-87%; I² = 0.0%) and 42% (95% CI, 28-57%; I² = 6.2%) for the extended criterion, respectively. The diagnostic accuracy significantly differed between the two criteria (p = 0.02).

CONCLUSIONS

For determining resectability on CT, the ordinary criterion might be highly specific but insensitive for predicting R0 resection, whereas the extended criterion increased sensitivity but would decrease specificity. Further investigations using quantitative parameters may improve the identification of R0 resection.

KEY POINTS

• CT-determined resectability of PDAC after neoadjuvant treatment using the ordinary criterion shows low sensitivity and high specificity in predicting R0 resection. • With the extended criterion, CT-determined resectability shows higher sensitivity but lower specificity than with the ordinary criterion. • CT-determined resectability with both criteria achieved suboptimal diagnostic performances, suggesting that care should be taken while selecting surgical candidates and when determining the surgical extent after neoadjuvant treatment in patients with PDAC.

Use of imaging as staging and surgical planning for pancreatic surgery

Importance

In the past few decades, there has been rapid advancements in imaging technologies that have become irreplaceable in the pre-operative assessment of patients with pancreatic tumors. Modern imaging modalities, including computed tomography (CT) and endoscopic ultrasound (EUS), can provide critical information of the absence or presence of metastatic disease in pancreatic cancer, as well as details on the local extent and resectability, allowing for the selection of stage appropriate treatments and pre-operatively determined surgical approach.

Objective

The aim of this review is to discuss staging, resectability, and imaging for patients with pancreatic tumors.

Evidence Review

A literature review was performed of articles relevant to the topics of staging, resectability, and imaging of pancreatic tumors. Imaging modalities included CT, EUS, magnetic resonance imaging (MRI), positron emission tomography (PET), antibody-based and narrow band imaging.

Findings

CT pancreas protocol combined with EUS serve as the primary modalities in diagnosis, staging, and surgical planning in patients with pancreatic tumors. MRI is an alternative to CT with near equivalent utility in the pre-operative setting. In some circumstances, PET-CT may be a cost-effective initial study to detect distant disease.

Conclusions and Relevance

Current imaging technologies play a critical role in the evaluation of patients with pancreatic tumors. Advances in the past 3 decades in imaging technologies have revolutionized the process of assessment of stage and resectability in patients with pancreatic tumors. Future imaging technologies will address current limitation in the evaluation of occult metastatic disease.

CT-determined resectability of borderline resectable and unresectable pancreatic adenocarcinoma following FOLFIRINOX therapy

OBJECTIVES

We aimed to assess the ability of CT-determined resectability, as defined by a recent version of NCCN criteria, and associated CT findings to predict margin-negative (R0) resection in patients with PDAC after neoadjuvant FOLFIRINOX chemotherapy.

METHODS

Sixty-four patients (36 men and 28 women; mean age, 58.8 years) with borderline resectable or unresectable PDAC who received neoadjuvant FOLFIRINOX were evaluated retrospectively. CT findings were independently assessed by two abdominal radiologists according to NCCN criteria (version 3. 2019). Tumor resectability was classified as resectable, borderline resectable, or unresectable, and change in resectability was classified as regression, stability, or progression. The associations of R0 resection rate with CT-determined resectability and change in resectability categories were evaluated, as were the sensitivity and specificity of NCCN criteria for R0 resection. Factors associated with R0 resection were identified by logistic regression analysis.

RESULTS

R0 resection rate did not differ significantly among the resectable, borderline resectable, or unresectable PDAC (67-73%, p = 0.95) or among PDAC with regression, stability, or progression (56-77%, p = 0.39). The sensitivity and specificity for R0 resection were 67% and 37%, respectively, for resectability (resectable/borderline vs. unresectable) and 80% and 21%, respectively, for changes in resectability (regression/stable vs. progression). Low-contrast enhancement of soft tissue contacting artery (≤ 46.4 HU) was independently associated with R0 resection (p = 0.01).

CONCLUSION

CT-determined resectability after neoadjuvant FOLFIRINOX chemotherapy was relatively insensitive and non-specific for predicting R0 resection. Low-contrast enhancement of soft tissue contacting artery may increase the ability of CT to predict R0 resection.

KEY POINTS

• Margin-negative resection rate of pancreatic cancer following FOLFIRINOX therapy did not differ among each resectability (67-73%, p = 0.95) based on NCCN criteria or changes in resectability categories (56-77%, p = 0.39). • The sensitivity and specificity for margin-negative resection were 67% and 37% for resectability (resectable/borderline vs. unresectable) and 80% and 21% for changes in resectability (regression/stable vs. progression). • Low-contrast enhancement of soft tissue contacting artery (≤ 46.4 HU) was independently associated with margin-negative resection (p = 0.01).

Outcome of Patients with Borderline Resectable Pancreatic Cancer in the Contemporary Era of Neoadjuvant Chemotherapy

INTRODUCTION

Approximately, 20% of patients with pancreatic ductal adenocarcinoma have resectable disease at diagnosis. Given improvements in locoregional and systemic therapies, some patients with borderline resectable pancreatic cancer (BRPC) can now undergo successful resection. The outcomes of patients with BRPC after neoadjuvant therapy remain unclear.

METHODS

A prospectively maintained single-institution database was utilized to identify patients with BRPC who were managed at the Johns Hopkins Pancreas Multidisciplinary Clinic (PMDC) between 2013 and 2016. BRPC was defined as any tumor that presented with radiographic evidence of the involvement of the portal vein (PV) or superior mesenteric vein (SMV) that was deemed to be technically resectable (with or without the need for reconstruction), or the abutment (< 180° involvement) of the common hepatic artery (CHA) or superior mesenteric artery (SMA), in the absence of involvement of the celiac axis (CA). We collected data on treatment, the course of the disease, resection rate, and survival.

RESULTS

Of the 866 patients evaluated at the PMDC during the study period, 151 (17.5%) were staged as BRPC. Ninety-six patients (63.6%) underwent resection. Neoadjuvant chemotherapy was administered to 142 patients (94.0%), while 78 patients (51.7%) received radiation therapy in the neoadjuvant setting. The median overall survival from the date of diagnosis, of resected BRPC patients, was 28.8 months compared to 14.5 months in those who did not (p < 0.001). Factors associated with increased chance of surgical resection included lower ECOG performance status (p = 0.011) and neck location of the tumor (p = 0.001). Forty-seven patients with BRPC (31.1%) demonstrated progression of disease; surgical resection was attempted and aborted in 12 patients (7.9%). Eight patients (5.3%) were unable to tolerate chemotherapy; six had disease progression and two did not want to pursue surgery. Lastly, four patients (3.3%) were conditionally unresectable due to medical comorbidities at the time of diagnosis due to comorbidities and failed to improve their status and subsequently had progression of the disease.

CONCLUSION

After initial management, 31.1% of patients with BRPC have progression of disease, while 63.6% of all patients successfully undergo resection, which was associated with improved survival. Factors associated with increased likelihood of surgical resection include lower ECOG performance status and tumor location in the neck.