Reporting the margin in pancreaticoduodenectomies: R0 versus R1

Prognostic importance of margin clearance in ampullary adenocarcinoma following pancreaticoduodenectomy in a Danish population-based nationwide study

BACKGROUND

In this Danish nationwide population-based study, we evaluated the prognostically relevant minimum tumour-free margin width following pancreaticoduodenectomy (PD) for ampullary adenocarcinoma (AAC) and evaluated whether certain margins hold independent prognostic information.

METHODS

We included 128 patients who underwent PD for AAC from 2015 to 2019. Clinical and pathological data including well-known prognostic factors were retrieved from the Danish Pancreatic Cancer Database. Missing data were obtained by review of pathology reports and re-microscopy of resection specimens. All PD specimens were examined using a standardised pathological protocol including multicolour inking, axial slicing and exact reporting of margin widths. The cohort was dichotomised into involved and uninvolved groups, using different margin clearance definitions (0.5-≥3.0 mm).

RESULTS

Following PD for AAC, margin clearance of ≥1 mm was independently associated with improved chance of survival compared with <1 mm (HR: 0.30, 95 % CI: 0.14-0.64 (p = 0.002)). Posterior and anterior margin widths were narrower compared with superior mesenteric artery and vein margins. Posterior margin and anterior surface had isolated prognostic significance in multivariable analysis.

CONCLUSION

Following PD for AAC, margin clearance of at least 1 mm is independently associated with improved survival. Our data further indicate that anterior surface and posterior margin hold particular prognostic value.

Value of Non-Contrast-Enhanced Vessel Wall MR Imaging in Assessing Vascular Invasion of Retroperitoneal Tumors

BACKGROUND

Due to their location and growth patterns, retroperitoneal tumors often involve the surrounding blood vessels. Clinical decisions on a proper treatment depend on the information on this condition. Evaluation of blood vessels using non-contrast-enhanced vessel wall MRI may provide noninvasive assessment of the extent of tumor invasion to assist clinical decision-making.

PURPOSE

To investigate the performance and potential of non-contrast-enhanced vessel wall MRI in evaluating the degree of vessel wall invasion of retroperitoneal tumors.

STUDY TYPE

Prospective.

POPULATION

Thirty-seven participants (mean age: 60.59 ± 11.77 years, 59% male) with retroperitoneal tumors close to vessels based on their diagnostic computer tomography.

FIELD STRENGTH/SEQUENCES

3 T; vessel wall MRI sequences: two-dimensional T2-weighted MultiVane XD turbo spin-echo (2D-T2-MVXD-TSE) and three-dimensional T1-weighted motion sensitized driven equilibrium fat suppression turbo spin-echo (3D-T1-MSDE-TSE) sequences; conventional MRI sequences: T2-weighted fat suppression turbo spin-echo (T2-FS-TSE), T2-weighted turbo spin-echo (T2-TSE), modified Dixon T1-weighted fast field echo (T1-mDixon-FFE), and diffusion-weighted echo planar imaging (DWI-EPI) sequences.

ASSESSMENT

All patients underwent preoperative imaging using both non-contrast conventional and vessel wall MRI sequences. Images obtained from conventional and vessel wall MRI sequences were evaluated independently by three junior radiologists (3 and 2 years of experience in reading MRI) and reviewed by one senior radiologist (25 years of experience in reading MRI) to assess the degree of vessel wall invasion. MRI were validated results from the clinical standard diagnosis based on surgical confirmation or histopathological reports. Interobserver agreement was determined based on the reports from three readers with similar years of experiences. Intraobserver variability was assessed based on categorizing and recategorizing the vessels of 37 patients 1 month apart.

STATISTICAL TESTS

Intra-class correlation efficient (ICC), Chi-square test, McNemar test, area under the receiver-operating characteristic curve (AUC), Delong test, P < 0.05 was considered significant.

RESULTS

The accuracy of vessel wall MRI (91.96%, 95% CI: 85.43-95.71; 103 of 112) in detecting the degree of vessel wall invasion was significantly higher than that of conventional MRI (75%, 95% CI: 66.24-82.10; 84 of 112). The interobserver variability or reproducibility in categorization of the degree of vascular wall invasion was good in evaluating images from conventional and vessel wall MRI sequences (ICC = 0.821, 95% CI: 0.765-0.867 and ICC = 0.881, 95% CI: 0.842-0.913, respectively).

DATA CONCLUSION

Diagnosis of vessel wall invasion of retroperitoneal tumors and assessment of its severity can be improved by using non-contrast-enhanced vessel wall MRI.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 3.

Centralisation of Pancreatoduodenectomy in India: Where Do We Stand?

BACKGROUND

The volume-outcome relationship dictates that high-volume centres lead to improved patient outcomes after pancreatoduodenectomy (PD). We conducted a retrospective review to fathom the situation in India for PD and whether referral to high-volume centres would make a positive impact.

METHOD

A systematic literature search in MEDLINE was performed, and all articles published from Indian centres from 01.03.2008 to 30.11.2019 were scrutinised. Any series with less than 20 patients, case reports, abstracts, unpublished data and personal communications were excluded.

RESULTS

A total of 36 unique series including 6226 patients from 24 institutes across India were identified. Amongst the 24 institutes, 2 institutes reported less than 10 cases/year, 11 reported 10-25 cases/year and 11 reported ≥26 cases/year. Overall perioperative morbidity was 42.4%, 43.4% and 41% for centres doing <10, 10-25 and ≥26 cases/year, respectively. Operative mortality also improved with increasing number of cases/year (5.1% vs. 6.6% vs. 3.2%, respectively).

CONCLUSION

With increasing volume of cases per year, trend towards improved PD outcomes is observed. To optimise the use of healthcare facilities, it would be pragmatic to consider building an organised referral system for complex surgeries to deliver unsurpassed patient care with maximum utilisation of the available healthcare infrastructure.

Tumour origin and R1 rates in pancreatic resections: towards consilience in pathology reporting

To evaluate differences in the R1 rates of ampullary (AC), pancreatic (PC), and distal bile duct (DBD) cancers in pancreatoduodenectomies (PD) using standardised pathology assessment. Data of PD (2010-2011) analysed in accordance with the Royal College of Pathologists (UK) protocol, were retrieved. Clinicopathologic features, including frequency, topography, and mode of margin involvement in AC (n = 87), PC (n = 18), and DBD (n = 5) cancers were evaluated. The R1 rate was 7%, 67%, and 20% in the AC, PC, and DBD cancers (p < 0.001). Within the PC cohort, R1 rate was heterogeneous (chemo-naïve, 77%; post-neoadjuvant, 40%). Commonest involved margins were as follows: posterior in overall PD (35%), AC (43%), overall PC (33%), and post-neoadjuvant PC (100%); superior mesenteric artery margin in chemo-naïve PC (38%) and common bile duct margin in DBD (100%) cancers. In AC, majority (66%) of R1 were signet ring cell type. Indirect margin involvement due to tumour within lymph node, perineural sheath or lymphovascular space was observed in 26% cases, and altered R1 rate in AC, PC, and DBD cohorts by 1%, 12%, and 0%, respectively. Although not statistically significant, patients with R1 had lower disease-free survival than those with R0 (mean, 25.4 months versus 44.4 months). Tumour origin impacts R1 data in PD necessitating its accurate classification by pathologists. Indirect involvement, histology, and neoadjuvant therapy influence the R1 rate, albeit in a minority of cases. Generating cogent R1 data based on standardised pathology reporting is the foremost need of the hour.