Evaluation of National Surgical Practice for Lateral Lymph Nodes in Rectal Cancer in an Untrained Setting

BACKGROUND

Involved lateral lymph nodes (LLNs) have been associated with increased local recurrence (LR) and ipsi-lateral LR (LLR) rates. However, consensus regarding the indication and type of surgical treatment for suspicious LLNs is lacking. This study evaluated the surgical treatment of LLNs in an untrained setting at a national level.

METHODS

Patients who underwent additional LLN surgery were selected from a national cross-sectional cohort study regarding patients undergoing rectal cancer surgery in 69 Dutch hospitals in 2016. LLN surgery consisted of either 'node-picking' (the removal of an individual LLN) or 'partial regional node dissection' (PRND; an incomplete resection of the LLN area). For all patients with primarily enlarged (≥7 mm) LLNs, those undergoing rectal surgery with an additional LLN procedure were compared to those  undergoing only rectal resection.

RESULTS

Out of 3057 patients, 64 underwent additional LLN surgery, with 4-year LR and LLR rates of 26% and 15%, respectively. Forty-eight patients (75%) had enlarged LLNs, with corresponding recurrence rates of 26% and 19%, respectively. Node-picking (n = 40) resulted in a 20% 4-year LLR, and a 14% LLR after PRND (n = 8; p = 0.677). Multivariable analysis of 158 patients with enlarged LLNs undergoing additional LLN surgery (n = 48) or rectal resection alone (n = 110) showed no significant association of LLN surgery with 4-year LR or LLR, but suggested higher recurrence risks after LLN surgery (LR: hazard ratio [HR] 1.5, 95% confidence interval [CI] 0.7-3.2, p = 0.264; LLR: HR 1.9, 95% CI 0.2-2.5, p = 0.874).

CONCLUSION

Evaluation of Dutch practice in 2016 revealed that approximately one-third of patients with primarily enlarged LLNs underwent surgical treatment, mostly consisting of node-picking. Recurrence rates were not significantly affected by LLN surgery, but did suggest worse outcomes. Outcomes of LLN surgery after adequate training requires further research.

Monitoring beta cell survival after intrahepatic islet transplantation using dynamic exendin PET imaging: a proof-of-concept study in individuals with type 1 diabetes

Intrahepatic transplantation of islets of Langerhans (ITx) is a treatment option for individuals with complicated type 1 diabetes and profoundly unstable glycemic control, but its therapeutic success is hampered by deterioration of graft function over time. To improve ITx strategies, technologies to non-invasively monitor the fate and survival of transplanted islets over time, are of great potential value. We used [68Ga]Ga-NODAGA-exendin-4 (68Ga-exendin) positron emission tomography/computed tomography (PET/CT) imaging to demonstrate the feasibility to quantify beta cell mass in intrahepatic islet grafts in 13 individuals with type 1 diabetes, 9 after ITx with functional islet grafts and 4 non-transplanted controls. Beta cell function was measured by mixed-meal tolerance test. With dynamic 68Ga-exendin PET/CT images, we determined tracer accumulation in hepatic hotspots, and intrahepatic fat was assessed using magnetic resonance imaging and spectroscopy. Quantification of hepatic hotspots showed a significantly higher uptake of 68Ga-exendin in the ITx group compared to controls (0.55 [0.51-0.63] vs. 0.43 [0.42-0.45]). GLP-1 receptor expression was found in transplanted islets by immunohistochemistry. Intrahepatic fat was not detected in the majority of the individuals. Our study provides the first clinical evidence that radiolabeled exendin imaging can be used to monitor viable transplanted islets after intraportal ITx. (ClinicalTrials.gov number: NCT03785236).

Can MRI Be Used as a Sole Diagnostic Modality in Determining Clinical Stage in Cervical Cancer?

OBJECTIVE

The objective of this study was to compare staging by MRI to clinical staging in patients with cervical cancer and to determine the histological accuracy of staging by MRI and examination under anesthesia (EUA) in early stage disease.

METHODS

This was a retrospective cohort study of patients diagnosed with cervical cancer between 2010 and 2020 at the Radboud University Medical Centre, the Netherlands. Pretreatment stage (FIGO 2009) by MRI was compared with staging by EUA. Diagnostic accuracy in terms of sensitivity, specificity, positive, and negative predictive value was calculated for MRI and EUA in patients undergoing surgery (early stage disease) with histological results as a reference standard.

RESULTS

A total of 358 patients were included in the study and MRI-based stage differed from EUA stage in 30.7%. In 12.3% this meant a discrepancy in treatment assignment between MRI and EUA. Diagnostic accuracy of MRI in terms of sensitivity and specificity for detecting early stage disease was comparable to EUA in surgical patients. Further analyses showed that premenopausal status, early stage disease and a tumor diameter of <2 cm were associated with improved comparability of MRI and EUA (98%).

CONCLUSION

There is still a large discrepancy between MRI and EUA. In patients with suspected early stage disease, diagnostic accuracy of MRI is similar to EUA, especially for premenopausal women with early stage disease and a tumor diameter of <2 cm.

Poor response at restaging MRI and high incomplete resection rates of locally advanced mucinous rectal cancer after chemoradiation therapy

AIM

Mucinous carcinoma is a histological subtype of rectal cancer and has been associated with a poor response to neoadjuvant chemoradiotherapy (CRT). The primary aim of this study was to analyse the response on MRI of mucinous locally advanced rectal cancer (LARC) after CRT compared to regular adenocarcinoma.

METHOD

Patients with LARC (defined as cT4 and/or cN2), who underwent CRT followed by restaging MRI and surgery in two tertiary referral hospitals were retrospectively included in the study. Pre- and post-treatment MRI was reviewed by an experienced abdominal radiologist.

RESULTS

A total of 102 patients, of whom 29 were diagnosed with mucinous carcinoma, were included for analysis. At restaging MRI, adenocarcinoma patients demonstrated significantly less clinical involvement of the mesorectal fascia (37% vs. 62%, P = 0.003) while this was not demonstrated in mucinous carcinoma patients (86% vs. 97%, P = 0.16). Significant downstaging after CRT in adenocarcinoma patients (P = 0.01) was seen while, in mucinous carcinoma patients, no downstaging after CRT (P = 0.89) was seen. Pathology revealed significantly higher rates of an involved circumferential resection margin in mucinous carcinoma versus adenocarcinoma patients (27.6% vs. 1.4%; P < 0.001). After multivariate regression analysis, mucinous carcinoma remained an independent prognostic factor for local recurrence (hazard ratio 3.6; 95% CI 1.1-12.4), although no differences in overall or disease-free survival were observed.

CONCLUSION

Mucinous rectal carcinoma is associated with a poor clinical response at restaging MRI after CRT, leading to relatively higher rates of involved circumferential resection margins at pathology. In this cohort, mucinous carcinoma seems to be a prognostic factor for increased risk of local recurrence, without an effect on overall survival.

Response to Letter: Intrapatient Comparison of the Hepatobiliary Phase of Gd-BOPTA and Gd-EOB-DTPA in the Differentiation of HCA From FNH

LEVEL OF EVIDENCE

5 TECHNICAL EFFICACY STAGE: 3 J. Magn. Reson. Imaging 2020;52:1281-1282.