Development and multicenter validation of a multiparametric imaging model to predict treatment response in rectal cancer.

Objectives: To develop and validate a multiparametric model to predict neoadjuvant treatment response in rectal cancer at baseline using a heterogeneous multicenter MRI dataset.

Methods: Baseline staging MRIs (T2W (T2-weighted)-MRI, diffusion-weighted imaging (DWI) / apparent diffusion coefficient (ADC)) of 509 patients (9 centres) treated with neoadjuvant chemoradiotherapy (CRT) were collected. Response was defined as (1) complete versus incomplete response, or (2) good (Mandard tumor regression grade (TRG) 1-2) versus poor response (TRG3-5).

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.

Sources of variation in multicenter rectal MRI data and their effect on radiomics feature reproducibility.

Objectives: To investigate sources of variation in a multicenter rectal cancer MRI dataset focusing on hardware and image acquisition, segmentation methodology, and radiomics feature extraction software.

Methods: T2W and DWI/ADC MRIs from 649 rectal cancer patients were retrospectively acquired in 9 centers. Fifty-two imaging features (14 first-order/6 shape/32 higher-order) were extracted from each scan using whole-volume (expert/non-expert) and single-slice segmentations using two different software packages (PyRadiomics/CapTk).

Evolutions in rectal cancer MRI staging and risk stratification in The Netherlands.

Purpose: To analyze how the MRI reporting of rectal cancer has evolved (following guideline updates) in The Netherlands.

Methods: Retrospective analysis of 712 patients (2011-2018) from 8 teaching hospitals in The Netherlands with available original radiological staging reports that were re-evaluated by a dedicated MR expert using updated guideline criteria. Original reports were classified as "free-text," "semi-structured," or "template" and completeness of reporting was documented.

MRI predicts increased eligibility for sphincter preservation after CRT in low rectal cancer.

Unlabelled: Chemoradiation increases the eligibility for sphincter preservation in low rectal cancer, as assessed by MRI.

Introduction: We evaluated whether MRI can predict sphincter preservation after chemoradiation (CRT), and whether the feasibility of sphincter preservation increases after CRT, when compared with MRI before neoadjuvant treatment.

Methods: 85 patients with low rectal tumour (≤5 cm from anorectal junction (ARJ)) were included.

Radiomics performs comparable to morphologic assessment by expert radiologists for prediction of response to neoadjuvant chemoradiotherapy on baseline staging MRI in rectal cancer.

Purpose: To compare the performance of advanced radiomics analysis to morphological assessment by expert radiologists to predict a good or complete response to chemoradiotherapy in rectal cancer using baseline staging MRI.

Materials And Methods: We retrospectively assessed the primary staging MRIs [prior to chemoradiotherapy (CRT)] of 133 rectal cancer patients from 2 centers. First, two expert radiologists subjectively estimated the likelihood of achieving a "complete response" (ypT0) and "good response" (TRG 1-2), using a 5-point score (based on TN-stage, MRF/EMVI-status, size/signal/shape).

Automated and Semiautomated Segmentation of Rectal Tumor Volumes on Diffusion-Weighted MRI: Can It Replace Manual Volumetry?

Purpose: Diffusion-weighted imaging (DWI) tumor volumetry is promising for rectal cancer response assessment, but an important drawback is that manual per-slice tumor delineation can be highly time consuming. This study investigated whether manual DWI-volumetry can be reproduced using a (semi)automated segmentation approach.

Methods And Materials: Seventy-nine patients underwent magnetic resonance imaging (MRI) that included DWI (highest b value [b1000 or b1100]) before and after chemoradiation therapy (CRT).

Translabial three-dimensional ultrasonography compared with magnetic resonance imaging in detecting levator ani defects.

Objective: To assess the diagnostic performance of translabial three-dimensional ultrasonography in detecting major levator ani defects in women with pelvic organ prolapse compared with magnetic resonance imaging (MRI) and to assess the interobserver agreement in detecting levator ani defects with translabial three-dimensional ultrasonography.

Methods: In a multicenter cohort study, 140 women indicated for primary surgery of pelvic organ prolapse quantification stage II or more cystocele were included. Patients undergoing mesh surgery or concomitant stress incontinence surgery were excluded.

Interobserver reproducibility of diffusion-weighted MRI in monitoring tumor response to neoadjuvant therapy in esophageal cancer.

Objective: To investigate the reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) in assessing tumor response early in the course of neoadjuvant chemoradiotherapy in patients with operable esophageal cancer.

Methods: Eleven male patients (mean age 54.8 years) with newly diagnosed esophageal cancer underwent DW-MRI before and 10 days after start of chemoradiotherapy.

PET/CT-based metabolic tumour volume for response prediction of neoadjuvant chemoradiotherapy in oesophageal carcinoma.

Purpose: Neoadjuvant chemoradiotherapy is increasingly used in oesophageal cancer patients. In general, small tumours are associated with a survival benefit compared to large tumours. Little is known, however, about the relationship between initial tumour volume and response to chemoradiotherapy.

T-staging of rectal cancer: accuracy of 3.0 Tesla MRI compared with 1.5 Tesla.

Objectives: Magnetic resonance imaging (MRI) is not accurate in discriminating T1-2 from borderline T3 rectal tumors. Higher resolution on 3 Tesla-(3T)-MRI could improve diagnostic performance for T-staging. The aim of this study was to determine whether 3T-MRI compared with 1.

Protocol for translabial 3D-ultrasonography for diagnosing levator defects (TRUDIL): a multicentre cohort study for estimating the diagnostic accuracy of translabial 3D-ultrasonography of the pelvic floor as compared to MR imaging.

Background: Pelvic organ prolapse (POP) is a condition affecting more than half of the women above age 40. The estimated lifetime risk of needing surgical management for POP is 11%. In patients undergoing POP surgery of the anterior vaginal wall, the re-operation rate is 30%.

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part I. Are we able to predict tumor confined to the rectal wall?

Purpose: To retrospectively assess accuracy of magnetic resonance (MR) imaging after radiation therapy with concomitant chemotherapy for downsizing of the primary lesion to ypT0-2 tumor confined to rectal wall in locally advanced rectal cancer, with histopathologic findings as reference standard, and to evaluate additional value of volumetric analysis.

Materials And Methods: The institutional review board approved the study and waived informed consent. Sixty-seven patients met criteria of the study.

Can an FDG-PET/CT predict tumor clearance of the mesorectal fascia after preoperative chemoradiation of locally advanced rectal cancer?

Background And Purpose: More effective preoperative treatment in locally advanced rectal cancer gives rise to a more individualized, conservative surgical treatment strategy. This, however, requires accurate information on tumor response after chemoradiation (CRT). So far, MRI and CT have failed to provide such information.

Mesorectal fascia invasion after neoadjuvant chemotherapy and radiation therapy for locally advanced rectal cancer: accuracy of MR imaging for prediction.

Purpose: To retrospectively assess sensitivity and specificity of magnetic resonance (MR) imaging after chemotherapy and radiation therapy for predicting tumor invasion of the mesorectal fascia (MRF) in locally advanced primary rectal cancer, by using results of histologic examination and surgery as the reference standard, and to determine morphologic MR imaging criteria for MRF invasion.

Materials And Methods: The Ethical Committee of University Hospital Maastricht approved this study and waived informed consent. Two observers independently scored postchemoradiation MR images in 64 patients with rectal cancer (38 male [mean age, 60 years] and 26 female [mean age, 64 years] patients) for MRF tumor invasion with a confidence level scoring system defined by subjective criteria.

Rectal cancer: MR imaging in local staging--is gadolinium-based contrast material helpful?

Purpose: To determine retrospectively whether addition of gadolinium-enhanced T1-weighted magnetic resonance (MR) sequence to T2-weighted turbo spin-echo (SE) MR imaging is valuable for preoperative assessment of T stage and circumferential resection margin in patients with primary rectal cancer.

Materials And Methods: Local institutional review board approved study and waived informed patient consent. Eighty-three patients with operable primary rectal cancer underwent preoperative MR imaging.