Correlation Between Apparent Diffusion Coefficient Value on MRI and Histopathologic WHO Grades of Neuroendocrine Tumors. Issue 1 (30th January 2020)

• Record Type: Journal Article
• Authors: Mebis, Wouter; Snoeckx, Annemiek; Corthouts, Bob; El Addouli, Haroun; Nicolay, Simon; Van Hoyweghen, Astrid; Spinhoven, Maarten; de Beeck, Bart Op
• Is Part Of: Journal of the Belgian Society of Radiology. Volume 104:Issue 1(2020)
• Publication Date: 2020-01-30
• Subjects: apparent diffusion coefficient -- magnetic resonance imaging -- neuroendocrine tumor -- histopathological grade -- quantitative; Radiology -- Periodicals; Periodicals; 616.0757
• DOI: 10.5334/jbsr.1925
• Languages: English
• ISSNs: 2514-8281

Abstract

Background: The correlation of diffusion-weighted MRI and tumor aggressiveness has been established for different tumor types, which leads to the question if it could also apply for neuroendocrine tumors (NET). Purpose: To investigate the possible correlation between apparent diffusion coefficient (ADC) value on magnetic resonance imaging (MRI) and histopathologic WHO-grades of NET. Material and Methods: Electronic patient records from patients presented at the multidisciplinary neuro-endocrine tumor board between November 2017 and April 2019 were retrospectively reviewed. Patients with both available MR imaging (primary tumor or metastasis) and known WHO tumor grade were included (n = 47). Average and minimum ADC values (avgADC; minADC) were measured by drawing a freehand ROI excluding only the outermost border of the lesion. The largest axial size (primary tumor) or most clearly delineated lesion (metastasis) was used. Results: Forty seven patients met the inclusion criteria (mean age 59 ± 12 SD; 24F/23M). Twenty one patients (45%) were diagnosed with WHO G1 tumor, 17 seventeen with G2 (36%) and nine with G3 (19%) tumor. Twenty eight primary tumors and 19 metastases were measured. A significant difference was found between low-grade (G1+G2) and high-grade (G3) tumors (Mann-Whitney; avgADC: p < 0, 001; minADC: p = 0, 001). There was a moderate negative correlation between WHO-grade and avgADC/minADC (Spearman; avgADC: –0, 606; 95% CI [–0, 773; –0, 384]; minADC: –0, 581; 95% CI [–0.759; –0.353]). Conclusion: Our data show a significant difference in both average and minimum ADC values on MRI between low and high grade NET. A moderate negative correlation was found between histopathologic WHO grade and ADC value.