Emad Lotfalizadeh1, Maxime Ronot2,3,4, Mathilde Wagner1,5, Jérôme Cros6,7, Anne Couvelard6,7, Marie-Pierre Vullierme1, Wassim Allaham1, Olivia Hentic8, Philippe Ruzniewski8, Valérie Vilgrain1,6,5. 1. Department of Radiology, University Hospitals Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine, France. 2. Department of Radiology, University Hospitals Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine, France. maxime.ronot@bjn.aphp.fr. 3. University Paris Diderot, Sorbonne Paris Cité, Paris, France. maxime.ronot@bjn.aphp.fr. 4. INSERM U1149, Centre de Recherche Biomédicale Bichat-Beaujon, CRB3, Paris, France. maxime.ronot@bjn.aphp.fr. 5. INSERM U1149, Centre de Recherche Biomédicale Bichat-Beaujon, CRB3, Paris, France. 6. University Paris Diderot, Sorbonne Paris Cité, Paris, France. 7. Department of Pathology, University Hospitals Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine, France. 8. Department of Gastroenterology, University Hospitals Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine, France.
Abstract
OBJECTIVES: To evaluate the value of MR imaging including diffusion-weighted imaging (DWI) for the grading of pancreatic neuroendocrine tumours (pNET). MATERIAL AND METHODS: Between 2006 and 2014, all resected pNETs with preoperative MR imaging including DWI were included. Tumour grading was based on the 2010 WHO classification. MR imaging features included size, T1-w, and T2-w signal intensity, enhancement pattern, apparent (ADC) and true diffusion (D) coefficients. RESULTS: One hundred and eight pNETs (mean 40 ± 33 mm) were evaluated in 94 patients (48 women, 51 %, mean age 52 ± 12). Fifty-five (51 %), 42 (39 %), and 11 (10 %) tumours were given the following grades (G): G1, G2, and G3. Mean ADC and D values were significantly lower as grade increased (ADC: 2.13 ± 0.70, 1.78 ± 0.72, and 0.86 ± 0.22 10-3 mm2/s, and D: 1.92 ± 0.70, 1.75 ± 0.74, and 0.82 ± 0.19 10-3 mm2/s G1, G2, and G3, all p < 0.001). A higher grade was associated with larger sized tumours (p < 0.001). The AUROC of ADC and D to differentiate G3 and G1-2 were 0.96 ± 0.02 and 0.95 ± 0.02. Optimal cut-off values for the identification of G3 were 1.19 10-3 mm2/s for ADC (sensitivity 100 %, specificity 92 %) and 1.04 10-3 mm2/s for D (sensitivity 82 %, specificity 92 %). CONCLUSION: Morphological/functional MRI features of pNETS depend on tumour grade. DWI is useful for the identification of high-grade tumours. KEY POINTS: • Morphological and functional MRI features of pNETs depend on tumour grade. • Their combination has a high predictive value for grade. • All pNETs should be explored by MR imaging including DWI. • DWI is helpful for identification of high-grade and poorly-differentiated tumours.
OBJECTIVES: To evaluate the value of MR imaging including diffusion-weighted imaging (DWI) for the grading of pancreatic neuroendocrine tumours (pNET). MATERIAL AND METHODS: Between 2006 and 2014, all resected pNETs with preoperative MR imaging including DWI were included. Tumour grading was based on the 2010 WHO classification. MR imaging features included size, T1-w, and T2-w signal intensity, enhancement pattern, apparent (ADC) and true diffusion (D) coefficients. RESULTS: One hundred and eight pNETs (mean 40 ± 33 mm) were evaluated in 94 patients (48 women, 51 %, mean age 52 ± 12). Fifty-five (51 %), 42 (39 %), and 11 (10 %) tumours were given the following grades (G): G1, G2, and G3. Mean ADC and D values were significantly lower as grade increased (ADC: 2.13 ± 0.70, 1.78 ± 0.72, and 0.86 ± 0.22 10-3 mm2/s, and D: 1.92 ± 0.70, 1.75 ± 0.74, and 0.82 ± 0.19 10-3 mm2/s G1, G2, and G3, all p < 0.001). A higher grade was associated with larger sized tumours (p < 0.001). The AUROC of ADC and D to differentiate G3 and G1-2 were 0.96 ± 0.02 and 0.95 ± 0.02. Optimal cut-off values for the identification of G3 were 1.19 10-3 mm2/s for ADC (sensitivity 100 %, specificity 92 %) and 1.04 10-3 mm2/s for D (sensitivity 82 %, specificity 92 %). CONCLUSION: Morphological/functional MRI features of pNETS depend on tumour grade. DWI is useful for the identification of high-grade tumours. KEY POINTS: • Morphological and functional MRI features of pNETs depend on tumour grade. • Their combination has a high predictive value for grade. • All pNETs should be explored by MR imaging including DWI. • DWI is helpful for identification of high-grade and poorly-differentiated tumours.
Authors: James R Howe; Nipun B Merchant; Claudius Conrad; Xavier M Keutgen; Julie Hallet; Jeffrey A Drebin; Rebecca M Minter; Terry C Lairmore; Jennifer F Tseng; Herbert J Zeh; Steven K Libutti; Gagandeep Singh; Jeffrey E Lee; Thomas A Hope; Michelle K Kim; Yusuf Menda; Thorvardur R Halfdanarson; Jennifer A Chan; Rodney F Pommier Journal: Pancreas Date: 2020-01 Impact factor: 3.327