МРТ-оценка эффективности трансартериальной химиоэмболизации печени у пациентов с метастазами нейроэндокринных опухолей

Abstract

Purpose: Standard liver transarterial chemoembolization (TACE) response evaluation criteria are based on lesion and necrotic areas sizes, however, in the particular case of metastatic neuroendocrine tumor (mNET) these criteria lack accuracy and prognostic significance; so additional MRI parameters are proposed in the paper for TACE efficiency assessment in these patents. Material and methods: 31 liver mNET patients that undergone 61 TACE procedures were enrolled in the study. 108 MRI studies performed 3-86 days before (median - 28 days) and 17-108 days (median - 54 days) after TACE were analyzed. We acquired diffusion weighted images (DWI) with maps of apparent diffusion coefficient (ADC), T 1 -weighted images (T 1 -WI) fat-saturated (FS) before i.v. contrast injection and after on arterial, portal and delayed phases. TACE effect was estimated according to RECIST 1.1 (2008). Before and after TACE, we measured: maximum necrotic/fibrotic zone diameter and solid component thickness on its periphery at the largest targeted lesion, ADC and its standard deviation (SD) in the tumor solid component; MR contrast agent (MRCA) uptake dynamics and signal intensity (SI) SD on T 1 -WI FS on portal phases at same regions. Results: TACE effect was evaluated according to RECIST 1.1 as progressive disease in 4 (6.8 %), stabilization in 54 (88.4 %) and partial response in 3 (4.9 %) patients. The diameter of the fibrotic/necrotic areas after TACE demonstrated no changes, but thickness of the solid component on the periphery of the fibrotic/necrotic areas decreased significantly. ADC values and its SD increased, lesion MRCA accumulation on arterial and portal phase decreased, lesion MRCA wash-out time and SI SD on T 1-WI FS on portal phase increased in solid portions of mNETs after TACE. Positive prognostic factors associated with the time to progression were an increase in ADC values and its SD, a decrease in MRCA accumulation on portal phase. Conclusion: Mentioned above parameters may be useful for increasing the predictive value of MRI-assessment of TACE response in patients with liver mNETs and for determining the intervals of post-TACE MRI follow-up schedule.