Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany and.
Int J Hyperthermia. 2014 Feb;30(1):19-26. doi: 10.3109/02656736.2013.854931. Epub 2013 Nov 28.
The aim of this study was to evaluate the accuracy of real-time magnetic resonance imaging (MRI) T1-based treatment monitoring for predicting volume of lesions induced by laser-induced thermotherapy (LITT) of liver metastases.
This prospective study was approved by the institutional review board and informed consent from all included patients was obtained. In 151 patients, 237 liver metastases were ablated during 372 LITT procedures. 1.5 T MRI treatment monitoring was performed based on longitudinal relaxation time (T1) using fast low-angle shot (FLASH) sequences. Patients underwent additional contrast-enhanced MRI directly after LITT, 24 h after the procedure and during follow-up at 3, 6 and 12 months. The amount of energy necessary to induce a defined necrotic area was investigated within the various liver segments.
The total amount of energy applied during LITT varied from 6.12-225.32 kJ (mean 48.96 kJ). Ablation in liver segments 5 (2.12 kJ/cm(3)) and 8 (2.16 kJ/cm(3)) required the highest energy. The overall pre-ablative metastasis volume ranged from 0.5-51.94 cm(3) (mean 1.99 cm(3), SD 25.49 cm(3)) while the volume measured in the last available T1 image varied from 0.78-120 cm(3) (mean 26.25 cm(3), SD 25.66 cm(3)). Volumes measured via MRI T1-based treatment monitoring showed a stronger correlation with necrosis 24 h after LITT (r = 0.933, p < 0.001) than contrast-enhanced MRI directly after the procedure (r = 0.888, p < 0.001).
Real-time MRI T1-based treatment monitoring during LITT of liver metastases allows for precise estimation of the resulting lesion volume and improves control of the energy necessary during ablation.
本研究旨在评估实时磁共振成像（MRI）T1 基础治疗监测预测激光诱导热疗（LITT）治疗肝转移瘤体积的准确性。
这项前瞻性研究得到了机构审查委员会的批准，并获得了所有纳入患者的知情同意。在 151 名患者中，237 个肝转移瘤在 372 次 LITT 手术中被消融。1.5 T MRI 治疗监测是基于快速小角度激发（FLASH）序列的纵向弛豫时间（T1）进行的。患者在 LITT 后直接进行额外的对比增强 MRI，在手术后 24 小时以及 3、6 和 12 个月的随访时进行。在各个肝段内研究了诱导特定坏死区域所需的能量量。
LITT 过程中应用的总能量从 6.12-225.32 kJ（平均 48.96 kJ）不等。肝段 5（2.12 kJ/cm(3)）和 8（2.16 kJ/cm(3)）的消融需要最高的能量。所有可获得的 T1 图像中，术前转移瘤体积范围从 0.5-51.94 cm(3)（平均 1.99 cm(3)，SD 25.49 cm(3)）不等，而最后一次 T1 图像中测量的体积范围从 0.78-120 cm(3)（平均 26.25 cm(3)，SD 25.66 cm(3)）不等。MRI T1 基础治疗监测测量的体积与 LITT 后 24 小时的坏死有更强的相关性（r = 0.933，p < 0.001），而与术后直接对比增强 MRI 的相关性（r = 0.888，p < 0.001）较弱。
实时 MRI T1 基础治疗监测在 LITT 治疗肝转移瘤中可以精确估计治疗后病变体积，并有助于控制消融过程中所需的能量。
