Buijs Mara, de Bruin Daniel M, Wagstaff Peter Gk, J Zondervan Patricia, Scheltema Matthijs JV, W Engelbrecht Marc, P Laguna Maria, van Lienden Krijn P
Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
Department of Urology, Academic Medical Center, Amsterdam, The Netherlands; Department of Biomedical Engineering - Physics, Academic Medical Center, Amsterdam, The Netherlands.
Diagn Interv Radiol. 2021 Sep;27(5):654-663. doi: 10.5152/dir.2021.19575.
Ablation plays a growing role in the treatment of small renal masses (SRMs) due to its nephron sparing properties and low invasiveness. Irreversible electroporation (IRE) has the potential, although still experimental, to overcome current limitations of thermal ablation. No prospective imaging studies exist of the ablation zone in the follow up after renal IRE in humans. Objectives are to assess computed tomography (CT) and magnetic resonance imaging (MRI) on the ablation zone volume (AZV), enhancement and imaging characteristics after renal IRE.
Prospective phase 2 study of IRE in nine patients with ten SRMs. MRI imaging was performed pre-IRE, 1 week, 3 months, 6 months and 12 months after IRE. CT was performed pre-IRE, perioperatively (direct after ablation), 3 months, 6 months and 12 months after IRE. AZVs were assessed by two independent observers. Observer variation was analyzed. Evolution of AZVs, and relation between the needle configuration volume (NCV; planned AZV) and CT- and MRI volumes were evaluated.
Eight SRMs were clear cell renal cell carcinomas, one SRM was a papillary renal cell carcinoma and one patient had a non-diagnostic biopsy. On CT, median AZV increased perioperatively until 3 months post-IRE (respectively, 16.8 cm3 and 6.2 cm3) compared to the NCV (4.8 cm3). On MRI, median AZV increased 1-week post-IRE until 3 months post-IRE (respectively, 14.5 cm3 and 4.6 cm3) compared to the NCV (4.8 cm3). At 6 months the AZV starts decreasing (CT 4.8 cm3; MRI 3.0 cm3), continuing at 12 months (CT 4.2 cm3, MRI 1.1 cm3). Strong correlation was demonstrated between the planning and the post-treatment volumes. Inter-observer agreement between observers was excellent (CT 95% CI 0.82-0.95, MRI 95% CI 0.86-0.96). All SRMs appeared non-enhanced immediately after ablation, except for one residual tumour. Subtraction images confirmed non-enhancement on MRI in unclear enhancement cases (3/9). Directly after IRE, gas bubbles, perinephric stranding and edema were observed in all cases.
The AZV increases immediately on CT until 3 months after IRE. On MRI, the AZV increases at 1 week until 3 months post-IRE. At 6 months the AZV starts decreasing until 12 months post-IRE on both CT and MRI. Enhancement was absent post-IRE, except for one residual tumour. Gas bubbles, perinephric stranding and edema are normal findings directly post-IRE.
由于其保留肾单位特性和低侵袭性，消融在小肾肿块（SRM）治疗中发挥着越来越重要的作用。不可逆电穿孔（IRE）尽管仍处于实验阶段，但有潜力克服当前热消融的局限性。目前尚无关于人类肾IRE术后随访中消融区的前瞻性影像学研究。目的是评估计算机断层扫描（CT）和磁共振成像（MRI）对肾IRE后消融区体积（AZV）、强化情况及成像特征。
对9例患有10个SRM的患者进行IRE的前瞻性2期研究。在IRE前、IRE后1周、3个月、6个月和12个月进行MRI成像。在IRE前、围手术期（消融后即刻）、IRE后3个月、6个月和12个月进行CT检查。由两名独立观察者评估AZV。分析观察者间差异。评估AZV的演变以及针配置体积（NCV；计划的AZV）与CT和MRI体积之间的关系。
8个SRM为透明细胞肾细胞癌，1个SRM为乳头状肾细胞癌，1例患者活检未明确诊断。在CT上，围手术期至IRE后3个月，AZV中位数增加（分别为16.8 cm³和6.2 cm³），而NCV为4.8 cm³。在MRI上，IRE后1周直至IRE后3个月，AZV中位数增加（分别为14.5 cm³和4.6 cm³），而NCV为4.8 cm³。在6个月时，AZV开始减小（CT为4.8 cm³；MRI为3.0 cm³），在12个月时继续减小（CT为4.2 cm³，MRI为1.1 cm³）。计划体积与治疗后体积之间显示出强相关性。观察者间的一致性极佳（CT 95%CI 0.82 - 0.95，MRI 95%CI 0.86 - 0.96）。除1个残留肿瘤外，所有SRM在消融后即刻均未强化。减影图像在MRI上证实了强化不明确病例（3/9）的无强化情况。IRE后即刻，所有病例均观察到气泡、肾周条索状影和水肿。
在CT上，AZV在IRE后即刻直至3个月增加。在MRI上，AZV在IRE后1周直至3个月增加。在6个月时，AZV开始减小，直至IRE后12个月CT和MRI上均如此。IRE后除1个残留肿瘤外均无强化。气泡、肾周条索状影和水肿是IRE后即刻的正常表现。
