Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.
Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
BMC Med Imaging. 2019 Aug 20;19(1):71. doi: 10.1186/s12880-019-0360-2.
Compared to surgery, radiofrequency ablation(RFA) for colorectal liver metastasis(CRLM) is associated with higher local recurrence(LR) rates. A wide margin (at least 5 mm) is generally recommended to prevent LR, but the optimal method to assess ablation margins is yet to be established. The aim of our study was to evaluate the feasibility and reproducibility of CT-CT co-registration, using MIRADA software, in order to assess ablation margins of patients with CRLM.
In this retrospective study, pre- and post-ablation contrast-enhanced CT scans of 29 patients, treated with percutaneous RFA for a solitary CRLM, were co-registered. Co-registration was performed by two independent radiologist, based on venous structures in proximity to the tumor. Feasibility of CT-CT co-registration and inter-observer agreement for reproducibility and ablation margins was determined. Furthermore, the minimal ablation margin was compared with the occurrence of LR during follow-up.
Co-registration was considered feasible in 18 patients (61% male, 63.1(±10.9) year), with a perfect inter-observer agreement for completeness of ablation: κ = 1.0(p < 0.001). And substantial inter-observer agreement for measurement of the minimal margin (≤ 0 mm, 1-5 mm, ≥ 5 mm): κ = 0.723(p-value < 0.001). LR occurred in eight of nine(88.9%) incompletely ablated CRLM and in one of the nine completely ablated CRLM(11.1%).
Co-registration using MIRADA is reproducible and potentially a valuable tool in defining technical success. Feasibility of co-registration of pre- and post-ablation CT scans is suboptimal if scans are not acquired concordantly. Co-registration may potentially aid in the prediction of LR after percutaneous ablation.
与手术相比，射频消融（RFA）治疗结直肠癌肝转移（CRLM）的局部复发（LR）率较高。为了防止 LR，通常建议切除边缘至少 5mm，但尚未建立评估消融边缘的最佳方法。我们的研究目的是评估使用 MIRADA 软件进行 CT-CT 配准的可行性和可重复性，以评估 CRLM 患者的消融边缘。
在这项回顾性研究中，对 29 例接受经皮 RFA 治疗的单发 CRLM 患者的消融前和消融后增强 CT 扫描进行了配准。配准由两名独立的放射科医生根据靠近肿瘤的静脉结构进行。确定了 CT-CT 配准的可行性以及观察者间对重复性和消融边缘的可重复性的一致性。此外，还比较了最小消融边缘与随访期间 LR 的发生情况。
18 例患者（61%为男性，63.1(±10.9)岁）的配准被认为是可行的，对消融完整性的完全观察者间一致性为：κ=1.0(p<0.001)。对最小边缘（≤0mm、1-5mm、≥5mm）的测量也有很好的观察者间一致性：κ=0.723(p 值<0.001)。在未完全消融的 9 个 CRLM 中有 8 个（88.9%）和完全消融的 9 个 CRLM 中有 1 个（11.1%）发生了 LR。
使用 MIRADA 进行配准是可重复的，并且可能是定义技术成功的有价值的工具。如果扫描不是同时采集的，则 CT 扫描的配准的可行性是不理想的。配准可能有助于预测经皮消融后的 LR。
