Iijima Keiya, Hirato Masafumi, Miyagishima Takaaki, Horiguchi Keishi, Sugawara Kenichi, Hirato Junko, Yokoo Hideaki, Yoshimoto Yuhei
Departments of 1 Neurosurgery and.
Clinical Department of Pathology, Gunma University Hospital, Maebashi, Gunma, Japan.
J Neurosurg. 2015 Oct;123(4):978-88. doi: 10.3171/2014.10.JNS14963. Epub 2015 Mar 27.
Image-guided stereotactic brain tumor biopsy cannot easily obtain samples of small deep-seated tumor or selectively sample the most viable region of malignant tumor. Image-guided stereotactic biopsy in combination with depth microrecording was evaluated to solve such problems.
Operative records, MRI findings, and pathological specimens were evaluated in 12 patients with small deep-seated brain tumor, in which image-guided stereotactic biopsy was performed with the aid of depth microrecording. The tumors were located in the caudate nucleus (1 patient), thalamus (7 patients), midbrain (2 patients), and cortex (2 patients). Surgery was performed with a frameless stereotactic system in 3 patients and with a frame-based stereotactic system in 9 patients. Microrecording was performed to study the electrical activities along the trajectory in the deep brain structures and the tumor. The correlations were studied between the electrophysiological, MRI, and pathological findings. Thirty-two patients with surface or large brain tumor were also studied, in whom image-guided stereotactic biopsy without microrecording was performed.
The diagnostic yield in the group with microrecording was 100% (low-grade glioma 4, high-grade glioma 4, diffuse large B-cell lymphoma 3, and germinoma 1), which was comparable to 93.8% in the group without microrecording. The postoperative complication rate was as low as that of the conventional image-guided method without using microelectrode recording, and the mortality rate was 0%, although the target lesions were small and deep-seated in all cases. Depth microrecording revealed disappearance of neural activity in the tumor regardless of the tumor type. Neural activity began to decrease from 6.3 ± 4.5 mm (mean ± SD) above the point of complete disappearance along the trajectory. Burst discharges were observed in 6 of the 12 cases, from 3 ± 1.4 mm above the point of decrease of neural activity. Injury discharges were often found at 0.5-1 mm along the trajectory between the area of decreased and disappeared neural activity. Close correlations between electrophysiological, MRI, and histological findings could be found in some cases.
Image-guided stereotactic biopsy performed using depth microrecording was safe, it provided accurate positional information in real time, and it could distinguish the tumor from brain structures during surgery. Moreover, this technique has potential for studying the epileptogenicity of the brain tumor.
影像引导下的立体定向脑肿瘤活检不易获取深部小肿瘤的样本，也难以选择性地采集恶性肿瘤最具活力区域的样本。本研究评估了影像引导下的立体定向活检联合深度微记录技术以解决此类问题。
对12例深部小脑肿瘤患者的手术记录、MRI表现及病理标本进行评估，这些患者接受了借助深度微记录技术的影像引导下立体定向活检。肿瘤位于尾状核（1例）、丘脑（7例）、中脑（2例）和皮质（2例）。3例患者使用无框架立体定向系统进行手术，9例患者使用有框架立体定向系统进行手术。进行微记录以研究沿深部脑结构及肿瘤轨迹的电活动。研究了电生理、MRI及病理结果之间的相关性。还对32例表面或大脑大肿瘤患者进行了研究，这些患者接受了无微记录的影像引导下立体定向活检。
有微记录组的诊断阳性率为100%（低级别胶质瘤4例，高级别胶质瘤4例，弥漫性大B细胞淋巴瘤3例，生殖细胞瘤1例），与无微记录组的93.8%相当。术后并发症发生率与未使用微电极记录的传统影像引导方法一样低，且死亡率为0%，尽管所有病例中的目标病变均小且位于深部。深度微记录显示，无论肿瘤类型如何，肿瘤内神经活动均消失。沿轨迹在神经活动完全消失点上方6.3±4.5mm（均值±标准差）处神经活动开始下降。12例中有6例观察到爆发性放电，位于神经活动下降点上方3±1.4mm处。在神经活动下降和消失区域之间的轨迹上，常于0.5 - 1mm处发现损伤放电。在某些病例中可发现电生理、MRI及组织学结果之间存在密切相关性。
使用深度微记录技术进行的影像引导下立体定向活检是安全的，可实时提供准确的位置信息，且在手术过程中能将肿瘤与脑结构区分开来。此外，该技术在研究脑肿瘤的致痫性方面具有潜力。
