Yamano Akinari, Matsuda Masahide, Ishikawa Eiichi
Department of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
Cancers (Basel). 2024 Dec 28;17(1):62. doi: 10.3390/cancers17010062.
Skull base tumors such as meningiomas and schwannomas are often pathologically benign. However, surgery for these tumors poses significant challenges because of their proximity to critical structures such as the brainstem, cerebral arteries, veins, and cranial nerves. These structures are compressed or encased by the tumor as they grow, increasing the risk of unintended injury to these structures, which can potentially lead to severe neurological deficits. Preoperative imaging is crucial for assessing the tumor size, location, and its relationship with adjacent vital structures. This study reviews advanced imaging techniques that allow detailed visualization of vascular structures and cranial nerves. Contrast-enhanced computed tomography and digital subtraction angiography are optimal for evaluating vascular structures, whereas magnetic resonance imaging (MRI) with high-resolution T2-weighted images and diffusion tensor imaging are optimal for evaluating cranial nerves. These methods help surgeons plan tumor resection strategies, including surgical approaches, more precisely. An accurate preoperative assessment can contribute to safe tumor resection and preserve neurological function. Additionally, we report the MRI contrast defect sign in skull base meningiomas, which suggests cranial nerve penetration through the tumor. This is an essential finding for inferring the course of cranial nerves completely encased within the tumor. These preoperative imaging techniques have the potential to improve the outcomes of patients with skull base tumors. Furthermore, this study highlights the importance of multimodal imaging approaches and discusses future directions for imaging technology that could further develop preoperative surgical simulations and improve the quality of complex skull base tumor surgeries.
颅底肿瘤，如脑膜瘤和神经鞘瘤，在病理上通常是良性的。然而，由于这些肿瘤靠近脑干、脑动脉、静脉和颅神经等关键结构，对其进行手术具有重大挑战。随着肿瘤的生长，这些结构会被肿瘤压迫或包裹，增加了意外损伤这些结构的风险，这可能会导致严重的神经功能缺损。术前影像学检查对于评估肿瘤大小、位置及其与相邻重要结构的关系至关重要。本研究回顾了能够详细显示血管结构和颅神经的先进影像学技术。增强计算机断层扫描和数字减影血管造影最适合评估血管结构，而具有高分辨率T2加权图像和扩散张量成像的磁共振成像（MRI）最适合评估颅神经。这些方法有助于外科医生更精确地规划肿瘤切除策略，包括手术入路。准确的术前评估有助于安全地切除肿瘤并保留神经功能。此外，我们报告了颅底脑膜瘤的MRI对比剂缺损征象，这提示颅神经穿过肿瘤。这是推断完全被肿瘤包裹的颅神经走行的重要发现。这些术前影像学技术有可能改善颅底肿瘤患者的治疗效果。此外，本研究强调了多模态成像方法的重要性，并讨论了成像技术的未来发展方向，这些方向可能会进一步发展术前手术模拟并提高复杂颅底肿瘤手术的质量。
