Department of Neurosurgery, Medical University Vienna, Waehringer Gürtel 18-20, Vienna, 1090, Austria.
Comprehensive Cancer Center, Central Nervous System Tumours Unit (CCC-CNS), Medical University Vienna, Spitalgasse 23, BT86/E 01, Vienna, 1090, Austria.
Lasers Surg Med. 2021 Mar;53(3):300-308. doi: 10.1002/lsm.23294. Epub 2020 Jul 1.
Complete neurosurgical resection of intracranial meningiomas is essential to avoid residual tumor tissue and thus minimize the risk of tumor recurrence. However, local recurrence of meningiomas is not uncommon mainly due to insufficient intraoperative detection of residual tumor tissue within the tumor bulk or peritumoral tissue such as bone and satellite lesions. Although 5-aminolevulinic acid (5-ALA) induced fluorescence was found to visualize the majority of meningiomas, no comprehensive histopathological assessment of fluorescing samples from the tumor bulk and peritumoral tissue is available. The aim of our study was thus to histopathologically analyze a large series of tissue samples derived from meningioma surgery to assess the positive predictive value (PPV) of visible 5-ALA fluorescence.
STUDY DESIGN/MATERIALS AND METHODS: In this study, we retrospectively investigated a series of tissue samples with visible 5-ALA fluorescence collected during surgery of intracranial meningiomas from the tumor bulk and peritumoral tissue including the bone flap, dura/dural tail, arachnoidea, adjacent cortex, and satellite lesions. The tumor diagnosis was established according to the World Health Organization (WHO) criteria and all collected fluorescing samples were screened for presence of tumor tissue to calculate the PPV.
Altogether, 191 tissue samples with visible 5-ALA fluorescence derived during surgery of 85 meningiomas (63 WHO grade I, 17 WHO grade II, and 5 WHO grade III) were included. In detail, 158 samples from the tumor bulk and 33 specimens from the peritumoral tissue were investigated. According to histopathological analysis, the PPV of 5-ALA fluorescence was significantly higher in samples from the tumor bulk (100%) as compared with peritumoral tissue (73%; P < 0.001). With regard to peritumoral tissue, tumor tissue was present in most fluorescing samples from the satellite lesions (100%), the bone flap (92%), arachnoidea (83%), and dura/dural tail (75%). In contrast, tumor tissue was absent in the majority of samples from fluorescing cortex (six of seven samples; 86%). However, distinct reactive tissue alterations were found in all six tumor-free fluorescing cortex samples and additional vascular proliferation in two cases.
In this largest series to date, visible 5-ALA fluorescence is characterized by a high PPV detecting tumor bulk and peritumoral tissue in intracranial meningiomas. Thus, 5-ALA fluorescence supports the neurosurgeon in identifying residual tumor tissue at relevant surgical sites to optimize meningioma surgery and minimize the risk of local recurrence. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.
为避免肿瘤残留组织，降低肿瘤复发风险，颅内脑膜瘤的完全神经外科切除至关重要。然而，脑膜瘤的局部复发并不少见，主要是由于术中对肿瘤内或肿瘤周围组织（如骨和卫星病灶）中的肿瘤残留组织的检测不足。尽管 5-氨基酮戊酸（5-ALA）诱导的荧光被发现可以使大多数脑膜瘤可视化，但尚未对来自肿瘤和肿瘤周围组织的荧光样本进行全面的组织病理学评估。因此，我们的研究目的是通过组织病理学分析脑膜瘤手术中的大量样本，评估可见 5-ALA 荧光的阳性预测值（PPV）。
研究设计/材料与方法：在这项研究中，我们回顾性地调查了一系列在颅内脑膜瘤手术过程中收集的可见 5-ALA 荧光的组织样本，这些样本来自肿瘤、肿瘤周围组织，包括骨瓣、硬脑膜/硬脑膜尾、蛛网膜、临近皮质和卫星病灶。肿瘤诊断根据世界卫生组织（WHO）标准确立，所有收集的荧光样本均被筛查是否存在肿瘤组织，以计算 PPV。
总共纳入了 85 例脑膜瘤手术中可见 5-ALA 荧光的 191 个组织样本（63 例 WHO 分级 I，17 例 WHO 分级 II，5 例 WHO 分级 III）。详细地说，有 158 个样本来自肿瘤，33 个样本来自肿瘤周围组织。根据组织病理学分析，肿瘤内样本的 5-ALA 荧光 PPV 明显高于肿瘤周围组织（100%比 73%；P<0.001）。对于肿瘤周围组织，卫星病灶（100%）、骨瓣（92%）、蛛网膜（83%）和硬脑膜/硬脑膜尾（75%）的荧光样本中肿瘤组织较为常见。相比之下，在大部分来自荧光皮质的样本中（七例样本中的六例；86%）均未见肿瘤组织。然而，在所有六个无肿瘤荧光皮质样本中均发现了明显的反应性组织改变，且在两个样本中还发现了额外的血管增殖。
在迄今为止最大的系列研究中，可见的 5-ALA 荧光具有高 PPV，可检测颅内脑膜瘤的肿瘤内和肿瘤周围组织。因此，5-ALA 荧光有助于神经外科医生在相关手术部位识别残余肿瘤组织，从而优化脑膜瘤手术，降低局部复发风险。
