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Glioblastoma is the most common primary malignant brain tumor. Despite advances in multimodal concepts over the last decades, prognosis remains poor. Treatment of patients with glioblastoma remains a considerable challenge due to the infiltrative nature of the tumor, rapid growth rates, and tumor heterogeneity. Standard therapy consists of maximally safe microsurgical resection followed by adjuvant radio- and chemotherapy with temozolomide. In recent years, local therapies have been extensively investigated in experimental as well as translational levels. External stimuli-responsive therapies such as Photodynamic Therapy (PDT), Sonodynamic Therapy (SDT) and Radiodynamic Therapy (RDT) can induce cell death mechanisms via generation of reactive oxygen species (ROS) after administration of five-aminolevulinic acid (5-ALA), which induces the formation of sensitizing porphyrins within tumor tissue. Preliminary data from clinical trials are available. The aim of this review is to summarize the status of such therapeutic approaches as an adjunct to current standard therapy in glioblastoma. [ABSTRACT FROM AUTHOR]

Objective: 5-Aminolevulinic acid (5-ALA)–guided resection of gliomas in adults enables better delineation between tumor and normal brain, allowing improved resection and improved patients' outcome. Recently, several reports were published regarding 5-ALA for resection of pediatric brain tumors. The aim of the study was to determine the intracellular fluorescence of protoporphyrin IX (PPIX) in pediatric brain tumors by hyperspectral imaging and to compare it with visually observed intraoperative fluorescence. Methods: 5-ALA was administered orally 4 h prior to surgery. During tumor resection, the surgeon assessed the fluorescence signal to be strong, weak, or absent. Subsequently, fluorescence intensity of tumor samples was measured via spectroscopy. In addition, clinical data, imaging, and laboratory data were analyzed. Results: Eleven children (1–16 years) were operated. Tumor entities included three (n = 3) medulloblastomas, two (n = 2) pilocytic astrocytomas (PA), two (n = 2) anaplastic ependymomas and one (n = 1) diffuse astrocytoma, anaplastic astrocytoma (n = 1), pilomyxoid astrocytoma (n = 1) and anaplastic pleomorphic xanthoastrocytoma (n = 1). Strong fluorescence was visible in all anaplastic tumors and one PA; one PA demonstrated weak fluorescence. Visible fluorescence was strongly associated with intracellular fluorescence intensity and PPIX concentration (P < 0.05). Within all tumors with visible fluorescence, the intracellular PPIX concentration was greater than 4 μg/ml. Except for moderate and transient elevation of liver enzymes, no 5-ALA related adverse events were reported. Conclusion: We demonstrate a strong association between intraoperative observations and spectrometric measurements of PPIX fluorescence in tumor tissue. As in former studies, fluorescence signal was more commonly observed in malignant glial tumors. Further prospective controlled trials should be conducted to investigate the feasibility of 5-ALA-guided resection of pediatric brain tumors. [ABSTRACT FROM AUTHOR]

Background: 5-Aminolevulinic acid (5-ALA)-guided resection of gliomas in adults enables better differentiation between tumor and normal brain tissue, allowing a higher degree of resection, and improves patient outcomes. In recent years, several reports have emerged regarding the use of 5-ALA in other brain tumor entities, including pediatric brains tumors. Since gross total resection (GTR) of many brain tumors in children is crucial and the role of 5-ALA-guided resection of these tumors is not clear, we sought to perform a comprehensive literature review on this topic. Methods: A systematic literature review of EMBASE and MEDLINE/PubMed databases revealed 19 eligible publications encompassing 175 5-ALA-guided operations on pediatric brain tumors. To prevent bias, publications were revised independently by two authors. Results: We found that 5-ALA-guided resection enabled the surgeons to identify the tumor more easily and was considered helpful mainly in cases of glioblastoma (GBM, 21/27, 78%), anaplastic ependymoma WHO grade III (10/14, 71%), and anaplastic astrocytoma (4/6, 67%). In contrast, cases of pilocytic astrocytomas (PAs) and medulloblastomas 5-ALA-guided surgery did not show consistent fluorescent signals and 5-ALA was considered helpful only in 12% and 22% of cases, respectively. Accumulation of fluorescent porphyrins seems to depend on WHO tumor grading. One important finding is that when 5-ALA-guided resections were considered helpful, the degree of resection was higher than is cases where it was not helpful. The rate of adverse events related to 5-ALA was negligible, especially new postoperative sequelae. Conclusion: 5-ALA could play a role in resection of pediatric brain tumors. However, further prospective clinical trials are needed. [ABSTRACT FROM AUTHOR]

They report on a patient with suspected high-grade glioma operated on using the novel probe with the tumor turning out to be a meningioma. They report unexpected strong, tumor-linked fluorescence observed with the ORBEYE® exoscope device and corroborate tumor selectivity with several positively fluorescing tumor biopsies. This article is part of the Topical Collection on Tumor - Meningioma Dear Editor, With great interest, we have read the recent publication by Skjøth-Rasmussen and co-workers on a novel fluorescent probe for intraoperative detection of brain tumors, which appears to overcome some of the limitations of 5-ALA, a traditionally used intra-operative fluorophore [[1]]. [Extracted from the article]