Low dose 5-aminolevulinic acid: Implications in spectroscopic measurements during brain tumor surgery

Fluorescence-guided surgery (FGS) allows surgeons to have improved visualization of tumor tissue in the operating room, enabling maximal safe resection of malignant brain tumors. Over the past two decades, multiple fluorescent agents have been studied for FGS, including 5-aminolevulinic acid (5-ALA), fluorescein sodium, and indocyanine green (ICG). Both non-targeted and targeted fluorescent agents are currently being used in clinical practice, as well as under investigation, for glioma visualization and resection. While the efficacy of intraoperative fluorescence in studied fluorophores has been well established in the literature, the effect of timing on fluorophore administration in glioma surgery has not been as well depicted. In the past year, recent studies of 5-ALA use have shown that intraoperative fluorescence may persist beyond the previously studied window used in prior multicenter trials. Additionally, the use of fluorophores for different brain tumor types is discussed in detail, including a discussion of choosing the right fluorophore based on tumor etiology. In the following review, the authors will describe the temporal nature of the various fluorophores used in glioma surgery, what remains uncertain in FGS, and provide a guide for using fluorescence as a surgical adjunct in brain tumor surgery.

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COT-13 Luminance analysis of 5-aminolevulinic acid using Image J for malignant brain tumor

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab159.117 ◽

2021 ◽

Vol 3 (Supplement_6) ◽

pp. vi30-vi30

Author(s):

Takashi Kon ◽

Yusuke Kobayashi ◽

Yosuke Sato ◽

Katsuyoshi Shimizu ◽

Tohru Mizutani

Keyword(s):

Brain Tumor ◽

Malignant Glioma ◽

Aminolevulinic Acid ◽

Malignant Gliomas ◽

Malignant Brain Tumor ◽

Photodynamic Diagnosis ◽

Tumor Surgery ◽

Maximum Luminance ◽

Brain Tumor Surgery ◽

Average Maximum

Abstract Purpose: For malignant brain tumor surgery, photodynamic diagnosis (PDD) with 5-aminolevulinic acid (5-ALA) is useful for maximal removal of the tumor. Although it has the advantage of identifying the presence or absence of residual tumors during surgery, there are variations in positive rates, and the classification is limited, based on visual inspection such as Stummer’s classification (strong, vague, none). We analyzed the luminance of positive findings using software Image J for brain tumor surgery using 5-ALA, and we report the results. Materials and Methods: From April 2018 to March 2021, 31 patients with suspected malignant glioma before surgery were included. Intraoperative 5-ALA positive findings were analyzed by software Image J (Wayne Rasband: NIH), the luminance was measured with a histogram, and compared the maximum luminance titer. Results: Among the positive cases, the average maximum luminance value for malignant glioma was 101 (50–168), which consisted of 11 cases of Glioblastoma, 1 case of Oligodendroglioma, and 1 case of anaplastic astrocytoma. The average maximum brightness of metastatic brain tumors is lower than that of malignant gliomas, even if they are visually strong, 83.5 (28–121). Conclusions: Even if it is visually strong in the conventional Stummer classification, it may be possible to classify in detail by analyzing luminance with Image J. In addition, more objective index is necessary to classify the vague findings.

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