The Application of Image Segmentation to Determine the Ratio of Peritumoral Edema Area to Tumor Area on Primary Malignant Brain Tumor and Metastases through Conventional Magnetic Resonance Imaging

BACKGROUND: Primary malignant brain tumor and metastases on the brain have a similar pattern in conventional Magnetic Resonance Imaging (MRI), even though both require entirely different treatment and management. The pathophysiological difference of peritumoral edema can help to distinguish the case of primary malignant brain tumor and brain metastases. AIM: This study aimed to analyze the ratio of the area of peritumoral edema to the tumor using Otsu’s method of image segmentation technique with a user-friendly Graphical User Interface (GUI). METODS: Data was prepared by obtaining the examination results of Anatomical Pathology and MRI imaging. The area of peritumoral edema was identified from MRI image segmentation with T2/FLAIR sequence. While the area of tumor was identified using MRI image segmentation with T1 sequence. RESULTS: The Mann-Whitney test was employed to analyze the ratio of the area of peritumoral edema to tumor on both groups. Data testing produced a significance level of 0.013 (p < 0.05) with a median value (Nmax-Nmin) of 1.14 (3.31-0.08) for the primary malignant brain tumor group and a median value (Nmax-Nmin) of 1.17 (10.30-0.90) for the brain metastases group. CONCLUSIONS: There was a significant difference in the ratio of the area of peritumoral edema to the area of tumor from both groups, in which brain metastases have a greater value than the primary malignant brain tumor.

STMO-12 Efforts for safe malignant brain tumor surgery at our hospital

Although maximal safe resection is the current standard for glioblastoma surgery, its safety and removal rate conflict with each other. Electrophysiological monitoring, such as motor evoked potential monitoring and awake craniotomy, can be utilized as safety measures; not all facilities can perform them. Herein, we present a representative case report on our efforts for a safe malignant brain tumor surgery. Case: A 77-year-old woman with glioblastoma in the premotor cortex presented with seizure of the upper left lower limb. Her pyramidal tract ran from the medial bottom to the posterior of the tumor. We performed excision from the site using the lowest gamma entropy. We then removed all parts of the tumor, with the exception of the pyramidal tract infiltration, and no paralysis was observed. She was definitively diagnosed with glioblastoma and is currently on maintenance chemotherapy. As a preoperative examination, we performed cerebrovascular angiography. We then performed various other tests to ascertain the patient’s condition. Considering lesions that affect language, Wada tests were performed regardless of laterality. For all patients with epilepsy onset, preoperative 256-channel electroencephalogram measurement and intraoperative the gamma entropy analysis were performed to confirm epileptogenicity. Considering lesions that affect eloquence, subdural electrodes were placed and brain function mapping was performed the next day. Based on the results, the safest cortical incision site and excision range were determined, and excision was performed on the following day. Of the 14 operated glioblastoma cases after November 2018, more than 85% of the contrast-enhanced lesions were completely removed in 7 cases, partially removed in 5 cases, and underwent biopsy in 2 cases. Postoperative Karnofsky performance status scores remained unchanged in 11 cases, improved in 1 case, and deteriorated in 2 cases. Our efforts have resulted in safe and sufficient removal of malignant brain tumors during surgery.

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

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.

TAMI-43. HYPOXIC REGULATION OF GLIOBLASTOMA TUMOR GROWTH THROUGH L(3)MBTL1

Glioblastoma (GBM) is the deadliest and most common of all primary brain tumors. Drosophila brain tumor models have uncovered signaling pathways regulating tumor growth that are highly conserved in GBM. Our search for a novel tumor suppressor using Drosophila led to Lethal (3) malignant brain tumor [l(3)mbt], temperature-sensitive mutants of which cause neuroepithelial tumor-like overproliferation in optic lobes. dL(3)MBT and its human orthologs L3MBTL1-L3MBTL4 all harbor Malignant Brain Tumor (MBT) domains that recognize methylated lysines on histone tails. Like dL(3)MBT, hL(3)MBTL1 acts as a chromatin compaction factor that represses transcription and inhibits cytokinesis in GBM cell lines. The highly hypoxic tumor microenvironment (TME) in GBM drives its progression, recurrence, and therapeutic resistance. However, it remains unclear if L(3)MBTL1 is regulated by TME cues to promote GBM growth. Based on this knowledge gap and our preliminary data, we hypothesize that hypoxia directly regulates L(3)MBTL1 in favor of GBM growth. Analysis of TCGA data for IDH-wildtype gliomas revealed that L3MBTL1 gene expression is downregulated in GBM, which are necrotic and severely hypoxic, compared to histologic grade 2/3 gliomas, which do not contain necrosis, indicating that hypoxia could potentially suppress L3MBTL1 to enhance glioma progression. TCGA data also revealed a number of HIF pathway and hypoxia-inducible genes strongly correlating with L3MBTL1 expression, including HIF1a and VHL. Using patient-derived GBM neurosphere cultures, we exposed glioma cells to hypoxia (1% O2 for 24hrs) and found that L3MBTL1 protein levels were suppressed compared to normoxia (21%). Under these same conditions, we found more rapid cell proliferation under hypoxia. Exploration of hypoxic TME regulation of the novel tumor suppressor L3MBTL1 in glioma progression has the potential to uncover novel mechanisms involving epigenetic modulation and potentially new therapeutic strategies.

SPECT with a New Radiopharmaceutical Drug 99mTc-1-thio-D-glucose of Dynamic Observation of a Patient with a Diagnosis of a Malignant Brain Tumor

This publication demonstrates the possibility of dynamic observation of a patient with a diagnosis of a malignant brain tumor at the stages of combined treatment using SPECT with a new radiopharmaceutical drug 99mTc-1-thio-D-glucose. Also in the described clinical case, an attempt was made to semi-quantitatively assess the accumulation of 99mTc-1-thio-D-glucose drug in the tumor, reflecting the dynamics of changes occurring in the tumor tissue under therapeutic effect. The SPECT data with 99mTc-1-thio-D-glucose in the course of dynamic observation of the patient were supported by the results of MRI and, most importantly, by PET data with 11C-methionine. Based on the results presented, it was suggested that a promising method would appear for evaluating the results of treatment of malignant brain tumors, which is an alternative to PET with labeled amino acids, which favorably differ in the availability and cost of the diagnostic procedure.