5-aminolevulinic acid; Fluorescence intensity; Fluorescence-guided resection; Glioblastoma; Histopathology

Objasnění patologicko-anatomického korelátu k intenzitě peroperačně zaznamenané fluorescence. Během fluorescencí navigované resekce glioblastomu mohou být v chirurgickém poli identifikovány tři různé intenzity fluorescence posuzované tkáně za použití kyseliny 5-aminolevulinové: 1. červená, silně intenzivní zóna fluorescence; 2. růžová, slabě intenzivní zóna fluorescence; 3. tkáň bez fluorescence.

Jo ascertain correlation between histological findings and the intensity of intraoperative fluorescence. During 5-aminolevulinic acid fluorescence-guided glioblastoma resection, three different levels of fluorescence intensity of the examined tissue can be distinguished in the operative field: 1. red, highly intensive fluorescence zone; 2. pink, moderately intensive fluorescence zone; 3. none, tissue without fluorescence. Groups and metliods: A prospective study of 13 patients who underwent fluorescence-guided glioblastoma surgery. Representative specimens of the corresponding levels of fluorescence intensity were collected for histological examination. The semi-quantitative method was used to evaluation relative proportion of malignant cells in the tissue. Results;The histological examination from the highly intensive fluorescence zone biopsy samples revealed 75-100% proportion of malignant cells in the tissue. The infiltration reached 50-75% of the examined tissue in the moderately intensive fluorescence zone, and co-existence of glioblastoma and low grade glioma was noted in two cases, in six cases, there were no malignant cells in the negative fluorescence zone. However, seven specimens were positive for malignant cells, with the infiltration rate around 25% of the tissue. The correlation between the fluorescence intensity and the relative proportion of malignant cells in the tissue was statistically significant (p value < 0.001), and high positive predictive value of the fluorescence for the presence of malignant cells (PPV = 92%) was observed. Conclusion:The intensity of intraoperative fluorescence correlates with the relative proportion of malignant cells in the tissue. The presence of malignant cells beyond observable fluorescence was confirmed in more than a half of the biopsy samples.