High-grade glioma/glioblastoma multiforme: is there a role for photodynamic therapy?
ABSTRACT In the United States, the 5-year survival rate for patients of all ages with all types of brain tumors is approximately 20%, with the scale skewed toward even poorer survival in patients with gliomas. Although surgery and radiotherapy are primary treatment options, surgery is rarely curative and radiotherapy has had little impact on overall survival. Predominantly studied in adults with advanced high-grade gliomas, photodynamic therapy (PDT) represents a paradigmatic shift in the treatment of brain tumors. With no clear standard of care for brain tumors, PDT may emerge as a potential alternative, although challenges regarding its clinical use remain and studies confirming its promise are necessary.
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ABSTRACT: Background and Objectives In high-grade meningiomas and a subgroup of clinically aggressive benign meningiomas tumor control is still insufficient. Recently 5-ALA fluorescence in meningiomas was reported. The impact of 5-ALA fluorescence-guided surgery (FGS) on surgical decision-making and extent of resection has not yet been systematically analyzed, especially not in high-grade meningiomas. The present study deals with three main questions regarding 5-ALA FGS in meningiomas: to assess the potential for discriminating different WHO grades intra-operatively, to analyze the influence on surgical strategy and to evaluate the impact on extent of resection. Methods Data from 31 meningiomas operated with 5-ALA FGS were retrospectively analyzed. Intraoperative fluorescence was graded by the surgeon as “no”, “low” or “high”. Correlations between semi-quantitative fluorescence and histological features (WHO grade) were analyzed. The influence of 5-ALA fluorescence on surgical strategy and the impact of 5-ALA FGS on degree of resection (Simpson grade and post-operative imaging) were studied. In tumors showing infiltrative growth the extent of resection of fluorescence positive tissue was evaluated. Results The population comprised 19 WHO grade I, 8 grade II and 4 grade III tumors (61% benign and 39% high-grade meningiomas). 94% of the tumors showed positive fluorescence. Different fluorescence intensities were observed: “no” in two, “high” in 12 and “low” in 17 tumors, respectively. A significant correlation between fluorescence intensity and WHO grade was found (ρ=0.557, p = 0.001). 5-ALA improved the extent of resection in 3/16 (19%) of grade I and in 6/8 (75%) of grade II/III meningiomas. This improvement was not measurable by the Simpson grading as rated by the surgeon and controlled on post-operative imaging. Conclusions In the present population a strong correlation between fluorescence intensity and WHO grade was observed. 5-ALA FGS improved the extent of resection in meningiomas. Especially in high-grade tumors additional information on brain and neurovascular infiltration was provided. The improved resection was not measurable by Simpson's grading necessitating an additional item, which rates residual fluorescence. Long-term studies are necessary to evaluate a possible impact of FGS on recurrence and overall survival.Photodiagnosis and Photodynamic Therapy 08/2014; 11(4). DOI:10.1016/j.pdpdt.2014.07.008 · 2.52 Impact Factor