Introduction: Diagnostic yield and procedure-related risks are crucial points of the stereotactic needle biopsy. The attempt to increase the first, by multiple samplings, can often increase the second. In this balance, intraoperative adjuncts that could optimize the diagnosis are spreading in the course of time. The evidence that the fluorescein (FL) works as a marker of blood-brain barrier damage have led to consider it for diagnostic confirmation in stereotactic biopsies of contrast-enhancing brain tumors. The aim of this study is to contribute to validate this methods and the safety and feasibility of the procedure in awake patient.
Methods: We retrospectively analyzed 6 cases of patients with contrast-enhancing brain tumors (1 lymphoma, 1 WHO III glioma and 4 glioblastomas) underwent awake stereotactic needle biopsy (frameless pinless electromagnetic in 2 cases and frame-based in 4 cases) at our Unit by intraoperative FL-assistance (group 1), verifying fluorescence status under the YELLOW 560 filter integrated into operative microscope. Group 1 was matched with a control group of 9 patients with contrast-enhancing brain tumors underwent awake stereotactic biopsy during the last year without FL-assistance (group 2). In addition, concerning literature was reviewed in PubMed/Medline database.
Results: The awake procedure was well tolerated in all patients. Adverse reactions related to additional use of FL did not occur. In group 1 the mean of number of samplings was 1.17 (vs 2.33 of group 2, P<0.05) with a specificity of 100%. There were no intraoperative and post-operative surgical complications and the mean of hospitalization time after procedure was significantly lower than group 2. Literature analysis supports the usefulness of fluorescence-based technology (5-ALA and FL) in this field, even if concomitant awake procedures are not currently reported.
Conclusions: FL-assistance during stereotactic needle biopsy of contrast-enhancing brain tumors can give a real-time confirmation of tumor tissue, improving the diagnostic yield and reducing morbidity, time of procedure and hospitalization. The association with an awake procedure appears safe, feasible and minimally invasive.
Patient Care: This procedure can give a real-time confirmation of tumor tissue, improving the diagnostic yield and reducing morbidity, time of procedure and hospitalization. The association with an awake procedure appears safe, feasible and minimally invasive.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of the stereotactic biopsy guided by fluorescein. Discuss, in small groups about specificity and safety of fluorescin sodium for biopsy. Identify an effective treatment for deep brain tumors and lesions that deserve a biopsy.