Fluorescence-guided Resection of Malignant Gliomas With 5-Aminolevulinic Acid

Fluorescence-guided Resection of Malignant Gliomas With 5-Aminolevulinic Acid (5-ALA) vs. Conventional Resection

The aim of the study "Fluorescence-guided resection of malignant gliomas with 5-Aminolevulinic acid (5-ALA) vs. conventional resection" is to determine how accurately contrast agent-accumulating tumour can be removed by primary surgery and to assess the clinical usefulness of this method.

Malignant gliomas are locally invasive tumors that carry a dismal prognosis despite a combination of surgery, radiotherapy and chemotherapy. Cytoreductive surgery is generally considered beneficial but complete resection of contrast enhancing tumor is achieved in less than 20 % of patients, one reason being the difficulty in discerning marginal, enhancing tumor intraoperatively.

Five-aminolevulinic acid (5-ALA) leads to the accumulation of fluorescent porphyrins in malignant gliomas, a phenomenon under exploration for intraoperative identification and resection of these tumors. This study investigated the benefit derived from fluorescent-guided resections using 5-ALA on surgical radicality, progression-free survival and morbidity.

Inclusion Criteria:

• Radiological suspicion of a unilocular malignant glioma with distinct ring- or garland-shaped contrast agent-accumulating tumour structures and a core of reduced intensity in the MRI (central necroses) with no significant non-staining tumour tissue (exclusion of a secondary malignant glioma).
• Indication for surgical tumour resection. If radical resection is planned, the location of the contrast agent-accumulating tumour should allow complete resection.
• First operation of the tumour, no other tumour-specific pretreatment
• Karnofsky at least 70 %
• Patient's written informed consent
• Age 18-72 years

Exclusion Criteria:

• Tumour location in the midline, basal ganglia, cerebellum or brain stem
• More than one contrast agent-accumulating lesion unrelated to the primary tumour or extracerebral metastases
• Porphyria, hypersensitivity to porphyrins
• Renal insufficiency: Creatinine > 2.0 mg/dl
• Hepatic insufficiency: Bilirubin > 3 mg/dl
• Quick test < 60 %
• gamma-GT > 70 U/I
• Malignancies other than basaliomas
• Existing or planned pregnancy or lactation, or inadequate contraception
• Simultaneous participation in another clinical trial or participation in another clinical trial in the 30 days preceding randomisation