• 1. Percentage of patients with a histologically confirmed malignant glioma (grade III or IV –WHO) without definite residual contrast agent-accumulating tumour in the early post-operative control MRI (within 72 hours of the operation).
  
• 2. Progression-free survival 6 months after primary surgical treatment of a malignant gli-oma in patients with histologically confirmed malignant glioma (grade III or IV –WHO).
  

• 1. Overall survival.
  
• 2. Progression-free survival (PFS) 9, 12, 15 and 18 months after primary surgical treatment
  
• 3. Volume of residual tumour
  
• 4. Toxicity after oral administration of 5-Aminolevulinic acid.
  
• 5. Neurological condition 7 days, 6 and 12 weeks, 6, 9, 12, and 18 months after primary surgical treatment
  

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.