Fluorescence guided surgery (5 ALA) in the management of gliomas

Gliomas, particularly those of higher malignancy grade, are characterised by indistinct borders with normal brain tissue.

Under the operating microscope, the neurosurgeon often sees tissue that appears visually normal, while in reality it contains scattered cancer cells. This difficulty in visually distinguishing tumour from healthy tissue is one of the main reasons why complete surgical removal of a high‑grade glioma remains technically demanding.

Fluorescence‑guided surgery with 5‑ALA was developed precisely to address this problem.

What is fluorescence‑guided surgery?

This technique enables the surgeon to “see” cancer cells in real time during the operation, with the help of special illumination on the operating microscope.

Rather than relying solely on experience and visual assessment of tissue texture, the surgeon gains an additional, objective “guide” to the precise location of the tumour – something particularly useful near eloquent or otherwise sensitive areas of the brain.

How 5‑ALA works

5‑ALA (5‑aminolaevulinic acid) is given orally a few hours before surgery. Within cancer cells, it is selectively metabolised into a photosensitive substance that accumulates to a much greater degree in glioma cells than in normal brain tissue.

When, during the procedure, the surgeon switches the microscope illumination to a special blue light, the tumour takes on a characteristic pink‑red fluorescent hue, while healthy tissue remains dark blue.

This visual contrast allows discrimination that would not be possible with conventional white light alone.

Why it improves surgical outcomes

Greater accuracy in identifying tumour margins is associated with a higher rate of extensive, as complete as possible removal (gross total resection). This has practical significance, since the smaller the residual tumour volume after surgery, the more favourable the subsequent course of the disease tends to be, in conjunction with adjuvant treatments (radiotherapy, chemotherapy).

The technique does not replace the surgeon’s clinical judgement and experience, but acts as a valuable complementary tool in expert hands.

Dr Mazarakis’ experience

Dr Nektarios Mazarakis is certified in the use of 5‑ALA and has spent the majority of his surgical career in neurosurgical centres in the United Kingdom, where fluorescence‑guided surgery with 5‑ALA is established practice in operations for high‑grade gliomas.

This familiarity with advanced surgical protocols, gained over many years of clinical practice in major NHS centres, is a key component of his expertise in the surgical management of brain tumours.

When the technique is recommended

Fluorescence‑guided surgery is considered mainly in cases of higher‑grade gliomas, where visual differentiation between tumour and normal tissue is more difficult.

Suitability is assessed individually for each patient, based on imaging, tumour location and the overall clinical picture.