Diagnosis and Management of Brain Tumours

Brain tumour diagnosis and management follow a clear sequence: recognise the symptoms that localise the tumour, examine the whole patient, confirm the lesion on contrast MRI, then plan surgery that secures a tissue diagnosis and removes as much tumour as is safe. Dr. Rahul Gupta, Senior Director & HOD Neuro and Spine Surgery, Fortis Hospital, Noida, India, holds that surgery should not leave a patient who was well beforehand worse after it.

Dr. Gupta has more than 22 years of neurosurgical experience: eight years as a professor in a government institution and the last 13 years at Fortis Hospital, Noida, after residency at the Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh. His department performs 7 to 10 brain tumour operations and 60 to 75 brain and spine procedures every month, about 70% of them by Dr. Gupta himself. This guide sets out his framework for diagnosing a brain tumour, deciding what surgery should achieve, and understanding which tumours carry which outlook. The operating-theatre technology, the vascular and endoscopic techniques, and recovery are covered in depth in three companion articles.

How brain tumour surgery has changed in 25 years

When Dr. Gupta was a resident, about 25 years before this masterclass, the outlook after brain tumour surgery was far less certain. By his account, the success of the surgical procedure itself was up to 75 to 80%. Many patients developed cerebrospinal fluid (CSF) leaks, infection or brain swelling (oedema), and many needed a ventilator at a time when ventilators were hard to obtain.

He attributes the change since then to progress on three fronts at once:

• Diagnostics: high-quality MRI with newer sequences, and catheter angiography that shows a tumour's blood supply and allows it to be blocked before surgery.
• The operating theatre: good-quality operating microscopes, now available at most centres, together with fluorescence, ultrasonic aspirators, neuronavigation and endoscopes.
• Peri-operative care: dedicated neuroanaesthesia and neurocritical care teams who control brain swelling during surgery and manage the patient in the intensive care unit afterwards.

His own unit reflects that model. Fortis Hospital, Noida is a 500-bed hospital with three neurosurgeons, a neurosurgery trainee and assistant neurosurgeons, a separate neuroanaesthesia department covering both the operating theatre and the intensive care unit, a team of neurophysicians, 3 Tesla and 1.5 Tesla MRI scanners, CT, and a neuro catheterisation laboratory for endovascular procedures.

Brain tumour symptoms: what each one localises

A brain tumour announces itself through the function of the brain it presses on, which is why Dr. Gupta presents symptoms by location rather than as a single list.

• Headache. It can be mild or severe, continuous or intermittent. Vomiting is very often associated with it.
• Seizures. These can be focal (one limb or one side) or generalised.
• Weakness. Tumours in the motor cortex, brainstem or thalamus can cause loss of power in the limbs.
• Vision problems. These point mainly to suprasellar tumours (above the pituitary fossa, close to the optic nerves), tumours in the orbit, or occipital tumours at the back of the brain.
• Hearing loss. This can be associated with acoustic neuromas, benign tumours of the nerve that carries hearing and balance.
• Hormonal imbalance. Pituitary tumours are secretory or non-secretory. Secretory tumours can cause thyroid abnormalities, hyperprolactinaemia (excess prolactin), growth hormone excess with gigantism or acromegaly, or excess cortisol. Large tumours of either kind can compress the normal gland and cause hormone deficiency, including too little cortisol.
• Behaviour change. Frontal lobe tumours can alter personality, and Dr. Gupta notes that such patients may first see a psychiatrist rather than a neurologist or neurosurgeon.
• Drowsiness and sudden loss of consciousness. Large tumours cause drowsiness; bleeding inside a tumour can cause sudden collapse.
• Speech difficulty. Tumours in the dominant hemisphere involving the temporal, posterior temporal or inferior frontal lobe affect speech.
• Walking abnormalities. These are characteristic of cerebellar and brainstem tumours.

Many tumours cause no symptoms at all. They are found when a patient has an MRI for another reason, and are described as incidental tumours.

The clinical examination: neurological and general

Dr. Gupta treats a thorough neurological examination as non-negotiable: higher mental functions, lobar signs, the cranial nerves (which he singles out as very important), limb power, sensation and cerebellar signs. It is the same examination applied to any patient with neurological disease, and it tells the surgeon where the problem sits before any scan does.

The general physical examination matters as much, for a reason that surprises many non-specialists: the most common brain tumour is a metastasis, a deposit that has spread from a cancer elsewhere in the body. Examining the chest, abdomen and lymph nodes can reveal the primary cancer. The spine is examined because lesions may be present at several sites, and the skin is checked for signs of hereditary syndromes; neurofibromatosis, for example, produces characteristic skin spots.

Brain tumour diagnosis: why contrast MRI is the investigation of choice

When the symptoms and signs suggest a brain tumour, MRI of the brain is, in Dr. Gupta's words, the most important, most appropriate and most informative investigation. A plain MRI can occasionally miss a tumour, so a contrast-enhanced MRI, which is very sensitive, should be performed.

Once a tumour is found, special MRI sequences describe its character, map the functional areas of the brain and show where the major nerve fibre tracts run. Tractography, one such sequence, displays the motor tracts running down from the motor cortex so that the surgeon can plan a route that does not disturb them. These advances let the team characterise and measure the tumour precisely, so that the operating surgeon knows exactly what he is going into.

Can a CT scan miss a brain tumour?

Yes. A plain CT can miss a brain tumour in up to 10% of cases, so Dr. Gupta's advice to referring doctors is not to rely on a plain CT to rule one out. CT is less sensitive than MRI, but it still has a role: it shows midline shift, the state of the bone and hydrocephalus (a build-up of CSF), and it is useful for follow-up. For some tumours, cerebral angiography adds information about blood supply, which becomes central when embolisation is considered.

What brain tumour surgery aims to achieve

Dr. Gupta frames every operation around four aims:

1. A histopathological diagnosis. The team must know exactly what type of tumour it is, because that determines everything that follows.
2. Maximum safe removal. When a tumour is very large or sits in an important area, complete removal may not be possible, but reducing its bulk (debulking) allows other treatments to work afterwards.
3. Complete removal where it is safe. Certain benign tumours can be removed completely and safely, and should be.
4. Minimum morbidity and minimum recurrence. A patient who walked into hospital should not leave unconscious, bedridden or unable to use his limbs because the surgeon pursued complete removal and damaged normal structures. Other treatments exist for residual tumour; normal brain cannot be replaced.

Is surgery always needed for a brain tumour?

In Dr. Gupta's view, surgery is mandatory in 99.9% of cases, because treatment depends on a tissue diagnosis. The main exception is a diffuse brainstem glioma in a child, which can be treated with radiotherapy on its typical MRI appearance alone. For other deep-seated tumours expected to be gliomas, a stereotactic or navigation-guided biopsy usually comes first, because histology and molecular markers guide treatment and lookalike lesions, such as lymphoma, are treated differently. When the question is simply "what is this?", the definitive test is histopathological examination of the tissue taken at surgery.

The most common brain tumours and their outlook

Metastasis is the most common brain tumour, but Dr. Gupta now operates on few metastatic cases: with good radiotherapy and chemotherapy, most are managed by radiation and medical oncologists. Surgery is indicated when there is a solitary large metastasis, or when a metastasis causes mass effect and the patient is symptomatic.

The tumours his team most often removes are:

• Gliomas, tumours arising from the brain's supporting (glial) cells, graded from 1 to 4. Grade 4 gliomas, glioblastomas, are the worst and carry a very poor prognosis.
• Meningiomas, tumours of the membranes covering the brain. They usually have a good prognosis, but are occasionally atypical or malignant and then need radiotherapy, chemotherapy and close follow-up. Some sit at the skull base and encase the large blood vessels, which makes surgery difficult; after a subtotal excision, modern radiotherapy such as Gamma Knife or CyberKnife can treat the remainder.
• Pituitary tumours, benign tumours that Dr. Gupta's team usually removes endoscopically through the nose. Very large tumours extending beside or above the pituitary fossa sometimes need an approach through the skull.
• Intraventricular tumours, inside the fluid-filled cavities of the brain, which are less common.

For glioblastoma, the outlook remains poor, but chemotherapy and radiotherapy can extend survival and preserve quality of life for that time, and research into the disease is active. At the extremes of age, surgery, chemotherapy and radiotherapy may not benefit infants with very large tumours, or elderly patients with very large tumours involving critical areas of the brain.

What modern technology adds in the operating theatre

The theatre has changed as much as the scanner. Dr. Gupta's team combines the operating microscope, tumour fluorescence, neuronavigation, intraoperative imaging, neuromonitoring and awake craniotomy, so that tumours in speech and motor areas can be removed while the patient talks and moves. That toolkit, and the cases that show it, are set out in awake craniotomy, neuronavigation and fluorescence-guided surgery. Vascular skull-base tumours, endoscopic pituitary surgery and the paediatric cases from the session are covered in embolisation, endoscopy and paediatric brain tumour surgery. Complications, follow-up imaging, rehabilitation and the minimum facilities for safe surgery are covered in recovery and follow-up after brain tumour surgery.

For a patient-centred comparison of benign and malignant tumours from a separate masterclass, see Dr. Sonal Gupta's guide to benign and malignant brain tumours and her article on brain tumour headache and when to scan. Brain tumours in children, in the wider context of childhood cancer, are discussed in childhood solid tumours.

Where the field is heading

Dr. Gupta is candid that the work is a constant learning process: not every case succeeds, some tumours are very risky or inoperable, and surgeons improve by learning from their own mistakes and from those reported in the literature. His own learning sources are CMEs and workshops, observerships, fellowships, the internet and the opinion of colleagues.

He points to three developments. Robotic neurosurgery is coming, and robotic stereotactic biopsy is already available. Research into tumour biology is trying to explain why tumours recur and how their malignant behaviour can be reduced, alongside advances in chemotherapy and radiotherapy. Gamma Knife radiosurgery, a highly focused form of radiation, is now available for small brain tumours and metastatic lesions.

The questions doctors raised at the end of the session, on definitive diagnosis, complications, prognosis and resource-limited practice, are answered in the live discussion with Dr. Rahul Gupta. More about Dr. Gupta's practice is on his doctor profile, and other masterclasses in the field are collected under neurosurgery.