What is a chordoma?
Chordomas are a very rare tumour arising from embryonic cells (cells that are part of development in the womb). The 3 areas of the body in which chordomas may arise are the skull base, the spine and the sacrum. Skull base chordomas require management by a team with expertise in skull base surgery. Despite this being an extremely rare condition, The Brain and Spine Clinic offers such expertise.
What symptoms can they cause?
The symptoms that are produced by a chordoma relate to the invasion of the base of the skull and/or the consequences of the chordoma pressing on the brain. Chordomas will usually erode the bone of the skull base over time, and can therefore affect the structures passing through it, most notably the cranial nerves. Presenting features therefore depend on which cranial nerves are involved and can include double vision and disturbance of facial sensation.
What treatment is offered for chordomas?
The treatment is complex and challenging. It is mandatory to be managed by a clinical team with both experience and expertise in the condition.
The treatment of a skull base chordoma is through a combination of surgery and radiotherapy. Surgery is usually the first stage of treatment. The principal of surgery is to obtain maximal safe resection whilst not harming any critical structures. Chordomas arise from the base of the skull through which are passing the cranial nerves supplying function to the head and neck, the spinal cord and the vessels supplying blood to the brain (arteries) and draining blood from the brain (veins and venous sinuses). The nature of this surgery is therefore technically challenging and requires a multi-disciplinary surgical team. Surgery must also achieve tumour clearance from structures which are particularly sensitive to any subsequent radiotherapy, such as the brainstem and optic nerves. Invariably prior to the surgery, the surgical team (neurosurgery and ENT) will discuss with the radiotherapists the aims of surgery including which areas of the tumour can be removed and which cannot.
The nature of a chordoma, invading the base of the skull, is that surgical resection, however successful, does not cure the condition and it is for this reason that post-operative radiotherapy is required to try and minimise the chance of recurrence.
What is the role of proton beam therapy?
In recent years, a specialised form of radiotherapy, proton beam radiotherapy, has become increasingly considered to be the gold standard form of radiotherapy for chordomas. The reason for this relates to the physical nature of protons compared to the more usual photon radiotherapy. Protons are larger and so travel less far outside of the radiotherapy field. The risk of harm to the adjacent delicate neurological structures is therefore considered to be less.
At the present time, there is not yet a functional proton beam radiotherapy centre in the UK. However, the first such centre is currently being built at The Christie Hospital in Manchester, and the surgeons of The Brain and Spine Clinic are closely involved in the planning and delivery of this exciting new treatment facility.