Radiotherapy
Adjuvant Radiotherapy / Salvage Radiotherapy
The patient is treated with radical intent using external beam radiotherapy. A dose of 54 Gy in 30 fractions is prescribed.
Pre-simulation, informed consent is obtained from the patient.
The patient is simulated in the supine position with the head in a neutral position. A thermoplastic shell is made. A CT scan is performed through the region of interest.
Fusion with the pre-operative MRI is performed.
The pre-operative enhancing area, or abnormal area on FLAIR, is the GTV.
The CTV is formed by a 1 cm expansion, respecting tissue planes.
The PTV is formed by an additional 0.3 cm expansion, not respecting tissue planes.
Organs at risk vary depending on the specific site of the tumour but should include:
- Lens < 2 Gy
- Retina < 45 Gy
- Optic nerve and chiasm < 54 Gy
- Brainstem < 54 Gy
