Radiation Therapy

Indications

  1. To prevent progression of aggressive tumours after an incomplete surgical resection.
  2. To treat hormonally active tumours (e.g., acromegaly or Cushing’s) that failed to respond to surgical and medical therapy.

Modalities

There are two main modalities of radiation:

  1. Fractionated radiotherpy. The radiation dose is divided over time (fractions), typically in daily doses over 4-6 weeks, requiring daily treatment visits. Radiation is given to a field which includes both the tumour but also some surrounding healthy tissue, such as the normal pituitary gland.

  2. Radiosurgery (e.g., γ-knife radiosurgery). Using imaging guidance (stereotactics), a radiation beam can be more targeted at the lesion. This makes it possible to maximizes the radiation dose given to the lesion and minimizes the radiation exposure of the surrounding healthy tissue. The treatment is given in a single dose, requiring a single treatment visit. It is appropriate for lesions that are well-demarcated and not too close to the optic apparatus.

Targeted radiation with radio-labeled ligands is under investigation.

Complications

References