In most centers the standard of care is either:
- Surgery alone if the tumor can be completely resected without unacceptable morbidity
- A combination of surgery to debulk the cystic component principally followed by radical radiotherapy.
As this tumor is benign, the standard of care is to use very small margins around the tumor in order to treat effectively and also spare surrounding normal critical structures.
This is generally achieved with stereotactic techniques or proton therapy.
GTV = solid + cystic components
CTV = GTV + margin of 0.5 mm
Sometimes there may be cyst expansion during RT (and depending on the patient's history, it may be important during RT to repeat the MR to ensure that the cyst has not expanded outside the treatment volume).
The dose generally used in most centers is 54 Gy (in 180 cGy fraction size).