Expert: Claes-Gustaf Nordquist, M.D. - 2/8/2008

Question
Hello - I have a lesion intrinsic to my midbrain (tectal plate area). 16 years ago I presented with hydrocephalus, was shunted, and then followed with MRI every 2 years. For 12 years the tumor remained stable, and was relatively non-enhancing, but between 2004 and 2007 (3.5 years) it has begun enhancing on contrast and has grown 2 to 4 mm in diameter in that time (it is now about 1.8 cm in greatest diameter). Due to location, the oncologists (neuro-oncologist, neurosurgeons, and radiation oncologists) I've consulted are not recommending biopsy or surgery. It is presumed to be either a Grade I or II Astrocytoma, with the most consensus being that it is likely a pilocytic.

I have had several treatment recommendations, including:

1. Gamma Knife radiosurgery.
2. Intensity Modulated Fractionated Stereotactic Radiotherapy (30 treatments to 54 Gy).
3. Delay radiation and try Temodar on an experimental basis for 6-12 months.

The highest number of physicians seem to agree that going ahead with the fractionated IMRT is the better option (without pursuing chemo), since the long-term control rates seem to be high, and I am told Gamma Knife carries a slightly higher risk of necrosis; and that if somehow this turns out to be a Grade II GKS would not be the standard of care. I am told though, that there are not necessarily any "right" or "wrong" answers in this case.

Any advice on evaluating which of these options is better? Has proton therapy been used on these types of tumors with success? Thanks!

Answer
I agree there is no "right" or "wrong" answer here!  What has been said about this is correct. PERSONALLY (if I were you - which of course is not the case) I would consider the GammaKnife in spite of the necrosis risk etc. due to its ability to annihilate the lesion with the intensity modulated stereotactic  therapy as a close second. Proton beams are also a possibility but probably less well known in a case like this than the other 2 choices.
I do hope this has been of some help!