Expert: Claes-Gustaf Nordquist, M.D. - 11/8/2007

Question
Dear Dr. Nordquist

I had posted a couple questions about my brother's (Age 26) condition in the following months. He has recurrent anaplastic astrocytoma grade III in his left thalamus, and has had operation, radiotherapy two years ago and chemotherapy (Temodar)for more than a year. I had asked you that, as the tumor had started to regrow and reached more than 30 mm of size, if it was possible to think about Gamma-Knife treatment, and you had advised me to contact your old center in Sweden.

Since there was a Gamma-Knife center available at Hacettepe University in Turkey, we contacted our radiologist and our proffessor applied the procedure to my brother about three weeks ago.

Thanks again for your kind help. Now, I have some more questions:

1: My brother suffered almost no side effects at all from Gamma-Knýfe, no nausea, no vomitting, no seizures, no fatigue, nothing at all. Though I know that steroids has had a role in this, I still wonder if by any means, it can mean that he is insensitive to therapy?

2: They have given three quarters of the ordinary dose of radiation in Gamma-Knife, since my brother had received the upper limit of the radiation he could take in ordinary raditherapy. How much does it hinder the effectiveness of Gamma-Knife? Does it affect it correlatively, or in other words, is he going to benefit three quarters of the amount he could have benefited if he had had the normal dose?

3: Though he has not suffered any short term side effects, what is the mid-term side effects, since I know that Gamma-Knife takes weeks before its benefit can be monitored. We were told that, seizures could come (he has never had it in his life, even at times of his disease), he might lose capabilities in his extremities, he might have strokes. I also know that there is the risk of secondary cancer. Nothing has happened so far. For how long should we wait to be sure that there is no side effects?

4: His neurosurgeon also advised us to go for radiosurgery, since an open brain operation is very risky and he was in a good condition in terms of daily activities, so he preferred to keep the operation choice for the future. Is it a possible scenario that Gamma-Knife resulting in necrosis in tumor area, leaving the remaining tumor inoperable due to necrosis in the area?

Thank you again for your care and kindness.

Answer
1.Probably not. This therapy has very few side effects really. 2. Not necessarily, but all depends on what his tumour dose actually was. Now his tumour at the time of treatment was probably at the upper size limit for therapy. Only his drs. and the physicist in charge of dose planning and dose calibration can answer this unfortunately.
3. You will probably have to wait at least a couple of months. If nothing has happened after 6 months probably nothing will happen. Secondary cancers usually take many years even decades to develop and the risk is not big.
4. Due to already existing risks he was probably more or less inoperable already before this. So I do not see much real change anway. GammaKnife is a rather new treatment in situations like this so experience is limited. We will just have to wait and see. My wife speaks Turkish but she is not at home at present and I do not (her Jewish parents were both born in Istamboul, she was born in Jerusalem, Israel). So you will have to be satisfied with Good luck in English!