Patient Forum

The CyberKnife Patient Forum is designed to provide a place for people who have been diagnosed with cancer, their family and friends, to exchange useful information and provide support to one another. The Forum may also help people find answers to questions they have about the CyberKnife treatment experience. Accuray strives to facilitate these exchanges and encourage discussions. Recently we have experienced some aggressive or inappropriate spam postings. We are diligently working to resolve this issue and thank you in advance for your patience.

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Unsure about radiosurgery
Posted: Sunday, June 15, 2014 12:46 AM
Joined: 6/15/2014
Posts: 1

Hi everybody, I have a recurring AN. The original 5mm tumor was retrosigmoidally operated in 2001. I lost hearing on that side, but there was no damage to facial functions. The removal was partial, with some residue seen on the first post operative scan. Follow ups demonstrated a 5mm growth within a span of 10 year, from a 5mm tumor in 2002 to 10mm in 2012. The latest scan revealed a much faster growth, for an additional 10mm within just 21 months. The tumor is now 20mm with a cystic component, and protrudes the CPA. I have no facial weakness, headaches, dizziness, or vision problems. It is also worth mentioning that on the opposite ear I have a substantial and progressive hearing loss and tinnitus, but no tumor has ever been observed on that side. My treatment goals now are to preserve the facial nerve, and since there is a good chance my tumor will grow again I prefer the treatment that will provide the best starting point for the next intervention X years from now. I've consulted with a few doctors regarding my case, and am utterly confused. Translab surgery had been recommended by a few neurosurgeons, and seems like the logical choice, but I'm trying to keep an open mind. Additionally, with my post-surgery experience I'm not that eager to have my head cut open again. My questions regarding radiosurgery are: 1. If radiosurgery fails, neurosurgeons say they will have a harder time operating because of scarring and tissue adhesion. Is that correct? Some doctors also say that I already have internal damage from the previous surgery. In that case, does a radiation treatment add to the already exiting damage? 2. If radiosurgery fails, I might have to deal with a larger tumor due to the time between follow ups and because of possible radiation induced swelling of the tumor. How frequently do tumors expand post-irradiation? To what extent? For how long? 3. Some articles and doctors say that a cystic tumor is less responsive to radiation, but radiosurgeons seem to always say the opposite, how do I know who to believe? The same thing applies to the question whether a fast growing tumor is or is not well responsive to irradiation. 4. The radiosurgeons indicate a 95-98% success rate stopping growth of the tumor, and between 0-1% long term facial nerve damage. That does not seem to settle with forum posts I'm reading all over the web. Again, who can I believe? 5. Is there any difference in outcomes and side effects between GK, CK, LINAC? Single dose or fractioned? Thanks in advance!
Posted: Sunday, June 15, 2014 5:42 AM
Joined: 10/10/2008
Posts: 4435

1. SRS (radiosurgery) is about 95-98% effective, so saying that there is a good chance your tumor will grow again is really not realistic. It almost certainly won't. It re-grew the first time because it was not totally removed. Our experience is that adding SRS after surgery does not cause new problems. In the rare cases where we have seen recurrence, our surgeons don't report any more problem with surgical removal than they would ordinarily have 2. In the unlikely even that SRS fails it is likely to be years in the future, and swelling is gone by them. The tumor will possibly be larger, but because of growth, not swelling. And there is simply no excuse for a long wait between follow-ups. Every 6 months for the first few years is our standard, then annually if stable 3. In our experience, having a cystic component and having more rapid growth are not predictive of results. 4. The statistics you quote are correct. That data is published many times in peer-reviewed journals. It is reliable. Anything contradictory is not. 5. It does not matter whether you use CyberKnife or Gamma Knife if you are going to treat single fraction. Accuracy with a standard linac is probably less. Data on fractionation is limited with no randomized data. I think the most accurate assessment of the data is to say that there may be a small improvement in hearing preservation (not important in your case) with fractionated treatment, but the data is not clear on that point. There is no evidence of other good or bad effects from fractionation.


Clinton A. Medbery, III, M.D.
St. Anthony Hospital Cyberknife Center
(405) 272-7311

Mail to:
Clinton A. Medbery, III, M.D.
Southwest Radiation Oncology
1011 N. Dewey Ave. #101
Oklahoma City, OK 73102



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