Maximum AN size for Radiosurgery

[Mark]

Interesting comments on size limits for treating an AN by radiosurgery from Dr. Rosenberg on the CPSG board. Most of us have always worked under the  "3 cm rule".


Dr. Rosenberg


Size is very much a moving target. The "3cm rule" comes from historicaly Gamma Knife data. This is limited as Gamma Knife can deliver only single fraction dosing. In fact, we at Menorah have been pushing this and are currently collating our data on much larger tumors. Currently, our largest intracranial tumor which was also compressing the brainstem was 108 cc. This corresponds to a 6 cm diameter sphere. We have 9 month follow-up on this patient who is doing quite well. We are now following 77 patients with such large tumors treated and hope to have more information soon. In summary, I think that with different targeting (non-isocentric vs isocentric GK) and fractionation, we will be able to treat MUCH larger tumors with stereotactic radiosurgery than have been previously considered treatable.

Cathy, you might want to get your films and clinical information to a CyberKnife Center for consideration.


--------------------------------------------------------------------------------
William S. Rosenberg, MD
Medical Director, Menorah Medical Center CyberKnife
Midwest Neurosurgery Associates
6420 Prospect Street, Suite T411
Kansas City, MO 64132
(816) 363-2500
wsr@post.harvard.edu

[russ]

  Just to mention, John Hopkins Radiosurgery still employs the 3.0 cm. limit for FSR. There may be prudent others.
  Russ

[arcteryx]

That is hard to believe that they are treating such large tumors with radiation.  Of course, I'd have to see the actual data results, but it seems pretty risky when you read stories such as Val's (http://www.raccoonhouse.com/).

Best of luck.

[jamie]

Well, Dr. Rosenberg states they are following 77 patients with large tumors, I guess in tragic cases such as Val's, there was not much more that could have been done since they said the tumor was wrapped around a major blood supply to the brain. I think there are bad outcomes from just about every medical procedure you can name, and sometimes it seems some doctors get too confident when weighing the risks. But in cases like Val's, where the tumor grows so fast and they can't operate again, what other choice is there? Treat and hope it stops the growth, or just let it do what it will. The longer they wait before treating the larger the tumor grows and presents even more danger from swelling. That case seemed to be a catch 22. I didn't have any swelling from CyberKnife, I guess we'll have to see data on more cases to truly make the call...

[Kilroy1976]

I can't help wondering why anyone, doctors or patients, would want to go with radiosurgery for such a large tumor. Six CM in the brain is a massive tumor, capable of causing massive damage, and I would think that it would be best in almost all cases to get it out of there. At least remove the bulk of it surgically and use radiosurgery on the remainder.

Pushing the envelope is all fine and good, but wouldn't it be preferable to start with 3.5CM or 4CM tumors? There is a real risk to life when a 6CM AN is compressing the brainstem; is this the ideal situation to be testing new technology/techniques?

[jamie]

I can't help wondering why anyone, doctors or patients, would want to go with radiosurgery for such a large tumor.

If you're referring to the above case being discussed, she did have surgery but it could not be fully removed and it seems the surgeons said she couldn't have surgery again (not sure why), it seemed to grow rapidly after that. I think there was no other choice in this case unless I'm misunderstanding it. As for other cases, I'm not sure why they'd push the envelope either, I really don't think they would recommend it unless surgery is not an option though.

[Larry]

Interesting comments re size of AN's. There does seem to be a discrepancy on the way the measurement is done.

When getting a measurement, it should be noted to not include the growth in the bone. This was explained to me by my neurosurgeon who stated that this growth is like the stem of the AN and shouldn't really be counted as it doesn't do anything. But hey - all this stuff is pretty new and i guess standards of lots of things will change over time.


laz

[russ]

Hi Larry
  If the Neurosurgeon said the following: "the stem of the AN  shouldn't really be counted as it doesn't do anything.", it's obvious they have never personally experienced an AN in the IAC. Even the tiniest there can be devastating to hearing, balance, and the facial nerve.
  I just don't understand a statement like that. Even the tail in the IAC is calculated into the tumor volume if the person is to undergo irradiation. Of course, a neurosurgeon wouldn't consider radiation either.
  I would want more than just that person's opinion!!
  Best wwishes to you always!
  Russ

[Larry]

Russ,

You are so right. With the knowledge learned from this forum, I now get multiple views and opinions. I think it's good to share the info regardless coz then it opens up debate which is where I have learned the most from.

cheers



Laz

[marystro]

I think I have a 2.3 cm AN pending further testing (ABR) and review of MRI film, etc.  With only 25% hearing loss I really hope to avoid surgery and preserve hearing.  I am worried about doctors (neurosurgeons) that I will be talking to are biased towards surgery.  I would like to have recommendations that are not biased in one way or another.  What's the best means to get those recommendations?

Mary

[antoinette]

asterix, I read your mention of Valerie with emotion. She was a member of ANAUSA for a long time until she died. I still have her last post.
I wish to add that the person who did the FSR treatment on her has the reputation of doing very deplorable treatments, I have kept a few posts of those and your are welcome to them if you wish.
How did you get Val's story and her site maintained by her family?

best regards
ant

[arcteryx]

Hi,
I actually ran across her website just by doing a random google search.  I was very surprised to find it myself.  What a sad story, really made me cry reading it.  She sounds like a great person, wish I had gotten to know her when she was posting here.  I keep her website bookmarked now for those people who dismiss ANs as merely an inconvenience.  I can't believe how many doctors and nurses I've run across who have told me this isn't a serious health concern.

Thanks for the warning.  I'm aware of the doctor involved in Val's treatment and his history.  That's why I was surprised to learn that some other doctors are treating such large ANs with radiosurgery.  My AN was measured at 2.9cm, but most CK centers I spoke with strongly discouraged radiation without at least a debulking surgery first.  Believe me, I would've much rather skipped the brain surgery and probably would've saved my hearing!

I would definitely be interested in seeing the posts you have.

Thanks!