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T11-12 cord lesion
Julie G
Posted: Monday, July 19, 2010 3:02 PM
Joined: 9/1/2009
Posts: 20

Dr. Medbery: In the fall of 2009, I sent you images of my pelvis re: possibly treating two metastatic breast cancer lesions—one in the right acetabulum and one in the left iliac crest. I had also written to you on the CyberKnife forum in this regard. You thought then that my lesions might be candidates for CyberKnife, yet it turned out my insurance wouldn’t pay for this treatment as it’s not “standard of care.” I ended up treating the acetabulum in April of this year using conformal radiation--5 fractions at 2.5 Gy/fraction for a total of 37.5 Gy. This was fairly successful in controlling the tumor, plus my meds have helped decrease the FDG uptake of my left iliac lesion as well. Now I have a new lesion in my spinal cord. Here are my current questions: 1) What modality should be used to treat this, since it’s in the cord, not in bone? Is CyberKnife the best treatment due to its accuracy? If not, what is best for this anatomical location? 2) If rads damage the cord, what can be expected? In other words, how soon—on the average—would I see paralysis? Acute effects when? Late effects when? 3) I only have one right kidney, so how can it be protected re: T11-12 radiotherapy? Is accurate, hypofractionated dose better? Or is less focused, lower dose stereotactic treatment better? 4) In your opinion, what do you think the # of treatments and # Gy/treatment for this area should be? 5) I was told by one radiation oncologist that treatment to the cord should not exceed 10 Gy, and another told me 14 Gy. What is the maximum dose for the spinal cord? This location confuses me, as I thought the idea was to shield the cord from radiation as much as possible. Yet when the tumor is in the cord, how is this handled? As always thank you so much for all your help. Best to you, Julie G
Julie G
Posted: Wednesday, July 21, 2010 5:44 PM
Joined: 9/1/2009
Posts: 20

It occurs to me that I've written a message to Dr. Medbery, yet if he's out of town, perhaps someone else might be able to answer my questions. Thanks so very much. Best, Julie
Posted: Thursday, July 22, 2010 3:51 AM
Joined: 10/10/2008
Posts: 4435

1. That is a tough issue. Imaging is a tough problem for CK treatment, but it is more effective. When we have felt it necessary to use radiosurgery on this sort of tumor, we have usually sent the patient to Stanford where they have the most experience with the tumors that are actually in the spinal cord. Standard radiation is also a strong consideration. It avoids any immediate risks of radiosurgery, and may be successful. If not then radiosurgery could be used later, but at increased risk because of the previous treatment. 2. Months usually 3. The kidney would not be an issue with either form of radiation 4. That is a decision best left to the person designing the treatment and looking at all the information 5. Unknown. We have some general guidelines, but there is no absolute. It is highly dependent on volume. Very small volumes can be treated to considerably higher doses than you describe. 6. WHen the tumor is in the cord, you can't shield the cord. You allow it to get full dose and limit the amount you give when you use standard radiation. You simply try to reduce the amount of cord that gets significant dose if you use radiosurgery.


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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