I saw the following post and response on the CPSG board that I thought might be of interest to those considering radiosurgery. I don't recognize the poster name as anyone who frequents this board, so I'm not sure what "forum" they were getting the erroneous information from. The subject is whether radiosurgery provides long term control and again highlights the misinformation that we all need to navigate through in making our personal decisions.
Patient
"I have recently received some emails from people on another forum telling me that radiation is not a perment control for acoustic neuroma. A couple included some references that say radiation changes the DNA of a tumor and in time it will mutate into another form of tumor and grow rapidly. I was ask if I had ever heard of anyone that had tumor control after 15 or 20 years. I know radiation treatment has changed a lot over the years and the treatment is not the same as 15 or 20 years ago. However, I have looked for long term results on the internet and either I am overlooking somethng or most just report much shorter outcome results. Is there any study or report that gives these long term outcomes? I was told that successful treatment is just buying time before having to have surgery. I have talked with another lady that recently had GK for her AN and was told by a nurse that most medical professionals do not consider this to be a permenant control. What is your opinion?"
Dr Medberry
This is going to be on the MOST frequently asked question section when we get that re-done.
Doug Kondziolka has reported on patients followed over 15 years and they have 97% control with their treatment on the Gamma Knife. THere is no reason to think that CK won't be the same. From the standpoint of the tumor, x-rays and gamma rays are identical. This is just part of the nonsense that is put up to talk people into surgery. There are times when surgery is a good idea, and we are quite happy to recommend it in those situations. But in most cases, radiosurgery results in equal control rates with much less risk.
There have been a handful of cases in which acoustic neuromas have transformed into a more aggressive tumor. This has occurred after both surgery and radiation, and is the sort of one-in-a-million occurrence that should not enter into your decision making
J Neurosurg. 2005 Jan;102 Suppl:195-9. Related Articles, Links
Radiosurgery of vestibular schwannomas: summary of experience in 829 cases.
Lunsford LD, Niranjan A, Flickinger JC, Maitz A, Kondziolka D.
Department of Neurological Surgery and Radiation Oncology, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA. lunsfordld@upmc.edu
OBJECT: Management options for vestibular schwannomas (VSs) have greatly expanded since the introduction of stereotactic radiosurgery. Optimal outcomes reflect long-term tumor control, preservation of cranial nerve function, and retention of quality of life. The authors review their 15-year experience. METHODS: Between 1987 and 2002, some 829 patients with VSs underwent gamma knife surgery (GKS). Dose selection, imaging, and dose planning techniques evolved between 1987 and 1992 but thereafter remained stable for 10 years. The average tumor volume was 2.5 cm3. The median margin dose to the tumor was 13 Gy (range 10-20 Gy). No patient sustained significant perioperative morbidity. The average duration of hospital stay was less than 1 day. Unchanged hearing preservation was possible in 50 to 77% of patients (up to 90% in those with intracanalicular tumors). Facial neuropathy risks were reduced to less than 1%. Trigeminal symptoms were detected in less than 3% of patients whose tumors reached the level of the trigeminal nerve. Tumor control rates at 10 years were 97% (no additional treatment needed). CONCLUSIONS: Superior imaging, multiple isocenter volumetric conformal dose planning, and optimal precision and dose delivery contributed to the long-term success of GKS, including in those patients in whom initial microsurgery had failed. Gamma knife surgery provides a low risk, minimally invasive treatment option for patients with newly diagnosed or residual VS. Cranial nerve preservation and quality of life maintenance are possible in long-term follow up.
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Clinton A. Medbery, III, M.D.
St. Anthony Hospital Cyberknife Center
(405) 272-7311
buddy@swrads.org or cmedbery@coxinet.net
Patient
Dr. Medbery,
Thank you so much for your prompt reply. I think that answer will serve as both reassurance and as ammunition for those who have had radiation treatment and those considering that method. Maybe we can put this myth to rest on some of the other AN forums. The words Brain Tumor causes enough trauma without the added stress of miss-information. Again, thank you for all you do.
Hope this is helpful
Mark
