Quality of radiosurgery for single brain metastases with respect to treatment technology: a matached-pair analysis.
Wowra B, Muacevic A, Tonn JC.
European CyberKnife Center Munich, Max Lebsche Platz 31, 81377, Munich, Germany, Berndt.Wowra@cyber-knife.net.
Objective: A comparison of treatment parameters and quality of clinical outcome in patients with single brain metastases treated with two different technologies for radiosurgery (Gamma Knife and CyberKnife).
Methods: Treatment parameters were statistically analyzed. Clinical outcome was assessed by matched-pair analysis based on the treatment device, differences in dose prescription, and the date of the treatment. Patients were matched according to their tumor size, age, gender, primary cancer, and Radiation Therapy Oncology Group score. Survival post-radiosurgery, local and distant tumor control, and complications were analyzed. Predictive factors were investigated.
Results: 423 single brain metastases were treated with Gamma Knife and 73 with CyberKnife. Tumor volumes were similar. The parameters minimum tumor dose, maximum tumor dose, prescription isodose volume, conformality index, homogeneity index, volume of tissue receiving a dose of 10 Gy or more were significantly larger in Gamma Knife group. Sixty-three patients were good matches. These showed the same pattern in parameters. Concerning the outcome analysis, only overall survival differed significantly between groups, twice as long with CyberKnife (P < 0.03). According to pooled data, dose was predictive of local failure, whole brain radiation therapy and chemotherapy were predictive of toxicity, the Radiation Therapy Oncology Group score was predictive of survival after radiosurgery, and date of treatment was predictive of overall survival. No factor predicted new brain metastases, including whole brain radiation therapy.
Conclusions: The most important result of this study was the finding that the obvious differences in treatment-related parameters between Gamma Knife and CyberKnife had no impact on the quality of the clinical outcome after radiosurgery. Survival time increased chronologically, presumably due to an intensified anti-cancer therapy in the more recent era of the CyberKnife treatments.
PMID: 19184641
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CyberKnife vs GammaKnife
- By gpawelski
- Posted March 7, 2009 at 11:39 am · 4 replies
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- By antonella
- Posted April 11, 2009 at 7:42 pm
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Sorry, I feel rather dumb but what was the conclusion of the study? For a few small brain mets which is better cyber knife or Gamma knife. I just would like to know even though I don't have brain mets but rather to gather this amazing resourse and information to put in my back pocket for maybe later use. Wow thank-you for sharing all that info, What is your motivation for doing all that research?
thanks again Antonella
- By traceyred
- Posted April 12, 2009 at 7:37 am
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I'm with Antonella. I don't understand what the results say. Also, was this study done by the CyberKnife people? Wouldn't that give the study an obvious bias?
Tracey
- By gpawelski
- Posted April 12, 2009 at 9:20 am
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It's not a question of whether one is better than the other. Both are strategic radio surgery which is probably a more descriptive phrase. Each has their usefulness, depending on the type and size of tumor. The surgical strike of this type of radiation to the tumor kills its DNA. Without being able to repair that DNA, the tumor becomes necrotic (dead) and eventually shrinks away inside the brain (body).
GammaKnife is a Cobalt-60 based (photon) machine used in a handful of centers in the United States. In addition to brain tumors, it treats body cancers in a fractionated manner. The machines are ideal for smaller tumors, less than 3.5cm. My wife had Gamma-Knife. Her lesions were 4, 5, and 7mm. Very, very small lesions. It uses gamma rays.
Cyberknife is a linear accelerator based radiosurgery machine. It has the ability to easily treat large tumor volumes, over 3.5cm, by treating over several sessions. When treating over time, it is called fractionated stereotactic radiotherapy and not stereotactic radiosurgery (which is a one-session treatment). They too can be used throughout the body, the head and neck, as well as the brain. It uses alpha rays.
The third radiosurgery machine is the particle/proton beam machine. In addition to brain tumors, it treats body cancers in a fractionated manner. Due to the cost of the particle beam facility (>100 million), many of the costs are funded by endowments and public research centers.
- By Jo1216
- Posted April 13, 2009 at 12:00 pm
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They are now also treating brain tumors with a vaccine that is made from the patient's own body immune cells. This seems to be a promising approach. This is going on at Sutter Cancer Center in Sacramento Ca.
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