- J Neurooncol. 2009 Aug;94(1):69-77. Epub 2009 Feb 1.
- Quality of radiosurgery for single brain metastases with respect to treatment technology: a matched-pair analysis.Wowra B, Muacevic A, Tonn JC.European CyberKnife Center Munich, Max Lebsche Platz 31, Munich 81377, Germany.
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).
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