irradiation for metastatic brain tumors. Radiat Med. 2002
Cyberknife has been found to be very useful in
treating brain tumors because of the high degree of accuracy
and since it can be done frameless (a head frame which is
screwed into the skull, as is used for other techniques like
gamma knife) the treatments can be fractionated (dose
divided into more than one dose or fraction) which should
lower the risk of complications.
See discussion of brain metastases in the
metastases radiosurgery section
and all other types of brain tumors (benign and malignant) in
See the section on side effects and
and here and for pictures
of treated lesions
other cyberknife brain topics:
Shimamoto S, Inoue T, Shiomi H, Sumida I, Yamada Y, Tanaka E, Inoue T.
Department of Multidisciplinary Radiotherapy, Osaka University Graduate School of
Medicine, Suita, Japan.
The CyberKnife provides a new technique for performing frameless stereotactic irradiation.
So far, few reports have been published on clinical outcomes obtained with the CyberKnife.
This report summarizes our clinical experience with CyberKnife irradiation for metastatic
brain tumors. : Seventy-seven lesions (48 patients) were evaluated and analyzed,
and 66 lesions in 41 patients were treated with stereotactic radiosurgery (SRS). The
dose was 9 to 30 Gy. RESULTS: Freedom from progression of the tumors was more likely
with a prescribed dose of at least 24 Gy than with one of less than 20 Gy (p=0.0244;
log-rank test). The CR (complete response) rate was significantly higher when D99 was at
least 24 Gy (p=0.0045). There were no severe side effects. CONCLUSION: Stereotactic
irradiation with the CyberKnife for metastatic brain tumors is effective and safe.
should be at least 24 Gy for CyberKnife SRS treatment.
The role of cyberknife
radiosurgery/radiotherapy for brain metastases of multiple or
Nishizaki T, S.
Minim Invasive Neurosurg. 2006 Aug;49(4):203-9.
OBJECTIVE: Focused, highly targeted radiosurgery and
fractionated radiotherapy using the Cyberknife are useful
treatments for multiple or large metastases. Here we present our
results of Cyberknife radiosurgery for 71 patients with 148
metastatic brain lesions. METHODS: There were 32 women and 39
men with a median age of 63 (range: 30-88) years. Radiographic
follow-up was available for 60 patients with 104 lesions. The
mean and median initial volumes of the tumor per lesion were 6.6
and 2.9 cm(3) (range: 0.1-53.2 cm(3)), respectively, at the time
of the initial Cyberknife treatment. Forty patients (56%) had a
single lesion, and 31 (44%) had multiple lesions (range: 2-7) at
initial treatment. The number of fractions ranged from 1 to 3,
and forty (27%) of 148 lesions were treated by a fractionated
course of Cyberknife therapy. The
mean marginal dose was 20.2 Gy
(range 7.8-30.1 Gy, median: 20.7 Gy). RESULTS: At 44 weeks of
median follow-up, there were no permanent symptoms resulting
from radiation necrosis. Overall 6-month and 1-year survival
rates were 74% and 47%, respectively, and the
time was 56 weeks. The Karnofsky performance score and
extracranial metastasis were significant prognostic factors at 6
months and 1 year, respectively, in both univariate and
multivariate analyses. Age or multiple metastases did not
influence prognosis at 6 months and 1 year.
Local control was
achieved in 83% (86 lesions). After additional radiosurgical or
surgical salvage, no patient died as a result of intracranial
disease. Twenty-five patients developed 92 new metastases (range
1-13) outside of the treated lesions with 22.4 weeks of median
follow-up. Among them, 21 patients (84 lesions) were treated by
salvage Cyberknife. CONCLUSION: Despite the inclusion of an
unfavorable group of patients with large tumors, our results for
survival and tumor control rates are comparable to those of
published series. The Cyberknife provides the advantage of
allowing for fractionated treatment to multiple or large-size
Stereotactic radiosurgery in patients with
multiple brain metastases.
Chang SD, Lee E, Sakamoto GT, Brown NP, Adler
Neurosurg Focus. 2000 Aug 15;9(2):e3.
Department of Neurosurgery,
Stanford University School of Medicine, Stanford, California 94305, USA.
OBJECT: Patients with multiple brain
metastases are often treated primarily with fractionated whole-brain
radiation therapy (WBRT). In previous reports the authors have shown that
patients with four or fewer brain metastases can benefit from stereotactic
radiosurgery in addition to fractionated WBRT. In this paper the authors
review their experience using linear accelerator stereotactic radiosurgery
to treat patients with multiple brain metastases. METHODS: Fifty-three
patients with 149 brain metastases underwent stereotactic radiosurgery. The
mean age of patients was 53.1 years (range 20-78 years). There were 23 men
and 30 women. The primary tumor location was lung (27 patients), melanoma
(10), breast (six), ovary (six), and other (four). All patients harbored at
least two metastatic tumors treated with radiosurgery; 27 patients (51%)
harbored two lesions, 17 (32%) three lesions, eight (15%) four lesions, and
one patient (2%) harbored five lesions.
The mean radiation dose administered
was 19.6 Gy (range 14-30 Gy), and the mean secondary collimator size was
15.7 mm (range 7.5-40 mm). One hundred thirty-two (89%) of the 149 treated
tumors were available for review on magnetic resonance (MR) imaging at 3
months posttreatment. Fifty-two percent were smaller in size, 31% were
stable, 9% had increased in size, and 8% had disappeared. New metastatic
tumors appeared in 12 (23%) of the 53 patients on MR imaging within 6 months
posttreatment. Radiation-induced necrosis occurred at the site of eight
(5.4%) of the 149 tumors at 6 months. Seven tumors (4.7%) subsequently
required surgical resection for either tumor progression (four cases) or
worsening edema from radiation-induced necrosis (three cases).
actuarial survival was 9.6 months. CONCLUSIONS: Stereotactic radiosurgery
can be used to treat patients with up to four brain metastases with a 91%
rate of either decrease or stabilization in tumor size and a low rate of
radiation-induced necrosis. In the authors' study only a small number of
patients subsequently required surgical resection of a treated lesion.