Hypofractionated stereotactic radiotherapy alone without whole-brain irradiation for patients with solitary and oligo brain metastasis using noninvasive fixation of the skull.
OBJECTIVE
To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) using noninvasive fixation of the skull on solitary or oligo brain metastatic patients as an alternative to stereotactic radiosurgery (SRS) using invasive fixation.


METHODS
The subjects were 87 patients who had 4 or fewer brain metastases (50 solitary, 37 oligometastases). Treatment was conducted on 159 metastases by using a linac-based stereotactic system. The median isocentric dose was 35 Gy in 4 fractions. Whole-brain irradiation was not applied as an initial treatment. For the salvage treatment of metachronous brain metastases, repeat HSRT or whole-brain irradiation was applied.


RESULTS
The actuarial 1-year local tumor control rate was 81%. Treatment-related complications were observed in 4 patients in the early period (<3 months) and in 2 patients in the late period. The median survival period was 8.7 months. Metachronous brain metastases occurred in 30 patients, and none of the 18 patients who were eligible for salvage HSRT refused to receive it again.


CONCLUSIONS
Hypofractionated stereotactic radiotherapy achieved tumor control and survival equivalent to those of SRS reported in the literature. The results suggested that HSRT could be an alternative for solitary or oligo brain metastatic patients with less toxicity and less invasiveness compared to SRS.
Aoyama
Hidefumi
H
Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Shirato
Hiroki
H
Onimaru
Rikiya
R
Kagei
Kenji
K
Ikeda
Jun
J
Ishii
Nobuaki
N
Sawamura
Yutaka
Y
Miyasaka
Kazuo
K
D000206:Actuarial Analysis; D000368:Aged; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary*; D003072:Cognition Disorders; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007103:Immobilization; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects; D016879:Salvage Therapy; D013238:Stereotaxic Techniques / Q000009:adverse effects