Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study.
OBJECTIVE
The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases.


METHODS
In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm(3) or metastases in the brainstem.


RESULTS
The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy  with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different.


CONCLUSIONS
The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary.
Radiotherapy Centre West, Lijnbaan 32, 2512 VA, The Hague, The Netherlands. r.wiggenraad@mchaaglanden.nl
R
R
Wiggenraad
A
A
Verbeek-de Kanter
M
M
Mast
R
R
Molenaar
H B
HB
Kal
G
G
Lycklama à Nijeholt
C
C
Vecht
H
H
Struikmans
D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D017567:Karnofsky Performance Status; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008545:Melanoma / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012878:Skin Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden