Intraoperative 32P high-dose rate brachytherapy of the dura for recurrent primary and metastatic intracranial and spinal tumors.
BACKGROUND
Treatment of spinal and intracranial tumors with dural involvement is complicated by radiation tolerance of sensitive structures, especially in the setting of previous treatment.


OBJECTIVE
To evaluate whether intraoperative brachytherapy with short-range sources allows therapeutic dose delivery without damaging sensitive structures.


METHODS
The median doses of previous treatment were 3000 cGy (range, 1800-7200 cGy) for 8 patients with primary/recurrent and 17 patients with metastatic spinal tumors and 5040 cGy (range, 1300-6040 cGy) for 5 patients with locally recurrent and 2 patients with metastatic intracranial tumors. Patients underwent gross total or maximal resection of the tumor and were then treated with an intraoperative brachytherapy plaque consisting of a flexible silicone film incorporating P. A dose of 1000 cGy was delivered to a depth of 1 mm; the percent depth dose was less than 1% at 4 mm from the prescription depth. Median postoperative radiation doses of 2700 cGy (range, 1800-3000 cGy) were delivered to 15 spinal tumor patients and 3000 cGy (range, 1800-3000 cGy) to 3 intracranial tumor patients. The median follow-up was 4.4 months (range, 2.6-23.3 months) for spinal tumor patients and 5.3 months (range, 0.7-16.2) for intracranial tumor patients.


RESULTS
At 6-month follow-up, for all spinal tumor patients, local progression-free survival and overall survival rates were both 83.3% (95% confidence interval [CI]: 62.3%-94.3%); for all intracranial tumor patients, the local progression-free survival rate was 62.5% (95% CI: 23.8%-90.9%) and the overall survival rate was 66.7% (95% CI: 26.7%-92.9%). There were no intraoperative or postoperative complications secondary to radiotherapy.


CONCLUSIONS
Use of the P brachytherapy plaque is technically simple and not associated with increased risk of complications, even after multiple radiation courses. Local control rates were more than 80% in patients with proven radiation-resistant spinal disease.
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Michael R
MR
Folkert
Mark H
MH
Bilsky
Gil'ad N
GN
Cohen
Marco
M
Zaider
Lawrence T
LT
Dauer
Brett W
BW
Cox
Patrick J
PJ
Boland
Ilya
I
Laufer
Yoshiya
Y
Yamada
D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000556:secondary; D018572:Disease-Free Survival; D004388:Dura Mater; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010759:Phosphorus Isotopes / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000532:radiotherapy* / Q000556:secondary
D010759:Phosphorus Isotopes