Phase I study of intraoperative radiotherapy with photon radiosurgery system in children with recurrent brain tumors: preliminary report of first dose level (10 Gy).
OBJECTIVE
To describe the preliminary results after intraoperative radiotherapy (IORT) with the photon radiosurgery system in children with recurrent brain tumors treated at the first dose level (10 Gy) of a Phase I protocol.


METHODS
A Phase I IORT dose escalation protocol was initiated at Children's Memorial Hospital to determine the maximal tolerated IORT dose in children with recurrent brain tumors.


RESULTS
Fourteen children have received IORT thus far. Eight had been previously irradiated. Thirteen children had ependymoma. The median follow-up was 16 months. Three patients (21%) developed radiation necrosis on follow-up MRI scans 6 to 12 months after IORT. They had not been previously irradiated and had received 10 Gy to a depth of 5 mm. One required surgery and the other two had resolution of their lesions without treatment. All 3 patients were asymptomatic at the last follow-up. No other late toxicity was observed at the last follow-up visit. Eight patients (57%) had tumor control within the surgical bed after IORT.


CONCLUSIONS
Our findings have demonstrated the safety and feasibility of IORT to a dose of 10 Gy to 2 mm in children with previously irradiated brain tumors. IORT to a dose of 10 Gy at 5 mm was associated with a greater complication rate.
Division of Radiation, Oncology Northwestern University, Chicago, IL, USA. j-kalapurakal@northwestern.edu
John A
JA
Kalapurakal
Stewart
S
Goldman
Wendy
W
Stellpflug
John
J
Curran
Vythialingam
V
Sathiaseelan
Maryanne H
MH
Marymont
Tadanori
T
Tomita
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D002648:Child; D004806:Ependymoma / Q000532:radiotherapy / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D005354:Fibrosarcoma / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D020714:Maximum Tolerated Dose; D009336:Necrosis / Q000209:etiology; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy* / Q000601:surgery*; D017785:Photons / Q000627:therapeutic use*; D011832:Radiation Injuries / Q000209:etiology; D016634:Radiosurgery / Q000295:instrumentation; D011879:Radiotherapy Dosage