Local control after craniospinal irradiation, intensity-modulated radiotherapy boost, and chemotherapy in childhood medulloblastoma.
BACKGROUND
The current study was conducted to determine whether the use of cochlear-sparing intensity-modulated radiotherapy (IMRT) boost results in excess local failures in children with medulloblastoma.


METHODS
Fifty children with a median age of 7.8 years underwent resection, craniospinal irradiation (CSI), IMRT posterior fossa (PF) and/or tumor bed (TB) boost, and cisplatin-based chemotherapy for medulloblastoma. For standard-risk patients, the CSI dose was 18 to 23.4 grays (Gy) and was followed either by an IMRT PF boost to 36 Gy and a TB boost of 54 to 55.8 Gy (n = 29) or by an IMRT TB boost to 55.8 Gy (n = 4). For high-risk patients, the CSI dose was 36 to 39.6 Gy followed by an IMRT PF boost to 54 to 55.8 Gy (n = 8), an IMRT PF boost to 45 Gy and a TB boost to 55.8 Gy (n = 2), or an IMRT TB boost to 55.8 Gy (n = 7). For the TB boost, a 2-cm margin around the surgical bed was treated in most patients.


RESULTS
The 5-year overall and progression-free survival rates (±standard deviation) were 72% ± 6.6% and 68.3% ± 6.8%, respectively, for all patients; 77.8% ± 7.4% and 75.1% ± 7.6%, respectively, for standard-risk patients; and 60.8% ± 12.8% and 55.4% ± 12.8%, respectively, for high-risk patients. The 5-year PF control rate was 90.5% ± 4.6%. TB failures occurred in 3 patients (including 2 patients who had distant failure), whereas an isolated non-TB PF failure occurred in 1 patient.


CONCLUSIONS
The use of IMRT was associated with excellent local control and did not result in excess PF failures outside of the TB.
Paulino
Arnold C
AC
Department of Radiation Oncology, The Methodist Hospital and The Methodist Hospital Research Institute, Houston, Texas, USA. apaulino@tmhs.org
Mazloom
Ali
A
Teh
Bin S
BS
South
Michael
M
Okcu
M Fatih
MF
Su
Jack
J
Butler
E Brian
EB
Chintagumpala
Murali
M
D000293:Adolescent; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D016371:Cranial Irradiation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy* / Q000401:mortality / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D017211:Treatment Failure