Radiotherapy in pediatric medulloblastoma: quality assessment of Pediatric Oncology Group Trial 9031.
OBJECTIVE
To evaluate the potential influence of radiotherapy quality on survival in high-risk pediatric medulloblastoma patients.


METHODS
Trial 9031 of the Pediatric Oncology Group (POG) aimed to study the relative benefit of cisplatin and etoposide randomization of high-risk patients with medulloblastoma to preradiotherapy vs. postradiotherapy treatment. Two-hundred and ten patients were treated according to protocol guidelines and were eligible for the present analysis. Treatment volume (whole brain, spine, posterior fossa, and primary tumor bed) and dose prescription deviations were assessed for each patient. An analysis of first site of failure was undertaken. Event-free and overall survival rates were calculated. A log-rank test was used to determine the significance of potential survival differences between patients with and without major deviations in the radiotherapy procedure.


RESULTS
Of 160 patients who were fully evaluable for all treatment quality parameters, 91 (57%) had 1 or more major deviations in their treatment schedule. Major deviations by treatment site were brain (26%), spinal (7%), posterior fossa (40%), and primary tumor bed (17%). Major treatment volume or total dose deviations did not significantly influence overall and event-free survival.


CONCLUSIONS
Despite major treatment deviations in more than half of fully evaluable patients, underdosage or treatment volume misses were not associated with a worse event-free or overall survival.
Miralbell
Raymond
R
Quality Assurance Review Committee, Providence, RI, USA. Raymond.Miralbell@hcuge.ch
Fitzgerald
T J
TJ
Laurie
Fran
F
Kessel
Sandy
S
Glicksman
Arvin
A
Friedman
Henry S
HS
Urie
Marcia
M
Kepner
James L
JL
Zhou
Tianni
T
Chen
Zhengjia
Z
Barnes
Pat
P
Kun
Larry
L
Tarbell
Nancy J
NJ
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002945:Cisplatin / Q000008:administration & dosage; D016371:Cranial Irradiation / Q000379:methods; D005047:Etoposide / Q000008:administration & dosage; D006801:Humans; D015192:Infratentorial Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy; D008527:Medulloblastoma / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D011785:Quality Assurance, Health Care; D011878:Radiotherapy / Q000592:standards; D013125:Spinal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D015996:Survival Rate
D005047:Etoposide; D002945:Cisplatin