Treatments
All patients received initial maximum safe surgical tumor resection, and
then 36 Gy craniospinal radiotherapy with boost to the posterior fossa
at the 55.8 Gy cumulative dose with conventional fractionation at 1.8
Gy/d. Radiotherapy was initiated within 31 days after diagnostic surgery
for all patients.
There were 9 patients in MTX group refusing chemotherapy after the
completion of radiotherapy according to their parents’ willingness. All
of these patients developed relapsed disease 6 to 12 months after
radiotherapy. Therefore, a second surgery was performed for the relapsed
disease, and all of them received chemotherapy within 4 to 6 weeks after
surgery in the same procedure as other patients. The remaining 34
patients initiated 8 cycles of chemotherapy after a 4-6-week rest while
completing radiotherapy. The chemotherapy regimen consisted of 1.5
mg/m2 vincristine a day given intravenously over 15
min on days 1 and 8, 750 mg/m2 cyclophosphamide a day
given intravenously over 3 h on days 1 and 2, and 75
mg/m2 cisplatin a day given on day 1. A single dose of
MTX at 12.5 mg (2.5mg per milliliter of 0.9% sodium chloride solution)
was given on day 1 in MTX group, while control group received
cerebrospinal fluid (CSF) cytology analysis alone. Brain magnetic
resonance imaging (MRI) examination and spine MRT were performed
routinely after two, four, six and eight cycles of chemotherapy for all
patients.