PRIMARY OBJECTIVES:
I. To determine whether carboplatin radiosensitization increases long term event-free
survival for high risk medulloblastoma/primitive neuroectodermal tumor (PNET) patients.
II. To determine whether isotretinoin increases long term event-free survival for high
risk medulloblastoma/PNET patients.
CORRELATIVE SCIENCE OBJECTIVES:
I. To compare residual disease response to radiation alone versus radiation plus
carboplatin.
II. To identify molecular prognostic indicators suitable for patient stratification in
future trials.
III. To evaluate the health-related quality of life (HRQOL) during phases of active
treatment specific to treatment modalities.
IV. To describe the neuropsychological functioning of the study population and to
evaluate the relationship between neuropsychological status and health related quality of
life.
OUTLINE: Patients are randomized to Arm A or Arm B (Arms C and D closed to accrual as of
Amendment 3 1/27/15).
ARM A (standard chemoradiotherapy and standard maintenance therapy):
CHEMORADIOTHERAPY: Patients undergo radiation therapy once daily (QD) five days a week
for 6 weeks. Patients also receive vincristine sulfate intravenously (IV) over 1 minute
once weekly for 6 weeks. Six weeks after completion of chemoradiotherapy, patients
proceed to maintenance therapy.
MAINTENANCE THERAPY: Patients receive cisplatin IV over 6 hours on day 1, vincristine
sulfate IV over 1 minute on days 1 and 8, and cyclophosphamide IV over 1 hour on days 2
and 3. Patients also receive filgrastim subcutaneously (SC) or IV beginning on day 4 and
continuing until blood counts recover (at least 10 days). Treatment repeats every 28 days
for a total of 6 courses in the absence of disease progression or unacceptable toxicity.
Patients also undergo blood sample collection, lumbar puncture and magnetic resonance
imaging (MRI) throughout the study.
ARM B (standard chemoradiotherapy plus carboplatin and standard maintenance therapy):
CHEMORADIOTHERAPY: Patients receive vincristine sulfate and undergo radiation therapy as
in Arm I. Patients also receive carboplatin IV over 15 minutes on each day of radiation
therapy. Six weeks after completion of chemoradiotherapy, patients proceed to maintenance
therapy.
MAINTENANCE THERAPY: Patients receive maintenance therapy as in Arm I.
Patients also undergo blood sample collection, lumbar puncture and MRI throughout the
study.
ARM C (standard chemoradiotherapy, standard maintenance therapy plus isotretinoin, and
continuation therapy with isotretinoin - CLOSED TO ACCRUAL 1/27/15):
CHEMORADIOTHERAPY: Patients undergo chemoradiotherapy as in Arm I. Six weeks after
completion of chemoradiotherapy, patients proceed to maintenance therapy.
MAINTENANCE THERAPY: Patients receive isotretinoin orally (PO) twice daily (BID) on day 1
and days 16-28 and cisplatin, vincristine sulfate, cyclophosphamide, and filgrastim as in
Arm I maintenance therapy. Treatment repeats every 28 days for a total of 6 courses in
the absence of disease progression or unacceptable toxicity. Patients then proceed to
continuation therapy.
CONTINUATION THERAPY: Patients receive isotretinoin PO BID on days 15-28 every 28 days
for up to 6 courses in the absence of disease progression or unacceptable toxicity.
ARM D (standard chemoradiotherapy plus carboplatin, standard maintenance therapy plus
isotretinoin, and continuation therapy with isotretinoin - CLOSED TO ACCRUAL 1/27/15):
CHEMORADIOTHERAPY: Patients undergo chemoradiotherapy as in Arm II. Six weeks after
completion of chemoradiotherapy, patients proceed to maintenance therapy.
MAINTENANCE THERAPY: Patients receive maintenance therapy as in Arm III. Patients then
proceed to continuation therapy.
CONTINUATION THERAPY: Patients receive continuation therapy as in Arm III.
After completion of study treatment, patients are followed up periodically for 1 year.