Medulloblastoma

Question 1

In the majority of
cases the tumor arises in the ________ and projects
into the fourth ventricle. P

Answer 1

cerebellar vermis

Question 2

_________ at diagnosis is approximately 30% to 35% and investigation at diagnosis must include a gadolinium-enhanced MRI of the spinal axis and CSF cytology.

Answer 2

Leptomeningeal seeding

Question 3

Factors that correlate with outcome include ______.

Answer 3

age at diagnosis
the presence or absence of leptomeningeal spread at diagnosis, and
the completeness of the surgical resection

Question 4

Those who have undergone complete or subtotal resection with

Answer 4

1.5 cm2

Question 5

approach is now considered to be the standard of care for children with standard-risk medulloblastoma in North America.

Answer 5

CSI to a dose of 23.4 Gy in combination with weekly vincristine followed by adjuvant systemic chemotherapy consisting of vin-
cristine 1.5 mg/m2, cyclophosphamide, and cisplatinum 75 mg/
m2

Question 6

β-catenin nucleo-positivity is associated with
a ____ prognosis and MYC gene amplification with a ____
one

Answer 6

Better

Worse

Question 7

for high-risk medulloblastoma, while the standard of care in many centers in
Europe is now a _____ regimen given in combination with pre- and postradiotherapy chemotherapy

Answer 7

hyperfractionated accelerated radiotherapy

HART

Question 8

While up to half of infants have more favorable histologic types (desmoplastic/nodular or medulloblastoma with
extensive nodularity), the prognosis overall is ____ than in older children

Answer 8

Worse

The rate of complete resection is lower
in this age group and the frequency of leptomeningeal seeding
at diagnosis higher (as much as 50%), but also, many patients
do not receive optimal treatment.192 Because of the significant
risks with respect to neurocognitive function associated with
the use of radiotherapy in infants and very young children,
chemotherapy has been used in an attempt to either delay or
avoid radiotherapy altogether

Question 9

____ is the standard of care, and careful attention to coverage of the entire target volume that includes the meninges overlying the brain and spine including extensions along nerve roots
is critical.

Answer 9

CSI

Question 10

CSI is followed by a boost to the posterior fossa. Traditionally, the entire posterior fossa has been treated to a total dose of ____Gy

Answer 10

54 to 55.8 Gy

Question 11

Delay to radiotherapy may be associated with poorer outcomes, and CSI should ideally start within ____ days following surgery.

Answer 11

28 to 30

Question 12

Medulloblastoma accounts for ______% of all CNS tumors

Answer 12

15% to 20%