CNS cpt 32

Question 1

what is the current 5-year survival of patients with glioblastoma multiforme (GBM)?

Answer 1

35%

Question 2

From which cells do medulloblastomas arise?

Answer 2

primitive neuroectodermal tumor (PNET)

Question 3

what is the most common type of brain tumor?

Answer 3

Metastatic brain lesions

Question 4

what is the most common CNS tumor in children?

Answer 4

Medulloblastoma

Question 5

what is the most common source of brain metastases among the following: colon, lung, breast, melanoma

Answer 5

Lung

Question 6

which tumors spread through the cerebral spinal fluid?

Answer 6

Medulloblastoma

Question 7

which of the following cells is responsible for myelin production?

Answer 7

Schwann cells

Question 8

which is the following factors can limit the usefulness of surgery for CNS neoplasms?

Answer 8

all of the above (tumor location and extent, patient status, risk of causing neurologic damage)

Question 9

which portion of the brain is the site of intelligence and judgement?

Answer 9

Cerebrum

Question 10

which of the following conditions is a contraindication for stereotactic radiosurgery (SRS)

Answer 10

five lesions

Question 11

what is the 5-year survival rate for all CNS tumors combined?

Answer 11

35%

Question 12

which of the following is a late effect of brain irradiation in children?

Answer 12

decreased IQ

Question 13

which of the following is most significant to the prognosis of brain tumors?

Answer 13

grade

Question 14

what defines the inferior radiation field border for the treatment of the whole brain for palliation?

Answer 14

superior orbital ridge & external auditory meatus

Question 15

which of the following beam arrangements is most typical for a treatment of a malignant primary brain tumor?

Answer 15

small fields with 1-3 CM margins

Question 16

which of the following is the dose at which radiation necrosis of brain tissue is most likely to occur?

Answer 16

6000 cGy

Question 17

chemicals that enhance the lethal effects of radiation are known as?

Answer 17

radiosensitizers

Question 18

epilation may be permanent when the cranium is treated beyond the threshold dose of?

Answer 18

4000 cGy

Question 19

which class of chemotherapy drugs has the ability to cross the blood-brain barrier?

Answer 19

Nitrosoureas

Question 20

patients treated to the cranium should be advised to protect their heads from direct sunlight because the sun

Answer 20

enhances radiation-induced side effects