W/L Ch 32 CNS Quiz Flashcards
What is the current 5-year survival of patients with glioblastoma multiforme (GBM)?
a. 35%
b. 55%
c. 75%
d. 95%
a. 35%
From which cells to medulloblastomas arise?
a. Primitive neuroectodermal tumor (PNET)
b. Primitive neuroectodermal cells
c. Astrocytes
d. Lymphocytes
a. Primitive neuroectodermal tumor (PNET)
What is the most common type of brain tumor?
a. GBM
b. Astrocytoma
c. Meningioma
d. Metastatic brain lesions
d. Metastatic brain lesions
What is the most common CNS tumor in children?
a. Medulloblastoma
b. Metastatic lesion
c. Astrocytoma
d. Craniopharyngioma
a. Medulloblastoma
What is the most common source of brain metastases among the following?
a. Colon
b. Lung
c. Breast
d. Melanoma
b. Lung
Which tumors spread through the cerebral spinal fluid?
a. Astrocytoma
b. Oligodendroglioma
c. Medulloblastoma
d. Schwannoma
c. Medulloblastoma
Which of the following cells is responsible for myelin production?
a. Neurons
b. Schwann cells
c. Astrocytes
d. Ependymal cells
b. Schwann cells
Which of the following factors can limit the usefulness of surgery for CNS neoplasms?
a. Tumor location and extent
b. Patient status
c. Risk of causing neurologic damage
d. All of the above
d. All of the above
Which portion of the brain is the site of intelligence and judgment?
a. Cerebrum
b. Cerebellum
c. Brain stem
d. Thalamus
a. Cerebrum
Which of the following conditions is a contraindication for stereotactic radiosurgery (SRS)?
a. Spherical tumor
b. 2-cm tumor
c. Brain metastases
d. Five lesions
d. Five lesions
To be a candidate for SRS, the target volume should be spherical and as large as 3 cm only at its maximum dimension.
What is the 5-year survival rate for all CNS tumors combined?
a. 20%
b. 35%
c. 50%
d. 75%
b. 35%
Which of the following is a late effect of brain irradiation in children?
a. Leukemia
b. Decreased IQ
c. Gigantism
d. Chronic fatigue
b. Decreased IQ
Which of the following is most significant to the prognosis of brain tumors?
a. Tumor size
b. Lymph node involvement
c. Metastases
d. Grade
d. Grade
What defines the inferior radiation field border for the treatment of the whole brain for palliation?
a. 1-cm flash
b. Superior orbital ridge
c. External auditory meatus
d. Both b and c
d. Both b and c
Which of the following beam arrangements is most typical for treatment of a malignant primary brain tumor?
a. Parallel opposed whole brain fields
b. Small fields with 1 to 3 cm margins
c. Oblique fields to include the supraorbital ridge
d. Large fields with 5 to 10 cm margins
b. Small fields with 1 to 3 cm margins
Which of the following is the dose at which radiation necrosis of brain tissue is most likely to occur?
a. 6000 cGy
b. 4500 cGy
c. 4000 cGy
d. 2000 cGy
a. 6000 cGy
Radiation tolerance for normal tissues within the CNS include 5000 cGy for whole brain, 6000 cGy for partial brain, and 4500 to 5000 cGy for the spinal cord. These tolerances are based on TD5/5, which assumes a 5% incidence of complications at a 5-year period.
p. 698
Chemicals that enhance the lethal effects of radiation are known as ____________.
a. cytotoxins
b. corticosteroids
c. radioprotectors
d. radiosensitizers
d. radiosensitizers
Epilation may be permanent when the cranium is treated beyond the threshold dose of ______ cGy.
a. 1000
b. 2000
c. 3000
d. 4000
d. 4000
Which class of chemotherapy drugs has the ability to cross the blood-brain barrier?
a. Antimetabolites
b. Plant alkaloids
c. Nitrosoureas
d. Hormonal agents
c. Nitrosoureas
The nitrosourea drugs are lipid soluble, allowing them to cross the blood-brain barrier.
Patients treated to the cranium should be advised to protect their heads from direct sunlight because the sun _____________________________.
a. enhances radiation-induced side effects
b. causes lower white cell blood counts
c. enhances feelings of nausea
d. lowers tolerance to anti-inflammatory medications
a. enhances radiation-induced side effects
