Mosby 3 Flashcards
the therapist may see a patient treated in the seated position because of
shortness of breath and/or weight exceeds the couch limit
indian club needles have
one hot end
dense metal accessories should be placed at a suitable distance from the patients skin surface in order to prevent contamination from secondary
electrons and neutrons
during radiation treatment to the thorax, the arm position should be
consistent throughout the treatment course
beam symmetry and flatness are defined over what percentage of the field
80
which of the following equipment produces extra nuclear indirectly ionizing radiation
linear accelerator
a low residue diet would be recommended for the patient receiving radiation to the
bladder
the pituitary gland is situate in the
sella turcica of the sphenoid bone
the most important method used to confirm malignancy is
histopathological study
the backscatter factor depends on
energy and field size
what is a nonmalignant condition treated by stereotactic radiosurgery
arteriovenous malformation
the td 5/5 for the lens of the eye is
500 cGy
which of the following radioisotopes is sometimes administered into the peritoneal cavity in the treatment of gynecological malignancies
Phosphorus-32
a good surface landmark to approximate the apex of the lung is
clavicle
in a linear accelerator, microwave amplification occurs in the
klystron
a patient undergoing treatments to the oral cavity and oral pharynx will experience
altered taste, sore throat, difficulty swallowing
the use of the wedge filter helps to
achieve a more homogenous dose distribution, compensate for the absence or presence of tissue, avoid hot spots
the process of cellular growth and development is called
proliferation
what technique is used to treat early pre-cancers of the cervix
loop electrosurgical excision
which of the following radiation interactions with matter occur independently of atomic number
Compton effect
bite block systems may be used in head and neck irradiation for the purpose of
reducing the volume of oral mucosa in the field
how many joules are in 1 electron volt
1.6x10^-19 J
Bragg peak is
maximum ionization near the end of the range of a heavy, charged particle
between the thyroid notch and the cricoid cartilage lies the
larynx
the basic types of interaction between x-radiation and matter include all of the following except
radiative bremmstralung production
increasing the dose rate on a linear accelerator will ___ the percent depth dose
not change
the treatment field for a right upper lobe tumor has the central axis at the level of the sternal angle. the verification port will likely show the central axis at about the level of the
carina
in an SSD treatment technique dose is normalized to
Dmax
the greater the distance between the radiation source and the barrier, the
less exposure incident on the barrier
radon is a natural radioactive gas with a half-life of
4 days
a method of radiation therapy in which the source is moved around the patient, but only through certain sectors of a circle is called
arc therapy
the range in water of a 20 MeV electron beam is approximately
10 cm
the record and verify system is intended to do all of the following except verify the
patient position
lucite is often used as the material for positioning devices. one major concern when this material is in the path of the treatment beam is
beam attenuation
what factors contributes to cancer fatigue
pain, metabolic changes, and treatment
Wilm’s tumor originates in the
kidney
the attenuation of cerrobend is less dense than lead by
15%
increasing the field size from 5x5 to 20x20, with all other factors remaining the same, the percent depth dose will
increase
in the adult, a platelet count within normal range would be approximately __mm^3
150-450,000
a breast bridge may be used to
immobilize the breast tissue
the preferred material for the patient couch as part of the CT simulator or linear accelerator is carbon fiber. this material is preferred due to its
radiolucency, low attenuation
the tolerance dose (TD 5/5) for the optic chiasm
60 Gy
in radiation therapy, which of the following interactions with matter are least important
photoelectric effect
the unit of radiation dose REM stands for
roentgen equivalent in man
the prodromal stage of acute radiation syndrome consists of
nausea
in primary bone tumors, the primary mode of distant metastasis is through
vasculature
the depth of inguinal lymph nodes
can range from 2-18 cm depending on patient size
the rate of kinetic energy lost per unit path length is referred to as
stopping power
the French American British staging system is used to classify
acute leukemia
which of the following is an example of indirectly ionizing radiation
neutrons
electron contamination of high energy photon beams may result from photon interactions with the
collimators
a fletcher-suite applicator consists of
tandem and a pair of ovoids
the type of nutrition that bypasses the gastrointestinal tract and introduces nutrients into the veins is called
parenteral
a grade 1 morbidity score for the colon would indicate
change in frequency of bowel habits
the most likely photon beam energy used to treat areas in the head and neck would be
6 MV
early stage ovarian cancer can be successfully treated with
surgery followed by chemotherapy
A patient treated with two fields separated by 120 degrees, likely needs a __ degree wedge inserted for even dose distribution
30
a 30 year old radiation worker would be allowed __ rem whole-body cumulative exposure
30
which part of the larynx contains the true vocal cords
glottis
which of the following is true of Beta+ decay
a proton is converted to a neutron
light field and radiation field congruence should be checked
monthly
placing marks on the central axis only is
insufficient for daily realignment and targeting
if radiation is used preoperatively for the management of colon cancer, the total tumor dose would be __ Gy
50
when calibrating ion chambers, which of the following correction factors are needed
barometric pressure, volume of the chamber, and temperature
which SI unit of measure expresses the strength of the magnetic field during MRI
tesla
the highest dose from manmade radiation comes from
medical and dental use
squamous cell carcinoma would be the likely histological classification for a malignant growth in the
larynx
which theory of radiation interaction is illustrated by the operating principles of an ionization chamber
bragg-gray cavity theory
