quality assurance Flashcards
orthovoltage machines operate in the ____ range
150-500 kV
neurons, chondrocytes, osteoblasts, and lymphocytes which has the highest radiosensitivity
osteoblasts
the physical field size is defined as the __
50% isodose line
when radiation interacts with radiographic film contained in a radiographic film badge, after development:
the film darkens proportional to the exposure
which has the highest frequency? xrays, visible light, microwaves, radio waves
x-rays
when shielding a linac vault where photon beam energies are greater than 10 MV …
shielding for neutron contamination must be taken into account
which radioactive isotope is most commonly used in HDR after loading brachytherapy
Ir 192
when a patient is treated with radioactive 131, the room should have a label that reads,
caution: radioactive materials
the mathematical correction for the effect of temperature and pressure on ionization is based on a standardized barometric pressure of:
760 mmHg
a pocket dosimeter is
a low energy dosimeter
a traditional unit of absorbed dose equivalent is
rem
which radiation interactions with matter occur independently of atomic number?
Compton effect
what is the energy threshold for triplet production?
2.044 MV
the si unit for absorbed dose is the gray while the traditional unit is the …
RAD!
which element of the hematopoietic system shows the earliest response to radiation
lymphocytes
how many volts are in a joule?
1= 1.6021 x 10 (^-19) J
which proton interaction with matter involves direct photon interaction with the nucleus
pair production
an area where radiation level could reach 60 mrem/ hr would be classified as
radiation area
an example of a nonstochastic effect from radiation exposure is
erythema
the patient experiencing dry desquamation should be advised to
apply radiation dermatitis ointments no sooner than 1 hour before treatment
if the threshold energy of 1.022 MeV is not present for Beta+ decay to occur, then a nucleus with an excess number of protons will release energy by
electron capture
brachial plexopathy is an adverse effect following the high dose radiation to the
supraclavicular fossa
the radionuclide Tc99 is an example of a
isomer
what is the approximate location of the external iliac lymph nodes?
1 cm lateral of the pelvic rim
which of the following does not provide protection for the brain?
cerebellum
it is important to detect a neoplasm early, when it is small, because smaller tumors show
fewer cells
earlier generation therapy machines called orthovoltage machines operated in the range of
150 to 500 kV
When radiation passes through matter, it may produce positively and negatively charged particles known as:
ions
when treating the maxillary antrum, the organ at the greatest risk for damage is the
lens
treatment should be withheld if
patient refuses, and unexpected side effects are reported
in the maintenance phase of of managing ALL, whole brain irradiation may be given with the inferior border of the treatment field at the
C2
For portal verification, bone tissue contrast is better using a kilovoltage imager rather than a megavoltage imager due to the absence of:
photoelectric interactions in the MV beam
the most common type of leukemia in children is
ALL
the amount of energy transferred in a medium per unit mass is referred to as
KERMA
the primary function of area control activities, personnel monitoring, and proper radioactive material disposal is for the:
determination of appropriate ALARA procedures and process
The class of cytotoxic agents that has the potential to burn the skin of the administerer is:
alkalizing agents
the tail of the pancreas is at the
in the hilum of the spleen
linear energy transfer is measured in
keV/micrometer
electrons are liberated through a process called
thermionic emission
the parathyroids are located
on the posterior surface of both thyroid lobes
the maximum allowable transmission through the multi leaf collimators is
5%
You have an emergency spinal cord compression at the level of lumbar spine 2. The physician orders a preliminary field to cover L1 to L3. The approximate field size will be:
8x10
which tumor marker among the following is helpful in the diagnosis of testicular cancer
alpha fetoprotein
with all other factors remaining the same, increasing the field size from 6x6 to 10x10 would
increase - delete this question
