Mosby 4 Flashcards
assuming ideal patient contour, the optimal hinge angle for a 45 degree wedged pair is
90
kidney tolerance td 5/5 in the adult would be
2000 cgy
when protons interact with matter
the rate of ionization increases as the proton is slowed down in matter and they recoil for nuclei
you may acquire a new external contour by using
plaster of Paris, solder wire, CT
breast self examinations should be performed
monthly
which of the following physical hazards associated with MR imaging is caused by the strong stationary magnetic field
projectile effect
which of the following photon interactions with matter involves energy being converted mass?
pair production
the field size of an x-ray or gamma ray beam is defined the area enclosed within the boundary of the ___%depth dose line
50
endometrial cancers are typically detected at an early stage. an early sign of endometrial cancer is
abnormal vaginal bleeding
Co-60 and Co-57 are elements that have
the same number of protons but different number of neutrons
in the adult, a platelet count within normal range would be approximately ___ mm3
400,000
early stage ovarian cancer can be successfully treated with
surgery followed by chemo
which part of the larynx contains the true vocal cords
glottis
what percentage of adenomatous polyps of the colon contains invasive cancer cells
3% to 5%
regarding management of skin reactions, all of the following are true except
erythematous areas should be kept moist
which theory of radiation interaction is illustrated by the operating principles of an ionization chamber
Bragg-gray cavity theory
electron beams are useful in radiation therapy primary because they
have a definite range in tissue
when caring for a patient on oxygen therapy, the therapist must remember that oxygen
must be ordered by the physician
what is the standardized barometric pressure
760 mmHg
standardized temperature
273.2 Kelvin
normal rectal temperature for the adult in Fahrenheit is
99.6
mucositis is more likely to occur in which of the following malignant conditions
leukemia
what type of dose response model applies to MR to address biologic effects of the magnetic fields used to image patients
nonlinear, threshold
reductions in ___ intake have coincided with ___ rates in colon cancer
fiber, increasing
the use of iodine or barium contrast in CT scanning exploits the characteristics of
photoelectric effect
which of the following is true of Co-60 decay
excess energy is given off as two gamma rays of discrete energies
when treating opposed oblique fields for a lung tumor
ssds for each field should be read and documented
the basic types of interaction between x-radiation and matter include all of the following except
radiative bremsstrahlung production
photon production from a diagnostic X-ray tube requires
direct current and voltage potential
the mass attenuation coefficient is
independant of density
it is important to detect a neoplasm early, when it is small, because smaller tumors show
fewer cells
the ___ nature of cancer cells affects their sensitivity to radiation
undifferentiated
the backscatter factor depends on
field size and energy
which histological type would a tumor of the larynx likely be?
squamous cell carcinoma
total dose to the lumpectomy site following accelerated partial breast irradiation utilizing high dose rate brachytherapy will be approximately
45 Gy
chemotherapy related side effect characterized by a decrease in MANY cellular components of the blood is
pancytopenia
if radiation is used preoperatively for the management of colon cancer, the total tumor dose would be __ Gy
50
the tredelenberg position is appropriate for a patient experiencing a medical emergency such as
shock
which of the following factors influences brightness of an image displayed on a viewing monitor
window level
which modalities are commonly used for IGRT
CT and ultrasound
when treating a patient with prostate cancer, which of the following factors would not cause prostate movement
cecum volume
which photon interaction with matter involves direct photon interaction with the nucleus
pair production
the pulse in the adult is most commonly evaluated at all the following sites except
aorta
shoulder retractors are important for
pulling the shoulders out of the treatment field
cellular radiosensitivity is __ proportional to the rate of cell division and ___ proportional to the degree of cell differentiation
directly; inversely
a good surface landmark for the true vocal cords is the
thyroid cartilage
in the usual orientation of the three planes with respect to the patient
the transverse plane lies across the patient
the best position for treating vertex field is
chin flexed
which of the following sites is most likely to show bone metastasis
thoracic spine
