boards Flashcards
what’s the site of distant mets for medulloblastoma
bone
hodgkin lymphoma patients who experience the symptoms of unexplained weight loss lose how much in how long?
10% in 6 months
why is a testicular shield used for male patients in pelvic irradiation of Hodgkin Lymphoma
to reduce internal scatter
T/F Peu d’orange skin is a sign of good prognosis in patients with breast cancer
false
what single agent chemo drug is commonly used to treat breast cancer
adriamycin
a supraclav field is included in the treatment for breast cancer when ___ axillary nodes are positive
4
what’s the most common cancer site in American women?
breast cancer
the pituitary gland is located
2 cm superior and 2 cm anterior to the EAM
the parotid gland is located
2.5 cm inferior and 2.5 cm anterior to the EAM
the presence of which cell, along with other hematological findings are most indicative of Hodgkin’s disease
reed-sternberg cells
lymphatic spread of testicular cancers follow a specific pattern, what is the correct order
para-aortic, mediastinal, supraclavicular
what is the lymphatic drainage for the lip
submandibular, preauricular, facial nodes
because meninges encase the whole brain and extend along the optic nerve into the orbit it is imperative the __ is included in the treatment field
total orbital, the tip of the temporal lobe, the first two cervical spines
the prostate is located
inferior to the urinary bladder and anterior to the rectum
which lobe of the brain is treated in a German helmet technique that is not necessarily encompassed in a standard clinical brain field arrangement
temporal
occupational annual non-stochastic effective dose equivalent limit
500 mSv
involvement of the __ nodes is most common when the lesion located in the lower third of the vagina
inguinal
what are the borders for a mantle field
mastoid to T10
tissue air ratio is mostly related to ___ set ups
isocentric
what type of monitoring device should be worn during brachytherapy by physics personel
film badge and TLD ring badge
the wedge angle specifies the
the angle between a perpendicular line through the central axis and the 50% isodose line
Mayneord’s F-factor is used to convert
inverse square correction for PDD
PDD has a direct relationship with
field size, energy, and SSD
if a table moves during the treatment and the off button on the console does not work what do you do first
main power breaker
the off axis ratio is the
ratio of the dose at a given depth at a point away from the central axis and the dose at a point along the central axis at the same depth
A T1 larynx treatment involves
wedges, opposed lateral treatment portals
what is the average transmission leaf for a varian linac
<2.5%
Which of the following are true of integral dose?
I. Measures total absorbed dose in the treatment volume
II. Product of mass and dose if dose received is uniform
III. Unit of measure is the gram-rad
I, II, III
in IMRT therapy a patient will receive
- no port films
- less skin surface dose and max tumor dose
- more skin surface dose and less tumor dose
- none of the above
less skin surface dose and max tumor dose
The proper way of source disposal is to.
- Flush it down the drain
- Put in the trash
- Seal it in a lead container then put in the trash
- Put in a lead container and after it’s been calculated to be safe and then put in the trash
put it in a lead container and after it’s been calculated to be safe and then put in the trash
a dynamic wedge
- employs moving collimation to alter isodose distributions
- requires repeated insertion and removal of various individual wedges during treatment
- both of the above
- none of the above
employs moving collimation to alter isodose distribution
According to the 1987 NCRP recommendations, the annual dose limit for non-stochastic (somatic) effects to all tissues, other than the eye, should not exceed.
500 mSv- 50 rem
the symptoms of early radiation sickness, nausea and vomiting, at doses of radiation between 1 and 2 gray are classified as the
prodromal syndrome
the energy absorbed in the surrounding medium around a gas filled cavity can be determined by the
Bragg gray theory
the process by which energy from an ionizing radiation is transferred from an irradiated molecule to a non irradiated molecule is called the
indirect hit theory
which of the following is not considered a somatic non- stochastic effect of radiation
leukemia
neutron contamination outside of the radiotherapy beam is of concern for which energy
18 MV
most of the energy imparted to tissue in the radiotherapy range is due to
Compton effect
the dose build up region is
0.5 cm
if the room temperature should significantly increase during a calibration session, the standard readings taken with an open ionization chamber would.
Fall
According to the 1987 NCRP recommendations, the guidance level for cumulative exposure should be calculated using the formula.
Age x 10 mSv
during a split field test for longitudinal displacement of the collimator for jaw symmetry, the collimator is rotated to angles of
90 degres
machine dose rate constancy is most commonly checked using
ion chambers
when calibrations are attempted for electron beams, the preferred phantom material is
distilled water
constancy checks for all linear accelerator should be performed
daily
during the calibration of a high energy x-ray beam, an increase in field size will increase the exposure rate. the principle reason for this is:
collimator scattering
1 Sv = __ rem
100 rem
1 Gy= __ rad
100 rad
the photoelectric effect is principally associated with
absorption of incident photon
which of the following is found around the renal hilus
renal pelvis
the longest portion of the large intestine is the
transverse colon
the quality factor for x, gamma or beta radiation
1
the quality factor for alpha particles
20
the quality factor for neutrons of unknown energy
10
the quality factor for high energy protons
10
what is the saclike dilatation of the upper end of the stomach
fundus
