Ch 8 Flashcards
Thermoluminescence refers to emission of:
A. High intensity light from electron beams
B. High intensity light from photon beams
C. Light from certain materials when heated
D. Light from thermonuclear reaction
C. Light from certain materials when heated
The light signal produced from thermoluminescence dosimetry is amplified by:
A. An electrometer
B. A densitometer
C. A photomultiplier tube
D. A calorimeter
C. A photomultiplier tube
The most commonly used thermoluminescence material used in radiation dosimetry is:
A. Ca So4
B. Ca F2
C. Li F
D. Li2 B
C. Li F
For megavoltage dosimetry, thermoluminescence dosimetry can provide accuracy of:
A. ± 20%
B. ± 10%
C. ± 3%
D. ± 1%
C. ± 3%
A radiographic film consists of:
A. Acrylic coated with toner
B. Cellulose acetate coated with an emulsion containing silver bromide
C. Acrylic coated with cellulose acetate
D. Cellulose acetate coated with polystyrene
B. Cellulose acetate coated with an emulsion containing silver bromide
During the development of the film:
A. Silver is added to the film
B. Silver is removed from the film
C. Silver bromide affected by radiation is reduced to small crystals of silver
D. None of the above
C. Silver bromide affected by radiation is reduced to small crystals of silver
During the fixing of the developed film, the:
A. Unaffected granules of silver bromide are fixed in the film
B. Unaffected granules of silver bromide are removed from the film
C. Affected granules are removed
D. Affected granules are fixed
B. Unaffected granules of silver bromide are removed from the film
If Io and It are incident and transmitted light intensities, respectively, the optical
density is defined as:
A. Io / It
B. 100 x Io / It
C. Log (Io / It)
D. Log (Io - It
C. Log (Io / It)
The H-D curve for a type of film is a plot of:
A. Incident vs. transmitted light intensities
B. The optical density vs. exposure
C. Net light intensity vs. transmitted light intensity
D. Net light intensity vs. incident light intensity
B. The optical density vs. exposure
Film Dosimetry is extremely useful for:
A. Absolute dosimetry
B. Relative dosimetry
C. In-vivo dosimetry
D. Radiobiological dosimetry
B. Relative dosimetry
With megavoltage film dosimetry, isodose curves can be measured to within
A. ± 10%
B. ± 7%
C. ± 3%
D. ± 1%
C. ± 3%
Film badges for personnel dosimetry have a reliability of:
A. ± 50%
B. ± 30%
C. ± 10%
D. ± 1%
C. ± 10%
Radiochromic films are best suited for measurements of:
A. Low dose radiation (less than 1 millirad)
B. High dose levels (10Gy-10^4 Gy)
C. Temperature
D. None of the above
B. High dose levels (10Gy-10^4 Gy)
Radiochromic film requires:
A. Extensive processing
B. Immediate processing
C. No processing
D. Low temperature storage
C. No processing
Measurements on a radiochromic film are made with:
A. An electrometer
B. Spectrometer or densitometer
C. Magnetometer
D. None of the above
B. Spectrometer or densitometer
The response of radiochromic films is:
A. Independent of pressure
B. Dependent on room temperature
C. Dependent on room light intensity
D. Independent of all of the above
B. Dependent on room temperature
The reproducibility of radiation measurements with radiochromic film is about:
A. ± 1%
B. ± 5%
C. ± 7%
D. ± 10%
B. ± 5%
For use in the clinical range of photon and electron therapy beams, the response of radiochromic
film is:
A. Independent of energy
B. Slightly energy-dependent
C. Very dependent
D. None of the above
E. ± 1%
B. Slightly energy-dependent
A diode dosimeter is:
A. An ionization chamber coated with silicon
B. A vacuum tube
C. A solid state device
D. Baldwin Farmer chamber
C. A solid state device
In megavoltage therapy, diodes are well suited for:
A. Absolute dosimetry
B. Relative dosimetry
C. Thermometry
D. Imaging
B. Relative dosimetry
In megavoltage therapy, typical use(s) of diodes is for:
A. Patient dosimetry
B. Beam scanning
C. Quality assurance
D. All of the above
D. All of the above
Which of the following is best suited for calibration of a megavoltage beam:
A. Diode detector
B. Thermoluminescence dosimetery
C. Film
D. Ionization chamber
D. Ionization chamber
Acceptance testing of a radiation therapy machine relates to:
A. Developing a better design of its components
B. Comparing the specifications in the purchase order to the measured performance of the machine
C. Adjusting the electrical and mechanical parameters of the machine
D. Measuring the performance of subsystems
B. Comparing the specifications in the purchase order to the measured performance of the machine
The commissioning of a therapy machine requires:
A. Measuring equipment
B. Acquisition of clinical data
C. Calibration of all the physical and radiation parameters
D. All of the above
D. All of the above
Calibration of a machine primarily deals with:
A. Radiation beam parameters
B. Mechanical parameters
C. Digital displays
D. Laser equipment
E. All of the above
E. All of the above
A good standard of practice requires that a treatment machine should undergo a
complete calibration at least:
A. Before any treatment
B. Daily
C. Weekly
D. Monthly
E. Annually
E. Annually
A consistency check of radiation beams should be performed at least:
A. Daily
B. Weekly
C. Monthly
D. Annually
B. Weekly
