Radiation Factors And Dose Designs

Question 1

What is the Radiation Weighting factor?

Answer 1

It is also known as the Quality factor and depends on the LET of the type of radiation.

Question 2

What is the Radiation Weighting Factor for X-rays?

Answer 2

1

Question 3

What is the Radiation Weighting Factor for Gamma rays?

Answer 3

1

Question 4

What is the Radiation Weighting Factor for Neutrons?

Answer 4

5-20

Question 5

What is the Radiation Weighting Factor for Protons?

Answer 5

2

Question 6

What is the Radiation Weighting Factor for Alpha particles?

Answer 6

20

Question 7

What is the leakage radiation requirement for Orthovoltage and Superficial voltage?

Answer 7

Leakage radiation must be reduced to less than 1 cGy/hour at a distance of one meter from the housing.

Question 8

What is the leakage rate for Teletherapy Equipment?

Answer 8

Leakage is less than 0.1% of the highest primary beam rate at 1 meter for the largest field size.

Question 9

What is the function of an isocentric unit with a beam interceptor?

Answer 9

It should reduce the output of the useful beam to less than 0.1%.

Question 10

What is the collimation requirement for X-ray beams?

Answer 10

X-ray beam and light must coincide to within +/- 2% of the SID.

Question 11

What is a Controlled Area?

Answer 11

A defined area in which the occupational exposure of personnel to radiation is under the supervision of the radiation protection supervisor.

Question 12

What is the radiation exposure limit for a Controlled Area?

Answer 12

1 mSv/week.

Question 13

What is an Uncontrolled Area?

Answer 13

An area that requires more shielding in the wall than a Controlled Area.

Question 14

What is the radiation exposure limit for a Public or Uncontrolled Area?

Answer 14

0.02 mSv per week and 0.02 mSv in any one hour.

Question 15

What is the dose limit for non-controlled public areas?

Answer 15

1 mSv/yr is the dose limit that is used when computing barrier thickness for non-controlled public areas.

Question 16

What is the dose limit for controlled areas?

Answer 16

10 mSv/yr is the dose limit that is used when computing barrier thickness for controlled areas.

Question 17

What is the Primary Barrier Equation?

Answer 17

P = BWUT/(d^2)

P: Transmitted dose (cGy/week), W: Workload, U: Use, T: Occupancy, d: Distance (Meters), B: Transmission

Question 18

What does P represent in the Primary Barrier Equation?

Answer 18

P represents the transmitted dose in cGy/week.

Question 19

What does W stand for in the Primary Barrier Equation?

Answer 19

W stands for Workload.

Question 20

What does U represent in the Primary Barrier Equation?

Answer 20

U represents Use.

Question 21

What does T stand for in the Primary Barrier Equation?

Answer 21

T stands for Occupancy.

Question 22

What does d represent in the Primary Barrier Equation?

Answer 22

d represents Distance in meters.

Question 23

What does B stand for in the Primary Barrier Equation?

Answer 23

B stands for Transmission.

Question 24

What is the NCRP recommendation for the floor?

Answer 24

1

Represents the factor for the floor in dose calculation.

Question 25

What is the NCRP recommendation for each wall that may be struck by the primary beam?

Answer 25

0.25 ## Footnote Represents the factor for each wall in dose calculation.

Question 26

What is the NCRP recommendation for the ceiling?

Answer 26

0.25 ## Footnote Represents the factor for the ceiling in dose calculation.

Question 27

What is workload (W) in dose calculation?

Answer 27

Total dose delivered to the isocenter per week in cGy/week.

Question 28

How is workload (W) calculated?

Answer 28

Treatments multiplied by isocenter dose.

Question 29

What is Occupancy (T)?

Answer 29

Occupancy (T) refers to the exact occupancy that can be determined by calculating the percentage of a 40-hour workweek that the space is occupied.

Question 30

What is the occupancy factor for control areas/workrooms, darkrooms, waiting rooms, restrooms used by occupationally exposed personnel, children's play areas, and living quarters?

Answer 30

1

Question 31

What is the occupancy factor for hallways, utility rooms, restrooms not used by occupationally exposed personnel, elevators with operators, and uncontrolled parking lots?

Answer 31

0.25 or 1/4

Question 32

What is the occupancy factor for stairways, automatic elevators, outside areas used only by pedestrians or vehicular traffic, and closets?

Answer 32

0.0625 or 1/16