Fundamental Principles Of RADIOBIOLOGY Ch 33

Question 1

Principal Aim of the Study of Radiobiology

Answer 1

To understand radiation dose-response

relationships

Question 2

A mathematical & graphic function that

relates radiation dose to observed response

Answer 2

Dose-Response Relationship

Question 3

Theorized & observed that radiosensitivity
was a function of metabolic state of tissue
being irradiated

Answer 3

Jean Bergonie & Louis Tribondeau (1906)

Question 4

Physical Factors That Affect Radiosensitivity

Answer 4

Linear Energy Transfer (LET), Relative
Biologic Effectiveness (RBE), Protaction &
Fractionation

Question 5

A measure of the rate at which energy is
transferred from ionizing radiation to soft
tissue

Answer 5

Linear Energy Transfer (LET)

Question 6

Factor used in radiation protection that
accounts for differences in biologic
effectiveness between different radiations

Answer 6

Radiation Weighting Factor (WR)

Question 7

Ratio of the dose of standard radiation
necessary to produce a given effect to the
dose of test radiation needed for the same effect

Answer 7

Relative Biologic Effectiveness (RBE)

Question 8

The standard radiation by convention

Answer 8

Orthovoltage X-rays

Question 9

The dose is delivered continuously but at a

lower dose rate

Answer 9

Protraction

Question 10

The dose is delivered at the same dose in

equal portions at regular intervals

Answer 10

Fractionation

Question 11

Biologic Factors That Affect Radiosensitivity

Answer 11

Oxygen Effect, Age, Recovery, Chemical

Agents & Hormesis

Question 12

Ratio of the dose necessary to produce a
given effect under anoxic conditions to the
dose necessary to produce the same effect
under aerobic conditions

Answer 12

Oxygen Enhancement Ratio (OER

Question 13

It occurs when the cell dies before

replicating

Answer 13

Interphase Death

Question 14

It is due to a repair mechanism inherent in

the biochemistry of the cell

Answer 14

Intracellular Repair

Question 15

Replication by surviving cells

Answer 15

Repopulation

Question 16

agents that enhance the

effect of radiation

Answer 16

Chemical Agents

Question 17

A mathematical relationship between
various radiation dose levels & magnitude if
the observed response

Answer 17

Radiation Dose-Response Relationship

Question 18

Two Important Applications in Radiology

Answer 18

• It is used to design therapeutic treatment
  routines for patient with cancer
• It revealed provide the basis for radiation
  control activities

Question 19

Two Types of Radiation Responses

Answer 19

Deterministic & Stochastic

Question 20

Early radiation response

Answer 20

Deterninistic

Question 21

Late radiation response

Answer 21

Stochastic

Question 22

Two Characteristic of Dose-Response Relationship

Answer 22

• Linear or Nonlinear

- Threshold or Nonthreshold

Question 23

The level below which there is no response

Answer 23

Threshold Dose

Question 24

The response is directly proportionate to the

dose

Answer 24

Linear Dose-Response Relationship

Question 25

The response is not directly proportional to

the dose

Answer 25

Nonlinear Dose-Response Relationship

Question 26

Estimation of value beyond the range of

known values

Answer 26

Extrapolation