Biological Effects of Radiation

Question 1

Laws of Bergonie and Tribondeau

Answer 1

Immature/stem cells, younger tissues, high metabolic cells, greater growth rate tissues all have a higher sensitivity to radiation.

Question 2

Most radiosensitive cells

Answer 2

lymphocytes, spermatogonia, erythroblast, intestinal crypt cells

Question 3

Measure of the rate at which energy is deposited as a charged particle travels through matter

Answer 3

Linear Energy Transfer (LET)

Question 4

LET of diagnostic xray

Answer 4

3.0

Question 5

Comparison of a dose of test radiation to a dose of 250 keV xray that produces the same biological effect.

Answer 5

Relative Biological Effectiveness (RBE)

Question 6

RBE of diagnostic xray

Answer 6

1.0

Question 7

Response of biologic tissue to radiation is greater when irradiated in the oxygenated state

Answer 7

Oxygen Enhancement Ratio (OER)

Question 8

When are we most radiosensitive?

Answer 8

Before birth - fetus-alters DNA

Question 9

Genetic damage follows which dose-response relationship?

Answer 9

Linear Non-threshold

Question 10

Linear dose-response

Answer 10

directly proportional to dose

Question 11

Non-linear dose-response

Answer 11

Not directly proportional to dose

Question 12

Threshold dose-response

Answer 12

a radiation level in which no effects are observed

Question 13

Non-threshold

Answer 13

Assumes any level of radiation produces an effect

Question 14

Dose response of Sigmoid Curve

Answer 14

Nonlinear-threshold