5 weeks // Fundamental Principles of RadBio

Question 1

It is the law that states that the radiosensitivity of living tissue varies with maturation and metabolism of the tissue being irradiated

Answer 1

Law of Bergonie and Tribondeau

Question 2

? cells are radiosensitive; ? cells are radioresistant

Answer 2

Stem cells are radiosensitive; Mature cells are radioresistant

Question 3

Younger ? and ? are radiosensitive

Answer 3

Younger tissues and organs are radiosensitive

Question 4

Tissues with ? metabolic activity are radiosensitive

Answer 4

Tissues with high metabolic activity are radiosensitive

Question 5

A ? proliferation rate for cells and a ? growth rate for tissues result in increased radiosensitivity

Answer 5

A high proliferation rate for cells and a high growth rate for tissues result in increased radiosensitivity

Question 6

Three physical factors that affects radiosensitivity

Answer 6

Linear Energy Transfer

Relative Biologic Effectiveness

Protraction and Fractionation

Question 7

In physical factors that affects radiosensitivity, it is a measure of the rate at which energy is transferred from ionizing radiation to soft tissue

As this increases, ionization occurs frequently. It increases the ability to produce biologic damage and it increases the probability of interaction with the target molecule.

Answer 7

Linear Energy Transfer (LET)

Question 8

Two Ways of Lengthening the Time of Irradiation

Answer 8

Protraction and Fractionation

Question 9

The Five Biological Factors that Affect Radiosensitivity

Answer 9

Oxygen Enhancement Ratio
Age
Recovery
Chemical Agents
Hormesis

Question 10

In factors that affect radiosensitivty, it is the 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 10

Oxygen Enhancement Ratio

Question 11

In OER, it is when tissue is more sensitive to radiation when irradiated in the oxygenated or aerobic state than when irradiated under anoxic and hypoxic condition

Answer 11

Oxygen Effect

Question 12

In OER, it has been used in radiation oncology

Answer 12

Hyperbaric/High Pressure Oxygen

Question 13

In factors that affect radiosensitivity, it is when humans are most sensitive before birth.
After birth, the sensitivity decreases until maturity.
In old age, humans again become more radiosensitive.

Answer 13

Age

Question 14

In factors that affect radiosensitivity, it is when the radiation dose is not sufficient to kill the cell before its next division, then given sufficient time, the cell will recover from the sublethal radiation damage it has sustained

Answer 14

Recovery

Question 15

In factors that affect radiosensitivity, it has radiosensitizers and radioprotectors

Answer 15

Chemical Agents

Question 16

In chemical agents, this is the agents that enhance the effect of radiation such as halogenated pyrimidines, methotrexate, actinomycin D, hydroxyurea and vitamin K

Answer 16

Radiosensitizers

Question 17

In chemical agents, this is the compounds that include molecules that contain a sulfhydryl group (sulfur and hydrogen bound together), such as cysteine and cysteamine

Answer 17

Radioprotectors