RADBIO & RADPRO 5

27問 • 1年前

通報

問題一覧

"For the cell to die after radiation exposure its target molecule must be inactivated"

Target Theory

2 Models of Cell Survival

• SINGLE-TARGET, SINGLE-HIT MODEL • MULTI-TARGET, SINGLE-HIT MODEL

The lethal effects of radiation are determined by observing _________

Cell survival

• Applies to biologic targets • Enzymes, viruses, bacteria

Single Target, Single Hit Model

• When the radiation dose reaches a level sufficient to kill 63% of the cells (37% survival) • A measure of the radiosensitivity of the cell

D37

___ D37: highly radiosensitive ___ D37: highly radiosesistant

- Low - High

If there were no wasted hits (uniform interaction), ____ is the dose that would would be sufficient to kill 100% of the cells

D37

The lethal effects of radiation are determined by observing _______, not cell death

Cell Survival

interacts randomly with matter

Radiation

A __ is not simply an ionizing event but rather an ionization that inactivates the target molecule.

Hit

• Applies to more complicated biologic targets • Human cells • It represents a threshold

Multi target, Single Hit Model

• This is constantly related to radiosensitivity of the cell. • Larger number indicates radioresistant cell. • Small number indicate radiosensitive cell

• This is related to the cell ability to recover from sublethal damage. • This is used to measure the capacity to accumulate sublethal damage and the ability to recover from the

The average time from one mitosis to another

Cell Cycle Effects

Duration of Cell cycle effects of human cells

24 hrs

duration of Cell cycle effects of neurons

hundreds of hrs

the most time variable of cell phases

LET where cell survival kinetics follows the single-target, singlehit model

Very High LET

LET where cell survival kinetics follows the multi-target, single-hit model

At Low LET

Estimation of Patient Dose EMG

• Entrance Skin Dose (ESE) • Mean Marrow Dose (MMD) • Genetically Significant Dose (GSD)

• X-ray exposure to the skin • Most often is referred to as the patient dose • Expressed in: mR • It is used widely • Rationale: • Easy to measure • Reasonably accurate estimates can be made

Entrance Skin Dose (ESE)

Average fluoroscopic examination can have ESD of what

40 mGy/min

• Three Methods of Estimation of Entrance Skin Dose UUK

• Use of TLD • Use of nomogram • Know the output intensity for at least one operating condition

• Average radiation dose to the entire active bone marrow • Estimated from ESE • 50% of active bone marrow

Mean Marrow Dose (MMD)

modality that is difficult to estimate ESD

Fluoroscopy

Average gonadal dose given to members of the population who are of childbearing age • Annual Dose: 100 mrad/yr (in US)

Genetically Significant Dose (GSD)

the gonad dose that, if received by every member of the population, would produce the total genetic effect on the population as the sum of the individual doses actually received.

Genetically Significant Dose (GSD)

physiology of circulation academic weaponizer

E · 24問 · 2年前

physiology of circulation academic weaponizer

24問 • 2年前

reproductive academic weaponizer

E · 55問 · 2年前

reproductive academic weaponizer

55問 • 2年前

cells prelim acad weaponizer

E · 24問 · 2年前

cells prelim acad weaponizer

24問 • 2年前

respiratory/body cavities prelim acad weaponizer

E · 20問 · 2年前

respiratory/body cavities prelim acad weaponizer

20問 • 2年前

integumentary prelim acad weaponizer

E · 29問 · 2年前

integumentary prelim acad weaponizer

29問 • 2年前

skeletal prelim acad weaponizer

E · 33問 · 2年前

skeletal prelim acad weaponizer

33問 • 2年前

tissue prelim acad weaponizer

E · 42問 · 2年前

tissue prelim acad weaponizer

42問 • 2年前

membrane prelim acad weaponizer

E · 20問 · 2年前

membrane prelim acad weaponizer

RPC L2

RPC L2

RPC L3

RPC L3

RPC L4

RPC L4

ALE

ALE

RPC L5

RPC L5

RPC M1

RPC M1

RPC M1/2

RPC M1/2

RPC M2

RPC M2

RPC M2.5

RPC M2.5

RPC M3

RPC M3

問題一覧

"For the cell to die after radiation exposure its target molecule must be inactivated"

Target Theory

2 Models of Cell Survival

• SINGLE-TARGET, SINGLE-HIT MODEL • MULTI-TARGET, SINGLE-HIT MODEL

The lethal effects of radiation are determined by observing _________

Cell survival

• Applies to biologic targets • Enzymes, viruses, bacteria

Single Target, Single Hit Model

• When the radiation dose reaches a level sufficient to kill 63% of the cells (37% survival) • A measure of the radiosensitivity of the cell

D37

___ D37: highly radiosensitive ___ D37: highly radiosesistant

- Low - High

If there were no wasted hits (uniform interaction), ____ is the dose that would would be sufficient to kill 100% of the cells

D37

The lethal effects of radiation are determined by observing _______, not cell death

Cell Survival

interacts randomly with matter

Radiation

A __ is not simply an ionizing event but rather an ionization that inactivates the target molecule.

Hit

• Applies to more complicated biologic targets • Human cells • It represents a threshold

Multi target, Single Hit Model

• This is constantly related to radiosensitivity of the cell. • Larger number indicates radioresistant cell. • Small number indicate radiosensitive cell

• This is related to the cell ability to recover from sublethal damage. • This is used to measure the capacity to accumulate sublethal damage and the ability to recover from the

The average time from one mitosis to another

Cell Cycle Effects

Duration of Cell cycle effects of human cells

24 hrs

duration of Cell cycle effects of neurons

hundreds of hrs

the most time variable of cell phases

LET where cell survival kinetics follows the single-target, singlehit model

Very High LET

LET where cell survival kinetics follows the multi-target, single-hit model

At Low LET

Estimation of Patient Dose EMG

• Entrance Skin Dose (ESE) • Mean Marrow Dose (MMD) • Genetically Significant Dose (GSD)

Entrance Skin Dose (ESE)

Average fluoroscopic examination can have ESD of what

40 mGy/min

• Three Methods of Estimation of Entrance Skin Dose UUK

• Use of TLD • Use of nomogram • Know the output intensity for at least one operating condition

• Average radiation dose to the entire active bone marrow • Estimated from ESE • 50% of active bone marrow

Mean Marrow Dose (MMD)

modality that is difficult to estimate ESD

Fluoroscopy

Average gonadal dose given to members of the population who are of childbearing age • Annual Dose: 100 mrad/yr (in US)

Genetically Significant Dose (GSD)

the gonad dose that, if received by every member of the population, would produce the total genetic effect on the population as the sum of the individual doses actually received.

Genetically Significant Dose (GSD)