Radiation Dose-Response Curves

Radiation Dose-Response Relationship

It is a mathematical relationship between various radiation dose levels and magnitude of the observed response

Radiation Dose-Response Relationship

It is also referred to as dose-response curves, are a graphical relationship received between observed effects (response) from radiation and dose of radiation

dose-response curves

Radiation Dose-Response Relationship is also referred to as ______

therapeutic treatment

cancer

Radiation Dose-Response Relationship

2 important applications in radiology:

These are used to design the _____ routines for patients with ______

effects of low dose irradiation

diagnostic radiology

Radiation Dose-Response Relationship

2 important applications in radiology:

It yields information on the ______ which provide the basis for the radiation control activities and are particularly significant for _____

1. Early or Late, High Dose or Low Dose response

2. Deterministic or Stochastic response

2 Categories of Human exposure to radiation:

Deterministic response

The radiation response usually follow high-dose radiation exposure and an early response

Deterministic response

Radiation-induced skin burns

Stochastic response

The radiation response usually follow low radiation exposure and appear as late radiation response

low radiation exposure

late radiation response

Stochastic response a radiation response usually follow ____ and appear as _____

high-dose radiation exposure

early response

Deterministic response a radiation response usually follow ____ and an ______.

Stochastic response

Cancer, Leukemia, or genetic effects.

1. Linear or Non-linear

2.Threshold or Non-threshold

2 Important Characteristics of Radiation Response:

*This can be described mathematically or by graph

Response

Area of dose but no response

Dose

Threshold

directly proportional

It is named as linear dose-response relationship since the response _____ with the dose.

doubled

When radiation dose is doubled, the response to radiation is likewise

Leukemia, breast cancer, and other genetic damage

are believed to follow the linear dose-response relationship

Nonthreshold

Dose-response relationships A and B intercept the dose axis at either zero or on the y-axis, they are considered ____

nonthreshold dose-response relationships

exhibit a response, regardless of the dose. This is by demonstrated by relationships A and B.

response

All nonthresholddose-response relationships exhibit a ____, regardless of the dose. This is by demonstrated by relationships A and B

measurable response (ambient or natural response)

Even at zero dose, nonthreshold relationships exhibit a ____ (____ or ____).

natural response level

indicates that even without radiation exposure, that type of response, such as cancer occurs.

Diagnostic radiology

is concerned almost exclusively with late effects of radiation exposure and therefore, with linear, non threshold dose-response relationships.

Threshold

Dose response relationships C and D intercept the dose (x) axis at a dose value greater than zero. Thus, C and D are considered ____

no response

At doses below the respective C and D values, ____ would be anticipated.

linear

At low doses, the curve is

curvilinear

At higher doses, the curve becomes

Nonthreshold

The curve is

toe

The portion of the curve where increases in dose show no or little increase in effect is named the

shoulder

is considered the area of the curve in which a leveling off occurs, again demonstrating no or little increase in effect

Linear Quadratic Response Curves

This model underestimates the low dose effect of radiation, as the linear part of the curve is somewhat leveled off or flattened

low dose effect of radiation

This model underestimates the ____, as the linear part of the curve is somewhat leveled off or flattened

leveled off or flattened

This model underestimates the low dose effect of radiation, as the linear part of the curve is somewhat _____

radiation protection guidelines

are established using the linear nonthreshold dose-response relationship model

sigmoid dose response curve

is applied predominately to the high dose effects observed in radiotherapy.

threshold below

There is normally a _____ which no observable effects occur.

nonlinear relationship

There is a ______ between dose and effect, meaning that the effect is not directly proportional to the dose

not directly proportional

there is a nonlinear relationship between dose and effect, meaning that the effect is ____ to the dose.

Linear No-Threshold (high dose rate)

Linear Quadratic

Linear No-Threshold (Low dose rate)

Linear Threshold