Linear Energy Transfer (LET)

different biological responses

Comparing radiation types is important because different types of radiation = ___________ ___________ ___________.

radionuclide

High LET is at greatest concern during internal contamination such as when a _____________ is implanted, ingested, injected, or inhaled.

low

High Let has _____ penetrating power, lose energy rapidly and have direct action on DNA.

linear

Ionizing energy is deposited/ transferred in a __________ manner as it travels thru tissue.

damage potential

LET allows us to compart the ________ ________ of different types of radiation.

mass and charge

LET depends largely on the ________ ___ ______ of the radiation.

rate

LET meausres the ______ at which energy (IR) is transferred to soft tissue per unit traveled.

3 keV

LET of diagnostic x-rays is ______ (relatively low LET).

weighting factor

Linear energy transfer determines the radiation _________ _________ Wr (Q-quality factor) of each type of radiation.

radiation quality

Linear energy transfer is a way to express _________ _________.

kiloelectron volt (keV)

Linear energy transfer is expressed in units of _________ ______ of energy transferred per micrometer of soft tissue.

the speed of light

Low LET has no mass or charge. It travels at _____ _________ ___ __________.

randomly

Low LET is highly penetrating and interacts ________. It loses energy slowly.

indirect

Rapid travel doesnt allow fro much energy to be deposited (low energy transfer) in tissue; mainly causes _________ damage (sublethal, repairable?) involving free radicals.

direct

Slow travel allows for more energy to be deposited (high energy transfer) to tissue, cause of _________ damage (lethal, irreparable) to DNA.

alpha particles

Some IR has mass and charge, such as; ______ ______.

photons

Some IR has no mass or charge, such as; x-rays, gamma rays, are just ________ (bundles of electromagnetic energy).

quality

The _________ of the radiation has an effect on the extent or degree of the biologic response.

LET

___=average energy deposited/transferred per unit length of track (unit of distance) in tissue.

high LET

____ _______ travels through on a few cells, but deposits all of its energy directly into these few cells.

low LET

_______ ________ travels through 10000s of cells and may or may not interact.

mass

_________- weight; identifiable form or quantity of material.

x-rays and gamma rays

low LET radiation:

increases

As LET increases, radiation's ability to cause biological response ___________.

particulate radiation

Example of High LET radiation:

frequently

High LET = ionizations occur __________.

slowly

High LET has a large mass and charge, they travel ________, and lose energy quickly.