RadSci 311 - Stochastic & Deterministic Effects of Radiation by

Stochastic

kyleegloriajg — 2024-10-14 01:32:44 UTC

Official Definition: "Random, involving chance or probability of an event of effect" (Powerpoint Slide)

My Definition: Events that occur by any chance from radiation exposure

Deterministic

kyleegloriajg — 2024-10-14 01:38:43 UTC

Official Definition: "A specific level of exposure to ionizing radiation before it can occur is called a deterministic effect" (International Atomic Energy Agency)

My Definition: Predictable reaction from the somatic tissues

Stochastic

kyleegloriajg — 2024-10-14 01:43:31 UTC

Stochastic effects:

cancer
genetic effects

Low-level, chronic, or high-level (one-time) exposure can trigger stochastic effects

Deterministic

kyleegloriajg — 2024-10-14 01:45:59 UTC

Deterministic effects:

Early Effects:

decreased blood counts
tissue fibrosis
epilation

Late Effects:

cataracts
organ atrophy
decreased fertility/sterility
loss of permanent parenchymal cells

Stochastic

kyleegloriajg — 2024-10-14 01:53:29 UTC

As we know from the definition, stochastic effects are random. They are dependent on the type, energy of radiation, and dose received. That makes the probability of occurrence proportional to the dose. This is an all-or-none response (cancer, genetic effects).

The occurrence of radiation-induced cancer increases with absorbed dose. If cancer is induced, it does not matter what dose caused it.

genetic mutations are the same

Deterministic

kyleegloriajg — 2024-10-14 02:05:08 UTC

For these effects to take place, it generally takes a larger dose. While these effects aren't likely diagnostic, it mainly happens in fluoroscopic procedures such as cardiac cath lab. There are two types of deterministic effects, early and late. The severity is dependent on the dose received, which is the opposite of stochastic. Early effects are especially dose-dependent. Some low-dose effects include erythema, hematopoietic damage, fibrosis, and epilation. High-dose effects are acute radiation syndrome. Late effects can occur months to years after exposure. This includes cataracts, fibrosis, organ atrophy, and decreased fertility or sterility. Erythema and cataracts are more likely to occur after exposures greater than 2 Gy.

Short Term

kyleegloriajg — 2024-10-14 02:07:02 UTC

Decreased blood counts

I think decreased blood count is a short-term effect because you can take supplements to get your blood count back up. A decrease in blood count is from high doses of radiation, which can lead to cell death. This is a deterministic effect and is an early effect. Cellular repair mechanisms can help with decreased blood counts because they can replace the blood but that does not mean the organ will be back to its pre-irradiated state.

Erythema

I think erythema is a short-term effect because it is the skin reddening due to radiation. This also requires high doses of radiation, which can damage the basal cells. This is a deterministic effect and is also an early effect. I think cellular repair mechanisms wouldn't be able to help in this case because the basal cells are only damaged, not dead.

Cataracts

I think cataracts is a short-term effect. I struggled placing this one because cataracts can be long-term, but there are surgeries now to fix cataracts. Cataracts are from high doses of radiation, making this a deterministic effect. I think cellular repair wouldn't be able to help with this effect, only surgery would be able to help.

Long-Term Effects

kyleegloriajg — 2024-10-14 02:07:07 UTC

Cancer

I think cancer is a long-term effect because cancer can often be terminal. The people who are fortunate enough to defeat cancer could be left with lingering effects from the cancer. Cancer is a stochastic effect, which means it can be random and can occur from low doses of radiation. I think cellular repair mechanisms can help because it can repair the damaged tissue from radiation that caused the cancer.

Genetic Effects

I think genetic effects is a long-term effect because there is often no "cure" for them. They are just managed for the patient's pain tolerance. This is also a stochastic effect, so it can be from low doses. This could have been caused by radiation while the fetus was still in embryo during the first trimester. I don't think cellular repair mechanisms would be able to help this effect because this effect is permanent.

Tissue Fibrosis

I think tissue fibrosis is a long-term effect because the tissues become scarred and hardened, which is permanent. This is a late deterministic effect, which means it was caused by high doses of radiation. I think cellular repair plays a part in this since it replaces the damaged cells with scar tissue.

Loss of parenchymal cells

I think loss of parenchymal cells is a long-term effect because this is when organs stop functioning correctly, which is permanent. This also is a deterministic effect and takes high doses of radiation. I think cellular repair mechanisms can help with this effect because it can replace the damaged tissue, which would prevent loss of function.

Epilation

I think epilation is a long-term effect. From high doses of radiation, epilation can be permanent, which leads to long-term effects. This is considered to be a deterministic effect. I think cellular repair mechanisms can help with this effect if it is low dose, but with high doses, it is permanent hair loss.

Organ Atrophy

I think organ atrophy is a long-term effect because there is no fix for it. This is also considered to be a deterministic effect because of the high dose of radiation that caused it. Cellular repair mechanisms can help with organ atrophy because it can repair the damaged cells and prevent atrophy.

Decreased infertility/sterility

I think decreased infertility/sterility is a long-term effect because this can prevent people from having kids if they choose to. If people wanted to have kids and weren't able to due to infertility/sterility, it can stick with them for the rest of their lives. They could also adopt but maybe it doesn't feel the same as having their own. This is also considered a deterministic effect, due to the high doses of radiation. I think cellular repair can help with this effect because it can help protect the sperm or ovum cells.