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16 Cards in this Set
- Front
- Back
What are the 3 acute radiation syndromes?
What is the radiation dose required to cause this? Is this considered a deterministic or stochastic effect? |
1. Hematopoietic
2. Gastrointestinal 3. Neurovascular At least 1 Gy deterministic |
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What are prodromal symptoms of acute radiation syndrome?
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nausea, vomiting, fatigue, headache, fever and erythema
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Hematopoietic Syndrome
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Aplastic anemia, leukopenia and thrombocytopenia
requires at least 1Gy |
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Gastrointestinal syndrome
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Nausea, vomiting, diarrhea, loss of appetite and abdominal pain
requires at least 5 Gy |
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Neurovascular syndrome
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Confusion, seizures, dizziness and loss of consciousness, Invariably fatal.
20-30 Gy |
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What radiation dose is associated with cataracts?
Does it matter if the exposure in acute or protracted? |
0.5 Gy
Doesn't matter |
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What is the principle concern for exposure below 1 Gy?
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Stochastic risk of carcinogenesis
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What are the 4 studies of radiation effects in humans?
What has been studies the most What study is the most important long term acquisition and analysis of health data from the atomic bomb survivors? |
Atomic Bomb Survivor studies
Medical radiation Occupational Radiation Environmental Radiation Atomic bomb has been the most extensively studied The life span studies (LSS) |
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What are the 4 basic cancers related to excess radiation?
The increased risk is only evident above what doses? |
Lung, Breast, Thyroid, Leukemia
>100 mGy |
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How many people would you need to study to find a statistically significant increase in cancer mortality after exposure to a radiation dose of 50mGy or 20 mGy, respectively?
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100,000 and 1,000,000 respectively
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Whats it called when a risk factor results in a negative risk estimate?
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hormesis
In the case of radiation, it would mean that radiation is good for you |
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What is the most conservative and most frequently used model to extrapolate cancer rates to radiation doses?
Why do we use these models? Does this really apply to medical imaging doses? |
Linear no-threshold model
because statistically significant cancer risk below an exposure of 100mGy cannot be demonstrated. So, we extrapolate backward from Japanese Survivor Data No |
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How do you calculate effective dose?
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Absorbed dose x radiation weighting factor x target organ weighting factor.
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What is Excess Relative Risk (ERR)
What is Excess Absolute Risk (EAR) What document has these values based on provided studies? |
ERR= rate of disease of exposed/unexposed -1
EAR= Rate of disease of exposed - unexposed BEIR VII |
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What is the lifetime attributable Risk (LAR) model
What is the dose and dose rate effectiveness factor (DDREF) |
likelihood of developing radiation induced cancer over one's lifetime and incorporates a weighted mean of EAR, ERR, Dose and dose rate effectiveness factor
DDREF= fudge factor to correct for the fact that the linear no-threshold model overestimates cancer risk. it equals 1.5. Cancer risk is divided by 1.5 |
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Remember that this is all highly speculative nonsense
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