L 10: Radiation Carcinogenesis Flashcards
1
Q
Stochastic Effect
A
- Single cell event
- Eg: induction mutation
- Measured in Sv
2
Q
Deterministic Effect
A
- Dose related effect tissue effects
- Eg: Radiation induced cataracts
3
Q
CLL
A
Not induced by radiation
4
Q
AML/CML
A
Can be induced from radiation
5
Q
Radiation induced cancers based on tissues
A
6
Q
Latent period after exposure
A
Thyroid Ca - 4+ years
Leukemia - 3yrs
Solid tumors - 20 yrs
7
Q
Solid tumors in order of frequency
A
Bladder
Breast
Lung
Thyroid
Colon
Stomach
Liver
8
Q
Models for risk estimate
A
- Absolute risk
- Relative risk
- Time-dependent relative risk
9
Q
Radiation induced childhood tumors
A
- Childhood tumors—primaries were neuroblastomas, HD, NHL, Wilm’s Tumor, Bone tumors—received RT
- Secondary tumors that developed—breast, thyroid, malignant CNS tumors, soft tissue tumors (recently also skin tumors)
- Risk is 20y+ and may have continuous increase
10
Q
Summary of Cancer Risk
A
- Radiation exposure causes an excess risk throughout life—risk decreases with time since exposure but never reaches no risk (except leukemia)
- Risks vary with age: young are usually more radiosensitive because they will live longer
- Variation in risk associated with cancer site
- Female is more likely to develop cancer than male—breast cancer is most common difference
- Decrease dose rate and also decrease risk
11
Q
Summary
A
- A variety of human populations have been used to estimate cancer risks from radiation exposure.
- Risks are age-dependent at the time of exposure and dose- and dose-rate dependent
- Radiation has been associated with the development of some secondary malignancies in the field
- A variety of different national and international agencies are charged with assessing the risks of radiation exposure as they relate to cancer induction.
12
Q
Dose dose rate for cancer risk
Board question
A
eg: city is exposed to 0.2 Sv exposure, what is the risk in whoel population.
The table gives PER Sv. MAke sure to convert or multiply for every Sv.
