chapter 33 radiobiology
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Interphase death | Radiation effect that kills a cell before its next division
🗑
|
||||
| Linear energy transfer | Measure of the rate at which energy is transferred from a particular type of radiation to soft tissue. Approximately 3 keV/m for diagnostic x-rays.
🗑
|
||||
| Standard Radiation | Orthovoltage x-radiation in the 200 to 250 kVp range
🗑
|
||||
| Oxygen enhancement ratio | measure of the increased radiosensitivity of tissue in the presence of oxygen
🗑
|
||||
| Repopulation | One mode of cellular recovery from radiation damage
🗑
|
||||
| Extrapopulation | Continuing a straight-line relationship into an unmeasured area
🗑
|
||||
| Threshold dose | Dose below which no effect occurs
🗑
|
||||
| Dose protraction | Extending exposure of a total dose by delivering continuously but at a reduced rate
🗑
|
||||
| Radiation weighting factor | Value assigned to different types of radiation based on their LET
🗑
|
||||
| Tribondeau | An early radiobiologist
🗑
|
||||
| The formula for relative biologic effectiveness | RBE = dose of standard radiation to produce an effect, divided by dose of test radiation to produce the same effect
🗑
|
||||
| An example of fractionated radiation | Patients receive the radiation dose at the same dose rate but broken into equal values and given over time (a little today, a little next month, and perhaps a little next year). Radiation oncology patients receive prescribed doses fractionated daily.
🗑
|
||||
| Why is high pressure (hyperbaric) oxygen used in radiation oncology | To force oxygen into tumors and make them more radiosensitive
🗑
|
||||
| Formula for the oxygen enhancement ratio | OER = dose necessary under anoxic conditions to produce a given effect divided by the dose necessary under aerobic oxygenated conditions to produce the same effect
🗑
|
||||
| How does age affect the radiosensitivity of tissue | The younger the tissue, the more radiosensitive it is.
🗑
|
||||
| When a radiobiologic experiment is conducted in vitro, what does this mean | Outside of the human body. At the cellular or molecular level.
🗑
|
||||
| Name three agents that enhance the effects of radiation | Methotrexate, actinomycin D, hydroxyurea, vitamin K, halogenated pyrimidines
🗑
|
||||
| Name three radioprotective agents | Cysteine, cysteamine, and other sulfhydryl groups
🗑
|
||||
| Are radioprotective agents used for human application | No. To be effective, they must be administered in toxic levels.
🗑
|
||||
| Explain the meaning of a radiation dose response relationship | Graphical representation of radiation dose and effect
🗑
|
||||
| Explain why the linear, non-threshold dose-response is used as a model for diagnostic imaging radiation management | An equal amount of radiation dose will not necessarily produce an equal response. Non-threshold implies that no dose of radiation is so small that there is no degree of risk.
🗑
|
||||
| Two of the corollaries to the law of bergonie and tribondeau | Stem cells are most sensitive. Young tissue and organs are more radiosensitive than old tissues and organs. Tissue in a high state of metabolic activity also has high radiosensitivity. As cellular proliferation increases, so does cellular
🗑
|
||||
| What are the units of OER | keV/m radiosensitivity.
🗑
|
||||
| how are RBE and LET related | With increasing LET, RBE increases to a maximum value of approximately 3
🗑
|
||||
| Is occupational radiation exposure fractionated, protracted, or continuous | Fractionated
🗑
|
||||
| How OER and LET are related | OER is LET-dependent. OER is highest for low LET radiation, and decreases for high LET radiation (see Figure 33-2).
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
hseratt
Popular Radiology sets