Term
| Q1 What is linear energy transfer (LET)? |
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Definition
| When ionizing radiation travels through a medium energy is lost. The amount of energy lost per unit length of track (length of medium) is LET. Displayed in kiloelectron volts (keV) per micron (1um =10^-6 m). Basically keV/um. |
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Term
| Q2 Wave-particle duality states that the x-ray photons have what mass and charge? |
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Definition
| Photons have no mass and no charge. |
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Term
| Q3 What are free radicals and at what LET level are they more likely to be made? |
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Definition
| Free radicals are highly reactive atoms or molecules that rebind with the surrounding tissue. Likely to be made at a low LET level |
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Term
| Q4 What can cause complete chromosome breakage in the x-ray field? |
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Definition
| Complete chromosome breakage can happen when high LET damages the same rung in the strand of DNA which leads to cell death. |
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Term
| Q5 What is relative biologic effectiveness (RBE) |
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Definition
| Relative biologic effectiveness is a way of testing how much stronger or weaker of a difference two shots are that have the same dose when producing a biological effect. |
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Term
| Q6 What is radiation weighting factor (WR) |
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Definition
| Radiation weighting factor is a factor that is given to a type of ionizing radiation in order to find the equivalent dose. |
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Term
| Q7 oxygen enhancement ratio (OER) |
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Definition
| OER is the ratio of the radiation dose required to cause a particular biologic response of cells or organisms in an oxygen-deprived environment over the radiation dose required to cause an identical response under normal oxygenated conditions. |
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Term
| Q8 What is a direct action |
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Definition
| This is biologic damage that occurs as a result of straight interaction incident ionization of atoms on essential molecules such as DNA (aka x-rays mess up vital parts of the cell directly by messing with the molecules) |
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Term
| Q9 What is an indirect action |
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Definition
| This is when x-rays interact with water molecules. The water molecules release free radicals that affect other vital molecules that may lead to cell death. |
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Term
| Q10 What is a point lesion |
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Definition
| This is a single break in the DNA chain most likely a result of low LET |
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Term
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Definition
| This is the loss or change of a base in the DNA chain that results in changes to the DNA. |
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Term
| Q12 What is target theory |
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Definition
| The target theory is that there is a molecule that is irreplaceable in your cells. If that molecule is damaged too much the cell will die. |
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Term
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Definition
| This is a programmed cell death that happens during the interphase portion of the cell life cycle. |
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Term
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Definition
| This is a study to see the ability of cells to come back from varying types of LET values and doses that are recorded and put on a graph. |
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Term
| Q15 law of Bergonié and Tribondeau |
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Definition
| This law states that the radiosensitivity of cells is directly proportional to their reproductive activity and inversely proportional to their degree of differentiation. |
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Term
| Q16 what is interstrand cross-links |
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Definition
| An interstrand cross-link is when a covalent bond forms between two parts of the same DNA strand |
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Term
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Definition
| When the breaks in DNA rejoin in their original configuration with no visible damage |
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Term
| Q18 What is Broken-end rearrangement |
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Definition
| without much visible damage to the chromatids, this is when part of the chromatid breaks off two parts of the chromatid and attaches to the wrong strand. |
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Term
| Q19 When does instant death of a large portion of cells happen |
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Definition
| when a volume is irradiated with an x-ray or gamma-ray dose of approximately 1000 Gyt in a period of seconds or minutes. |
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Term
| Q20 When does reproductive death happen and what is it |
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Definition
| Reproductive death generally results from exposure of cells to doses of ionizing radiation in the range of 1 to 10 Gy. This leads to the cell losing its ability to duplicate itself |
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