Module 14 (Radiotherapy) Flashcards
Most common rays used for radiotherapy?
Xrays
Radioactivity SI unit is?
Becquerel (curie)
What is radiation exposure and its SI unit?
Amount of radiation in air. Coulumb/kg
What is absorbed dose? What is its SI unit?
Amount of radiation absorbed per unit gram of material or tissue. Gray (Gy)
What is dose equivalent? What is its SI unit?
It indicates potential danger to health. Sievert
What is Bragg peak effect?
Loss of energy from ionizing radiation as it travels through matter can be calculated using Bragg curve. Point where there is maximum loss of energy is called Bragg peak
Why is proton therapy used?
Peak loss of energy (Bragg peak) occurs when it is coming to rest. So you can direct the proton to tumour sites and stop it there hence getting a burst of energy
What is used for external beam radiotherapy EBRT
Cobalt 60 and LINAC (xray)
What are deterministic effects and stochastic effect?
Deterministic side effects increase on increasing dose of radiation.
Stochastic side effects are a rare phenomenon
Dose limit of cumulative radiation exposure in pregnancy?
1 mSv
What is respiratory gating?
Respiratory movement interferes with beam radiotherapy in lung carcinoma. So when you do gating, radiation is only delivered when the tumour is in the target field and the device switches off when it moves outside the target field.
What is stereostatic radio surgery?
Surgery done using radiation as blade
What is gamma knife?
A stereo static radio surgery done for brain (Tumors and others)
What is cyber knife?
Treats tumors all over body
What is TLD badge?
Thermoluminescent DOSIMETER used for personal monitoring of radiation.
