Modifying Dose At The Skin Surface and At Depth
A specific thickness of bolus can be applied to the skin to alter the dose received at depth in the tissue and on the skin surface. A typical example of this is the application of a defined thickness of bolus to a chest wall for post-mastectomy chest wall treatment, to increase the skin dose. The thickness of bolus applied is dependent on the skin dose required and the angle of incidence of the treatment beams. For example is oblique 6 MV beams are used for tangential pair, 1 cm of bolus effectively becomes 1.5 cm, i.e., ‘full bolus.’
When a full bolus is applied, bolus thickness equal to the depth of the build-up region removes the skin-sparing effect of a megavoltage x-ray beam.
Read more about this topic: Bolus (radiation Therapy)
Famous quotes containing the words modifying, dose, skin, surface and/or depth:
“If one had to worry about one’s actions in respect of other people’s ideas, one might as well be buried alive in an antheap or married to an ambitious violinist. Whether that man is the prime minister, modifying his opinions to catch votes, or a bourgeois in terror lest some harmless act should be misunderstood and outrage some petty convention, that man is an inferior man and I do not want to have anything to do with him any more than I want to eat canned salmon.”
—Aleister Crowley (1875–1947)
“When a mother quarrels with a daughter, she has a double dose of unhappiness—hers from the conflict, and empathy with her daughter’s from the conflict with her. Throughout her life a mother retains this special need to maintain a good relationship with her daughter.”
—Terri Apter (20th century)
“Whether you want it or not,
your genes have a political past,
your skin a political tone.
your eyes a political color.
...
you walk with political steps
on political ground.”
—Wislawa Szymborska (b. 1923)
“I have passed down the river before sunrise on a summer morning, between fields of lilies still shut in sleep; and when, at length, the flakes of sunlight from over the bank fell on the surface of the water, whole fields of white blossoms seemed to flash open before me, as I floated along, like the unfolding of a banner, so sensible is this flower to the influence of the sun’s rays.”
—Henry David Thoreau (1817–1862)
“Manners are the happy way of doing things; each once a stroke of genius or of love—now repeated and hardened into usage. They form at last a rich varnish, with which the routine of life is washed, and its details adorned. If they are superficial, so are the dewdrops which give such depth to the morning meadows.”
—Ralph Waldo Emerson (1803–1882)