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)
“Some day I will go to Aarhus
To see his peat-brown head,
The mild pods of his eye-lids,
His pointed skin cap.”
—Seamus Heaney (b. 1939)
“We say justly that the weak person is flat, for, like all flat substances, he does not stand in the direction of his strength, that is, on his edge, but affords a convenient surface to put upon. He slides all the way through life.... But the brave man is a perfect sphere, which cannot fall on its flat side and is equally strong every way.”
—Henry David Thoreau (1817–1862)
“It is true, that a little Philosophy inclineth Mans Minde to Atheisme; But depth in Philosophy, bringeth Mens Mindes about to Religion.”
—Francis Bacon (1560–1626)