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:
“Many working mothers feel guilty about not being at home. And when they are there, they wish it could be perfect.... This pressure to make every minute happy puts working parents in a bind when it comes to setting limits and modifying behavior.”
—Cathy Rindner Tempelsman (20th century)
“Whipping and abuse are like laudanum: you have to double the dose as the sensibilities decline.”
—Harriet Beecher Stowe (1811–1896)
“And even so, he’s stale, he’s been there too long.
Touch him, and you’ll find he’s all gone inside
just like an old mushroom, all wormy inside, and hollow
under a smooth skin and an upright appearance.”
—D.H. (David Herbert)
“A novelist is, like all mortals, more fully at home on the surface of the present than in the ooze of the past.”
—Vladimir Nabokov (1899–1977)
“Narrowed-down by her early editors and anthologists, reduced to quaintness or spinsterish oddity by many of her commentators, sentimentalized, fallen-in-love with like some gnomic Garbo, still unread in the breadth and depth of her full range of work, she was, and is, a wonder to me when I try to imagine myself into that mind.”
—Adrienne Rich (b. 1929)