skin dose

The thickness of bolus applied is dependent on the skin dose required and the angle of incidence of the treatment beams.

The relationship between cumulative skin dose and peak skin dose is highly variable, as has been demonstrated in a number of publications.

For planar or projection imaging, the recorded values may be exposure, skin dose or some other value that may not be patient's body or organ dose.

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.

Radiation doses to the patient depend greatly on the size of the patient as well as length of the procedure, with typical skin dose rates quoted as 20-50 mGy/min.

However, these systems, known as dose-area-product meters (DAP meters), do not directly provide skin dose information without further knowledge of the sizes of the x-ray beam during the entire procedure.

Because of shielding by the tissue surrounding the bones, the bone marrow only receives about 0.67 cGy when the air exposure is 1 röntgen and the surface skin dose is 1 cGy.

In most cases, healing occurs by regenerative means; however, very large skin doses can cause permanent hair loss, damaged sebaceous and sweat glands, atrophy, fibrosis, decreased or increased skin pigmentation, and ulceration or necrosis of the exposed tissue.

The fishing ship Daigo Fukuryu Maru was affected by the fallout as well; the crew suffered skin doses between 1.7-6.0 Gy, with beta burns manifesting as severe skin lesions, erythema, erosions, sometimes necrosis, and skin atrophy.

In this experiment, the doll has measured the radiation doses of the separate components of the ionizing cosmic radiation at the skin surface and at different locations inside a realistic human torso, in order to establish the relation between skin doses and organ doses.

In May 2010 the National Council on Radiation Protection and Measurements issued a press release in response to the health risk claims from UCSF and Columbia University (claims of excessive skin dose and risks to large populations vs. individuals).

With interventional fluoroscopy, because of the high skin doses that can be generated in the course of the intervention, some procedures have resulted in early (less than two months after exposure) and/or late (two months or more after exposure) skin reactions, including necrosis in some cases.

Dr. Steve Smith, inventor of the body scanner in 1991, and president of Tek84, one of the companies that produces the machines, has stated that the concerns of Dr. Brenner and UCSF Scientists regarding the skin dose of backscatter scanners is incorrect.

Coolidge X-ray tubes become brighter at higher energies, but by using external filters to haverst the useful photons without having the tissue to be exposed to unnecessary skin dose, the X-ray tube fluence must typically reduce by two orders or more in brightness, which is not an ideal case for therapy applications.