The Patient Survey in the U.S. in 2014 by the national Acoustic Neuroma Association showed that 29% of VS patients reported radiosurgery (17%) or radiotherapy (12%) as their treatment of choice. Radiosurgery is the delivery to the VS of a concentrated high radiation dose in a one-day session, whereas radiotherapy involves multiple treatment sessions where the total radiation dose is spread out in fractions over a few days or 3–4 weeks. The main objective in either case is tumor control by damaging tumor cell DNA and stopping blood vessel proliferation (angiogenesis) needed for tumor growth. Tumors may swell following radiation, but this increase in size is transient and does not signal a failed procedure. A failed radiosurgery is uncommon. Radiation doses are calculated in terms of Gray/Gy—the measure of energy deposited by ionizing radiation per kilogram of matter -- "named after the British physicist Louis Harold Gray (1905–1965), a pioneer in the measurement of X-ray and radium radiation and their effects on living tissue." Since VSs are noninvasive and well-demarcated from surrounding tissues, as is apparent on MRI scans, radiosurgeons are able to target the tumor volume closely and minimize normal tissue damage. Multisession radiotherapy recommends the advantage of giving time between sessions for biological repair of any damage to normal tissues that may occur, and allows for radiation of the tumor at different times in the cell growth cycle. The CyberKnife radiation system introduced in 1994 recommends a protocol of three sessions known as hypofractionation.
Impetigo herpetiformis is a form of severe pustular psoriasis occurring in pregnancy which may occur during any trimester.It is the only well known pustular psoriasis which is treated with steroids. See also
Dermatoses of pregnancy
List of cutaneous conditions

Notes
References
Yap FBB (4 June 2008). "Impetigo herpetiformis: A case report and review of literature". Egyptian Dermatology Online Journal. 1 (4). ISSN 1687-3831. Retrieved 2009-07-09. == External links ==