Dose estimation in postoperative keloid irradiation with special consideration of ovarian dose.

For a long time now, surgery followed by irradiation has been the preferred therapy in the treatment of keloids. Radiation can be administered by means of X-rays (energy level less than or equal to 100 KV), electrons (energy level less than or equal to 5 MeV) or 192Ir wires. The choice of one of these methods depends on the availability of suitable facilities within a short period of time (less than 24 hours postoperatively), and the possibility of adapting the irradiation field quickly and easily to the scar. A further criterion is the dose received by underlying organs possibly, especially the ovaries of women of child-bearing age. It consists of primary and secondary (scattered) parts of radiation and was measured in two standard field sizes for the various types of radiation so as to allow a rapid evaluation. Apart from the types of radiation mentioned above, such measurements were also carried out for 125I seeds. With a field size of 20 x 1.5 cm2 and a surface dose of 10 Gy, ovaries at a depth of 10 cm in the central beam will receive a dose of between less than 1 m Gy in electron therapy to around 1 Gy in X-ray therapy (100 KV).