Total skin electron therapy: A technique which can be implemented on a conventional electron linear accelerator

Abstract

Purpose : A technique for treating whole-body skin with an electron linear accelerator with nominal energies in the range 4–8 MeV is presented. Stationary fields at an extended source-skin distance are used with the patient treated in a reclined position. Methods and Materials : The relative beam data, absolute dosimetry measurements and the patient setup parameters are presented. The calculations required to correct for patient size are discussed. Results : The technique described uses a six field circumferential cycle, with longitudinally matched fields along thelength of the patient. Treatment times are reasonable using the standard dose rate of the machine. The uniformity of the skin dose measured on three patients was found to be comparable to that of other total skin treatment techniques. Conclusion : A technique for treating conditions like mycosis fungoides is presented requiring relatively simple supporting dosimetry. No modifications to the unit are required and no sophisticated treatment apparatus is necessary, which makes the technique attractive to smaller Institutions, especially in developing countries, where technical support may be limited.