Dosimetric comparison of TSEI's delivery techniques

Total skin electron beam irradiation (TSEI) is one of the most sophisticated and complex treatment techniques of modern radiation oncology practice. TSEI is used in cutaneous T-cell lymphoma, mycosis fungoides (MF), and Kaposi's sarcoma. The main aim of TSEI to uniformly deliver a specified dose over the entire skin surface to a particular depth, by the proper choice of electron energy, the depth dose characteristics of the electron beam it is possible to treat large surfaces of the skin. The study presented here is a patient specific dosimetric study, which compares two different techniques - usage of six-single beam and six-dual field irradiation techniques. Thereby comparing its effect on dose uniformity, dose distribution and the dose delivered in the overlapping regions. The relative dosimetry of this study is carried out using a silicon diode and ionisation chamber in a standard water phantom. Phantom studies were carried out as identical to the treatment setup in order to determine the exact beam characteristics. Absolute dosimetry was carried with a calibrated ionisation chamber to determine the dose contribution per monitor unit