Radiotherapy technique for conservatively treated early breast cancer

Conservative surgery with associated radiotherapy for early breast cancer is gradually gaining acceptance even in Japan as an alternative to modified radial mastectomy. The standard tangential field technique for this conservative therapy was briefly described, and discussed the various factors affecting to the dose distribution within the breasts, such as heterogeneity of their size and shape and intervening organs within the radiation portals. It is important to make small the volume of normal tissues, for example, lungs, heart and liver involved in the treatment volume, and avert spinal cord and esophagus from the irradiation field, especially when the three-field technique is employed. (author)