Technique for breast irradiation using custom blocks conforming to the chest wall contour.

A technique for the treatment of the breast and regional nodes is presented. The technique involves the use of tangential fields to treat the breast and chest wall. Customized blocks which conform to the slope of the chest wall are made for each tangent field. Simulation and treatment with this technique requires no special equipment. The setup is simple and quick. A three-field technique is also described using the custom half-beam blocks; this technique avoids the use of tangential field corner blocks, thus simplifying simulation and treatment.