[Radiotherapy of the breast after conservative surgery for primary carcinoma. Irradiation technic with matched...

The authors report their technique for breast radiotherapy following conservative surgery (quadrantectomy + axillary dissection). The breast and chest wall are irradiated with photons from a 60Co unit through two fixed opposing tangential fields. The posterior field edges must be parallel and coplanar to the chest wall. A routine treatment plan using simulator, pantograph and computerized console is standardized by mathematical formulae elaborated from geometric breast measurement parameters. Gammagraphies acquired prior to and during therapy allow verification and control of treatment parameters. For 35 patients the therapy plan as described was compared with that obtained by CT images. Our procedure proved valid and an accurate treatment plan could be elaborated even without CT images. The use of wedges, half-field blocks and the dose scattered to the contralateral breast are also discussed.