A blended beam technique to decrease toxic effects of post mastectomy irradiation by combining and sequentially mixing electrons and photons.
We studied 24 patients with Stage II or Stage III breast carcinoma, post total mastectomy, who had received adjuvant loco-regional irradiation (16 patients) or were irradiated for chest wall recurrence (8 patients), along with systemic chemotherapy and/or hormonotherapy. A technique is described for combining and sequentially mixing electron and photon beams. This blended beam method results in less severe acute and chronic skin reactions. Dose distribution to the chest wall and mediastinum are improved compared to the traditional photon-only techniques. At a median followup of four years our expected loco-regional control rates are not compromised. This technique is recommended for selected post mastectomy patients to reduce toxic effects of chest wall irradiation, particularly when chemotherapy lowers skin tolerance and the reserves of the heart, lung and bone marrow.