Long-term cosmesis and toxicity following 3-dimensional conformal radiation therapy in the delivery of accelerated partial breast irradiation.

ABSTRACT

PURPOSE: To evaluate cosmesis and toxicity in early-stage breast cancer patients treated with adjuvant 3D-CRT who received accelerated partial breast irradiation (APBI). METHODS AND MATERIALS From November 2003 to June 2006, 60 breasts on 59 patients were treated with 3-dimensional conformal radiation therapy (3D-CRT) APBI. Patients with stage 0, I, or II breast cancer were eligible if a <3-cm tumor was resected with negative surgical margins, and axillary evaluation documented 0-3 positive nodes. The mean age was 58.7 years (range, 31-88 years). Target volume and critical structure definitions, as well as dose delivery guidelines, were consistent across both institutions. Treatment was twice daily for 5 consecutive days with 3.85 Gy per fraction to 38.5 Gy. Clinical follow-up was conducted at regular intervals that included history, physical exam, and mammography. The overall cosmesis was graded using the Harvard scale and toxicity was graded according to the Common Toxicity Criteria (v4.0), including hyperpigmentation, edema, telangiectasia, mastalgia, surgical defect, fibrosis, and fat necrosis. Dose-volume histogram and treatment parameters were collected and analyzed. RESULTS: At a mean follow-up of 44.3 months (range, 2-94 months), there were 4 cases of grade 3-4 toxicity (7%) 1 patient with mastalgia; 1 patient with mastalgia and fat necrosis; 1 patient with telangiectasia; and 1 patient with fibrosis. There was no statistical correlate between dosimetric parameters and cosmetic outcome. Overall cosmetic outcome was good or excellent in 58 breasts (95%) and "fair to poor" in 3 (5%). There were no local-regional failures; 3 patients failed distantly (5%). CONCLUSIONS: Accelerated partial breast irradiation using 3D-CRT is safe and the risk of serious chronic side effect is low and acceptable.