Clinical effects of accelerated partial breast irradiation using three-dimensional conformal radiotherapy in patients with early breast cancer after breast-conserving therapy

Abstract

Objective To assess the clinical effects of accelerated partial breast irradiation (APBI)using three-dimensional conformal radiotherapy (3DCRT) in patients with low-risk early breast cancer after breast-conserving therapy (BCT) with respect to dosimetric parameters,local control,toxicities,and cosmetic outcome.Methods Thirty-nine patients with early breast cancer (stage 0-1) were enrolled in a prospective phase Ⅱ trial of APBI using 3DCRT in 2008-2010.Of all the patients,28 had invasive ductal carcinoma,5 had ductal carcinoma in situ,and 6 had other types of invasive carcinoma.The prescribed dose was 38.5 Gy/10 fractions twice daily,with an inter-fraction interval greater than 6 h.The toxicities were assessed according to the National Cancer Institute Common Toxicity Criteria,version 3.0.The cosmetic outcome was assessed according to the Harris breast cosmesis scale.Results The planning target volume coverage and normal-tissue dosimetry were appropriate in the APBI using 3DCRT.Dose homogeneity without deviation was achieved in 33 patients (85％).Of the total 39 patients,46％ ASTRO's cautionary criteria,and 18％ met unsuitable criteria; also,31％ GEC-ESTRO's intermediate-risk criteria,and 3％ met high-risk criteria.The follow-up rate was 100％.No patient experienced local recurrence,and no grade 3-4 toxicities were found.Cosmesis was good to excellent in 35 patients (90％)at 6 months after APBI.Conclusions The patients with early breast cancer after BCT are properly selected for APBI using 3DCRT,with satisfactory preliminary assessment results for local control,toxicities,and cosmetic outcome. Key words: Breast neoplasms/three-dimensional radiotherapy; Accelerated partial breast irradiation ; Breast neoplasms/surgery; Mastectomy, segmental; Treatment outcome