Background: Breast conserving treatment (BCT) consists of breast-conserving operation and followed by whole-breast irradiation (WBI). Accelerated partial breast irradiation (APBI) is being considered as a possible alternative to WBI. Neoadjuvant APBI might provide more benefit than postsurgical APBI because tumor downstaging will enhance the likelihood of BCT.
Methods: APBI was delivered as 50 Gy in 5 fractions over 5 days before operation for patients with breast cancer of 3 to 4 cm in diameter. Patients with tumors 3 cm or less were deemed to be candidates for breast-conserving operation.
Results: Between September 1998 and August 1999, 12 women were enrolled. The mean tumor diameter and volume were reduced from 3.4 to 1.8 cm (reduction rate: 47%) and from 8.1 to 2.2 cm3 (reduction rate: 71%), respectively. The mean pathologic tumor size was 1.5 cm, and a complete pathologic response was found in 1 patient (8%). All patients were eligible for breast-conserving operation. No ipsilateral breast recurrences have been observed to date.
Conclusions: This is the first report of neoadjuvant APBI for relatively large breast cancers. Although the number of participants was small, these results would encourage the development of clinical trials exploring the efficacy of neoadjuvant APBI.