Tumor boost after whole breast irradiation (WBI) has been the standard radiotherapy technique in early breast cancer patients with breast conserving surgery. The purpose of this analysis was to determine whether or not it is necessary to do boost radiotherapy after WBI in patients with quadrantectomy
We retrospectively analyzed the consecutive seventy-three patients who had undergone radiotherapy after quadrantectomy with clear resection margin and/or chemotherapy between 1996 and 2001. The most frequent decade in age was 40 and median age was 44. WBI was done using 6 or 10MV photons and standard fractionation of daily 180-200 cGy to 45-50 Gy, followed by a boost to the tumor bed using an electron beam to a median total tumor bed dose of 60 Gy. Chemotherapy regimen was variable and the usual number of cycle was over 4. Anti-estrogen therapy was combined in patients positive with estrogen or progesterone receptor. The median follow-up was 9 years. The primary end-point for this analysis was to compare in-breast tumor recurrence according to the tumor boost. Survival rates were estimated using Kaplan-Meier method and comparison of in-breast tumor recurrence between two groups was done using chi-square test.
The 10-yr overall and disease-free survival rate of all patients was 89.3% and 87.1%. The in-breast tumor recurrence was shown in 3 (4.1%) patients and supraclavicular failure was in 4 (5.5%) patients (one combined with axillary failure) and distant metastasis was in 8 (11%) patients. Boost therapy was not performed in 24 patients who were early time period of study and then, given to 49 patients intentionally to decrease the local recurrence further in the more recent years of the study period. Patients and tumor characteristics were well balanced between two groups. The in-breast recurrence was 4.2% (1/24) in patients without boost and 4.1% (2/49) in patients with boost (p> 0.05). Three patients with in-breast tumor recurrence were undergone mastectomy and one has survived until now and two succumbed to the distant metastases.
WBI without tumor boost seems to be safe technique in early breast cancer patients with quadrantectomy with clear resection margin.
Ahn, S,
Tumor Boost or Not in Early Breast Cancer Patients with Quadrantectomy and Whole Breast Irradiation. Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL.
http://archive.rsna.org/2007/6000745.html
