A novel schedule of accelerated partial breast radiation using intensity-modulated radiation therapy in elderly patients: survival and toxicity analysis of a prospective clinical trial.
OBJECTIVE
Several accelerated partial breast radiation (APBR) techniques have been investigated in patients with early-stage breast cancer (BC); however, the optimal treatment delivery techniques remain unclear. We evaluated the feasibility and toxicity of APBR delivered using intensity-modulated radiation therapy (IMRT) in elderly patients with stage I BC, using a novel fractionation schedule.


METHODS
Forty-two patients aged ≥65 years, with stage I BC who underwent breast conserving surgery were enrolled in a phase I/II study evaluating APBR using IMRT. Forty eligible patients received 40 Gy in 4 Gy daily fractions. Patients were assessed for treatment related toxicities, and cosmesis, before APBR, during, and after completion of the treatment.


RESULTS
The median age was 73 years, median tumor size 0.8 cm and the median follow-up was 54 months. The 5-year locoregional control was 97.5% and overall survival 90%. Erythema and skin pigmentation was the most common acute adverse event, reported by 27 patients (69%). Twenty-six patients (65%) reported mild pain, rated 1-4/10. This improved at last follow-up to only 2 (15%). Overall the patient and physician reported worst late toxicities were lower than the baseline and at last follow-up, patients and physicians rated cosmesis as excellent/good in 93% and 86 %, respectively.


CONCLUSIONS
In this prospective trial, we observed an excellent rate of tumor control with daily APBR. The acceptable toxicity profile and cosmetic results of this study support the use of IMRT planned APBR with daily schedule in elderly patients with early stage BC.
Department of Radiation Oncology, University of Vermont Medical Center, Burlington, VT, USA.
Mutlay
M
Sayan
University of Vermont Cancer Center, Burlington, VT, USA.
Karen
K
Wilson
Department of Radiation Oncology, University of Vermont Medical Center, Burlington, VT, USA.
Carl
C
Nelson
Department of Radiation Oncology, University of Vermont Medical Center, Burlington, VT, USA.
Havaleh
H
Gagne
Department of Radiation Oncology, University of Vermont Medical Center, Burlington, VT, USA.
Deborah
D
Rubin
Department of Radiation Oncology, University of Vermont Medical Center, Burlington, VT, USA.
Ruth
R
Heimann
Breast neoplasms; Dose hypofractionation; Intensity-modulated radiotherapy