Background: Hypofractionated adjuvant radiotherapy (RT) in breast cancer patients treated by conservative surgery has been increasingly used in recent years. We present our experience regarding tolerance/acute toxicity of a hypofractionated RT schedule.
Methods and materials: We report on 339 patients treated for 4 years (March 2003-2007) by 42.5 Gy/16 fractions at the RT Department of Larissa University Hospital. Electron boost of 9-10 Gy/3-4 fractions was given to 104/339 (31%). Axillary/supraclavicular RT was given to the node-positive patients with the same fractionation schedule. Median follow-up time was 24 months.
Results: RTOG grades 0, 1, 2, 3, and 4 for acute skin toxicity were 9.7, 68.7, 17.5, 4, and 0.3%, respectively. Radiation pneumonitis (resolved promptly by steroids) was suspected/diagnosed in 11/339 (3.2%). A total of 8/11 had been treated by regional lymphatics RT. In the univariate analysis, the following variables were examined as predictive of skin (grade >1) and lung (any grade) reactions: age, chemotherapy, endocrine treatment, RT of regional lymphatics, and boost RT. The only significant correlation was that of radiation pneumonitis and RT of regional lymphatics (Fisher's exact test, P = 0.000).
Conclusion: Our current results are similar to those from other centers, although they need to be evaluated for a longer time. This fractionation seems to be effective with acceptable side effects, while it facilitates the treatment for both patients and RT centers.