Hypofractionation with concomitant boost using intensity-modulated radiation therapy in early-stage breast cancer in Mexico.

Aim: To evaluate whether hypofractionation with integrated boost to the tumour bed using intensity-modulated radiation therapy is an acceptable option and to determine whether this treatment compromises local control, toxicity and cosmesis.

Background: Retrospective studies have demonstrated that patients who are treated with HF and integrated boost experience adequate local control, a dosimetric benefit, decreased toxicity and acceptable cosmesis compared with conventional fractionation.

Materials And Methods: A retrospective, observational and longitudinal study was conducted from January 2008 to June 2015 and included 34 patients with breast cancer (stage 0-II) who were undergoing conservative surgery.The prescribed doses were 45 Gy in 20 fractions (2.25 Gy/fraction) to the breast and 56 Gy in 20 fractions (2.8 Gy/fraction) to the tumour bed.

Results: Thirty-four patients were included. The mean follow-up was 49.29 months, and the mean age was 52 years. The mean percentage of PTV from the mammary region that received 100% of the prescribed dose was 97.89% (range 95-100), and the mean PTV percentage of the tumour bed that received 100% of the dose was 98% (95-100).The local control and the overall survival were 100%, and the cosmesis was good in 82% of the patients. Grade 1 acute toxicity was present in 16 patients (47%), and grade 1 chronic toxicity occurred in 6 cases (18%).

Conclusion: The results of the present study demonstrate that hypofractionation with integrated boost using intensity-modulated radiation therapy is an acceptable option that provides excellent local control and low toxicity.