Breast radiotherapy is standard management in early breast cancer. In Australia, standard fractionation (SF) have historically extended over 5-6 weeks. Hypofractionation (HF), over 3-4 weeks, has shown to be essentially equivalent and consensus guidelines now recommend HF as standard therapy. Acute radiation dermatitis (RD) is a common toxicity of radiotherapy, causing significant morbidity and requiring significant nursing care. The aim of this study was to review changing patterns of treatment with time and assess how this may impact the time course and severity of RD.
This was a single centre retrospective review of patients undergoing radiotherapy to the breast after local surgery from January 2012 to July 2018. Acute skin toxicity was routinely recorded at weekly treatment reviews during radiotherapy using the NCI CTCAE v3 scoring system.
A total of 942 patients with at least 1 acute toxicity score were included. The median number of scores recorded were 4 and 3 for SF and HF respectively. More patients were treated with HF later in the study period (32% in 2012 vs 86% in 2017) and tended to be older (mean age 55 SF vs. 66 HF). There were no RD scores above 3. The percentage of patients with grade 1, 2 or 3 RD for SF and HF was 97%, 67%, 4% vs. 93%, 30%, 1% respectively. Median peak RD occurred earlier for the HF group (6 weeks vs. 4 weeks for SF and HF respectively).
HF patients show a more rapid development of any grade RD but less grade 2 or 3 toxicity. This supports HF as a treatment both shorter in duration and potentially more tolerable than SF. The altered pattern of toxicity has implications in how RD is monitored during treatment to ensure timely availability of medical and nursing care when it is most likely to be required.