One-Year Toxicity of Ultrahypofractionated Breast Radiotherapy (+/- Sequential Boost) and a Survey of Patient Experience

PURPOSE/OBJECTIVE(S): In March 2020, a 1-week hypofractionated adjuvant breast radiotherapy schedule, 26 Gy in 5 fractions, was implemented to reduce the risk of COVID 19 virus for patients and staff without compromising on cancer outcomes. This prospective observational study aims to report late toxicities at 1-year and to confirm feasibility and acceptability of this new schedule for patients. MATERIALS/METHODS: – Patient reported outcome measures were recorded at baseline, 3 months, 6 months and 1 year following treatment completion. The presence of breast pain, swelling, hypersensitivity and skin problems, arm or shoulder pain, restricted arm movement and arm swelling were recorded using the EORTC QLQ BR45. Virtual teleconferencing without video was utilized at baseline, 3 months, 6 months and 1-year. Patients were invited to use video at the 1-year assessment for a physician-based assessment. To assess the experience of patients, a survey including 12 questions related to understanding, experiences of and benefits of ultrahypofractionated radiotherapy was developed and patients were invited to participate at the 1-year consultation. RESULTS: In total, 135 consecutive patients were enrolled Mar - Aug 2020. 121/135 (90%) patients completed the 1-year toxicity assessment and at least one other assessment. 30/121 (25%) patients received a sequential boost. The majority of patients reported no toxicity or a mild toxicity at all three time points, 76% (83/109) at 3 months, 76% (82/108) at 6 months, and 82% (99/121) at 1-year. At 1 year 17% (20/121) of patients reported a moderate toxicity, the most common being breast pain (6/121). 2% (2/121) of patients reported a marked toxicity, both reported multiple marked toxicities including appearance of breast, firmness and skin changes. For the 30 patients who received a boost a moderate toxicity was reported by 17% (5/30) at 1 year and 3% (1/30) reported a marked toxicity. There was one confirmed case of ipsilateral recurrence at 1-year. Only 30/121 patients were open to using video for the 1-year physician-based assessment. Regarding patient reported experience 90% (101/112) felt informed about the 1-week radiotherapy schedule, and 88% (99/112) felt informed about possible side effects and 94% (105/122) felt supported by the medical team throughout their treatment course. Only 49% (55/112) reported they would have been open to video consultations. CONCLUSION: Most patients undergoing ultrahypofractionated breast radiotherapy experience no toxicities or mild toxicities. These data suggest that adding a sequential boost following 26 Gy in 5 fractions to the whole breast is safe and does not lead to unacceptable 1-year toxicity. Patient satisfaction with ultrahypofractionated treatment and virtual consultations without video was high. However, less than half of patients may be open to virtual consultations and breast examination using video.