Physician- and Patient-Reported Outcomes of the MC1635 Phase 3 Trial of Ultrahypofractionated Versus Moderately Hypofractionated Adjuvant Radiation Therapy After Breast-Conserving Surgery

Ultrahypofractionated Adjuvant Breast Radiation Therapy (± Boost) and Virtual Consultations: Patient Perspectives at 1 Year

Purpose

In March 2020, a 1-week ultrahypofractionated adjuvant breast radiation therapy schedule, 26 Gy in 5 fractions, and telehealth were adopted to reduce the risk of COVID-19 for staff and patients. This study describes real-world 1-year late toxicity for ultrahypofractionation (including a sequential boost) and patient perspectives on this new schedule and telehealth workflows.

Methods and Materials

Consecutive patients were enrolled between March and August 2020. Patient-reported outcome measures, including the presence of breast pain, swelling, firmness, and others, were recorded using the European Organisation for research and treatment of cancer quality of life questionairre (EORTC QLQ) BR45 at baseline, 3 months, 6 months, and 1 year. Virtual teleconferencing without video was used. Patients were invited to use video at 1 year for a physician-based assessment, including breast inspection. Patient-reported experience measures were also collected at 1 year to capture how a shortened schedule and telehealth influenced patient experience.

Results

In total, 121 of 135 patients completed at least 2 assessments, of which 33 (25%) received a sequential boost. The majority of patients reported no toxicity or mild toxicity at all 3 time points: 76% at 3 months, 76% at 6 months, and 82% at 1 year. When comparing 26 Gy in 5 fractions alone versus 26 Gy in 5 fractions followed by a sequential boost, there was no difference in toxicity reported at 1 year. A total of 94% felt supported by the medical team throughout their treatment course using telehealth-only consultations. Only 27% actually agreed to video consultation for the purpose of breast inspection when offered.

Conclusions

Ultrahypofractionated breast radiation therapy leads to acceptable late toxicity at 1 year, even when followed by a hypofractionated tumor bed boost. Patient satisfaction with ultrahypofractionated treatment and virtual consultations without video was high. Further investigation concerning the patient's acceptance of video consultations for a physician-based assessment, including breast inspection, is warranted.

Ultra-hypofractionated one-week locoregional radiotherapy for patients with early breast cancer: Acute toxicity results

Purpose

Moderate hypofractionated radiotherapy is the standard of care for all patients with breast cancer, irrespective of stage or prior treatments. While extreme hypofractionation is accepted for early-stage tumours, its application in irradiating locoregional lymph nodes remains controversial.

Materials and methods

A prospective registry analysis from July 2020 to September 2023 included 276 patients with early-stage breast cancer treated with one-week ultra-hypofractionation (UHF) at 26 Gy in 5 fractions on the whole breast (58.3 %) or thoracic wall (41.7 %) and ipsilateral regional lymph nodes and simultaneous integrated boost (58.3 %). Primary endpoint was assessment of acute adverse events (AEs). Secondarily, onset of early-delayed toxicity was assessed. A minimum 6-month follow-up was required for assessing potential treatment-related early-delayed complications. Acute or late complications attributable to treatment were assessed at inclusion using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria.

Results

With a median follow-up of 19 months (range 1-49 months), 159 (57.6 %) patients reported AEs, predominantly grade (G) 1 (n = 139, 50.4 %) and G2 (n = 20, 7.8 %). Skin acute toxicity was common (G1/2: 134, G3: 14), while breast oedema occurred in 10 patients (G1: 9, G2: 1), and 15.9 % reported breast pain (G1: 42, G2: 2). Ipsilateral arm oedema was observed in 1.8 % patients. For patients with a follow-up beyond 6 months (n = 213), 23.4 % patients reported G1/G2 skin AEs, 8.8 % had G1/G2 breast/chest wall oedema, and 8.9 % experienced arm lymphedema. There were no cases of brachial plexopathy or G3 toxicity in this group of patients.

Conclusions

One-week UHF adjuvant locoregional radiation is well-tolerated, displaying low-toxicity profiles comparable to other studies using similar irradiation schedules.