Accelerated partial breast irradiation (APBI) represents a valid option for adjuvant therapy of selected early breast cancer (BC). This single-institution prospective randomized study compares the health-related quality of life (HRQoL) between women treated with the highly conformal-external beam APBI technique and those with the more commonly used moderately hypofractionated whole breast irradiation (hypo-WBI). Eligible patients were women over 50 years with early BC (G1/2 DCIS ≤ 25 mm or G1/2 invasive non-lobular luminal-like HER2 negative carcinoma ≤ 20 mm) after breast-conserving surgery with negative margins. APBI arm consisted of 30 Gy in 5 consecutive daily fractions and WBI arm of 40 Gy in 15 fractions plus 10 Gy in 5 fractions boost to the tumor bed. Patients were requested to complete the official Czech translation of the EORTC QoL questionnaires, including QLQ-C30 and QLQ-BR45, before radiation (baseline), at the end of radiation (M0) and 1 (M1), 3 (M3), 6 (M6), 12 (M12), and 24 (M24) months after radiation. Linear regression models were used to analyze differences in HRQoL between the arms. The 85 enrolled patients exhibited no differences in HRQoL scores between the two arms at baseline. Patients in the APBI arm reported more favorable global health status at M6 (p = 0.055). Other functional scales showed a decrease in the WBI arm at M0 (p = 0.027 for physical functioning). During radiation, symptoms scores increased. Significant between-group differences were observed for the pain (p = 0.002), systemic therapy side effects (p = 0.004), and breast symptoms (p < 0.001) scales at M0, with higher scores in the WBI arm. During follow-up, scores on symptoms scales returned to at least the baseline values. Early BC patients treated with APBI showed non-inferior short-term and late HRQoL outcomes compared to hypo-WBI. In addition to previous findings regarding toxicity, promising pain and breast symptoms results, suggest that APBI should be strongly considered as a treatment option for selected low-risk patients.Trial registration NCT06007118, August 23, 2023 (retrospectively registered).

• Keywords
• Accelerated partial breast irradiation, Adjuvant radiotherapy, Clinical trial questionnaires, Early breast Cancer, Health-related quality of life, QoL questionnaires, Whole breast irradiation,
• MeSH
• Radiotherapy, Adjuvant adverse effects   methods   MeSH
• Quality of Life * MeSH
• Middle Aged MeSH
• Humans MeSH
• Breast Neoplasms * radiotherapy   surgery   psychology   MeSH
• Prospective Studies MeSH
• Surveys and Questionnaires MeSH
• Mastectomy, Segmental MeSH
• Aged MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH

BACKGROUND: Accelerated partial breast irradiation (APBI) is an alternative breast-conserving therapy approach where radiation is delivered in less time compared to whole breast irradiation (WBI), resulting in improved patient convenience, less toxicity, and cost savings. This prospective randomized study compares the external beam APBI with commonly used moderate hypofractionated WBI in terms of feasibility, safety, tolerance, and cosmetic effects. METHODS: Early breast cancer patients after partial mastectomy were equally randomized into two arms- external APBI and moderate hypofractionated WBI. External beam technique using available technical innovations commonly used in targeted hypofractionated radiotherapy to minimize irradiated volumes was used (cone beam computed tomography navigation to clips in the tumor bed, deep inspiration breath hold technique, volumetric modulated arc therapy dose application, using flattening filter free beams and the six degrees of freedom robotic treatment couch). Cosmetics results and toxicity were evaluated using questionnaires, CTCAE criteria, and photo documentation. RESULTS: The analysis of 84 patients with a median age of 64 years showed significantly fewer acute adverse events in the APBI arm regarding skin reactions, local and general symptoms during a median follow-up of 37 months (range 21-45 months). A significant difference in favor of the APBI arm in grade ≥ 2 late skin toxicity was observed (p = 0.026). Late toxicity in the breast area (deformation, edema, fibrosis, and pain), affecting the quality of life and cosmetic effect, occurred in 61% and 17% of patients in WBI and APBI arms, respectively. The cosmetic effect was more favorable in the APBI arm, especially 6 to 12 months after the radiotherapy. CONCLUSION: External APBI demonstrated better feasibility and less toxicity than the standard regimen in the adjuvant setting for treating early breast cancer patients. The presented study confirmed the level of evidence for establishing the external APBI in daily clinical practice. TRIAL REGISTRATION: NCT06007118.

• Keywords
• APBI, Adjuvant radiotherapy, Early breast cancer, External beam radiotherapy, Surgical bed,
• MeSH
• Infant MeSH
• Combined Modality Therapy MeSH
• Quality of Life MeSH
• Humans MeSH
• Mastectomy MeSH
• Breast Neoplasms * radiotherapy   surgery   pathology   MeSH
• Child, Preschool MeSH
• Prospective Studies MeSH
• Mastectomy, Segmental MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Randomized Controlled Trial MeSH