Comparison of brachytherapy and external beam radiotherapy boost in breast-conserving therapy: Patient-reported outcome measures and aesthetic outcome.

OBJECTIVE: This study aimed to estimate the probability of an unfavourable aesthetic outcome (AO) 2 years after breast-conserving therapy (BCT) and evaluate the possible influence of brachytherapy (BT) and external beam radiotherapy (EBRT) boost on patient-reported outcomes (PROs) and AO. PATIENTS AND METHODS: Patients treated with BCT starting April 2015 were prospectively included. Selection of the boost technique followed an in-house flowchart based on the depth of the tumour bed. An electron boost was performed for a superficial clinical target volume (maximum 28 mm under the epidermis), a BT boost was proposed in all other cases. Patients were followed-up for 2 years. AO was scored by the BCCT.core software and the patient. Further PROs were measured with the EORTC QLQ-C30, QOL-BR23 and the BIBCQ questionnaires.
RESULTS: The analysis included 175 patients, 80 received a BT boost and 95 an EBRT boost. BT patients were significantly older; had a higher breast cup and band size, body mass index and surgical specimen weight of the wide excision; more seroma at baseline and less positive surgical section margins than patients in the EBRT group, and more patients drank alcohol. Cancer- and breast cancer-specific quality of life (QOL) and body image did not differ between the boost techniques over time. Although mean scores for breast symptoms and sexual enjoyment did differ significantly over time (p = 0.05 and < 0.01, respectively), the effect was due to differences before boost administration. Measured with BCCT.core, AO was unfavourable in 28% of patients 2 years after treatment (31% scored by the patient) and results were similar in the BT and EBRT groups.
CONCLUSION: Using the presented flowchart (See Verhoeven et al. [16]), AO and PROs on QOL or body image up to 2 years after BCT are not influenced by the boost technique.