High intensity focused ultrasound in the treatment of breast fibroadenomata: Results of the HIFU-F feasibility trial

Objectives: Breast fibroadenomata (FAD) are the most common breast lumps in women. High intensity focused ultrasound (HIFU) is a non-invasive ablative technique that can be used to treat FAD but is associated with prolonged treatment times. In the HIFU-F trial, we evaluated the change in volume over time with circumferential HIFU treatment of FAD and compared this to no treatment. Methods: Patients ≥18 years, diagnosed with symptomatic, palpable FAD, visible on ultrasound (US) were recruited. Twenty patients were treated using US-guided HIFU under local anaesthesia. Another 20 participants underwent an US 6 months after diagnosis. Outcome measures included: reduction in treatment time compared to whole lesion ablation; feasibility to achieve a 50% reduction in volume after 6 months; decrease in volume compared to a control group and reduction in symptoms. Results: Circumferential ablation reduced the mean treatment time by 37.5% (SD 20.1%) compared to whole lesion ablation. US demonstrated a significant mean reduction in FAD volume of 43.5% (SD 38.8%; p = 0.016, paired t-test) in the HIFU group compared to 4.6% (SD 46.0%; p = 0.530) in the control group after 6 months. This mean reduction in FAD volume between the two groups was significant in favour of the HIFU group (p = 0.002, grouped t-test). Pre-treatment pain completely resolved in 6 out of 8 patients 6 months post-treatment. Conclusion: Circumferential HIFU ablation of FAD is feasible, with a significant reduction in pain and volume compared to control participants. It provides a simple, non-invasive, outpatient-based alternative to surgical excision for FAD.