High intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)

Background: High intensity focused ultrasound (HIFU) is a non-invasive ablative technique utilising the application of high frequency ultrasound (US) pressure waves to cause tissue necrosis. This emerging technology is currently limited by prolonged treatment times. The aim of the HIFU-F trial was to perform circumferential HIFU treatment as a means of shortening treatment times. Methods: A prospective trial was set up to treat 50 consecutive patients ≥18 years of age. Eligible patients possessed symptomatic fibroadenomata, visible on US. Patients ≥25 years of age required histological confirmation of the diagnosis. Primary outcome measures were reduction in treatment time, reduction in volume on US after 12 months and complication rates. Results: HIFU treatment was performed in 51 patients (53 treatments) with a mean age of 29.8 years (SD 7.2 years) and diameter of 2.6 cm (SD 1.4 cm). Circumferential ablation reduced treatment times by an estimated 19.9 minutes (SD 25.1 minutes), which is a 29.4% (SD 15.2%) reduction compared to whole lesion ablation. Volume reduction of 43.2% (SD 35.4%; p<0.005, paired t-test) was observed on US at 12 months post-treatment. Local complications completely resolved at one month apart from skin hyper-pigmentation, which persisted in nine cases at three months, six cases at six months and six at 12 months. Conclusion: Circumferential HIFU treatment for breast fibroadenomata is feasible to reduce both lesion size and treatment time. HIFU is a non-invasive alternative technique for the treatment of breast fibroadenomata

Optimization of SPIO injection for sentinel lymph node dissection in a rat model

The magnetic technique, consisting of a magnetic tracer and a handheld magnetometer, is a promising alternative technique for sentinel lymph node dissection (SLND) and was shown to be non-inferior to the standard technique in terms of identification rates. In this study, injection characteristics (iron dose, dilution, time course and massaging) were evaluated to optimize magnetic tracer uptake in the sentinel lymph nodes (SLN) in a rat hindleg model. 202 successful SLNDs were performed. Iron uptake in the SLN is proportional (10% utilization rate) to the injection dose between 20 and 200 μg, showing a plateau uptake of 80 μg in the SLN around 1,000 μg injection. Linear regression showed that time had a higher impact than dilution, on the SLN iron uptake. Massaging showed no significant change in iron uptake. The amount of residual iron at the injection site was also proportional to the injection dose without any plateau. Time was a significant factor for wash-out of residual iron. From these results, preoperative injection may be advantageous for SLN detection as well as reduction in residual iron at the injection site by potential decrease in required injection dose

High-intensity focused ultrasound in the treatment of breast tumours

High-intensity focused ultrasound (HIFU) is a minimally invasive technique that has been used for the treatment of both benign and malignant tumours. With HIFU, an ultrasound (US) beam propagates through soft tissue as a high-frequency pressure wave. The US beam is focused at a small target volume, and due to the energy building up at this site, the temperature rises, causing coagulative necrosis and protein denaturation within a few seconds. HIFU is capable of providing a completely non-invasive treatment without causing damage to the directly adjacent tissues. HIFU can be either guided by US or magnetic resonance imaging (MRI). Guided imaging is used to plan the treatment, detect any movement during the treatment and monitor response in real-time. This review describes the history of HIFU, the HIFU technique, available devices and gives an overview of the published literature in the treatment of benign and malignant breast tumours with HIFU

High-intensity focused ultrasound in the treatment of breast tumours

High-intensity focused ultrasound (HIFU) is a minimally invasive technique that has been used for the treatment of both benign and malignant tumours. With HIFU, an ultrasound (US) beam propagates through soft tissue as a high-frequency pressure wave. The US beam is focused at a small target volume, and due to the energy building up at this site, the temperature rises, causing coagulative necrosis and protein denaturation within a few seconds. HIFU is capable of providing a completely non-invasive treatment without causing damage to the directly adjacent tissues. HIFU can be either guided by US or magnetic resonance imaging (MRI). Guided imaging is used to plan the treatment, detect any movement during the treatment and monitor response in real-time. This review describes the history of HIFU, the HIFU technique, available devices and gives an overview of the published literature in the treatment of benign and malignant breast tumours with HIFU

Feasibility study evaluating a magnetic marker in an ex-vivo porcine model

The magnetic technique using a magnetic tracer and handheld magnetometer was successfully evaluated in breast surgery. Residual tracer at the injection site can cause susceptibility artefacts on breast magnetic resonance imaging (MRI), therefore for lesion localization a solid marker would be preferable. Four magnetic markers were developed for localization to evaluate its clinical applicability. Methods: Comparison was made of the maximum magnetic counts and artefact-volume on MRI. Results: All markers were successfully detected, the spring marker showed the highest mean magnetic counts (627.8 ± 400.2, mean ± SD) with unequal variances (p <.001) and the butterfly marker showed the smallest mean artefact-volume (11.1 ± 2.3 cm3) with a significant difference between markers (p =.049). Conclusion: Localization using a magnetic marker is feasible and further evaluation is required within a clinical trial

Feasibility study evaluating a magnetic marker in an ex-vivo porcine model

The magnetic technique using a magnetic tracer and handheld magnetometer was successfully evaluated in breast surgery. Residual tracer at the injection site can cause susceptibility artefacts on breast magnetic resonance imaging (MRI), therefore for lesion localization a solid marker would be preferable. Four magnetic markers were developed for localization to evaluate its clinical applicability. Methods: Comparison was made of the maximum magnetic counts and artefact-volume on MRI. Results: All markers were successfully detected, the spring marker showed the highest mean magnetic counts (627.8 ± 400.2, mean ± SD) with unequal variances (p &lt;.001) and the butterfly marker showed the smallest mean artefact-volume (11.1 ± 2.3 cm3) with a significant difference between markers (p =.049). Conclusion: Localization using a magnetic marker is feasible and further evaluation is required within a clinical trial

High-intensity focused ultrasound in the treatment of breast fibroadenomata (HIFU-F trial)

BACKGROUND: High-intensity focussed ultrasound (HIFU) is a non-invasive ablative technique utilising the application of high frequency ultrasound (US) pressure waves to cause tissue necrosis. This emerging technology is currently limited by prolonged treatment times. The aim of the HIFU-F trial was to perform circumferential HIFU treatment as a means of shortening treatment times. METHODS: A prospective trial was set up to treat 50 consecutive patients ≥18 years of age. Eligible patients possessed symptomatic fibroadenomata, visible on US. Patients ≥25 years of age required histological confirmation of the diagnosis. Primary outcome measures were reduction in treatment time, reduction in volume on US after 12 months and complication rates. RESULTS: HIFU treatment was performed in 51 patients (53 treatments) with a mean age of 29.8 years (SD 7.2 years) and a diameter of 2.6 cm (SD 1.4 cm). Circumferential ablation reduced treatment times by an estimated 19.9 min (SD 25.1 min), which is a 29.4% (SD 15.2%) reduction compared with whole lesion ablation. Volume reduction of 43.2% (SD 35.4%; p &lt; 0.005, paired t-test) was observed on US at 12 months post-treatment. Local complications completely resolved at 1 month apart from skin hyper-pigmentation, which persisted in nine cases at three months, six cases at 6 months and six at 12 months. CONCLUSION: Circumferential HIFU treatment for breast fibroadenomata is feasible to reduce both lesion size and treatment time. HIFU is a non-invasive alternative technique for the treatment of breast fibroadenomata. ISRCTN registration: 76622747.</p