Technical aspects of osteoid osteoma ablation in children using MR-guided high intensity focussed ultrasound
International Journal of Hyperthermia
Children; Clinical trials-thermal ablation; High intensity focused ultrasound; Osteoid osteoma; Thermal ablation
© 2017 Informa UK Limited, trading as Taylor & Francis Group. Background: Osteoid osteoma (OO) is a painful bone tumour occurring in children and young adults. Magnetic resonance imaging-guided high intensity focussed ultrasound (MR-HIFU) allows non-invasive treatment without ionising radiation exposure, in contrast to the current standard of care treatment with radiofrequency ablation (RFA). This report describes technical aspects of MR-HIFU ablation in the first 8 paediatric OO patients treated in a safety and feasibility clinical trial (total enrolment of up to 12 patients). Materials and methods: OO lesions and adjacent periosteum were treated with MR-HIFU ablation in 5–20 sonications (sonication duration = 16–48 s, frequency = 1.2 MHz, acoustic power = 20–160 W). Detailed treatment workflow, patient positioning and coupling strategies, as well as temperature and tissue perfusion changes were summarised and correlated. Results: MR-HIFU ablation was feasible in all eight cases. Ultrasound standoff pads were shaped to conform to extremity contours providing acoustic coupling and aided patient positioning. The energy delivered was 10 ± 7 kJ per treatment, raising maximum temperature to 83 ± 3 °C. Post ablation contrast-enhanced MRI showed ablated volumes ranging 0.46–19.4 cm3 extending further into bone (7 ± 4 mm) than into soft tissue (4 ± 6 mm, p = 0.01, Mann–Whitney). Treatment time ranged 30–86 min for sonication and 160 ± 40 min for anaesthesia. No serious treatment-related adverse events were observed. Complete pain relief with no medication occurred in 7/8 patients within 28 days following treatment. Conclusions: MR-HIFU ablation of painful OO appears technically feasible in children and it may become a non-invasive and radiation-free alternative for painful OO. Therapy success, efficiency, and applicability may be improved through specialised equipment designed more specifically for extremity bone ablation.
Yarmolenko, P., Eranki, A., Partanen, A., Celik, H., Kim, A., Oetgen, M., Beskin, V., Santos, D., Patel, J., Kim, P., & Sharma, K. (2018). Technical aspects of osteoid osteoma ablation in children using MR-guided high intensity focussed ultrasound. International Journal of Hyperthermia, 34 (1). http://dx.doi.org/10.1080/02656736.2017.1315458