Technical aspects of osteoid osteoma ablation in children using MR-guided high intensity focussed ultrasound.

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.

Comparison of Noninvasive High-Intensity Focused Ultrasound with Radiofrequency Ablation of Osteoid Osteoma.

OBJECTIVE: To evaluate clinical feasibility and safety of magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) treatment of symptomatic osteoid osteoma and to compare clinical response with standard of care treatment. STUDY DESIGN: Nine subjects with radiologically confirmed, symptomatic osteoid osteoma were treated with MR-HIFU in an institutional review board-approved clinical trial. Treatment feasibility and safety were assessed. Clinical response was evaluated in terms of analgesic requirement, visual analog scale pain score, and sleep quality. Anesthesia, procedure, and recovery times were recorded. This MR-HIFU group was compared with a historical control group of 9 consecutive patients treated with radiofrequency ablation. RESULTS: Nine subjects (7 male, 2 female; 16 ± 6 years) were treated with MR-HIFU without technical difficulties or any serious adverse events. There was significant decrease in their median pain scores 4 weeks within treatment (6 vs 0, P < .01). Total pain resolution and cessation of analgesics were achieved in 8 of 9 patients after 4 weeks. In the radiofrequency ablation group, 9 patients (8 male, 1 female; 10 ± 6 years) were treated in routine clinical practice. All 9 demonstrated complete pain resolution and cessation of medications by 4 weeks with a significant decrease in median pain scores (9 vs 0, P < .001). One developed a second-degree skin burn, but there were no other adverse events. Procedure times and treatment charges were comparable between the 2 groups. CONCLUSION: This pilot study shows that MR-HIFU treatment of osteoid osteoma refractory to medical therapy is feasible and can be performed safely in pediatric patients. Clinical response is comparable with standard of care treatment but without any incisions or exposure to ionizing radiation. TRIAL REGISTRATION: ClinicalTrials.govNCT02349971.

Perioperative Surgical Home in Pediatric Settings: Preliminary Results.

BACKGROUND: The Perioperative Surgical Home (PSH) is a patient-centered, team-based approach that aims to improve the value of perioperative care. We implemented a PSH for patients with adolescent idiopathic scoliosis who were undergoing posterior spinal fusion at Children's National Health System. We hypothesized that this PSH would improve patient surgical outcomes and reduce hospital length of stay (LOS). METHODS: A multidisciplinary group created evidence-based protocols for the preoperative, operative, postoperative, and postdischarge care of this patient population. After a 5-month design and training period, PSH for spinal fusion was implemented in March 2015, with reduction in LOS as the primary outcome measure. Anesthesia comanagement of patients additionally allowed a new pathway for patients to recover in the postanesthesia care unit and reduce intensive care unit utilization. Patients before and after the implementation of the PSH were compared on clinical and efficiency metrics. RESULTS: The spinal fusion PSH achieved the primary outcome measure by a significant reduction in LOS. Care improvement was illustrated by achievement of the secondary outcome measure of reduced perioperative transfusion. CONCLUSIONS: The PSH model presented a ready structure that proved successful at our institution for patients with adolescent idiopathic scoliosis who underwent posterior spinal fusion.