Efficacy of percutaneous radiofrequency ablation of osteoid osteoma in children

Abstract

Sir, We read with a great deal of interest the article by Donkol et al. “Efficacy of percutaneous radiofrequency ablation of osteoid osteoma in children” [1] that describes the authors’ experience in treating osteoid osteoma (OO) in 23 children. From June 2001 to now we have treated over 140 osteoid osteomas in children (age range 3–16 years; girl/ boy ratio 1:1.7). We fully agree with the authors regarding the advantages of radiofrequency ablation (RFA) for the treatment of OO in children. To avoid skin burns when the lesion is very superficial or involves small bones, besides placing the active tip in the bone, we put ice on the skin near the needle throughout RF delivery, and in addition, we use a low mA and two adhesive plates (10×15 cm) near the lesion. We have never had a case of hyperthermia. Our patients resume normal daily activities around 12 h after the thermal ablation procedure, with the exception of sport that is resumed after 3 months. The patients usually need no further treatment at home. The diagnosis is based on the correlation of history, clinical examination, and radiological data (conventional radiographs, CT, MRI). We hardly ever perform scintigraphy (to avoid further radiation exposure). When possible, we also prefer to use spinal rather than general anaesthesia, although in very small or uncooperative children there is no choice. Antibiotic (cefazolin 1–2 g) is administered intravenously as a single dose during the procedure. We use a coaxial system formed by the 14-G Bonopty needle biopsy set (Radi, Uppsala, Sweden) after inserting an 18-G needle and Kirschner wire (0.8 mm) as a guide. The needle electrode and the generator are the same type as used by Donkol et al., and we use three different lengths of active tip (5, 10, and 15 mm) according to the dimensions of the lesion. Before delivering the RF we always perform a biopsy and only then insert the needle electrode. The delivery temperature never exceeds 95°C. The procedure time is approximately 20–30 min. We agree with the Donkol et al. regarding the greater risk of recurrences in children, which we think might be because of the greater “skeletal activity”. Despite this high recurrence rate, albeit lower than that reported in the literature for surgical treatment, we believe that thermal ablation of OO with RFA should be considered the gold standard for children as well as adults.