Open resection of osteoid osteoma guided by a gamma-probe.

Osteoid osteoma is the third most common type of bone tumour. Radiofrequency ablation and other percutaneous procedures are the treatment of choice. However, in some sites these methods are difficult or dangerous. Our objective of this study was to evaluate whether open resection and intraoperative nidus detection with a hand-held gamma probe is an efficient method for treating this type of tumour. Fifty-three patients with osteoid osteomas were submitted to surgical treatment. The first group (gamma group) consisted of 34 patients submitted to open nidus resection guided by a hand-held gamma probe. The control group consisted of 19 patients operated on by conventional technique. In the postoperative period, histopathology, imaging studies, and clinical outcome were evaluated. The gamma group patients were followed up for an average 26.2 months; the control group patients were followed up for an average 38 months. There was no difference with regard to pain relief and histopathology findings between the two groups. However, in the postoperative imaging studies, there was significantly less nidus present in the gamma group (p = 0.01).The gamma probe helped to locate the osteoid osteoma nidus more precisely, as demonstrated by the postoperative imaging studies.