Intraoperative gamma probe application in patients prediagnosed with osteoid osteoma

INTRODUCTION: Osteoid osteoma is a benign but painful bone tumor that is treated with the excision of the nidus. Due to difficulties in reaching the tumor, intraoperative localization may be needed for complete excision without unnecessary resection of the surrounding bone. AIM: The aim of this study was to evaluate the effectiveness of intraoperative gamma probe application in the preoperative planning and for intraoperative localization of osteoid osteoma. MATERIALS AND METHODS: The study included a total of 26 patients, comprising 10 females and 16 males with a mean age of 19.6 years (range: 6–45 years), who were prediagnosed with osteoid osteoma based on clinical and radiological findings. All patients were admitted for surgery following bone scintigraphy. All operations were performed with the use of a gamma probe. RESULTS: Clinical results were obtained from the postoperative pain evaluation, and excised bone tissue fragments were evaluated histopathologically. Localization of the lesion area was made intraoperatively using a gamma probe in all patients. A statistically significant difference was determined between the radioactivity counts in the normal peripheral bones of the lesion and the lesion area itself (P < 0.001). The ratio of lesion to normal tissue was 4/1 on average. The radioactivity level dropped by 62% on average (30%–90%) in the cavity cleaned after postresectional excision of the pathological tissue. The radioactivity counts in the cavity after resection was found to be significantly lower than those of the lesion area before resection (P < 0.001). CONCLUSION: The use of a gamma probe in intraoperative localization following a preoperative injection of99mTc-methylene diphosphonate, is an easy and safe method that helps in the localization of osteoid osteoma nidus during surgery and guides a limited but complete resection of the tumor.