Sestre Milosrdnice University hospital and Institute of Clinical Medical Research
Abstract
Two cases of osteoid osteoma tumor (OO ) are presented and our early experience with intraoperative gamma probing to localize OO during surgery is reported. The concept of radioguided surgery was developed 60 years ago and the gamma detection probe technology for radioguided biopsy and/or resection of bone lesions has been applied since the early 1980s. Bone scintigraphy is very important for initial diagnosis of OO with almost 100% sensitivity. The bone scan finding is specific, with so called double density appearance, very intense accumulation of radiopharmaceutical in the nidus and therefore great difference between the nidus and the surrounding healthy bone, thus making possible to treat this lesion with probe guided surgery. Three phase bone scintigraphy and single photon emission computed tomography were conducted in our patients for initial diagnosis of OO . A second bone scintigraphy was performed before surgery. The surgery followed 12-15 hours later by intraoperative nidus detection with a hand-held gamma probe. Gamma hand-held probe is a system that detects gamma photons. The count rate in the nidus area on the day of surgery was 3 to 4 times higher than in the healthy bone area. Drilling was performed until the counts decreased to the level of the surrounding bone counts, thereby confirming complete excision. This is the method of choice for minimizing bone resection, the risk of pathologic fracture, the need of bone grafting, and reducing the period of convalescence. Evidence for the treatment efficiency is pain disappearance after the surgery.U radu se prikazuju dva klinička slučaja kod kojih smo koristili detekcijsku gama sondu za intraoperacijsku navigaciju
prilikom kiretaže tumora osteoidnog osteoma (OO ). Zahvati su izvršeni na Klinici za traumatologiju Kliničkog bolničkog centra “Sestre milosrdnice”. Koncept radionavigacije u kirurgiji razvijao se zadnjih 60 godina, a primjena tehnologije gama detekcijske sonde za biopsiju ili resekciju koštanih lezija datira od ranih osamdesetih. Uz RTG te kompjutoriziranu tomografiju scintigrafija kosti je jedna od najvažnijih metoda u dijagnostici OO , s gotovo 100%-tnom osjetljivošću. Za početnu dijagnozu učinjena je trofazna scintigrafija kosti i SPE CT – jednofotonska emisijska kompjutorizirana tomografija. Druga scintigrafija kosti učinjena je prije zahvata. Operacija je uslijedila 12-15 sati kasnije uz intraoperacijsko otkrivanje gnijezda ručnom gama sondom. Na dan operacije brojčana vrijednost bila je 3-4 puta viša na mjestu lezije u odnosu na zdravu kost. Kiretaža tumora provođena je sve dok brojčana vrijednost nije pala na razinu vrijednosti okolne kosti, na taj način potvrđujući potpuno uklanjanje lezije. Ovo je jedna od metoda izbora liječenja OO , jer na najmanju mjeru svodi resekciju kosti te time smanjuje rizik od mogućih patoloških prijeloma i skraćuje razdoblje rekonvalescencije. Dokaz uspješnosti kirurškog zahvata bio je nestanak boli u operiranih bolesnika
