[The peroperative isotopic location of osteoid osteomas and other lesions exhibiting increased uptake on scintigraphy].

The technique, advantages and pitfalls of the isotopic localization and control during operation in orthopaedic surgery were evaluated throughout 28 interventions on lesions, which exhibited an increased uptake of a radioactive bone-seeker: the dimethyl-aminodiphosphonate, provisionally designated SF44 (Laboratoires Solabco, Coutras, France). For bone scanning, following the injection of this radiopharmaceutical that increased by 25% the lesion to normal bone ratio compared to the data for the diphosphonates in current use, the localization of lesions at surgical sites was carried out with the use of a sterilisable small radiation probe of a circular cross section 2 mm in diameter (Quartz et Silice, Paris, France). The probe was connected to a portable electronic device that converted the rates of radioactive disintegration into an acoustic signal, which increased with increasing radioactivity (Novelec, Meylan, France). The method was atraumatic and has proved to be useful at various times of the operation. More often, it was used to locate the lesion on the exposed bone. It enabled monitoring the progress of excisions and allowed to shorten their dimensions. The method was of great value at the end of the intervention for ensuring a complete excision as indicated by the lack of any residual focus of increased uptake detectable on the periphery of the operative site. Isotopic control during an operation is fully efficient to locate osteoid osteomas and other circumscribed lesions of the skeleton that give rise to an increased uptake of radioactivity.