 In a prospective series, patients with benign bone tumors were treated by minimal invasive intervention with a bi-phasic and injectable ceramic bone substitute CERAMENTTM BONE VOID FILLER, composed of 60 weight synthetic calcium sulfate CaS and 40 weight hydroxyapatite HA powder was mixed with a water-soluble radio-contrast agent iohexol 180 mgml to make the material radiopaque. The defects were treated by either mini-invasive surgery solid tumors or percutaneous injection cysts and followed clinically and radiologically for 12 months. CT scan was performed after 12 months to confirm bone remodeling of the bone substitute. All patients were allowed full weight bearing immediately after surgery. 