RITM - A MINI GAMMA-CAMERA FOR PRE AND PEROPERATIVE RADIO GUIDED CANCER-SURGERY EVALUATION FOR BONE-TUMOR LOCALIZATION IN THEATER BLOCKS

We have developed a multi-functional portable gamma radio-imager (RITM ) based on a position sensitive photo-multiplier tube (PSPMT) in order to evaluate the potential of such a mini gamma camera concept in radi o-pharmacology and nuclear medicine. We report here an evaluation of o ur RITM device for bone surgery. It concerns localization of the Osteo id Osteoma (benign bone tumor) performed in the theater block before s kin incision and during the surgical lesion extraction. In the over 13 cases we studied, the diagnosis furnished by RITM was always confirme d by post-operation anatomopathological analysis. This shows how RITM can be used as an additional indicator to monitor. the operation. Foll owing RITM experience, we are developing a new small field of view gam ma per-operative compact imager (POCI) with submillimeter spatial reso lution performance. It consists of a high resolution collimator and a YAP:Ce crystal assembly coupled to an intensified position sensitive d iode (IPSD). This hand-held imaging probe is first dedicated to intra- operative monitoring for thyroid tumor and neuroblastoma removal. Char acteristics of the POCI device and preliminary results are briefly pre sented.