RITM and POCI: pre and per-operative mini γ cameras evaluation for bone tumor localization in theater blocks

We have developed a multi-functional portable γ radio-imager (RITM) based on a position sensitive photo-multiplier tube (PSPMT) in order to evaluate the potential of such miniature γ camera concept in radio-pharmacology and nuclear medicine. We report here an evaluation of our RITM device for cancer surgery. It concerns localization of the osteoid osteoma (bone benign tumor) performed in theater block before skin incision and during the surgical lesion extraction. Over 13 cases we studied, the diagnosis furnished by RITM was always confirmed by postoperation anatomo-pathological analysis. This shows how RITM can be used as an additional indicator to monitor the operation. Following this first experience, we are developing a new small field of view γ per operative compact imager (POCI) performing a sub-millimeter spatial resolution. It consists of a high resolution collimator and a YAP:Ce crystal assembly coupled to an intensified position sensitive diode (IPSD). This hand held imaging probe is first dedicated to intra-operative monitoring for thyroid and neuroblastoma tumor removal. Characteristics of the POCI device and preliminary results are presented