An operative gamma camera for sentinel lymph node procedure in case of breast cancer

Abstract

Large field of view gamma cameras are widely used to perform lymphoscintigraphy in thesentinel lymph nodes (SLN) procedure in case of breast cancer. However, they are not specified for thisapplication and their sizes do not enable their use in the operative room to control the excision of the allSLN. We present the results obtained with a prototype of a new mini gamma camera developed especiallyfor the operative lymphoscintigraphy of the axillary area in case of breast cancer. This prototype iscomposed of 10 mm thick parallel lead collimator, a 2 mm thick GSO:Ce inorganic scintillating crystalfrom Hitachi and a Hamamatsu H8500 flat panel multianode (64 channels) photomultiplier tube(MAPMT) equipped with a dedicated electronics. Its actual field of view is 50 × 50mm2. The gammainteraction position in the GSO scintillating plate is obtained by calculating the center of gravity of thefired MAPMT channels. The measurements performed with this prototype demonstrate the usefulness ofthis mini gamma camera for the pre, per and post-operative identification of SLN's and how itscomplementary role with an intraoperative handheld gamma probe enables to improve the efficiency ofthis practice. A 100 × 100mm2 field of view camera designated to cover the entire axillary area is underinvestigation.