L. Menard et al., Performance characterization and first clinical evaluation of a intra-operative compact gamma imager, IEEE NUCL S, 46(6), 1999, pp. 2068-2074
The growing interest of cancer surgeons in intraoperative probes has led to
the development of several prototypes of high resolution mini gamma camera
s. The aim of this paper is to present a global characterization of the one
that we developed and the corresponding first evaluation in a clinical con
text. The current prototype of POCI (peroperative compact imager) is a 24 m
m diameter intensified position sensitive diode optically coupled to a scin
tillation crystal plate and a novel parallel hole tungsten collimator. In o
rder to face the various clinical situations, two sets of collimator/scinti
llator imaging heads have been developed either for high spatial resolution
or high efficiency purposes. Both of them have first been optimized for Tc
-99m labeled tumor detection. Performances of POCI for these two head modul
es are presented using phantom studies. The results show spatial resolution
values ranging between 1 and 1.9 mm (without significant distortion) and a
corresponding detection efficiency ranging from 6.10(-3) up to 0.2 events/
kBq/sec. Finally, first clinical evaluation of this new high-resolution com
pact camera concerned sentinel lymph node imaging which is included in mela
noma and breast cancer staging protocols. Preliminary results already demon
strate that the performance characteristics of POCI are compatible with int
ra-operative imaging purposes and suggest how such mini-cameras can improve
the success rate of tumor removal surgeries.