156P The effectiveness of intraoperative administration of both radioactive isotope and blue dye without pre-surgery gamma imaging in comparison with the conventional technique for sentinel node biopsy

Abstract

Our departmental audit revealed some problems associated with the conventional technique of SLNB such as scheduling issues for OT, co-ordination issues and time lost in the process. Our analysis showed us that the sentinel node was always in axilla, appeared soon after injection, the injection was painful, and the location of the node did not influence the incision. We sat with our nuclear medicine colleagues and evolved a strategy to overcome these problems: Do away with the imaging under gamma camera; shift injection venue to the operating room, thus avoiding a lot of co-ordination and scheduling issues; avoid pain by injecting isotope after induction of general anaesthesia and; train persons to inject the radioactive material. This study is looking at 200 patients of SLN biopsy done by the conventional technique compared to the next 200 patients done with the dual technique. Intraoperative dual SLN mapping consisted of subareolar injection of technetium 99m- labelled filtered sulphur colloid (15-37 MBq) and 2 ml of 1% iso sulfan blue dye just after anaesthetic induction. The conventional technique consisted of subareolar injection of radioactive colloid in Nuclear medicine followed by SPECT imaging and subareolar injection of blue dye intraoperatively. In both cases the SLN was detected using gamma probe and blue colour. SLN’s identified during these procedures were classified as “blue-hot” nodes, “hot-only” nodes, or “blue-only” nodes. Table: 156PConventional techniqueDual techniqueP valueTotal patients202238Sentinel node detected196 (97%)232 (97.47%)0.773Hot and blue159 (81.12%)204 (87.9%)0.054Hot only36 (18.36%)25 (10.7%)0.027 (significant)Blue only1 (0.51%)3 (1.29%)0.399SLN +VE, Other nodes -VE32240.070Only non SLN +VE620.096SLN +VE, NON SLN +12150.875 Open table in a new tab SLN detection rate of dual technique was equivalent to conventional technique. Thereby, even in the absence of Nuclear medicine facility within the hospital, the SLNB can still be performed by procuring the radioactive colloid from a source at a distant site in the same town or city and using the hand-held gamma probe without affecting sensitivity or detection rates.