8th thematic workshop: International Symposium On Advanced Intraoperative Imaging of Radioisotopes and Presymposium workshop TOF PET

Performance characteristics of a newly developed intra-operative gamma camera: Evaluation of sentinel lymph node detection in an experimental animal model and preliminary clinical experience

6 Sept 2009, 16:30

30m

Hotel Baia delle Zagare

Symposium Session 7

Speaker

Dr Doron Kopelman (Department of Surgery BHaEmek Medical Center & Faculty of Medicine Technion, Israel Institute of Technology)

Description

Hypothesis: The ability to obtain detailed visual assessments of radio-labeled tissues intra-operatively is expected to improve localization and removal of such targets. We have tested the capacity of a newly developed portable gamma camera to precisely locate sentinel lymph nodes using an injected radiotracer contrast agent both in an animal model and a preliminary clinical study. Design: Animal study: Two sets of experiments were performed on 8 pigs under general anesthesia. 99mTc-nanocolloid and dye complex was injected into the sub muscular layer of the small bowel in the first set, and subcutaneously in the knee region in the second set of experiments. Images were acquired at various distances from the injection sites following the lymphatic expansion towards the inguinal sentinel nodes. Image acquisition of the sentinel nodes was performed with the camera placed at various angles also. The nodes were then excised and scanned in vitro. The node sites were scanned again after node removal to prove the completeness of the excision. Clinical study: Four patients with breast cancer underwent axillary lymph node dissection and were evaluated with the portable gamma camera during the routine procedure. Results: Animal study: In each experiment, a mosaic of images was obtained encompassing the injection sites, lymphatic pathways and sentinel lymph nodes. By acquiring images of the sentinel nodes with various angular perspectives, three dimensional visualizations were obtained allowing the precise location and complete excision of these nodes. Clinical study: More hot nodes were detected by the camera. Excellent views were obtained. Easy localization of hot nodes was possible. Conclusions: The use of the portable gamma camera allowed the rapid visualization of the lymphatic pathways leading from the injection sites to the sentinel nodes and precise location of these nodes, even if they were located deep below the surface. The camera was also useful to verify the complete removal of the labeled target tissues, even in the presence of a general background activity from the surgical field. The camera served as an excellent guidance device to the surgeon. Acknowledgement: These studies were performed with the financial assistance of the MAGNET Program, Office of the Chief Scientist, Ministry of Industry and Trade, State of Israel.