Surgical gamma probe for identification of sentinel lymph node

Abstract

Surgical gamma probes have been widely used in oriented surgery, to locate the sentinel lymph nodes in breast cancer and malignant melanoma during the surgery. In this technique, the intra-operative localisation of the sentinel lymph node is carried out using a surgical gamma probe. A radiotracer, such as colloidal suspensions of 99mTc in human albumin emitting γ-rays of 140 keV is administered (in the tumour site or close) in the patient, before operation, and the radiotracer travels from the tumour to the sentinel lymph node. Then the probe measures the labelled radioactivity, identifying and locating the sentinel lymph node once a visually occult disease, in order to remove it surgically. In this work, a pilot group of surgical gamma probes were developed at IPEN/CNEN-SP with high nationalisation indices, included the detector set. The probes final sizes were 14.0 mm diameter and 170 mm long and their characteristics were compared with imported probes and finally they were used in actual surgeries.