Detection of metastatic spread in lymph nodes at an early stage of disease can be achieved by imaging techniques such as PET and fluoride-labelled tumour cells. Intraoperative detection of small metastases can be problematic, especially in minimally invasive surgery.
To facilitate intraoperative localisation of lymph nodes, a gamma radiation sensor can be placed in the situs. In the minimally invasive setting, the sensor must fit through the trocar, and for robotic procedures, a small, capsule-like device is advantageous. Size reduction could be achieved by using only a few simple electronic components packaged in a disposable sensor head, also resulting in a low-cost device. The evaluation of the electronics is done with a microcontroller and the system communicates with the user via an acoustic interface.
A first prototype is based on a suitable low-cost diode placed in a sensor head (Ø 12 mm). For a first detection experiment, a 137Cs source (138 kBq activity, 612 keV) was placed under a wooden plate and had to be localised.
Publications
- Behling M, Wezel F, Pott PP, Miniature low-cost γ-radiation sensor for localization of radioactively marked lymph nodes, submitted