Researchers from the Division of Diagnostic Oncology at the Netherlands Cancer Institute are investigating imaging technologies that help improve surgical guidance. The main focus is on using so-called multimodal imaging agents to combine the planning of an intervention via 3D SPECT/CT imaging with optical surgical guidance. For this purpose a clinically applied albumin radiocolloid was functionalized with on average 61 fluorescent indocyanine green dyes per particle. This chemical modification makes these colloidal particles both radioactive and fluorescent, allowing accurate detection in both (clinical) settings (see figure). Instrumental for the rapid clinical translation of this technology is the self-assembly of two clinically approved components to generate a novel nanoparticle that is ready for pilot testing.

The value of the multimodal nanoparticles was studied in the preclinical setting under conditions that accurately mimic the clinical situation. For this purpose we have used an orthotopic mouse tumour model for metastatic mammary carcinoma. Similar to the clinical situation, this tumour model generates initial metastasis in the axillary lymph node. In this model system the reported multimodal imaging agent could effectively visualize the tumour-draining lymph nodes via both 3D SPECT/CT imaging and fluorescence imaging. This pre-clinically validated sentinel lymph node imaging approach is now being applied in actual clinical trials at our institute.

The researchers presented their work in the journal Nanotechnology.