Eindverslag
Evaluation of 68Ga-NOTA-Anti-HER2 Nanobody uptake in brain metastasis of breast carcinoma patients using PET/CT scan - Keyaerts Marleen
In patients with brain metastasie, diagnosis and evaluation of therapy response can be challenging. The location makes it quite difficult to perform biopsy in a safe way, so medical imaging is the method of choice to assess lesions in the brain. However, changes in brain lesions can occur due to (radio)therapy as well as due to tumor growth, and may lead to uncertainties about the benefits of the applied therapy. In breast cancer patients, the HER2-positive subtype is notorious to result in brain metastasis, while the rest of the body can be disease-free.
We therefore investigated the anti-HER2 imaging compound termed 68Ga-NOTA-Anti-HER2-Nanobody as a novel imaging agent for radionuclide PET/CT imaging of brain metastases. Because Nanobodies are antibody-fragments that are 10-fold smaller than classical antibodies, they have been shown to penetrate well in difficult-to reach tissues, and might therefore hold promise in imaging HER2-positive brain metastasis.
In our project, we included both HER2-positve and HER2-negative breast cancer patients with brain metastases. Lesions as small as 8 mm could be correctly identified using 68Ga-NOTA-Anti-HER2-Nanobody, while HER2-negative lesions as well as lesions that were radiation-induced scar tissue did not show uptake of this imaging tracer. This underscores the sensitivity and specificity of this imaging approach.
Based on these results, a larger clinical trial in multiple centres is under development.