In order to preclinically assess the efficacy of anti-EGFR nanobody 99mTc-D10 to detect small tumours in different tumour entities, MDA-MB-468 and MDA-MB-231 human mammary carcinoma cells were implanted orthotopically in the fat pad of the right abdominal mammary gland of nude mice. Here, EGFR is linked to neoplasm.