Fig 3. Detection of neoangiogenesis.

Upper panel: (A) Coronal image section from a ¹⁸FGalacto-RGD PET of a patient with a malignant melanoma and a lymph node metastasis at the right axilia obtained 60 min after tracer injection. The image shows a clearly contrasting tumour and rapid predominately renal elimination with low background activity in almost all areas of the body. (B, C) Patient with a soft tissue sarcoma dorsal of the right knee joint. (B) The image fusion of the ¹⁸FGalacto-RGD PET and the corresponding CT scan shows that the regions of intense tracer uptake correspond with the enhancing tumour wall, whereas the non-enhancing hypodense centre shows no tracer uptake. (C) Immunohistochemistry of a peripheral tumour section using the anti-α_vβ₃ monoclonal antibody LM609 demonstrates intense staining predominantly of tumour vasculature.

Lower panel: (D) Immunohistochemical staining of tumour sections using the anti-α_vβ₃ mAb LM609 demonstrates that the squamous cell carcinoma of human origin do not express the α_vβ₃ integrin. (E) In contrast, staining of sections with an antibody against the murine β₃-subunit indicates that the tumour vasculature is α_vβ₃-positive. (F, G) Transaxial images of nude mice bearing a human squamous cell carcinoma at the right shoulder acquired 90 min after ¹⁸FGalacto-RGD injection show a clearly contrasting tumour. The signal reflects tracer accumulation due to α_vβ₃ expression exclusively in the tumour vasculature. Tracer accumulation can be blocked by injecting 18 mg cyclo(-Arg-Gly-Asp-dPhe-Val-) per kilogram mouse 10 min prior to tracer injection indicate receptor-specific accumulation. (figure adapted from Haubner et al. PLoS Med. 2004)