Evaluation of a Pretargeting Strategy for Molecular Imaging of the Prostate Stem Cell Antigen with a Single Chain Antibody.

In pretargeted radio-immunotherapy, the gradual administration of a non-radioactive tumor antigen-addressing antibody-construct and the subsequent application of a radioactive labeled, low molecular weight substance enable a highly effective and selective targeting of tumor tissue. We evaluated this concept in prostate stem cell antigen (PSCA)-positive cancers using the antigen-specific, biotinylated single chain antibody scFv(AM1)-P-BAP conjugated with tetrameric neutravidin. To visualize the systemic biodistribution, a radiolabeled biotin was injected to interact with scFv(AM1)-P-BAP/neutravidin conjugate.

Theranostic and nanotheranostic probes in nuclear medicine.

In nuclear medicine, a theranostic probe describes a substance that combines diagnostic and therapeutic capabilities by radiolabeling it with different radionuclides. Next to a brief description of the different emitters (α, β, β, γ) used for imaging and/or therapy, the aim of this review is to summarize the most commonly used theranostic probes in nuclear medicine. Another goal is to give an idea which chemical requirements need to be fulfilled for radiolabeling with either therapeutic and/or diagnostic relevant nuclides.