This is the first in a series of articles looking at the hot topic of the patenting of radiopharmaceuticals. In the theranostic pair of technetium and radium, a compound comprising radioactive technetium is used to image a disease-affected region such as a tumour, and the same compound comprising radioactive rhenium is then used to treat the region. Due to the similarities of the chemistries of the two isotopes, the imaged region will correspond to the treated region. Even though the technology field is in its infancy, at least one product has already reached the clinical trial phase. In the last couple of decades nuclear imaging and systemic radiotherapy have become viable detection and treatment options in the fight against cancer. As a result of extensive research, more and more patent applications are being filed directed to inventions involving radiopharmaceuticals. In a series of articles, we will review the patent landscape of radiopharmaceuticals looking at trends and new advances in the area during the last ten years (2006-2015). Each article will focus on a radioisotope or radioisotope pair. Here we focus on technetium and rhenium and their use as a theranostic pair in diagnosis and therapy.