RecruitingRadiation therapySPECT Imaging for Pharmacokinetics and dosimEtry Towards TREATment OptimizationThe investigators will study SPECT imaging of radiopharmaceutical therapies given as standard of care or as part of other compatible research protocols. The goal is to validate the quantitative SPECT image reconstruction methods developed in this proposal, and to investigate the relation between dosimetry calculated from SPECT images and the outcomes. Patients will be recruited for SPECT/CT imaging during treatment. This is an observational study no additional new drugs or activities will be administrated. The investigators will perform SPECT imaging on a total of 80 patients (\~20 each from year 2 to year 5). Each participant will be imaged 3 times after the first and last cycles of planned radiopharmaceutical therapy.