In this review of the literature and general practice in the use of radiopharmaceuticals for therapy, an argument is provided to demonstrate that the use of patient-individualized radiation dose assessment should become routine in these forms of therapy, as they are in other uses of radiation in therapy. Individual objections to patient-specific dosimetry will be raised and addressed, using findings presented in the literature. Such approaches are superior to the use of a fixed activity or activity per unit body weight approach in nuclear medicine therapy, which is current practice. It will be demonstrated that standardized and automated methods, with adjustment for patient-specific physical and biokinetic data, are of similar cost and difficulty to those used in other therapeutic modalities. Most importantly, the data show that careful use of patient-individualized dose calculations will produce calculated radiation dose estimates that correlate well with observed effects and that use of a dosimetry-based approach will result in better patient outcomes, improving the quality of medical care for patients and reducing costs for the institutions involved. The conclusion of this analysis is that the time has come for this reasonable paradigm to become routine practice.