positron emission tomography (pet) with an organ-targeted approach has a potential to significantly improve the diagnosis of a variety of diseases through higher detection efficacy and a reduced dose of radioactivity than when conventional whole-body (wb) pet systems are used. the application of functional imaging with organ-targeted pet to breast-cancer screening and diagnosis brings with it the benefits of visualizing malignant growths at the early stages of the disease as well as being unaffected by dense breast tissue. this acts as a workaround to one of the most notable current issues with anatomical x-ray imaging techniques for breast cancer of having a lower specificity of detection because of masking effects of dense cancerous tissues with a similarly dense tissue background. experimental evaluation of a novel solid-state pet detector technology, called the radialis pet camera, has demonstrated that through the modular architecture of pet flat-panel detectors, system performance parameters including spatial resolution, sensitivity, and detector count rates can be improved significantly. in clinical settings these improvements are translated into accurate detectability of small cancerous lesions even at a 10-fold reduction in radiotracer activity in comparison with standard wb pet dose and therefore, will ultimately allow for the implementation of organ-targeted low-dose pet imaging to breast cancer screening, diagnosis, and treatment follow-up. [...]