Clinical studies have shown that it is possible to improve image contrast up to 30% when time of flight (TOF) technology is used compared to non­TOF technology [1]. On the other hand, it has been shown that, combined with the point spread function (PSF) information and current ordered-subset-maximum-likelihood (OSEM) algorithm, image quality for overweight patients could be significantly improved by applying TOF. This encourages further study and a change of the dose model based on patient weight. This change would result in the revision of the existing EANM procedure guidelines, either replacing them or combining them with a system based on a body­mass­index (BMI) concept, and thus result in significant dose reductions with stronger patient­based dose optimisation. This will also reduce exposure of the nuclear medicine staff. Bearing in mind that the compromise in clinical practice is either to reduce the time of the scan or to reduce the patient dose, and that this depends mostly on whether a facility has a medical cyclotron or not, this work focuses on the overview of possibilities for potential reduction of patient dose based on appropriate clinical studies.

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