[Initiation of clinical multicentre studies with local radiotracer production - Regulatory environment and radiopharmaceutical-organisational aspects].

The aim of this paper is to highlight key aspects to be considered from a radiopharmaceutical point of view when performing prospective multicentre clinical trials using short-lived PSMA-PET-radiopharmaceuticals as investigational medicinal product (IMP). Early prospective multicentre clinical trials are playing an increasingly important role in nuclear medicine translational research; in order to be able to establish new PET tracers with a short physical half-life (e. g. for prostate cancer diagnostics) in the regulatory approval process, nuclear medicine centres are working together across multiple sites in order to be able to achieve the required number of patients to be included within the clinical study in a reasonable time frame. In the following, we discuss the necessary regulatory environment for the preparation of PSMA PET-radiopharmaceuticals as corresponding investigational medicinal product (IMP) using the example of the prospective multicentre clinical trial (phases-I and -II) "[68 Ga]Ga-PSMA-11 in high-risk prostate cancer", and discuss regulatory and organisational issues that need to be taken into account in a decentralized PSMA-PET tracer production from the radiopharmacy perspective.