Sola Dosis Facit Venenum: Dosimetry for Molecular Radiotherapy in Bad Berka

The estimation of the absorbed dose is an essential factor for the determination of risks and therapeutic benefit of internal radiation therapies. Optimal dose estimations require time-consuming and sophisticated methods, which are difficult owing to practical purposes mainly related to the patients’ status and physical reasons. Nevertheless, to make patient-specific dosimetry available, we use a special developed dosimetry procedure, which can be used in daily clinical routine. The so-called Bad Berka Dose Protocol (BBDP) is a hybrid method based on serial planar whole body scans and SPECT/CT acquisitions and represents a compromise between the calculation model and practical conditions. It has ensured dose estimation in daily clinical routine with a reasonable effort and within acceptable time. Our protocol allows each of our patients to undergo dosimetry after therapy using Lu-177-labeled radiopharmaceuticals, especially PRRT or PSMA RLT. In consequence, dosimetry based on our protocol helps to identify optimal ligands, for PRRT as well as for PSMA RLT. It helps to plan the individual treatment. Additionally, dosimetry is important for the evaluation of the therapy: concerning response, benefit and toxicity. Besides PRRT and PRLT, the BBDP can be used to make dose estimations for all kinds of different tracers. Dosimetry adds a lot of important information to clinical and medical facts in order to find the optimal therapeutic path for each individual patient.