Richard P. Baum MD, PhD, Presenter: Stockholder, OctreoPharm Sciences GmbH Principal Investigator, AAA Research Consultant, Novartis AG Research Consultant, Ipsen SA Research Grant, ITG-Medical, Inc

1) Definition of THERANOSTICS, personalized and precision medicine. 2) Indications for Ga-68 somatostatin receptor [SSTR] PET/CT in neuroendocrine tumors (NET): staging, restaging, detection of unknown primary tumors. 3) Molecular imaging (quantification of receptor density by SUV measurements) for selection of NET patients for PRRT and therapy response evaluation after PRRT by Ga-68 SSTR PET/CT. 4) Indications for PRRT, methodology and clinical results (survival, PFS in patients with G1 and G2 NET). 5) Possible adverse effects of PRRT and how to reduce/avoid side effects. 6) Future developments: new peptides (e.g. SSTR antagonists, CXCR4), new indications (e.g. diagnosis and treatment of recurrent prostate cancer using Ga-68 PSMA and Lu-177 labeled PSMA ligands).

The overexpression of specific receptors on tumors enables peptide-based receptor imaging and radionculide therapy (PRRT). 68Gallium is a generator-produced positron emitter for labeling of peptides, e.g. somatostatin analogues (SA) like DOTATOC or DOTATATE for molecular imaging of somatostatin receptors (SSTR) expressing tumors. Since 2004, we have performed over 9,500 68Ga PET/CT studies in patients with neuroendocrine tumors (NET) and have established SSTR PET/CT as the new gold standard for imaging G1 and G2 NET. The same somatostatin-binding peptides can be labeled with 177Lutetium or 90Yttrium for internal radionuclide therapy, a form of personalized treatment (THERANOSTICS approach). Since 1999 we have treated more than 1,200 patients (>4,000 therapy cycles) using 177Lu and/or 90Y labeled peptides. A German multi-institutional registry study with prospective follow up in 450 patients indicates that PRRT is an effective therapy for patients with G1-2 neuroendocrine tumors, irrespective of previous therapies, with a survival advantage of several years compared to other therapies and only minor side effects. Median overall survival of all patients from start of treatment was 59 months. Median progression-free survival (PFS) accounted to 41 months. Median PFS for pancreatic NET was 39 mo and for small bowel NET 51 mo. Grade 3-4 nephro- or hematotoxicity were observed in only 0.2% and 2% of patients, respectively. In patients with progressive NET, personalized PRRT with lower doses of radioactivity given over a longer period of time (Bad Berka Concept) results in excellent therapeutic responses. By this approach, severe hematological and/or renal toxicity can be avoided and quality of life/clinical symptoms can be significantly improved.The concept of THERANOSTICS has now been translated to other malignancies (e.g. prostate cancer using PSMA as ligand). Current state and future perspectives of this fascinating precision treatment of malignancies will be discussed.

http:// www.prrtinfo.org

Baum, R, Radiopeptide Receptor Radionuclide Therapy (PRRT): Current Status and Future Opportunities in Theranostics.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019821.html