Theranostics 2012, 2(5) http://www.thno.org 437 Theranostics 2012; 2(5):437-447. doi: 10.7150/thno.3645 Review THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy – The Bad Berka Experience Richard P. Baum  , Harshad R. Kulkarni Department of Nuclear Medicine/ Center for PET/CT, Zentralklinik Bad Berka, ENETS Center of Excellence, Zentralklinik Bad Berka, 99437 Bad Berka, Germany.  Corresponding author: Professor Dr. Richard P. Baum, Chairman and Clinical Director, Dept. of Nuclear Medicine / Center for PET/CT, ENETS Center of Excellence, Zentralklinik Bad Berka, 99437 Bad Berka, Germany. Tel. +49 364 585 2200, Fax +49 364 585 3515, richard.baum@zentralklinik.de. © Ivyspring International Publisher. This is an open-access article distributed under the terms of the Creative Commons License (http://creativecommons.org/ licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited. Received: 2011.10.16; Accepted: 2011.12.02; Published: 2012.05.07 Abstract The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by ap- plying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction. Key words: THERANOSTICS, molecular imaging, personalized radionuclide therapy. INTRODUCTION The term theranostics epitomizes the insepara- bility of diagnosis and therapy, the pillars of medi- cine. In the context of nuclear medicine, it refers to the use of molecular targeting vectors (e.g. peptides) la- beled either with diagnostic radionuclides (e.g. posi- tron or gamma emitters), or with therapeutic radio- nuclides for diagnosis and therapy respectively of a particular disease, targeted specifically by the vector at its molecular level. Therefore molecular imaging and diagnosis of the disease can be effectively fol- lowed by personalized treatment utilizing the same molecular imaging vectors. One of the classic exam- ples of theranostics is the use of Ga-68 labeled tracers, wherein the diagnosis using this generator-derived radionuclide can be effectively followed by the ther- apy using therapeutic radionuclides like Lu-177 and Y-90 labeled with the same tracer for personalized radionuclide therapy. Addition of two important fac- ets namely individualized patient dosimetry by pre- or post therapeutic imaging, and assessment of ther- apy response using quantitative imaging by Ga-68 positron emission tomography/ computed tomogra- phy (PET/CT) fulfills the potential of personalized medicine. Ga-68 is an easily-available generator-derived diagnostic trivalent radio metal with convenient la- Ivyspring International Publisher