ZusammenfassungDie vorliegende Handlungsempfehlung dient als Grundlage zur Qualitätssicherung der Somatostatinrezeptor (SSTR-) PET/CT bei onkologischen Patienten. Die Leitlinie wurde interdisziplinär erarbeitet und enthält neben der Definition und Zielsetzung einen Konsens hinsichtlich der erforderlichen klinischen Hintergrundinformationen, Indikationsstellung, Durchführung, Auswertung, Dokumentation und Befunderstellung. Dabei werden die beiden gebräuchlichsten Radiotracer der SSTRPET/ CT (68Ga-DOTATOC und 68Ga-DOTATATE) vertieft dargestellt. Die SSTR-PET/CT erfordert eine enge Interaktion zwischen den zuweisenden und ausführenden Fachdisziplinen unter Berücksichtigung bereits vorhandener Leitlinien und Handlungsempfehlungen europäischer und deutscher Fachgesellschaften, namentlich der European Association of Nuclear Medicine (EANM), der Deutschen Gesellschaft für Endokrinologie (DGE), Deutschen Gesellschaft für Nuklearmedizin (DGN) und Deutschen Röntgengesellschaft (DRG).

Neuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up, follow-up and somatostatin receptor targeted therapies.These guidelines are aimed to assist nuclear medicine physicians in recommending, performing, interpreting and reporting the results of somatostatin receptor (SSTR) PET/CT imaging using Ga-DOTA-somatostatin analogues (SSA), and F-DOPA for various neuroendocrine neoplasms (NENs). The previous procedural guideline by EANM regarding the use of PET/CT tumour imaging with 68Ga-DOTA-SSAs has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts.

This document describes the guideline for peptide receptor radionuclide therapy (PRRT) published by the German Society of Nuclear Medicine (DGN) and accepted by the Association of the Scientific Medical Societies in Germany (AWMF) to be included in the official AWMF Guideline Registry. These recommendations are a prerequisite for the quality management in the treatment of patients with somatostatin receptor expressing tumours using PRRT. They are aimed at guiding nuclear medicine specialists in selecting likely candidates to receive PRRT and to deliver the treatment in a safe and effective manner. The recommendations are based on an interdisciplinary consensus. The document contains background information and definitions and covers the rationale, indications and contraindications for PRRT. Essential topics are the requirements for institutions performing the therapy, e.g. presence of an expert for medical physics, intense cooperation with all colleagues involved in the treatment of a patient, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how treatment has to be carried out technically. Here, quality control and documentation of labelling are of great importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with the involved medical disciplines. Generally, the decision for PRRT should be undertaken within the framework of a multi-disciplinary tumour board.

ZusammenfassungDiese Handlungsempfehlung soll eine Grundlage für die Qualitätssicherung der Peptid - rezeptor-Radionuklidtherapie (PRRT) von Patienten mit Somatostatinrezeptor-exprimierenden Tumoren schaffen, die zurzeit in Deutschland bei fehlenden gleichwertigen oder besseren Therapiealternativen im Rahmen eines individuellen Heilversuches erfolgt. Sie wurde interdisziplinär erarbeitet und enthält neben Definition, allgemeiner Zielsetzung und klinischen Hintergrundinformationen Angaben zu Indikationen und Kontraindikationen der PRRT. Im Mittelpunkt stehen die Anforderungen, die an das Behandlungszentrum gestellt werden, wie die enge Zusammenarbeit der an der Behandlung beteiligten Fachgebiete. Weiterhin wird spezifiziert, welche Untersuchungsbefunde vor der Therapie vorliegen müssen und wie die PRRT technisch und organisatorisch durchzuführen ist. Nach der Behandlung ist eine langfristige Nachsorge/Kontrolle der therapierten Patienten – u. a. zur Gewinnung onkologischer Qualitätsparameter – unabdingbar. Die gesamte Behandlung einschließlich der Nachsorge muss in enger Abstimmung und Zusammenarbeit der beteiligten Fachdisziplinen erfolgen, wobei in der Regel die Empfehlung zur PRRT durch ein multidisziplinäres Tumorboard erfolgen sollte.

Problemstellung: Die Selektive interne Radiotherapie (SIRT) mit Yttrium-90 ist eine palliative Therapieoption von nicht resektablen primären und sekundären Lebertumoren die keine weitere Chemotherapie oder perkutane Ablation erhalten können. Das Ziel dieser retrospektiven Studie war das radiologische Ansprechen und Überleben von Patienten mit Lebertumoren nach SIRT zu evaluieren.

Purpose: Abundant expression of somatostatin receptors (sst) is a characteristic of neuroendocrine tumors (NET). Thus, radiolabeled somatostatin analogs have emerged as important tools for both in vivo diagnosis and therapy of NET. The two compounds most often used in functional imaging with positron emission tomography (PET) are 68Ga-DOTATATE and 68Ga-DOTATOC. Both analogs share a quite similar sst binding profile. However, the in vitro affinity of 68Ga-DOTATATE in binding the sst subtype 2 (sst2) is approximately tenfold higher than that of 68Ga-DOTATOC. This difference may affect their efficiency in detection of NET lesions, as sst2 is the predominant receptor subtype on gastroenteropancreatic NET. We thus compared the diagnostic value of PET/CT with both radiolabeled somatostatin analogs (68Ga-DOTATATE and 68Ga-DOTATOC) in the same patients with gastroenteropancreatic NET. Patients and Methods: Twenty-seven patients with metastatic gastroenteropancreatic NET underwent 68Ga-DOTATOC and 68Ga-DOTATATE PET/CT as part of the workup before prospective peptide receptor radionuclide therapy (PRRT). The performance of both imaging methods was analyzed and compared for detection of individual lesions per patient and for eight defined body regions. A region was regarded as positive if at least one lesion was detected in that region. In addition, radiopeptide uptake in terms of the maximal standardized uptake value (SUVmax) was compared for concordant lesions and renal parenchyma. Results: Fifty-one regions were found positive with both 68Ga-DOTATATE and 68Ga-DOTATOC. Overall, however, significantly fewer lesions were detected with 68Ga-DOTATATE in comparison with 68Ga-DOTATOC (174 versus 179, p < 0.05). Mean 68Ga-DOTATATE SUVmax across all lesions was significantly lower compared with 68Ga-DOTATOC (16.9 ± 6.8 versus 22.1 ± 12.0, p < 0.01). Mean SUVmax for renal parenchyma was not significantly different between 68Ga-DOTATATE and 68Ga-DOTATOC (12.6 ± 2.6 versus 12.6 ± 2.7). Conclusions: 68Ga-DOTATOC and 68Ga-DOTATATE possess similar diagnostic accuracy for detection of gastroenteropancreatic NET lesions (with a potential advantage of 68Ga-DOTATOC) despite their evident difference in affinity for sst2. Quite unexpectedly, maximal uptake of 68Ga-DOTATOC tended to be higher than its 68Ga-DOTATATE counterpart. However, tumor uptake shows high inter- and intraindividual variance with unpredictable preference of one radiopeptide. Thus, our data encourage the application of different sst ligands to enable personalized imaging and therapy of gastroenteropancreatic NET with optimal targeting of tumor receptors.

By targeting somatostatin receptors (sst) radiopeptides have been established for both diagnosis and therapy. For physiologically normal human tissues the study provides a normative database of maximum standardized uptake value (SUVmax) and sst mRNA.

Question: There is some controversy around the value of sentinel lymph node excision (SLNE) because of the high false negative rate, the potential high morbidity and the high operating costs. In order to improve preoperative threedimensional mapping of sentinel lymph nodes (SLN) by means of hybrid s