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ZusammenfassungDie Positronenemissionstomografie (PET) mit 18F-Fluorodesoxyglukose (FDG) in Kombination mit der Computertomografie (CT) ist integraler Bestandteil der initialen Diagnostik aggressiver Lymphome. Mehrere Studien und Metaanalysen haben gezeigt, dass die FDG-PET/CT die genaueste nicht invasive Methode bei Staging und Restaging von Hodgkin- (HL) und Non-Hodgkin-Lymphomen (NHL) darstellt. Die PET-basierte Risikostratifizierung liefert wesentliche prognostische Informationen. Im Laufe der letzten Jahre hat sich diese Hybridbildgebung auch zur frühen Beurteilung des Therapieansprechens und somit als Instrument der Therapiesteuerung etabliert. So kann auf Basis der FDG-Avidität von Restlymphomen das therapeutische Regime personifiziert ggf. eskaliert oder deeskaliert werden, um den Therapieerfolg zu verbessern. Neue PET-bildbasierte Biomarker wie das Metabolic Tumor Volume (MTV) lassen in naher Zukunft eine weitere Verbesserung dieser Risikostratifizierung erwarten. In der vorliegenden Übersichtsarbeit werden die relevanten Anwendungsbereiche der FDG-PET/CT bei der Beurteilung des Therapieansprechens maligner Lymphome dargestellt.

Aim [99mTc]Tc-PSMA-based radioguided surgery (TPRS) represents a curative approach for localized relapse of prostate cancer. For its simplified regulatory permission, the radiation protection authorities require a 99mTc- activity below the exemption limit of 10 MBq at the time of surgery. Our aim was to determine the optimal amount of radioactivity (OAR) to comply with that limit and to estimate the maximum number of TPRS procedures per year and surgeon without triggering the full monitoring obligations. Methods In this retrospective study, a dose rate meter was calibrated using measurements on phantoms and from recently injected (1 min p. i.) patients to determine the activity in the patient from measured dose rates. The effective half-life of 99mTc-PSMA-I&S in patients was determined from repeated dose rate measurements to estimate dose parameters of relevance for radiation protection. External exposures of the surgeons were measured with personal dosimeters calibrated in Hp(10). The surgeon’s finger dose Hp(0.07) is estimated from radioactivity measured in resected lymph nodes. Potenzial incorporations were estimated for an activity of 10 MBq. Results From the first 6 subsequent patients, an effective half-life of 4.15 h was observed. Assuming an operation time 24 h p. i., the OAR was 550 MBq. Operations lasting in average 2 h in a distance of 0.25 m to the patient imply a body dose for surgeons of 4.16 µSv per procedure. Based on these estimates, the surgeon’s Hp(10) is less than 1 mSv per year with up to 241 operations per year. Hp(0.07) and potential incorporation of activity do not lead to further limitations. Summary All radiation protection regulations are met with adherence to OAR recommended here without triggering the full monitoring obligations from radiation protection regulations.

Overexpression of the neurotensin receptor type 1 (NTS1R), a peptide receptor located at the plasma membrane, has been reported for a variety of malignant tumors. Thus, targeting the NTS1R with 18F- or 68Ga-labeled ligands is considered a straightforward approach towards in vivo imaging of NTS1R-expressing tumors via positron emission tomography (PET). The development of suitable peptidic NTS1R PET ligands derived from neurotensin is challenging due to proteolytic degradation. In this study, we prepared a series of NTS1R PET ligands based on the C-terminal fragment of neurotensin (NT(8–13), Arg8-Arg9-Pro10-Tyr11-Ile12-Leu13) by attachment of the chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) via an Nω-carbamoylated arginine side chain. Insertion of Ga3+ in the DOTA chelator gave potential PET ligands that were evaluated concerning NTS1R affinity (range of Ki values: 1.2–21 nM) and plasma stability. Four candidates were labeled with 68Ga3+ and used for biodistribution studies in HT-29 tumor-bearing mice. [68Ga]UR-LS130 ([68Ga]56), containing an N-terminal methyl group and a β,β-dimethylated tyrosine instead of Tyr11, showed the highest in vivo stability and afforded a tumor-to-muscle ratio of 16 at 45 min p.i. Likewise, dynamic PET scans enabled a clear tumor visualization. The accumulation of [68Ga]56 in the tumor was NTS1R-mediated, as proven by blocking studies.

ZusammenfassungNeun Jahre nach der letzten bundesweiten Erhebung von Daten zur Häufigkeit und Strahlenexposition nuklearmedizinischer Untersuchungen wurde in 71 Einrichtungen erneut ein umfangreicher Datensatz für die Jahre 2016 und 2017 zusammengetragen und analysiert. Die Auswertung basierte auf möglichst vollständigen Daten sämtlicher Untersuchungen des Erhebungszeitraums. Erstmalig wurden ebenfalls Daten zu computertomografischen (CT)-Untersuchungen im Rahmen der Hybridbildgebung erfasst. Die relative Häufigkeit untersuchter Organbereiche hat sich im Vergleich zur Vorgängerstudie relevant geändert. Die relative Häufigkeit von Schilddrüsen- und Skelettuntersuchungen ist deutlich rückläufig. Der Anteil der PET-Bildgebung hat sich mehr als verdoppelt. Die anhand applizierter Aktivitäten berechnete effektive Dosis sank im Mittel um mehr als 25 %, was jedoch vornehmlich auf Änderungen in den Dosiskoeffizienten zurückzuführen ist. Bei Untersuchungen, für die diagnostische Referenzwerte (DRW) existieren, sind Konvergenzen applizierter Aktivitäten zu diesen Werten erkennbar. Bei anderen Untersuchungen ist die Verteilung der in Einrichtungen im Mittel applizierten Aktivitäten teilweise recht heterogen. Die Höhe der Dosis der CT-Untersuchungen, die im Rahmen der Hybridbildgebung durchgeführt werden, unterscheidet sich relevant zwischen einzelnen Einrichtungen. Darüber hinaus besteht eine deutliche Überlappung der Verteilungen der Dosiswerte bei diagnostischen CT-Untersuchungen und solchen, die nach Aussage der Anwender ausschließlich zur Schwächungskorrektur und anatomischen Koregistrierung durchgeführt wurden.

A retrospective, single-center analysis of 14 cases of Candida endocarditis (from 355 candidemia cases during the years 2012–2019) revealed a high in-hospital mortality (57.1%), a high proportion of healthcare-associated infections (13/14) and a high treatment preference for echinocandins. Transthoracic echocardiography and 18F-FDG PET/CT had a sensitivity of 54.5% and 57.1%, respectively. Patients were older than previously described and most patients with Candida endocarditis had persistent candidemia for ≥ 3 days despite antifungal therapy. Electronic supplementary material The online version of this article (10.1007/s11046-020-00492-3) contains supplementary material, which is available to authorized users.

Recently, dose reference levels (DRLs) have been defined in Germany for auxiliary low-dose CT scans in hybrid SPECT/CT and PET/CT examinations, based on data from 2016/17. Here, another survey from 2020 was evaluated and compared with the new DRLs as well as with similar surveys from foreign countries.The survey, which had already been conducted in the Nordic countries, queried for various examinations including the following values: patient weight and height, volume CT dose index (CTDIData from 15 SPECT/CT and 13 PET/CT systems from 15 nuclear medicine departments were collected. For the following examinations datasets from more than 10 systems were submitted: SPECT lung VQ, SPECT bone, SPECTPET cardiac, PET brain, PET oncology. Especially for examinations of the thorax and heart, the new DRLs are very strict compared to this study. The CTDIFor certain examination types, there is a need for dose optimization at some clinics and devices in order to take into account the new DRLs in Germany in the future.ZIEL: Seit Kurzem gibt es in Deutschland für auxiliäre Niedrigdosis-CT-Aufnahmen bei SPECT/CT- und PET/CT-Untersuchungen Dosisreferenzwerte (DRW), welche auf Daten von 2016/17 basieren. Hier wurde eine weitere Umfrage aus dem Jahr 2020 ausgewertet und mit den neuen DRW sowie mit ähnlichen Umfragen aus anderen Ländern verglichen.Die Umfrage, welche bereits in den nordischen Ländern durchgeführt wurde, erfasste für unterschiedliche Einsatzbereiche u.a. folgende Werte: Patientengewicht/-größe, volumenbezogener CT-Dosisindex (CTDIDaten von insgesamt 15 SPECT/CT- und 13 PET/CT-Geräten aus 15 Zentren wurden erhoben. Hierbei beinhalteten die Daten z.B. folgender Untersuchungen mehr als 10 Geräte: Lungen-SPECT, Knochen-SPECT, kardiologisches SPECTPET, Hirn-PET, onkologisches PET. Besonders für Untersuchungen des Thorax und des Herzens sind die neuen DRW im Vergleich zu dieser Studie sehr streng. Die CTDIFür einzelne Untersuchungstypen besteht bei einigen Kliniken und Geräten Dosisoptimierungsbedarf, um die neuen DRW in Deutschland zukünftig zu berücksichtigen.

ZusammenfassungDie Positronen-Emissions-Tomografie (PET) mit 18F-Fluorodesoxyglukose (FDG) in Verbindung mit einer Computertomografie (CT) wird bei speziellen Indikationen in der Diagnostik bei Patienten mit Kopf-Hals-Tumoren eingesetzt. Die Einsatzmöglichkeiten umfassen die Suche nach einem okkulten Primärtumor bei zervikaler Lymphknotenmetastasierung mit zuvor inkonklusiver Diagnostik, das lokale Staging, die Beurteilung des Therapieansprechens nach Radio(chemo)therapie sowie Nachsorgeuntersuchungen, wenn zwischen therapieinduzierten Gewebealterationen und einem Tumorrezidiv differenziert werden muss. Der Erfolg einer Bestrahlung in Hochpräzisionslagerungstechnik (Stereotaxie) bzw. einer intensitätsmodulierten Strahlentherapie scheint durch die Bestimmung des Tumorvolumens unter Einbeziehung der PET/CT verbessert zu werden. Die kombinierte PET/Magnetresonanztomografie (MRT) bietet in diesem Indikationsfeld durch höhere anatomische Detailgenauigkeit Vorteile beim Staging hinsichtlich der Beurteilung des lokalen und lokoregionären Befundes, ist der PET/CT bei der Detektion pulmonaler Metastasen/Zweittumoren jedoch deutlich unterlegen.Auf dem höchstmöglichen Evidenzniveau einer randomisierten Studie wurde gezeigt, dass man bei Patienten mit lokal fortgeschrittenem Kopf-Hals-Tumor bei unauffälliger FDG-PET/CT nach Radiochemotherapie operative Eingriffe ohne Überlebensnachteil vermeiden kann. Die FDG-PET/CT bei Kopf-Hals-Tumoren konnte dadurch vom Gemeinsamen Bundesausschuss (G-BA) als notwendige Leistung für die Versorgung gesetzlich Versicherter anerkannt werden.

Zusammenfassung Ziel Bei der Behandlung somatostatinrezeptor-exprimierender neuroendokriner Tumoren hat sich in den letzten Jahren die Peptidrezeptor-Radionuklidtherapie (PRRT) mit 177Lu-HA-DOTATATE als neue Möglichkeit entwickelt. Da außer Tumor und Metastasen auch die Nieren Somatostatinrezeptoren besitzen, die Aktivität in diesen akkumuliert, sind sie als Risikoorgane einzustufen und sollten dosimetrisch evaluiert werden. Die Bestimmung der Nierenaktivität aus planaren Aufnahmen ist durch Überlagerung der Nieren mit anderen Organen ungenau und führt zu ihrer Dosisüberschätzung. Ziel dieser Studie war es, den Beitrag der Nieren in den konjugierten Sichten ohne SPECT/CT in der individuellen Nierendosimetrie zu berücksichtigen. Material und Methoden Für die Bestimmung der Nierendosis wurde ein Algorithmus entwickelt, der mit EXCEL (Microsoft) umgesetzt wurde. Die Patientenmessdaten aus drei Modalitäten einer individuell kalibrierten Gammasonde, einem Ganzkörperszintigramm und drei SPECT-Akquisitionen zu verschiedenen Zeitpunkten wurden hierfür zusammengeführt. Die Methode wurde mit Daten von 85 Nieren von Patienten, die mit 177Lu-HA-DOTATATE behandelt worden waren, evaluiert. Die Nierenvolumina wurden mittels CT-Volumetrie gewonnen. Ergebnisse Der entwickelte Algorithmus kombiniert die Daten aus drei Modalitäten: Gamma-Sonde, SPECT und Ganzkörperszintigraphie. Der Quotient aus den Ereignissen der Nieren-VOI und der Anzahl der Ereignisse in der Nieren-ROI des koronaren Summationsbildes ist der Beitrag der Niere im Summationsbild und repräsentiert somit über die Kalibrierung aus der Ganzkörperszintigraphie die Aktivität in der Niere. Da die Abbildungseigenschaften in den SPECT-Akquisitionen zu den verschiedenen Zeiten konstant sind, folgt aus dem Verlauf der Zählraten in den jeweiligen Nieren-VOIs auch der Aktivitätsverlauf in den Nieren. Daraus kann über einen monoexponentiellen Fit der Aktivitätsausscheidung unter Berücksichtigung der Akkumulationskinetik die Nierendosis bestimmt werden. Der mittlere Anteil in der Niere, bezogen auf deren Projektion im Summationsbild, wurde mit 49 % (17 %–78 %) und 45 % (18 %–75 %) für die linke bzw. rechte Niere berechnet. Die sich daraus ergebenden Nierendosen lagen zwischen 0,13 und 0,77 Gy/GBq (Mittelwerte 0,36 Gy/GBq und 0,39 Gy/GBq für die linke und die rechte Niere). Schlussfolgerung Die vorgestellte Methode eignet sich, um mit Gammasonde und Szintigraphie/SPECT (auch ohne SPECT/CT), eine individuelle Nierendosimetrie durchzuführen.

Die kombinierte Positronen-Emissions-Tomographie und Computertomographie mit 18F‑Fluorodesoxyglucose (FDG-PET/CT) ist international anerkannter Standard zur Diagnostik und Therapiesteuerung bei Non-Hodgkin-Lymphomen (NHL). Auch bei dieser Tumorentitat etabliert sich in Deutschland zunehmend der Einsatz der PET. Klinisch relevante Indikationen der FDG-PET/CT in der Versorgung von Patienten mit indolenten und aggressiven NHL werden dargestellt. Relevante Leitlinien werden ausgewertet, typische Befundkonstellationen exemplarisch dargestellt sowie klinisch relevante Expertenempfehlungen und Erstattungssituationen in Deutschland diskutiert. Die FDG-PET/CT ist die genaueste nichtinvasive Methode zum Staging und Restaging bei NHL. Internationale Leitlinien enthalten fundierte Empfehlungen zum gezielten Einsatz der FDG-PET/CT bei NHL-Patienten. Indikation und Ausmas der Bestrahlung bei follikularen Lymphomen hangen wesentlich von PET/CT-Befunden ab. Bei aggressiven NHL lassen Zwischenergebnisse der OPTIMAL>60-Studie einen Uberlebensvorteil bei Nachbestrahlung ausschlieslich PET-positiver Bulk-Reste erwarten. Die Messung des Tumorgesamtvolumens mit der PET erlaubt eine uberragende Prognoseabschatzung. Die Verfugbarkeit der PET in der deutschen Versorgung ist noch durch die inhomogene Erstattungssituation bei gesetzlich Versicherten limitiert. Der gezielte Einsatz der FDG-PET/CT bei Patienten mit NHL ist internationaler Versorgungsstandard und kann bei Staging, Risikostratifizierung, Beurteilung des Therapieansprechens und Therapiesteuerung helfen. Parallel zur Entwicklung internationaler Empfehlungen und nationaler S3-Leitlinien sollten fruhere negative Beschlusse des Gemeinsamen Bundesausschusses zur PET bei Lymphomen angepasst werden.

Treatment of advanced melanoma with combined PD-1/CTLA-4 blockade commonly causes serious immune-mediated complications. Here, we identify a subset of patients predisposed to immune checkpoint blockade-related hepatitis who are distinguished by chronic expansion of effector memory CD4+ T cells (TEM cells). Pre-therapy CD4+ TEM cell expansion occurs primarily during autumn or winter in patients with metastatic disease and high cytomegalovirus (CMV)-specific serum antibody titres. These clinical features implicate metastasis-dependent, compartmentalised CMV reactivation as the cause of CD4+ TEM expansion. Pre-therapy CD4+ TEM expansion predicts hepatitis in CMV-seropositive patients, opening possibilities for avoidance or prevention. 3 of 4 patients with pre-treatment CD4+ TEM expansion who received αPD-1 monotherapy instead of αPD-1/αCTLA-4 therapy remained hepatitis-free. 4 of 4 patients with baseline CD4+ TEM expansion given prophylactic valganciclovir and αPD-1/αCTLA-4 therapy remained hepatitis-free. Our findings exemplify how pathogen exposure can shape clinical reactions after cancer therapy and how this insight leads to therapeutic innovations., Checkpoint blocking therapies are used to treat metastatic melanoma, but can have adverse immune-mediated effects, including liver pathology. Here the authors identify an expanded pool of CD4+ effector memory T cells resulting from prior CMV exposure as a risk factor for this adverse effect in these patients.

Purpose Fluorine-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) is the standard for staging aggressive non-Hodgkin lymphoma (NHL). Limited data from prospective studies is available to determine whether initial staging by FDG PET/CT provides treatment-relevant information of bone marrow (BM) involvement (BMI) and thus could spare BM biopsy (BMB). Methods Patients from PETAL (NCT00554164) and OPTIMAL>60 (NCT01478542) with aggressive B-cell NHL initially staged by FDG PET/CT and BMB were included in this pooled analysis. The reference standard to confirm BMI included a positive BMB and/or FDG PET/CT confirmed by targeted biopsy, complementary imaging (CT or magnetic resonance imaging), or concurrent disappearance of focal FDG-avid BM lesions with other lymphoma manifestations during immunochemotherapy. Results Among 930 patients, BMI was detected by BMB in 85 (prevalence 9%) and by FDG PET/CT in 185 (20%) cases, for a total of 221 cases (24%). All 185 PET-positive cases were true positive, and 709 of 745 PET-negative cases were true negative. For BMB and FDG PET/CT, sensitivity was 38% (95% confidence interval [CI]: 32–45%) and 84% (CI: 78–88%), specificity 100% (CI: 99–100%) and 100% (CI: 99–100%), positive predictive value 100% (CI: 96–100%) and 100% (CI: 98–100%), and negative predictive value 84% (CI: 81–86%) and 95% (CI: 93–97%), respectively. In all of the 36 PET-negative cases with confirmed BMI patients had other adverse factors according to IPI that precluded a change of standard treatment. Thus, the BMB would not have influenced the patient management. Conclusion In patients with aggressive B-cell NHL, routine BMB provides no critical staging information compared to FDG PET/CT and could therefore be omitted. Trial registration NCT00554164 and NCT01478542

Background and objective[99mTc]Tc-PSMA-based radioguided surgery (TPRS) represents a curative approach for localized relapse of prostate cancer. For its simplified regulatory permission, the radiation protection authorities require a 99mTc activity below the exemption limit of 10 MBq at the time of surgery. Our aim was to determine the optimal amount of radioactivity (OAR) to comply with that limit and to estimate the maximum number of TPRS procedures per year and surgeon without triggering the full monitoring obligations.MethodsIn this retrospective study, a dose rate meter was calibrated using measurements on phantoms and from recently injected (1 min p.i.) patients to determine the activity in the patient from measured dose rates. The effective half-life of [99mTc]Tc-PSMA-I&S in patients was determined from repeated dose rate measurements up to 27 h p.i. to estimate dose parameters of relevance for radiation protection. External exposures of the surgeons were measured with personal dosimeters calibrated in Hp(10). ResultsFrom the first 6 subsequent patients, an effective half-life of 4.15 h was observed. Assuming an operation time 24 h p.i., the OAR was 550 MBq. Operations lasting in average 2 h in a distance of 0.25 m to the patient imply a body dose for surgeons of 4,16 µSv per procedure. Based on these estimates, the surgeon’s Hp(10) is less than 1 mSv per year with up to 241 operations per year. The effective dose for surgeons during the procedure determined with an electronic dosimeter is 4±1 µSv. SummaryAll radiation protection regulations are met with adherence to OAR recommended here without triggering the full monitoring obligations from radiation protection regulations.

Simple Summary Approximately 75–80% of according to the classification of world health organization (WHO) grade II and III gliomas are characterized by a mutation of the isocitrate dehydrogenase (IDH) enzymes, which are very important in glioma cell metabolism. Patients with IDH mutated glioma have a significantly better prognosis than patients with IDH wildtype status, typically seen in glioblastoma WHO grade IV. Here we used a prospective O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) positron emission tomography guided single-voxel 1H-magnetic resonance spectroscopy approach to predict the IDH status before surgery. Finally, 34 patients were included in this neuroimaging study, of whom eight had additionally tissue analysis. Using a machine learning technique, we predicted IDH status with an accuracy of 88.2%, a sensitivity of 95.5% and a specificity of 75.0%. It was newly recognized, that two metabolites (myo-inositol and glycine) have a particularly important role in the determination of the IDH status. Abstract Isocitrate dehydrogenase (IDH)-1 mutation is an important prognostic factor and a potential therapeutic target in glioma. Immunohistological and molecular diagnosis of IDH mutation status is invasive. To avoid tumor biopsy, dedicated spectroscopic techniques have been proposed to detect D-2-hydroxyglutarate (2-HG), the main metabolite of IDH, directly in vivo. However, these methods are technically challenging and not broadly available. Therefore, we explored the use of machine learning for the non-invasive, inexpensive and fast diagnosis of IDH status in standard 1H-magnetic resonance spectroscopy (1H-MRS). To this end, 30 of 34 consecutive patients with known or suspected glioma WHO grade II-IV were subjected to metabolic positron emission tomography (PET) imaging with O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) for optimized voxel placement in 1H-MRS. Routine 1H-magnetic resonance (1H-MR) spectra of tumor and contralateral healthy brain regions were acquired on a 3 Tesla magnetic resonance (3T-MR) scanner, prior to surgical tumor resection and molecular analysis of IDH status. Since 2-HG spectral signals were too overlapped for reliable discrimination of IDH mutated (IDHmut) and IDH wild-type (IDHwt) glioma, we used a nested cross-validation approach, whereby we trained a linear support vector machine (SVM) on the complete spectral information of the 1H-MRS data to predict IDH status. Using this approach, we predicted IDH status with an accuracy of 88.2%, a sensitivity of 95.5% (95% CI, 77.2–99.9%) and a specificity of 75.0% (95% CI, 42.9–94.5%), respectively. The area under the curve (AUC) amounted to 0.83. Subsequent ex vivo 1H-nuclear magnetic resonance (1H-NMR) measurements performed on metabolite extracts of resected tumor material (eight specimens) revealed myo-inositol (M-ins) and glycine (Gly) to be the major discriminators of IDH status. We conclude that our approach allows a reliable, non-invasive, fast and cost-effective prediction of IDH status in a standard clinical setting.

Purpose: Retrospective study to investigate the impact of image derived biomarkers from [18F]FDG PET/CT prior to surgical resection in patients with initial diagnosis of oral squamous cell carcinoma (OSCC), namely SUVmax, SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary tumor to predict overall survival (OS). Materials and Methods: 127 subsequent patients with biopsy-proven OSCC were included who underwent [18F]FDG PET/CT before surgery. SUVmax, SUVmean, MTV and TLG of the primary tumor were measured. OS was estimated according to Kaplan-Meier and compared between median-splitted groups by the log-rank test. Prognostic parameters were analyzed by uni-/multivariate Cox-regression. Results: During follow-up 52 (41%) of the patients died. Median OS was longer for patients with lower MTV or lower TLG. SUVmax and SUVmean failed to be significant predictors for OS. Univariate Cox-regression identified MTV, TLG, lymph node status and UICC stage as prognostic factors. By multivariate Cox-regression MTV and TLG turned out to be independent prognostic factors for OS. Conclusions: The pre-therapeutic [18F]FDG PET/CT parameters MTV and TLG in the primary tumor are prognostic for OS of patients with an initial diagnosis of OSCC. TLG is the strongest independent prognostic factor for OS and outperforms established prognostic parameters in OSCC.

Background We assessed the diagnostic value of FDG PET/CT in a real-world cohort of patients with surgically managed infective endocarditis (IE). Methods We performed a retrospective analysis of all patients hospitalized in a tertiary IE referral medical center from January 2014 to October 2018 fulfilling the following criteria: ICD-10 code for IE and OPS code for both, heart surgery and FDG PET/CT. Results Final analysis included 29 patients, whereof 28 patients had surgically proven IE. FDG PET/CT scan was true-positive in 15 patients (sensitivity (SEN) 56%) and false-negative in 12 patients. Combination of Duke criteria (DC) with FDG PET/CT scan resulted in gain of SEN for all patients with confirmed IE (SEN of DC 79% vs SEN of combination DC and FDG PET/CT 89%), driven by a relevant gain in PVE patients only (SEN of DC 78% vs SEN of combination DC and FDG PET/CT 94%). Interestingly, higher prosthesis age was observed in patients with false-negative scans. Conclusions We found a SEN of 56% for FDG PET/CT in a real-world cohort of patients with surgically proven IE which was associated with a 16% gain of IE diagnosis in patients with PVE when combined with DC.

ZusammenfassungDie Positronen-Emissions-Tomografie (PET) mit 18F-Fluorodesoxyglukose (FDG) in Verbindung mit einer Computertomografie (CT) wird bei speziellen Indikationen in der Diagnostik bei Patienten mit Kopf-Hals-Tumoren eingesetzt. Die Einsatzmöglichkeiten umfassen die Suche nach einem okkulten Primärtumor bei zervikaler Lymphknotenmetastasierung mit zuvor inkonklusiver Diagnostik, das lokale Staging, die Beurteilung des Therapieansprechens nach Radio(chemo)therapie sowie Nachsorgeuntersuchungen, wenn zwischen therapieinduzierten Gewebealterationen und einem Tumorrezidiv differenziert werden muss. Der Erfolg einer Bestrahlung in Hochpräzisionslagerungstechnik (Stereotaxie) bzw. einer intensitätsmodulierten Strahlentherapie scheint durch die Bestimmung des Tumorvolumens unter Einbeziehung der PET/CT verbessert zu werden. Die kombinierte PET/Magnetresonanztomografie (MRT) bietet in diesem Indikationsfeld durch höhere anatomische Detailgenauigkeit Vorteile beim Staging hinsichtlich der Beurteilung des lokalen und lokoregionären Befundes, ist der PET/CT bei der Detektion pulmonaler Metastasen/Zweittumore jedoch deutlich unterlegen.Auf dem höchstmöglichen Evidenzniveau einer randomisierten Studie wurde gezeigt, dass man bei Patienten mit lokal fortgeschrittenem Kopf-Hals-Tumor bei unauffälliger FDG-PET/CT nach Radiochemotherapie operative Eingriffe ohne Überlebensnachteil vermeiden kann. Die FDG-PET/CT bei Kopf-Hals-Tumoren konnte dadurch vom Gemeinsamen Bundesausschuss (G-BA) als notwendige Leistung für die Versorgung gesetzlich Versicherter anerkannt werden.

Objectives We report on five patients with gadolinium-negative (non-enhancing magnetic resonance imaging–MRI) but 18F-fluoroethyl tyrosine positron-emission tomography (FET-PET) positive glioma (NEG) undergoing surgery under fluorescence-guidance with fluorescein sodium 10% (FL, Alkon, Germany) in combination with a dedicated light filter (YELLOW 560 nm, Carl Zeiss Meditec, Germany). Patients and method Since 2017, five patients (3 female, 2 male; mean age 45.4 years) underwent fluorescence-guided surgery for supratentorial, intracerebral lesions which showed no contrast-enhancement in the preoperative MRI but were, however, strongly suspicious for gliomas. Accordingly, all patients received a preoperative FET-PET scan and detailed histopathological workup was performed. After giving written informed consent, all patients received 5 mg/kg of FL at the induction of anesthesia. Surgery was conducted under white light and under the YELLOW 560 nm filter. We reviewed the surgical protocols, navigational storage and the image databases of our surgical microscopes for evidence of intraoperative fluorescence that corresponded to the FET-PET positive area. Results In all patients we found distinct accordances between the FET-PET positive areas and the fluorescing regions within the targeted lesions. Histopathological workup of the fluorescent tissue revealed anaplastic oligodendroglioma, IDH-mutant and 1p/19-codeleted (WHO grade III) (n = 2), anaplastic astrocytoma, IDH-mutant (WHO grade III) (n = 1), oligodendroglioma, IDH-mutant and 1p/19q-codeleted (WHO grade II) (n = 1) and pilocytic astrocytoma (WHO grade I) (n = 1). No adverse events were noted. Discussion and conclusion Despite the lack of gadolinium-enhancement in the preoperative MRI, all patients intravenously received FL to guide resection. Irrespective of the final grading, FL was extremely helpful in detecting the lesions and in identifying their border zones. In selected patients with NEG, but strong metabolic activity according to the FET-PET, FL may significantly increase the accuracy of surgery.

Brain and leptomeningeal metastasis (LMM) of non-small cell lung cancer is still associated with poor prognosis. Moreover, the current diagnostic standard for LMM often yields false negative results and the scientific progress in this field is still unsatisfying. We present a case of a 71-year old patient with an isolated LMM. While standard diagnostics could only diagnose a cancer of unknown primary, the use of [68Ga]-Pentixafor-PET/CT (CXCR4-PET/CT, a radiotracer targeting CXCR4) and a liquid biopsy of the cerebrospinal fluid revealed the primary NSCLC. The detection of L858R-EGFR, a common driver mutation in NSCLC, enabled us to treat the patient with Afatinib and monitor treatment using [68Ga]-Pentixafor PET/CT. To estimate the impact of CXCR4 signaling and its ligands in NSCLC brain metastasis we looked at their expression and correlation with EGFR mutations in a primary and brain metastasis data set and investigated the previously described binding of extracellular ubiquitin to CXCR4. In conclusion, we describe a novel approach to improve diagnostics towards LMM and underline the impact of the CXCL12/CXCR4 axis in brain metastasis in a subset of NSCLC patients. We cannot confirm a correlation of CXCR4 expression with EGFR mutations or the binding of extracellular ubiquitin as previously reported.

Introduction Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of aggressive lymphomas, which usually carry a poor prognosis. Malignant T-cells may overexpress programmed death ligand 1 (PD-L1), which signals via programmed death-1 (PD-1) receptor, and provides an inhibitory signal on normal T-cells further suppressing antitumor immunity. They can also express PD1 which may act as a tumor suppressor on malignant T-cells (Wartewig et al, Nature 2017). Thus, blocking the PD1/PDL1 synapse in PTCL may lead to tumor regression or progression. The NIVEAU trial is an ongoing international, multicenter, randomized, open label, phase 3 study testing Nivolumab (Nivo) in combination with (Rituximab), Gemcitabine, Oxaliplatin ((R-)GemOx) for patients with aggressive (B and T-cell) Non-Hodgkin Lymphoma in first relapse or progression not eligible for High-Dose Chemotherapy (NCT03366272). Here, we performed a preliminary analysis of the experimental arm (Nivo-GemOx) of the PTCL cohort to assess the safety and efficacy of this regimen in this population. Methods Key eligibility criteria include: first relapse or progression of peripheral T-cell lymphoma (PTCL), ineligibility for high dose therapy (defined as >65 years of age or older than 18 years if HCT-CI score > 2), only one prior chemotherapy regimen including an anthracycline. Pts were planned to receive 8 cycles Nivolumab (3mg/kg) plus Gemcitabine and Oxaliplatin in 2-wk intervals followed by additional 18 Nivolumab (3mg/kg) biweekly as consolidation or until progression. Response was evaluated after 4 and 8 cycles of GemOx. Each progression/relapse of PTCL had to be reported as a SAE. Results The analysis (data cut-off 13-July-2020) included 12 PTCL pts enrolled in the experimental arm (Table 1): 4 (33%) PTCL NOS, 3 (25%) AITL, 1 (8%) PTCL TFH-type, 2 (17%) ALCL ALK-, 1 (8%) EATL, and 1 (8%) MEITL. Median age was 69.5 years (range, 53-80), 7 (58%) patients were male, 2 (17%) had received a prior autologous stem cell transplantation, and 5 (42%) were refractory to first line therapy. At enrollment, performance status was 0-1 in 9 (75%) pts and 2 in 3 (25%) pts, 11 (92%) had Ann Arbor stage III-IV, 2 (17%) had B-symptoms, 7 (58%) had more than one extra-nodal site and 4 (33%) had elevated LDH. PD1 and PD-L1 were expressed by the tumor cells in 6/10 (60%) and 2/11 (18%) patients, respectively (Table 1). Pts have received a median of 6 (1-8) cycles of GemOx and 7 (1-26) infusions of nivolumab. Treatment was prematurely discontinued in 9 pts (7 during induction and 2 during consolidation), due to lymphoma progression (n=6), toxicity (n=2) and an intercurrent disease (n=1). There were 26 SAE in 10 patients, including 8 progressive diseases. Nine (75%) patients achieved an objective response (4 CR and 5 PR). Two patients (pt 9: MEITL PD1-negative; and pt 12: PTCL-NOS strongly PD1-positive) experienced primary progression upon Nivo-GemOx (Table 1). Median PFS2 (time from randomisation to 2nd rel/prog/death) was 6.9 months (95% CI: 1.9-11.9) vs 7.7 months (95% CI: 7.2-8.2) for PFS1 (time from diagnosis to 1st rel/prog). PFS2 was superior to PFS1 in 2 out of 8 patients (25%), and not informative in 4 pts: 3 who are still on therapy (ongoing PFS) and 1 who died prematurely due to infection (pt 8) (Figure 1). Median OS was 24.8 months (95% CI: 0-49.8). After a median follow-up of 22.8 months, 7 patients have died (5 from lymphoma and 2 from infection (1 COVID-19 infection and 1 yeast septicemia)), and 5 remain alive. Conclusions Nivolumab in combination with GemOx was well tolerated in PTCL. The response rate and PFS2 (compared to PFS1) are encouraging. Marked differences in PFS2 might reflect heterogeneity of biology and susceptibility to PD-1 blockade in combination with GemOx chemotherapy. Furthermore, the translational research program of the study might help to identify markers which are predictive for efficacy of PD-1 blockade in PTCL. This phase 3 trial is actively enrolling patients and an update of these results will be presented at the meeting. Disclosure: ISR financially supported by Bristol Myers Squibb. Disclosures Houot: Celgene: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Roche: Honoraria; Kite: Honoraria; Gilead: Honoraria; MSD: Honoraria; Bristol-Myers Squibb: Honoraria. Poeschel:Roche: Other: Travel, Accommodations, Expenses; Amgen: Other: Travel, Accommodations, Expenses; Abbvie: Other: Travel, Accommodations, Expenses. André:Abbvie: Consultancy; Celgene: Other, Research Funding; Roche: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Takeda: Consultancy; Bristol-Myers-Squibb: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Karyopharm: Consultancy; CHU UCL Namur, site Godinne, Yvoir, Belgium: Current Employment; Seattle Genetics: Consultancy; Gilead: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Johnson & Johnson: Research Funding; Novartis: Consultancy, Research Funding; Amgen: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding. Dreyling:Beigene: Consultancy; Bayer: Consultancy, Speakers Bureau; Astra Zeneca: Consultancy; Abbvie: Research Funding; Roche: Consultancy, Research Funding, Speakers Bureau; Gilead: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy; Celgene: Consultancy, Research Funding, Speakers Bureau. Tilly:BMS: Honoraria. Casasnovas:Gilead: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Roche: Consultancy, Honoraria, Other: travel, accomodations, expenses, Research Funding; Abbvie: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Amgen: Consultancy, Honoraria; MSD: Consultancy, Honoraria. Le Gouill:Roche Genentech, Janssen-Cilag and Abbvie, Celgene, Jazz pharmaceutical, Gilead-kite, Loxo, Daiichi-Sankyo and Servier: Honoraria; Loxo Oncology at Lilly: Consultancy. Cartron:Celgene: Consultancy, Honoraria; Gilead: Honoraria; Abbvie: Honoraria; Jansen: Honoraria; Sanofi: Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria. Kerkhoff:BMS: Honoraria. De Leval:Lausanne University Hospital & Lausanne University Institute of Pathology: Current Employment; Lunaphore Technologies SA: Consultancy, Honoraria; Abbvie: Honoraria; Roche Diagnostics: Honoraria. Gaulard:takeda: Honoraria, Research Funding; innate pharma: Research Funding. Held:Roche: Consultancy, Other: travel grants, Research Funding; MSD: Consultancy; Acrotech, Spectrum: Research Funding; Amgen: Research Funding; BMS: Consultancy, Other: Travel Grants, Research Funding. OffLabel Disclosure: Nivolumab in peripheral T-cell lymphoma

Since the mid-1990s, 18F-fluorodeoxglucose (FDG)-positron emission tomography (PET) in combination with computed tomography has come to play a prominent role in the management of malignant lymphomas. One of the first PET applications in oncology was the detection of lymphoma manifestations at staging, where it has shown high sensitivity. Nowadays, this imaging modality is also used during treatment to evaluate the individual chemosensitivity and adapt further therapy accordingly. If the end-of-treatment PET is negative, irradiation in advanced-stage Hodgkin lymphoma patients can be safely omitted after highly effective chemotherapy. Thus far, lymphoma response assessment has mainly been performed using visual criteria, such as the Deauville five-point scale, which became the international standard in 2014. However, novel measures such as metabolic tumor volume or total lesion glycolysis have recently been recognized by several working groups and may further increase the diagnostic and prognostic value of FDG-PET in the future.

Positron emission tomography (PET) withDie Positronen-Emissions-Tomografie (PET) mit

C-X-C chemokine receptor 4 (CXCR4) is a transmembrane chemokine receptor involved in growth, survival, and dissemination of cancer, including aggressive B-cell lymphoma. MRI is the standard imaging technology for central nervous system (CNS) involvement of B-cell lymphoma and provides high sensitivity but moderate specificity. Therefore, novel molecular and functional imaging strategies are urgently required. Methods: In this proof-of-concept study, 11 patients with lymphoma of the CNS (8 primary and 3 secondary involvement) were imaged with the CXCR4-directed PET tracer 68Ga-pentixafor. To evaluate the predictive value of this imaging modality, treatment response, as determined by MRI, was correlated with quantification of CXCR4 expression by 68Ga-pentixafor PET in vivo before initiation of treatment in 7 of 11 patients. Results:68Ga-pentixafor PET showed excellent contrast with the surrounding brain parenchyma in all patients with active disease. Furthermore, initial CXCR4 uptake determined by PET correlated with subsequent treatment response as assessed by MRI. Conclusion:68Ga-pentixafor PET represents a novel diagnostic tool for CNS lymphoma with potential implications for theranostic approaches as well as response and risk assessment.

Peptide receptor radionuclide therapy (PRRT) with An algorithm was developed to determine the kidney dose using an EXCEL (Microsoft) based program. Dosimetric data were drawn and merged from three modalities: an individually calibrated gamma probe, a whole-body scintigraphy (WBS) and SPECT-acquisitions. The method was evaluated for 85 kidneys. Kidney masses were obtained via CT volumetry. The developed algorithm combines data from the three modalities. The ratio of the events within a kidney-VOI and the events from the summed coronary SPECT views (kidney ROI) represents the contribution of the kidney to the whole-body kidney ROI. This fraction was calculated to 49 % (17 % - 78 %) and 45 % (18 % - 75 %) for the left and the right kidney, respectively. Quantification of activity was deduced from equalizing the WBS count with the concurrent gamma probe measurement. Monoexponential curves were fitted to the obtained kidney activities, with resulting doses of 0,13 to 0,77 Gy/GBq (average 0,36 and 0,39 Gy/GBq for the left and the right kidney). The presented method is suitable to perform kidney dosimetry by using a gamma probe and a gamma camera, without using SPECT/CT.ZIEL: Bei der Behandlung somatostatinrezeptor-exprimierender neuroendokriner Tumoren hat sich in den letzten Jahren die Peptidrezeptor-Radionuklidtherapie (PRRT) mit Für die Bestimmung der Nierendosis wurde ein Algorithmus entwickelt, der mit EXCEL (Microsoft) umgesetzt wurde. Die Patientenmessdaten aus drei Modalitäten einer individuell kalibrierten Gammasonde, einem Ganzkörperszintigramm und drei SPECT-Akquisitionen zu verschiedenen Zeitpunkten wurden hierfür zusammengeführt. Die Methode wurde mit Daten von 85 Nieren von Patienten, die mit Der entwickelte Algorithmus kombiniert die Daten aus drei Modalitäten: Gamma-Sonde, SPECT und Ganzkörperszintigraphie. Der Quotient aus den Ereignissen der Nieren-VOI und der Anzahl der Ereignisse in der Nieren-ROI des koronaren Summationsbildes ist der Beitrag der Niere im Summationsbild und repräsentiert somit über die Kalibrierung aus der Ganzkörperszintigraphie die Aktivität in der Niere. Da die Abbildungseigenschaften in den SPECT-Akquisitionen zu den verschiedenen Zeiten konstant sind, folgt aus dem Verlauf der Zählraten in den jeweiligen Nieren-VOIs auch der Aktivitätsverlauf in den Nieren. Daraus kann über einen monoexponentiellen Fit der Aktivitätsausscheidung unter Berücksichtigung der Akkumulationskinetik die Nierendosis bestimmt werden. Der mittlere Anteil in der Niere, bezogen auf deren Projektion im Summationsbild, wurde mit 49 % (17 %–78 %) und 45 % (18 %–75 %) für die linke bzw. rechte Niere berechnet. Die sich daraus ergebenden Nierendosen lagen zwischen 0,13 und 0,77 Gy/GBq (Mittelwerte 0,36 Gy/GBq und 0,39 Gy/GBq für die linke und die rechte Niere). Die vorgestellte Methode eignet sich, um mit Gammasonde und Szintigraphie/SPECT (auch ohne SPECT/CT), eine individuelle Nierendosimetrie durchzuführen.

BACKGROUND: According to the Lugano classification (Cheson et al., JCO 2014, 32: 3059-3067) fludeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) is the standard for evaluation and staging of aggressive non-Hodgkin Lymphoma (NHL). It is a matter of debate whether FDG PET/CT is sufficient to determine bone marrow (BM) involvement. We performed a pooled analysis of data from the PETAL (EudraCT 2006-001641-33) and OPTIMAL>60 trials (EudraCT 2010-019587-36) as prospective, open-label, randomized, multicenter Phase-III trials to determine whether initial staging with FDG PET/CT would allow non-invasive diagnosis of BM involvement and thus could avoid established but potentially painful and unpleasant BM biopsy (BMB). PATIENTS AND METHODS: Patients treated within the trials were included if both FDG PET/CT and BMB were performed during initial staging. Only patients with a biopsy-proven, centrally confirmed diagnosis of diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma or follicular lymphoma grade 3b were included. FDG PET/CT images and BM findings were blinded for central review by board certified PET/CT readers. Discordant findings were documented and resolved after unblinding by interdisciplinary discussion using findings of complementary imaging and/or subsequent PET examinations. Based on literature (Berthet et al., J Nucl Med 2013), a newly defined gold standard was used to confirm BM involvement. It includes a positive BMB or a positive FDG PET confirmed by targeted biopsy, complementary CT imaging or targeted MRI, or concurrent disappearance of focal FDG-avid BM lesions with other lymphoma manifestations during immunochemotherapy. RESULTS: Out of 1,976 patients a total of 930 patients met the inclusion criteria. BMB confirmed BM involvement in 85 of 930 patients (9%). According to FDG PET/CT, BM was involved in 185 out of 930 patients (20%) with 36 discordances (4%) between negative initial FDG PET/CT and positive BMB ("false negatives" with respect to previous reference standard, PRS). Discordances between positive initial FDG PET/CT and negative BMB ("false positives" by PRS) occurred in 136 patients (15%). If only BMB is used as in the PRS, the negative predictive value (NPV) of FDG PET/CT was 709/745=95% (95% confidence interval [95%CI]: 93%-97%) with a sensitivity (Sens) of 58% (95%CI: 46%-68%) and a specificity (Spec) of 84% (95%CI: 81%-86%). After discussion of these cases, 185 out of 221 cases with BM involvement were identified as true positive, resulting in a Sens of 84% for FDG PET/CT (95%CI: 78%-88%). By means of FDG PET/CT 745 cases were negative of which 709 were confirmed as true negatives, resulting in an NPV of 95% (95%CI: 93%-97%). All 185 cases with positive FDG PET/CT were evaluated as true positive for BM involvement in the unblinded synopsis of all findings, resulting in a positive predictive value (PPV) of 100% (95%CI: 98%-100%). All 709 negative FDG PET/CT findings were finally confirmed as such, so Spec was 100% (95%CI: 99%-100%). Thus, the prevalence in our total cohort analyzed was 24%, since 221 out of 930 cases had confirmed BM involvement. Diagnostic performance parameters for BMB as compared to the newly defined gold standard were Sens 85/221=38% (95%CI: 32%-45%), Spec 709/709=100% (95%CI: 99%-100%), PPV 85/85=100% (95%CI: 96%-100%) and NPV 709/845=84% (95%CI: 81%-86%), respectively. Differences between the PRS in the diagnosis of BM involvement by only BMB and the newly defined gold standard result mainly from false negative BMB due to sampling errors, which are detected by FDG PET/CT. DISCUSSION: In the majority of patients with aggressive B-cell lymphoma, routine BMB does not give any additional relevant diagnostic or prognostic information over FDG PET/CT alone and could therefore be omitted. BMB should only be performed if results would have direct therapeutic impact e.g. in patients with limited stage disease and lack of further risk factors according to the international prognostic index (IPI). Disclosures Held: MSD: Consultancy; Bristol-Myers Squibb: Consultancy, Other: Travel support, Research Funding; Roche: Consultancy, Other: Travel support, Research Funding; Amgen: Research Funding; Acrotech: Research Funding. Stilgenbauer:Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Hoffmann La-Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau. Duehrsen:Amgen: Consultancy; University Hospital Essen, Germany: Employment; Takeda: Consultancy; Novartis: Consultancy; Gilead: Honoraria; Janssen: Honoraria; Gilead: Consultancy; AbbVie: Consultancy; Celgene: Research Funding; CPT: Consultancy; Takeda: Honoraria; Novartis: Honoraria; Amgen: Research Funding; Roche: Research Funding; AbbVie: Honoraria; Amgen: Honoraria; CPT: Honoraria. Hüttmann:University Hospital Essen: Employment; Takeda: Honoraria; Gilead: Honoraria. Poeschel:Amgen: Other: Travel, accommodations, expenses; Abbvie: Other: Travel, accomodations, expenses; Roche: Other: Travel, accomodations, expenses; Hexal: Speakers Bureau.

Implementation of the guidelines on the Competency-based Learning Objective Catalogue for Undergraduate Medical Education for a Nuclear Medicine curriculum on behalf of the committee on professional training and continuing education of the German Association of Nuclear Medicine (DGN) METHODS:: In 7 domains 100 learning objectives (LOs) were subject to a prioritization in 3 categories (A, B and C) by means of a questionnaire as part of a Delphi method, in collaboration with all members of the DGN holding a "venia legendi" as experts. Category A defined the essential LOs for each medical practitioner. The prioritization was made by ranking the frequency of the A-classifications. In the 2nd step of the Delphi method, a list of LOs with the ranking positions 1-5 in each domain was presented to the first round's experts as a core curriculum, asking either for acceptance or modifications.The results of the 1st step of the Delphi method deliver a return rate of 29% of the questionnaires (55 out of 184). The 2nd round shows a return rate of 30.9% (57 out of 184) and full approval of the proposed LOs in all LO domains by in median 72 % of the experts consulted (61%-81%). The present final version contains 37 competency-based LOs in the LO domains "legal basis and radiation protection", "basic science", indications and contra-indications for "PET/CT", "scintigraphy and SPECT", "patient preparation", "image interpretation" as well as "therapy".The Competency-based Learning Objective Catalogue for Nuclear Medicine describes the knowledge and competencies, every physician should have at the end of his medical studies. The LO catalogue is a living document, which needs to be adapted continuously to the progress of the medical and technological development.

ZusammenfassungUmsetzung der Vorgaben des Nationalen Kompetenzbasierten Lernzielkatalogs Medizin (NKLM, 2015) für ein Curriculum Nuklearmedizin im Auftrag des Ausschusses Fort- und Weiterbildung der Deutschen Gesellschaft für Nuklearmedizin (DGN). Methoden 100 Lernziele (LZ) in 7 Domänen wurden in einem Delphi-Verfahren unter Einbeziehung aller habilitierten Mitglieder der DGN als Experten durch einen Fragebogen einer Priorisierung in 3 Kategorien (A, B und C) unterzogen. Kategorie A definierte für die jeden Arzt unerlässlichen LZ. Die Priorisierung erfolgte durch Rangbildung nach dem Anteil der A-Klassifikationen. Eine LZ-Liste mit den Rangplätzen 1 – 5 in jeder Domäne wurde in der 2. Stufe des Delphi-Verfahrens den Experten der ersten Runde als Kern-Curriculum mit der Frage nach Akzeptanz bzw. Modifikationen vorgelegt. Ergebnisse Die Ergebnisse der 1. Stufe des Delphi-Verfahrens zeigte einen Rücklauf der Fragebögen von 29 % (55 von 184). Die 2. Runde erbrachte einen Rücklauf von 30,9 % (57 von 184) und eine uneingeschränkte Akzeptanz der vorgeschlagenen LZ in allen LZ-Domänen bei im Median 72 % der befragten Experten (61 %–81 %). Die vorliegende Endfassung enthält 37 kompetenzbasierte LZ in den LZ-Domänen „Gesetzliche Grundlagen und Strahlenschutz“, „naturwissenschaftliche Grundlagen“, Indikationen und Kontraindikationen zu „PET/CT“, „Szintigraphie und SPECT“, „Patientenvorbereitung“, „Befundanalyse und -interpretation“ sowie „Therapie“. Ausblick Der kompetenzbasierte LZ-Katalog Nuklearmedizin beschreibt die Kenntnisse und Kompetenzen, über die jeder Arzt am Ende seines Studiums verfügen sollte. Der LZ-Katalog ist ein lebendes Dokument, das fortlaufend an den Fortschritt der medizinischen und technologischen Entwicklung angepasst werden muss.

F-18-Natriumfluorid ist ein osteotropes Radiopharmakon fur die szintigrafische Darstellung des Knochenstoffwechsels. Seine FDA-Zulassung erhielt das Radiopharmakon bereits im Jahr 1972. Die Entwicklung von Tc-99m-markierten osteotropen Substanzen sowie deren bessere Verfugbarkeit drangte Natriumfluorid zunehmend in den Hintergrund. Der Molybdanengpass ist jedoch bereits einmal zu einem Problem fur die konventionelle Skelettszintigrafie geworden und wird dies wohl in Zukunft wieder. Durch die Entwicklung von modernen Hybridgeraten (PET/CT, PET/MR) erlaubt die Skelettdiagnostik mit F-18-Natriumfluorid des Weiteren eine viel sensitivere und spezifische Diagnostik als die spatstatische konventionelle Skelettszintigrafie und bringt daher diesen Tracer erneut in den Vordergrund. Wir zeigen hier Indikationen, Durchfuhrung, Datenakquisition und -auswertung sowie Befundungskonzepte der Untersuchung. Ein Vergleich von Natriumfluorid mit der konventionellen Skelettszintigrafie wird ebenfalls bei den verschiedenen Indikationen vorgenommen.