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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.

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.

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.

Background To evaluate predictive clinico-pathological characteristics on outcome in head and neck melanoma (HNM) in a population-based study with particular emphasis on the prognostic effect of sentinel lymph node biopsy (SLNB), Charlson comorbidity index (CCI) and distinct tumor localisations. Methods Here we primarily describe a retrospective multicenter population-based cohort study with 402 patients having undergone resection with curative intent of HNM between 2010 and 2017. SLNB was used in the diagnosis of 79 HNM patients. Outcome was analyzed, focusing on SLNB, CCI as well as tumor localisation. Overall survival (OAS) und recurrence free survival (RFS) was examined by uni- and multivariate analysis. Results Histopathologically verified lymph node metastasis according to SLNB was associated with impaired RFS in HNM patients (p = 0.004). Especially in higher tumor stages, the sole implementation of SLNB improved survival significantly in the present cohort (p = 0.042). With most of the HNM being located in the face, melanoma of the scalp and neck could be linked to deteriorated patient’s outcome in uni- as well as multivariate analysis (p = 0.021, p = 0.004). Conclusions SLNB is a useful tool in predicting development of distant metastasis after HNM resection with curative intent. Especially in higher tumor stages, performing a SLNB ameliorated survival of HNM patients. Additionally, CCI as well as a distinct tumor localisations in HNM were identified as important risk factors in our population-based cohort study.

AIM: To evaluate the effectiveness of complementary imaging of high-resolution ultrasound including CEUS with PET/CT for tissue characterization and tumor detection. MATERIAL AND METHODS: 100 patients were examined with PET/CT and US/CEUS between January 2018 until February 2020. All patients underwent PET/CT followed by selective US/CEUS within 4 weeks. Comparison regarding concordant or diverging findings in PET/CT and US. Analysis of the differences concerning the lesions number of found by PET/CT and US/CEUS or the possibility of a secured diagnosis following ultrasound causing therapeutic changes. RESULTS: Diverging findings regarding the number of liver lesions in PET/CT and CEUS were found in 35 out of 64 patients (54%). Regarding renal lesions, a more definite diagnosis following ultrasound, causing a change of therapeutic approach, was achieved in 89%. Concordant results in PET/CT and US were found in 83% of patients with splenic and nodal findings. In 78% of patients with increased musculoskeletal or soft tissue tracer uptake, US was able to make a secured diagnosis with therapeutic changes. CONCLUSION: The present results indicate a strong benefit of complementary imaging of PET/CT and selective, high-resolution ultrasound especially in patients with liver, renal and musculoskeletal or soft tissue findings.

Background Risks for living-liver donors are lower in case of a left liver donation, however, due to lower graft volume, the risk for small-for-size situations in the recipients increases. This study aims to prevent small-for-size situations in recipients using an auxiliary two-staged partial resection liver transplantation (LTX) of living-donated left liver lobes. Case presentation Two patients received a two-stage auxiliary LTX using living-donated left liver lobes after left lateral liver resection. The native extended right liver was removed in a second operation after sufficient hypertrophy of the left liver graft had occurred. Neither donor developed postoperative complications. In both recipients, the graft volume increased by an average of 105% (329 ml to 641 ml), from a graft-to-body-weight ratio of 0.54 to 1.08 within 11 days after LTX, so that the remnant native right liver could be removed. No recipient developed small-for-size syndrome; graft function and overall condition is good in both recipients after a follow-up time of 25 months. Conclusions Auxiliary two-staged partial resection LTX using living-donor left lobes is technically feasible and can prevent small-for-size situation. This new technique can expand the potential living-donor pool and contributes to increase donor safety.

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.

Purpose Treatment of patients with laryngeal squamous cell carcinoma with radiotherapy or chemoradiation is an established alternative to laryngeal surgery in many cases, but particularly for advanced tumors without cartilage invasion. Imaging modalities face the challenge of distinguishing between posttherapeutic changes and residual disease in the complex anatomic subsite of the larynx. Guidelines concerning restaging of head and neck squamous cell carcinomas (HNSCC) are presented by the National Comprehensive Cancer Network (NCCN) and other national guidelines, but clearly defined recommendations for routine restaging particularly for laryngeal cancer are lacking. Methods A systematic search was carried out in PubMed to identify studies evaluating routine restaging methods after primary non-surgical treatment of laryngeal squamous cell carcinoma from 2009 to 2020. Results Only three studies were deemed eligible, as they included at least ≥50% patients with laryngeal squamous cell carcinoma and evaluated imaging modalities to detect residual cancer. The small number of studies in our review suggest restaging with fluoro-deoxy-glucose positron-emission tomography/computed tomography (FDG PET/CT) 3 months after initial treatment, followed by direct laryngoscopy with biopsy of the lesions identified by FDG PET/CT. Conclusion Studies evaluating restaging methods after organ-preserving non-surgical treatment of laryngeal carcinoma are limited. As radiotherapy (RT), chemoradiotherapy (CRT), systemic therapy followed by RT and radioimmunotherapy are established alternatives to surgical treatment, particularly in advanced laryngeal cancers, further studies are needed to assess and compare different imaging modalities (e.g. PET/CT, MRI, CT, ultrasound) and clinical diagnostic tools (e.g., video laryngoscopy, direct laryngoscopy) to offer patients safe and efficient restaging strategies. PET or PET/CT 3 months after initial treatment followed by direct laryngoscopy with biopsy of the identified lesions has the potential to reduce the number of unnecessary laryngoscopies.

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.

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

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.

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.

Experiencing real weightlessness in space is a dream for many of us who are interested in space research. Although space traveling fascinates us, it can cause both short-term and long-term health problems. Microgravity is the most important influence on the human organism in space. The human body undergoes dramatic changes during a long-term spaceflight. In this review, we will mainly focus on changes in calcium, sodium and bone metabolism of space travelers. Moreover, we report on the current knowledge on the mechanisms of bone loss in space, available models to simulate the effects of microgravity on bone on Earth as well as the combined effects of microgravity and cosmic radiation on bone. The available countermeasures applied in space will also be evaluated.

Die Positronenemissionstomografie (PET) mit 18 F-Fluorodesoxyglukose (FDG) in Kombination mit einer Computertomografie (CT) ist eine etablierte und nutzliche Untersuchungsmethode bei der Diagnostik inflammatorischer/infektioser Erkrankungen, bei der Beurteilung neurologischer und kardiologischer Pathologien und v. a. im Rahmen von Staging und Nachsorge zahlreicher maligner Neoplasien. Nach intravenoser Applikation der FDG stellen sich durch Tracerakkumulation oder –exkretion Gehirn, Myokard, Gastrointestinaltrakt, Leber, Nieren und Harntrakt in der PET intensiv dar. In diesem Artikel wird die physiologische Aufnahme der 18 F-Fluorodesoxyglukose in der positronenemissionstomografischen Ganzkorperuntersuchung beschrieben. Daruber hinaus werden in einer topografischen Gliederung zahlreiche physiologische Normvarianten aufgelistet und diskutiert. Eine akkurate Interpretation der PET-Bilder setzt eine umfassende Kenntnis dieser normalen physiologischen Distribution des radioaktiven Tracers und der haufig zu beobachtenden Normvarianten oder aktivierungs- bzw. medikamenteninduzierten FDG-Speicherungen voraus, die mit malignen Lasionen verwechselt werden konnen. Auf diese Weise konnen Fehlinterpretationen vermieden und die exzellenten diagnostischen Moglichkeiten der FDG-PET/CT voll ausgeschopft werden.

Die PET-CT reprasentiert eine hybridisierte Bildgebungsmodalitat, in der die exzellent hohe Auflosung der Computertomografie mit der funktionellen Information aus der PET-Untersuchung in eine einzige Bildgebung fusioniert wird. Die Daten aus der Computertomografie werden dabei zum einen verwendet, um die funktionellen PET-Informationen anatomisch zu korrelieren, zum anderen um eine Schwachungskorrektur der PET-Daten bez. einer optimierten PET-Darstellung zu erreichen. Insgesamt erlaubt die simultane Bildgebung der PET-CT eine verbesserte diagnostische Genauigkeit, v. a. fur onkologische Krankheitsbilder. Besonders bei der Computertomografie sind multiple Artefakte in der Bildgebung bekannt, die bei ihrer Kenntnis und Verstandnis der Genese der Artefakte in der radiologischen Diagnostik in der klinischen Routine ein nur geringes Problem darstellen. In der Kombination mit der PET konnen diese Artefakte jedoch konsekutive Artefakte in der PET-Darstellung bei der hybridisierten PET-CT verursachen. Im folgenden Artikel werden kurz die wichtigsten Artefakte bei der radiologischen CT-Bildgebung erlautert und diskutiert. Dabei wird v. a. auf Atemartefakte sowie Aufhartungsartefakte durch rontgendichte Strukturen eingegangen. Darauf basierend wird dann im Anschluss der Einfluss dieser CT-Artefakte auf die kombinierte hybridisierte PET-CT-Bildgebung erlautert und Losungsvorschlage zur Reduktion oder Kompensation dieser Artefakte gegeben.

Real and simulated microgravity induce a variety of changes in human cells. Most importantly, changes in the cytoskeleton have been noted, and studies on microtubules have shown that they are gravisensitive. This study focuses on the effects of short-term real microgravity on gene expression, protein content, and cytoskeletal structure of human chondrocytes. We cultivated human chondrocytes, took them along a parabolic flight during the 24th Deutsches Zentrum für Luft- und Raumfahrt Parabolic (DLR) Flight Campaign, and fixed them after the 1st and the 31st parabola. Immunofluorescence microscopy revealed no changes after the 1st parabola, but disruptions of β-tubulin, vimentin, and cytokeratin networks after the 31st parabola. No F-actin stress fibers were detected even after 31 parabolas. Furthermore, mRNA and protein quantifications after the 31st parabola showed a clear up-regulation of cytoskeletal genes and proteins. The mRNAs were significantly up-regulated as follows: TUBB, 2-fold; VIM, 1.3-fold; KRT8, 1.8-fold; ACTB, 1.9-fold; ICAM1, 4.8-fold; OPN, 7-fold; ITGA10, 1.5-fold; ITGB1, 1.2-fold; TGFB1, 1.5-fold; CAV1, 2.6-fold; SOX9, 1.7-fold; BMP-2, 5.3-fold. However, SOX5 (-25%) and SOX6 (-28%) gene expression was decreased. Contrary, no significant changes in gene expression levels were observed during vibration and hypergravity experiments. These data suggest that short-term microgravity affects the gene expression of distinct proteins. In contrast to poorly differentiated follicular thyroid cancer cells or human endothelial cells, chondrocytes only exert moderate cytoskeletal alterations. The up-regulation of BMP-2, TGF-β1, and SOX9 in chondrocytes may play a key role in preventing cytoskeletal alterations.-Aleshcheva, G., Wehland, M., Sahana, J., Bauer, J., Corydon, T. J., Hemmersbach, R., Frett, T., Egli, M., Infanger, M., Grosse, J., Grimm, D. Moderate alterations of the cytoskeleton in human chondrocytes after short-term microgravity produced by parabolic flight maneuvers could be prevented by up-regulation of BMP-2 and SOX-9.

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.

We report the case of a 40-year-old woman with a progressive right-sided hemiparesis. Standard MRI revealed a contrast-enhancing brain lesion within the left basal ganglia. Ffluoroethyl-L-tyrosine (F-FET) PET showed a distinct tracer uptake (lesion-to-brain ratio [LBR]: LBRmax = 2.03, LBRmean = 1.68) with a significant larger metabolic lesion volume than contrast-enhancement in MRI, indicating cerebral glioma. Surprisingly, histopathologic analysis demonstrated central nervous system toxoplasmosis with pronounced inflammatory reaction (reactive astrogliosis, microglia activation, macrophage, and T-lymphocyte infiltration), which was associated with strong LAT1/LAT2/CD98 expression. In conclusion, inflammatory brain lesions, such as cerebral toxoplasmosis, represent a potential pitfall of F-FET PET mimicking a brain tumor.

Differentiated thyroid cancer (DTC) is a rare malignant disease, although its incidence has increased over the last few decades. It derives from follicular thyroid cells. Generally speaking, the prognosis is excellent. If treatment according to the current guidelines is given, cases of recurrence or persistence are rare. DTC requires special expertise by the treating physician. In recent years, new therapeutic options for these patients have become available. For this article we performed a systematic literature review with special focus on the guidelines of the American Thyroid Association, the European Association of Nuclear Medicine, and the German Society of Nuclear Medicine. For DTC, surgery and radioiodine therapy followed by levothyroxine substitution remain the established therapeutic procedures. Even metastasized tumors can be cured this way. However, in rare cases of radioiodine-refractory tumors, additional options are to be discussed. These include strict suppression of thyroid-stimulating hormone (also known as thyrotropin, TSH) and external local radiotherapy. Systemic cytostatic chemotherapy does not play a significant role. Recently, multikinase or tyrosine kinase inhibitors have been approved for the treatment of radioiodine-refractory DTC. Although a benefit for overall survival has not been shown yet, these new drugs can slow down tumor progression. However, they are frequently associated with severe side effects and should be reserved for patients with threatening symptoms only.

Several years ago, we detected the formation of multicellular spheroids in experiments with human thyroid cancer cells cultured on the Random Positioning Machine (RPM), a ground-based model to simulate microgravity by continuously changing the orientation of samples. Since then, we have studied cellular mechanisms triggering the cells to leave a monolayer and aggregate to spheroids. Our work focused on spheroid-related changes in gene expression patterns, in protein concentrations, and in factors secreted to the culture supernatant during the period when growth is altered. We detected that factors inducing angiogenesis, the composition of integrins, the density of the cell monolayer exposed to microgravity, the enhanced production of caveolin-1, and the nuclear factor kappa B p65 could play a role during spheroid formation in thyroid cancer cells. In this study, we performed a deep proteome analysis on FTC-133 thyroid cancer cells cultured under conditions designed to encourage or discourage spheroid formation. The experiments revealed more than 5900 proteins. Their evaluation confirmed and explained the observations mentioned above. In addition, we learned that FTC-133 cells growing in monolayers or in spheroids after RPM-exposure incorporate vinculin, paxillin, focal adhesion kinase 1, and adenine diphosphate (ADP)-ribosylation factor 6 in different ways into the focal adhesion complex.

Updated presentation of the spectrum of nuclear medicine in-vivo examinations and therapies from officially available statistics on out-patient and in-patient care as well as trends of structural data on nuclear medicine in Germany.Data from the German Federal Health Monitoring, from the frequency statistics of the statutory health insurance for out-patients and from the German Medical Association were used and supplemented by data from selective literature searches.In descending order, thyroid, bone and cardiac scans continue to be the most frequent nuclear medicine procedures. With a marked increase of PET/CT and SPECT/CT, the number of basic scintigraphies is declining. Cardiac, lung and brain scans as well as lymph scintigraphies are increasingly requested, bone and thyroid scan decrease. The consultation of nuclear medicine physicians in private practices is increasing by 4 % per year (2009: 2 164 664; 2015: 2 687 359). The number of nuclear medicine physicians in the out-patient sector rose significantly (2009: 756, 2015: 939, growth 24 %) and has remained constant due to restrictions since 2013. The specialist recognitions of women in nuclear medicine increased (proportion currently 46 %). In hospitals, more PET(/CT) scanners (2009: 97; 2015: 125) and fewer gamma cameras (2009: 594; 2015: 550) are operated. The number of non-thyroid (and also out-patient) radionuclide therapies continued to increase.With increased use of hybrid technologies, the nuclear medicine spectrum shows positive trends especially in nuclear cardiology and extra-thyroid therapy. These developments must be taken into account when amending regulations of specialist training and medical student teaching.

Sarcoidosis, a granulomatous T-cell-mediated multisystem disease with a yearly incidence of 10.9 to 35.5 cases per 100,000 in the United States, affects a variety of organ systems. Although the characteristic radiological finding of a bihilar lymphadenopathy still plays a diagnostic key role, FDG PET/CT is more sensitive in detecting and monitoring various manifestations. We present a rare case of a 37-year-old woman with bihilar, mediastinal, and abdominal lymphadenopathy in conjunction with a histologically proven cutaneous manifestation of sarcoidosis in a tattoo of the lower back exhibiting an increased uptake of FDG.