A consensus statement about indications for post-surgical radioiodine therapy (RIT) in differentiated thyroid cancer patients (DTC) was recently published by the European Thyroid Association (ETA) 1. This publication discusses indications for RIT on the basis of an individual risk assessment. Many of the conclusions of this consensus statement are well founded and accepted across the disciplines involved. However, especially from the perspective of nuclear medicine, as the discipline responsible for indicating and executing RIT, some of the recommendations may require further clarification with regard to their compatibility with established best practice and national standards of care. Assessment of the indications for RIT is strongly dependent on the weighing up of benefits and risks. On the basis of longstanding clinical experience in nuclear medicine, RIT represents a highly specific precision medicine procedure of proven efficacy with a favorable side-effect profile. This distinguishes RIT significantly from other adjuvant oncological therapies and has resulted in the establishment of this procedure as a usually well-tolerated, standard safety measure. With regard to its favorable risk/benefit ratio, this procedure should not be unnecessarily restricted, in the interest of offering reassurance to the patients. Both patients' interests and regional/national differences need to be taken into account. We would therefore like to comment on the recent consensus from the perspective of authors and to provide recommendations based on the respective published data.

Infective endocarditis displays a serious condition with high mortality rates. Establishing a reliable diagnosis can be challenging. This study evaluates granulocyte imaging with 99mTc-Besilesomab-SPECT/CT in order to determine the clinical value of the method and its possible redefinition through the addition of hybrid imaging. The study comprises 26 consecutive patients with suspected infectious endocarditis or prosthetic valve infection that underwent 99mTc-Besilesomab-SPECT/CT in our facility between December 2016 and September 2018. 99mTc-Besilesomab-SPECT/CT images were reviewed by two independent and blinded observers and results were evaluated by transesophageal echocardiography (TEE) and blood culture results as well as by pathological, bacteriological, and clinical findings. Target-to-Background-Ratios were calculated for semi-quantitative analysis. 13/26 patients were in a post-surgical stage. 99mTc-Besilesomab-SPECT/CT was positive in 6 cases. All 6 cases were true positive confirmed by pathological or clinical findings according to the modified Duke Criteria for infective endocarditis. Remaining 19/26 cases were true negative. Target-to-Background ratios were significantly higher in patients that were visually scored positive compared to negative cases. Inter-observer agreement was very good of deciding whether a scan was positive or negative. Sensitivity of 99mTc-Besilesomab-SPECT/CT was 86-100% and specificity was 100%. 99mTc-Besilesomab-SPECT/CT is a useful imaging method for the diagnosis of endocarditis, especially in difficult cases with prosthetic valves or cardiac devices and inconclusive findings in echocardiography. The added value of SPECT/CT was mainly finding and localizing increased uptake at a certain valve, prosthesis, or device cable.

SummaryPrevious findings of our group showed the chemokine receptor CXCR4 as a suitable target in PET/CT-imaging of axial bone infections, early postoperative osteomyelitis and periprosthetic infections. The aim of this study was to verify specific uptake of 68Ga-Pentixafor in chronic osteomyelitis. Methods: 29 consecutive patients who underwent 68Ga-Pentixafor-PET/CT with clinically suspected osteomyelitis were evaluated retrospectively. Bone tissues of 6 patients were available and evaluated by immunohistochemical staining for CXCR4 and autoradiography with 68Ga-Pentixafor. Staining was performed with an anti-CXCR4 antibody. In order to detect lymphocytic infiltration and CXCR4-expressing lymphocytes double immunofluorescence with an anti-CD3 and anti-CXCR4 antibody was performed. Results: 68Ga-Pentixafor-PET/ CT was true positive in 16 and true negative in 13 patients. In available bone tissue samples, immunohistochemical staining of CXCR4 expression and autoradiography with 68Ga-Pentixafor was highly positive. Double immunofluorescence was able to detect CXCR4-expressing T-lymphocytes within all bone samples while a control sample of noninfected tibial bone was negative for CXCR4. Conclusion: 68Ga-Pentixafor-PET/CT specifically shows CXCR4-expressing immune cells in chronic osteomyelitis and is therefore a suitable method for imaging chronic infection of the skeleton.

Because of its role in infection and inflammatory processes, the chemokine receptor CXCR4 might be a potent target in imaging of infectious and inflammatory diseases. The aim of this pilot study was to determine whether the CXCR4 ligand 68Ga-pentixafor is suitable for imaging chronic infection of the bone. Methods: The study comprised 14 patients with suspected infection of the skeleton who underwent 68Ga-pentixafor PET/CT between April 2015 and February 2017 in our facility. 68Ga-pentixafor PET/CT results were retrospectively evaluated against a histologic, bacteriologic, and clinical standard. The results were also compared with available bone scintigraphy, white blood cell scintigraphy, and 18F-FDG PET/CT results. Results: 68Ga-pentixafor PET/CT was positive in 9 of 14 patients. Diagnoses included osteitis or osteomyelitis of peripheral bone, osteomyelitis of the maxilla, and infected endoprostheses. Target-to-background ratios were 5.1–15 (mean, 8.7). Eight of 9 cases were true-positive as confirmed by pathology, bacteriology, or clinical observation. All negative cases were confirmed as true-negative by other imaging modalities and follow-up. Conclusion: Imaging of CXCR4 expression with 68Ga-pentixafor PET/CT appears suitable for diagnosing chronic infection of the skeleton. The findings of this study reveal a possible diagnostic gain in suspected chronic infections that are difficult to diagnose by other imaging modalities.

BACKGROUND: In previous work, a single administration of anticarcinoembryonic antigen (anti-CEA) I-131-labetuzumab radioimmunotherapy (RIT) after complete resection of colorectal liver metastases was well tolerated and significantly improved survival compared with controls. In the current phase 2 trial, the authors studied repeated RIT in the same setting, examining safety, feasibility, and efficacy. METHODS: Sixty-three patients (median age, 64.5 years) received RIT at 40 to 50 millicuries/m(2) per dose. Before the receipt of RIT, restaging was performed with computed tomography/magnetic resonance imaging and 18 F-fluorodeoxyglucose-positron emission to confirm that patients were "truly adjuvant." Patients who had elevated serum CEA levels or radiographically inconclusive new lesions were classified as "possibly nonadjuvant," but they also received RIT. Time to progression (TTP), overall survival (OS), and cause-specific survival (CSS) were calculated. The median follow-up was 54 months. RESULTS: After the first course of RIT, 14 of 63 patients experienced National Cancer Institute Common Toxicity Criteria grade 4 hematotoxicity; 19 patients did not receive the second course of RIT because of impaired performance status (N=5) or relapse (N=14). After the second course of RIT, 9 of 44 patients experienced National Cancer Institute Common Toxicity Criteria grade 4 hematotoxicity. Five patients developed myelodysplastic syndrome (MDS) from 22 to 55 months after their last RIT. The median TTP, OS, and CSS for all patients were 16, 55, and 60 months, respectively. The "truly adjuvant" patients (N=39) had an improved median TTP (not reached vs 6.1 months; hazard ratio, 0.12; P<.001), OS (75.6 vs 33.4 months; hazard ratio, 0.44; P=.014), and CSS (not reached vs 41.4 months; hazard ratio, 0.42; P=.014) compared with " possibly nonadjuvant" patients (N=24). CONCLUSIONS: Repeated RIT with I-131-labetuzumab is feasible but is associated with hematotoxicity. Survival is very encouraging, especially for "truly adjuvant" patients. However, the maximum safe dose of I-131-labetuzumab is a single administration of 50 millicuries/m(2). (C) 2016 American Cancer Society.

AbstractLymphadenopathy in Robbins level II-IV and VI is common in autoimmune thyroiditis but the diagnostic strategy of a distinct lymphadenopathy exceeding the known features in autoimmune thyroiditis patients is unknown. The aim of this study was to determine how the extent of cervical lymphadenopathy in autoimmune thyroiditis affects the diagnostic management.The study comprises one index-patient with autoimmune thyroiditis and distinct suspicious lymphadenopathy in all cervical levels as well as retroclavicular. In addition 10 patients with autoimmune thyroiditis and distinct suspicious lymphadenopathy limited to level VI were evaluated.Findings of high resolution ultrasound, fine-needle aspiration cytology, serological testing and clonal analysis are reported here. Further diagnostics of the index-patient included histology, immunohistochemistry, bcl-2-expression analysis and PET/CT.The index-patient showed distinct lymphadenopathy in level I-VI and retroclavicular. Lymph nodes did not display any sonographic malignancy criteria. Molecular analysis and immunohistochemistry revealed monoclonal CD10- and CD20-positive, Bcl-2 expressing follicular B-cells confirming the diagnosis of a follicular B-cell Non-Hodgkin lymphoma.10 additional patients with limited lymphadenopathy showed typical features of autoimmune thyroiditis and lymph nodes did not display sonographic malignancy criteria in all cases. Further tests excluded lymph node malignancies.Extensive diagnostics in autoimmune thyroiditis and distinct cervical lymphadenopathy is crucial. Whereas limited lymphadenopathy in AIT was proven benign, extensive lymphadenopathy exceeding the known amount and/or spreading to retroclavicular/mediastinal compartments is suspicious for malignancy. Even in the absence of sonographic malignancy criteria further tests have to be performed.

The diagnostic strategy in patients with fever or inflammation of unknown origin remains a major clinical challenge. The aim of this study was to evaluate the role of 18F-FDG-PET/CT in patients with unexplained elevated C-reactive protein with or without fever. Contribution of 18F-FDG-PET/CT to the final diagnosis was evaluated. In addition we determined whether a differentiation between patients with or without fever is clinically reasonable. PATIENTS, METHODS:We retrospectively analysed 72 consecutive patients with unexplained elevated C-reactive protein levels (above 8mg/l) that underwent 18F-FDG-PET/CT in our facility between 10/2009 and 11/2012. 18F-FDG-PET/CT was considered a so-called diagnostic scan when results decisively led to a final diagnosis and adequate therapy with a response of symptoms was initiated due to the PET/CT result. RESULTS:In 60/72 patients (83%) a final diagnosis was established. Diagnoses included infections (58%), non-infectious inflammatory diseases (29%) and malignancies (8%). 18F-FDG-PET/CT was true positive in 47 cases (65%) and the diagnostic scan in 29 patients (40%). Sensitivity of 18F-FDG-PET/CT was 81% and specificity was 86%. Diagnostics, final diagnoses, 18F-FDG-PET/CT results, SUVmax, C-reactive protein levels and the diagnostic scan did not differ significantly between patients with fever and patients without fever. CONCLUSION:18F-FDG-PET/CT is a useful method in the diagnostic workup of patients with inflammation of unknown origin. In our series there was no significant difference between patients with or without fever. Regarding 18F-FDG-PET/CT-imaging inflammation of unknown origin and unexplained fever can be joined to one entity.

Einleitung: Der Stellenwert einer adjuvanten systemischen Chemotherapie nach Resektion kolorektaler Lebermetastasen (KLM) wird kontrovers diskutiert, bei bisher nicht klar gezeigtem Vorteil für das Gesamtüberleben. In einer früheren Arbeit konnten wir zeigen, dass die einmalige Applikation einer anti-CEA-Radioimmuntherapie mit 131I-labetuzumab (RIT) nach R0-Resektion von KLM gut verträglich ist und zu einem verlängerten Gesamtüberleben im Vergleich zu einer Kontrollgruppe ohne adjuvante Therapie führt. In der hier vorliegenden Phase-II-Studie wurde die Sicherheit, Durchführbarkeit und Effizienz einer wiederholten RIT untersucht.

719 Background: Previously, single anti-CEA-radioimmunotherapy (RAIT) with 131iodine(I)-labetuzumab after complete (R0) resection of CEA-positive CLM was well tolerated and improved overall survival (OS) compared to a control group without RAIT. In this phase II study, we examined safety, feasibility, and long-term efficacy of repeated RAIT in the same setting. Methods: After R0-resection of CEA-positive CLM, 63 pts (42 m, 21 f; median age, 64.5 yrs) with synchronous (n=33) or metachronous (n=30) CLM received RAIT with 40-50 mCi/m2 per dose. 45 pts were intermediate/high risk for early metastatic relapse according to the Fong score. Restaging with CT/MRI and FDG-PET was performed prior to each RAIT. Pts with persistent elevated serum CEA-levels or inconclusive lesions during post-operative restaging received RAIT, but were classified as “non-adjuvant.” Toxicity was classified according to NCI-CTC v2.0. Time to progression (TTP), OS and cancer-specific survival (CSS) were calculated. The median follow-up was 54 (range 6-127) mos. Results: After the first cycle of RAIT 14 of 63 pts experienced grade 4 hematological toxicity. Nineteen pts did not receive the second cycle of RAIT due to prolonged toxicity, impaired performance status (n=6), or metastatic relapse (n=13). The latter were further treated by resection (n=3) or systemic chemotherapy (n=10). Forty-four pts received the planned second cycle of RAIT. Of these, 4 pts newly experienced grade 4 hematological toxicity. For all 63 pts, the median TTP, OS and CSS were 13, 57 and 92 months, respectively. The truly “adjuvant” pts (n=39) had a an improved median TTP (26 vs. 6.6 mos, p<0.0001), OS (76 vs. 42 mos, p=0.03) and CSS (not reached vs. 42 mos, p=0.003) in comparison to “non-adjuvant” pts (n=24). Conclusions: Repeated anti-CEA-RAIT with 131I-labetuzumab is safe, feasible, and well-tolerated (100% compliance), with expected hematological toxicity. The long-term survival after RAIT is very encouraging, in particular for pts deemed truly “adjuvant” post-salvage resection of CLM at restaging prior to RAIT.

Summary Objective: Primary risk factors in patients with differentiated thyroid carcinoma (DTC) are well established. In our institution, secondary risk stratification has been performed with stimulated Thyroglobulin (sTg; TSH > 30 mIU/l) within six months after primary therapy since 2001. In this study, we evaluated the predictive value of sTg for long-term disease- free survival (DFS). Patients, methods: Data of 202 consecutive patients with DTC were analyzed retrospectively. Median follow-up time was 6.4 years (12 months to 16.2 years). Patients were staged according to Union International Contre le Cancer (UICC) criteria. Primary risk stratification was carried out according to European Thyroid Association criteria. Initially, 134 patients (66%) were classified as low-risk and 68 patients (34%) as high-risk. The influence of established risk factors and sTg on DFS was analyzed at three different time points, up to 36 months after initial therapy. Results: In total, 169 (84%) of all patients remained in complete remission after surgery followed by radioiodine-therapy. Six patients (3%) developed tumour recurrence after initial complete remission. Primary risk factors for persistent disease were male sex, follicular or oncocytic tumour, primary tumour > 4 cm in diameter, initial lymph node involvement, initial metastatic disease and microscopic or macroscopic residual tumor. sTg ≤ 0.3 ng/ml measured within six months after initial therapy was a highly significant predictor (p ≤ 0.001) for lasting DFS, 99% of patients with sTg ≤ 0.3 ng/ml were in complete remission 36 months after initial therapy. Conclusions: A stimulated Tg ≤ 0.3 ng/ml within six months after initial therapy is a reliable predictor for long-term disease- free survival independent of primary risk stratification.

Aufgrund überzeugender Studienergebnisse bei Patienten mit einem rezidivierten oder refraktären B-NHL sind 90Y-Ibritumomab-Tiuxetan und 131I-Tositumomab zur Therapie von follikulären Lymphomen in der Rezidivsituation (90Y-Ibritumomab-Tiuxetan in Europa) und zur Therapie von rezidivierten oder refraktären Low-grade-B-NHL sowie transformierten B-NHLs (131I-Tositumomab in den USA) zugelassen. Zahlreiche Studien haben gezeigt, dass beide Radioimmunkonjugate sowohl in der Erstlinientherapie als auch in der Konsolidierungstherapie nach Erstlinientherapie entweder als Monosubtanz als auch in einem multimodalen Konzept außerordentlich wirkungsvoll sind. Ergebnisse zur RAIT bei aggressiven Lymphomen sind ebenfalls vielversprechend. Myeloablative Hochdosisprotokolle mit Stammzellgabe (ASCT) zeichnen sich durch eine hohe Rate kompletter und zum Teil dauerhafter Remissionen aus. Fraktionierte Therapien erscheinen durchaus erfolgversprechend, sind aber zurzeit nur unzureichend und nur für die Rezidivsituation evaluiert. Vom derzeitigen Kenntnisstand aus ist absehbar, dass Pretargetingsysteme die antineoplastischen Effekte der RAIT weiter verbessern werden.

In dieser Arbeit wird der Stellenwert der FDG-PET und der FDG-PET / CT im Rahmen der Strahlentherapie von Rekumkarzinomen untersucht. Da diese Tumoren bis auf Frühstadien grundsätzlich multimodal behandelt werden, müssen unterschiedliche Aspekte (Staging, Bestrahlungsplanung und Prognoseabschätzung bzw. Patientenstratifizierung) getrennt beurteilt werden. Der Stellenwert der FDG-PET und FDG-PET / CT im primären Tumorstaging ist bislang noch unzureichend definiert. In der Rezidivsituation ist die FDG-PET wegen der Möglichkeit zur Differenzierung zwischen Narbe und Rezidiv der konventionellen Schnittbilddiagnostik überlegen. Im Rahmen der Bestrahlungsplanung kann das FDG-PET / CT wesentlich zur Identifizierung der Tumorausdehnung im Planungs-CT beitragen und bei entsprechender Tumorlokalisation eine Schonung des Analsphinkters ermöglichen. Dennoch ist der generelle Einsatz zur Therapieplanung fraglich, da das Zielvolumens neben dem manifesten Tumor auch Regionen mit Befallsrisiko (Mesorektum und Lymphabfluss) beinhaltet. Erste kleinere Studien zeigen eine gute Korrelation zwischen metabolischem Ansprechen auf die Induktionstherapie und dem onkologischen Ergebnis. Besonders relevant wäre eine frühzeitige Vorhersage über den zu erwartenden Therapieerfolg unter laufender Radiochemotherapie, um die Patienten entsprechend stratifizieren zu können.

4080 Background: Within a phase-II study a single dose RAIT (40–60 mCi/m2131iodine-labetuzumab, Immunomedics, Inc., Morris Plains, NJ/USA) after salvage resection of CRC-LM has been well tolerated. Compared with a control group (OP±CTX) the RAIT-patients showed an improved overall survival (Ann Surg Oncol 2007, 14 (9): 2577–2590). The aim of the ongoing phase-II-study was to evaluate the toxicity and efficacy (DFS, OS) in pts who received a repeated RAIT with 50 mCi/m2 131iodine-labetuzumab after R0-resection of CRC-LM. Methods: 32 consecutive pts (age 61 years; 8x rectal cancer, 24x colon cancer; CRC-LM: 16x syn-, 16x metachroneous) were re-staged with CT/MRT and FDG-PET after R0-resection of extended CRC-LM prior to RAIT. On account of established risk scores (Nordlinger-, Fong- and Gayowski-Scores) 87% of the pts had an intermediate or high risk of recurrence of CRC-LM within the next 2 years (after R0- resection). During staging procedures 16 pts showed no suspect lesions (adjuvant), while 16 pts show...

A 22 year old female patient presented with fever, night sweats, weight loss and hepatomegaly associated with elevated inflammatory parameters and liver enzymes. Computer tomography revealed a mass located between the inferior vena cava and the psoas muscle as well as enlarged celiac, retroperitoneal and retrocaval lymph nodes. Biopsies of the retrocaval mass led to the diagnosis of retroperitoneal fibrosis. Within a few days of treatment with corticosteroids clinical presentation improved and imaging studies detected complete regression of the retrocaval mass after 6 months.

Dieser Artikel gibt einen evidenzgeleiteten Überblick über entzündungsszintigrafische Verfahren bei einigen seltenen Indikationen. Bei der Diagnostik und bei der Beurteilung der Aktivität einer chronisch-entzündlichen Darmerkrankung bleibt die Szintigrafie mit 99mTc-HMPAO-markierten autologen Leukozyten die nuklearmedizinische Standarduntersuchung. Eine Appendizitis kann sowohl mittels in vitro markierter Leukozyten als auch immunentzündungs-szintigrafisch mit hoher Sicherheit nachgewiesen und ausgeschlossen werden. Die späte SPECT (20-24 h p. i.) mit 99mTc-markierten monoklonalen Anti-CD-66-Antikörpern ist eine sinnvolle Zusatzuntersuchung zur transösophagealen Echokardiografie bei der Endokarditisdiagnostik. Infizierte Gefäßprothesen sollten mittels 99mTc-HMPAO-markierter autologer Leukozyten untersucht werden. Es muss diskutiert werden, ob die [18F]FDG-PET oder [18F]FDG-PET / CT bei dieser Fragestellung eine höhere diagnostische Genauigkeit aufweist.