Dependence of Renal Uptake on Kidney Function in [68Ga]Ga-PSMA-11 PET/CT Imaging.

(1) Background: PSMA ligand PET/CT is increasingly important for diagnostics of prostate cancer and other tumor diseases. In particular, the radiopharmaceutical [68Ga]Ga-PSMA-11 is widely used. Besides its tumor-specific binding, the uptake within the kidneys is dominant and seems to visualize the renal cortex specifically. Kidney diseases may alter the uptake of radiopharmaceuticals. Therefore, the correlation between renal uptake in PET/CT imaging and renal function should be investigated. (2) Methods: A group of 103 male patients were retrospectively evaluated for eGFR according to the CKD-EPI equation, tracer uptake intensity (SUVmax, SUVpeak, SUVmean), the molecular volume of the renal cortex, morphological kidney size, and total renal uptake. Manual and three different computer-assisted contouring methods (thresholds at 50% of SUVmax, 30% of SUVmax, and absolute SUV of 20) were used for measurements. Correlations between parameters were calculated using linear regression models. (3) Results: Renal SUVmax, SUVpeak, and SUVmean do not correlate with eGFR for manual or computer-assisted measurements. In contrast, molecular cortex volume shows a moderate correlation with eGFR (R2 = 0.231, p < 0.001), superior to morphological kidney size. A contouring threshold of 30% of SUVmax outperformed the other settings for renal cortex volume and total renal uptake. (4) Conclusions: Renal uptake of [68Ga]Ga-PSMA-11 cannot predict eGFR, but the functional renal cortex can be quantified by PET/CT imaging.

Transarterial Radioembolization (TARE) in Patients with Hepatocellular Carcinoma: A Comparison of Palliative with Bridging-to-Transplant Concepts.

We investigated transarterial radioembolization (TARE) as a palliative measure and bridging-to-transplant therapy in hepatocellular carcinoma (HCC) patients. A total of 167 patients (50 bridging, 117 palliative) with 245 TARE procedures were assessed. Fourteen patients underwent subsequent liver transplantation (LT). Patients undergoing LT exhibited significantly prolonged progression-free survival (PFS) compared to those with bridging-without-transplant (p = 0.033). No significant differences were observed between patients with bridging-without-transplant and palliative cases (p = 0.116). Median overall survival (OS) post-TARE was 16.6 months, with estimated OS rates at 6/12 months of 82.0%/60.5%, respectively. Patients who underwent LT demonstrated statistically significantly longer OS compared to those with bridging-without-transplant (p = 0.001). No marked outcome distinctions were found between bridging-without-transplant and palliative groups. The findings underscored the superiority of LT over alternative treatments. TARE served as an important component in non-LT scenarios, allowing for subsequent therapeutic options. The study reflected the highly variable and complex situations of patients with HCC, emphasizing the need for further investigations to define an optimal multimodal approach.

[Technical innovations to optimize ultrasound imaging]. / Technische Innovationen zur Optimierung der Ultraschallbildgebung.

Due to the high incidence of thyroid disease, ultrasound examination of the neck has high priority in many nuclear medicine departments. A precise sonogram with high spatial resolution and image sharpness over the entire imaging area, combined with minimal artifacts, is the prerequisite for meeting the demand for high diagnostic accuracy in modern medicine. In the last 20-30 years, a number of significant technical innovations have been implemented, such as the development of the matrix array, electronic image focusing, realtime compound imaging, artifact limitation by speckle reduction and harmonic imaging, as well as the possibility to extend the field of view.

[Standardized acquisition and documentation of cine loops on conventional thyroid ultrasound]. / Standardisierte Akquisition und Dokumentation von Videosequenzen bei der konventionellen Schilddrüsensonografie.

Ultrasound is the basic imaging method for the assessment of the thyroid gland. Due to the high prevalence of structural disease, the examination procedure is used very frequently in Germany, in many cases in the context of follow-up. The assessment of thyroid pathologies and their dynamics is subjected to relevant inter- and intraobserver variability. Findings that were not identified during live ultrasound cannot be assessed retrospectively. Applying an SOP for the acquisition and documentation of standardized video sequences of ultrasound images (so-called cine loops), allows for a secondary retrospective evaluation of the thyroid gland, taking into account previously acquired images analogous to other cross-sectional imaging methods such as CT or MRI. The cine loops can be acquired by non-physician personnel, stored to the local PACS and used for educational and research purposes.

[Normal values for adult thyroid volume on ultrasound - where do they come from and how should they be evaluated?] / Sonographische Normwerte für das Schilddrüsenvolumen Erwachsener ­ woher kommen sie und wie sind sie zu bewerten?

The upper limit for the thyroid volume is 18 ml for women and 25 ml for men. These reference values are used and taught in many clinics and practices across several disciplines. The thyroid volume is a relevant factor for the treatment course. But where do the standard values for thyroid volumes come from, what kind of studies have been carried out to establish them? Should these upper limits be used as an universal standard in clinical routine, and which factors can influence the physiological organ size? The following article is dedicated to a critical review of the commonly used reference values for the thyroid volume of adults.

68 Ga-Oxine-Labeled Erythrocytes as a New PET Tracer for the Localization of Gastrointestinal Bleeding.

ABSTRACT: A 69-year-old man presented with recurring drops in hemoglobin levels and suspected gastrointestinal bleeding. Endoscopy did not show a site of bleeding so further examinations became necessary. Scintigraphy and SPECT/CT with 99m TcO 4- -labeled red blood cells were performed without evidence of a hemorrhage. Based on an established protocol for splenic PET/CT, autologous erythrocytes can be labeled with 68 Ga-oxine and used as a tracer for the localization of active bleeding sites. In the patient, PET/CT with 68 Ga-oxine-labeled undamaged erythrocytes was performed successfully and revealed a hemorrhage of the gastric corpus that was confirmed and treated by endoscopy.

[Necrosis of the tongue as a clinical manifestation of giant cell arteritis]. / Zungennekrose als klinische Manifestation einer Riesenzellarteriitis.

An 83-year-old male patient presented due to a 3-week history of swelling of the tongue with tongue pain on eating, yellowish plaques, and a gray-brown lesion in the anterior portion of the tongue. Sudden loss of vision in the left eye and temporal headache occurred 3 days before presentation. Due to elevated C­reactive protein, sonography of the supraaortic arteries as well as positron emission tomography/computed tomography was performed. Imaging revealed inflammation of the great arteries as well as a halo sign on ultrasound of the temporal artery. Thus, a diagnosis of giant cell arteritis with necrosis of the tongue was made. Immunosuppressive therapy with glucocorticoids was initiated. Necrosis of the tongue is a rare manifestation of giant cell arteritis that requires immediate immunosuppressive therapy to prevent further complications to the tongue (e.g., complete necrosis of the tongue, superinfection, tongue amputation).

Image-Guided Fine-Needle Aspiration Cytology for BRCA Mutation Assessment of PSMA-Positive Lymph Node Metastases in a Patient With Metastatic Castration-Resistant Prostate Cancer.

ABSTRACT: A 64-year-old man with metastatic castration-resistant prostate cancer presented for prostate-specific membrane antigen (PSMA) PET/CT in preparation for 177 Lu-PSMA radioligand therapy. For precedent BRCA mutation assessment, fine-needle aspiration cytology of 2 PSMA-positive lymph node metastases was conducted. The acquired material was suitable for next-generation sequencing-based gene panel diagnostics and did not show a BRCA1 / 2 mutation, thus PSMA radioligand therapy was initiated. Fine-needle aspiration cytology of lymph node metastases may be a viable option in evaluating further therapeutic alternatives.

Noninvasive Verification of a Very Small Intraocular Prostate Carcinoma Metastasis by 68Ga-PSMA-11 PET/CT.

ABSTRACT: A male patient underwent 68Ga-PSMA-11 PET/CT for the evaluation of a suspected intraocular metastasis in the right eye. Although the choroidal thickening was very small (4 × 2 mm), and ophthalmoscopy as well as MRI were inconclusive, PET/CT imaging showed distinct PSMA expression in the suspected lesion, confirming prostate cancer metastasis. The ability of dedicated PSMA ligand PET/CT imaging to detect small metastases, even with 68Ga-labeled ligands, has been demonstrated. Therefore, the use of further invasive diagnostic procedures could be avoided. Thus, the possibility of detecting intraocular metastases of prostate cancer should be considered in routine PET/CT imaging.

Radionuclide Cisternography with [64Cu]Cu-DOTA.

Radionuclide cisternography (RNC) is a method for conducting imaging of the cerebrospinal system and can be used to identify cerebrospinal fluid leaks. So far, RNC has commonly employed radiopharmaceutical agents suitable only for single-photon emission tomography techniques, which are thus lacking in terms of image resolution and can potentially lead to false-negative results. Therefore, [64Cu]Cu-DOTA was investigated as an alternative radiopharmaceutical for RNC, employing positron emission tomography (PET) instead of single-photon emission tomography. A formulation of [64Cu]Cu-DOTA was produced according to the guidelines for good manufacturing practice. The product met the requirements of agents suitable for intrathecal application. [64Cu]Cu-DOTA was administered to a patient and compared to the approved scintigraphic RNC agent, [111In]In-DTPA. While no cerebrospinal fluid leak was detected with [111In]In-DTPA, [64Cu]Cu-DOTA RNC exhibited a posterolateral leak between the vertebral bodies C1 and C2. Thus, in this patient, PET RNC with [64Cu]Cu-DOTA was superior to RNC with [111In]In-DTPA. Since radiopharmaceuticals have a very good safety profile regarding the occurrence of adverse events, PET RNC with [64Cu]Cu-DOTA may become an attractive alternative to scintigraphic methods, and also to computed tomography or magnetic resonance imaging, which often require contrast agents, causing adverse events to occur much more frequently.

Clinical Results of Transarterial Radioembolization (TARE) with Holmium-166 Microspheres in the Multidisciplinary Oncologic Treatment of Patients with Primary and Secondary Liver Cancer.

Holmium-166 microspheres are used for the transarterial radioembolization (TARE) treatment of primary and secondary liver cancers. In this study, its efficacy regarding local tumor control and integration into the oncological treatment sequence of the first 20 patients treated in our institution were examined. A total of twenty-nine 166Ho-TARE procedures were performed to treat hepatocellular carcinoma (HCC, fourteen patients), metastatic colorectal cancer (mCRC, four patients), intrahepatic cholangiocarcinoma (ICC, one patient), and hemangioendothelioma of the liver (HE, one patient). In eight patients, 166Ho-TARE was the initial oncologic treatment. In patients with HCC, the median treated-liver progression-free survival (PFS), overall PFS, and overall survival after 166Ho-TARE were 10.3, 7.3, and 22.1 months; in patients with mCRC, these were 2.6, 2.9, and 20.6 months, respectively. Survival after 166Ho-TARE in the patients with ICC and HE were 5.2 and 0.8 months, respectively. Two patients with HCC were bridged to liver transplantation, and one patient with mCRC was downstaged to curative surgery. In patients with HCC, a median treatment-free interval of 7.3 months was achieved. In line with previous publications, 166Ho-TARE was a feasible treatment option in patients with liver tumors, with favorable clinical outcomes in the majority of cases. It was able to achieve treatment-free intervals, served as bridging-to-transplant, and did not prevent subsequent therapies.

The effect of butylscopolamine on [18F]FDG uptake in the gastrointestinal tract is negligible and regionally variable.

BACKGROUND: Butylscopolamine (or hyoscine butylbromide, trade name Buscopan®) is occasionally administered as a premedication to reduce non-specific FDG uptake in the gastrointestinal tract based on its antiperistaltic effect. To date, there are no consistent recommendations for its use. The aim of this study was to quantify the reduction in intestinal and non-intestinal uptake by butylscopolamine administration and to derive relevance for clinical evaluation. RESULTS: 458 patients (PET/CT for lung cancer) were retrospectively reviewed. 218 patients with butylscopolamine and 240 patients without butylscopolamine had comparable characteristics. While the SUVmean in the gullet/stomach and small intestine was significantly reduced with butylscopolamine, the colon and rectum/anus showed no difference. The liver and salivary glands showed a reduced SUVmean, while skeletal muscle and blood pool were unaffected. An effect of butylscopolamine was particularly evident in men and patients under 65 years of age. There was no difference in the perceived confidence in the assessment of intestinal findings in the subjective evaluation, although in the butylscopolamine group further diagnostics appeared advisable more frequently. CONCLUSIONS: Butylscopolamine reduces gastrointestinal FDG accumulation only in selected segments and, despite a significant effect, only to a small extent. A general recommendation for the use of butylscopolamine cannot be derived from these results, its use for specific issues could be considered individually.

A Novel Breast Cancer Xenograft Model Using the Ostrich Chorioallantoic Membrane-A Proof of Concept.

The avian chorioallantoic membrane (CAM) assay has attracted scientific attention in cancer research as an alternative or complementary method for in vivo animal models. Here, we present a xenograft model based on the ostrich (struthio camelus) CAM assay for the first time. The engraftment of 2 × 106 breast cancer carcinoma MDA-MB-231 cells successfully lead to tumor formation. Tumor growth monitoring was evaluated in eight fertilized eggs after xenotransplantation. Cancer cells were injected directly onto the CAM surface, close to a well-vascularized area. Histological analysis confirmed the epithelial origin of tumors. The CAM of ostrich embryos provides a large experimental surface for the xenograft, while the comparably long developmental period allows for a long experimental window for tumor growth and treatment. These advantages could make the ostrich CAM assay an attractive alternative to the well-established chick embryo model. Additionally, the large size of ostrich embryos compared to mice and rats could help overcome the limitations of small animal models. The suggested ostrich model is promising for future applications, for example, in radiopharmaceutical research, the size of the embryonal organs may compensate for the loss in image resolution caused by physical limitations in small animal positron emission tomography (PET) imaging.

Medical Students' and Radiology Technician Trainees' eHealth Literacy and Hygiene Awareness-Asynchronous and Synchronous Digital Hand Hygiene Training in a Single-Center Trial.

Next to the known nosocomial infections, the COVID-19 pandemic was an example for the need for the immediate implementation of functioning hygiene concepts and knowledge transfer. The aim of this study was to evaluate the self-assessment of ehealth literacy in terms of finding, using and critically evaluating health information and theoretical and practical hygiene awareness on a voluntary participation basis at the Jena University Hospital in 2022. The well-established and validated eHEALS and WHO questionnaire on hand hygiene (HH) knowledge for healthcare workers was completely filled by 204 participants (191 medical students; 13 healthcare trainees). In a second step, after the questionnaire, 77 participants completed additional asynchronous, digitally guided self-training using DesiCoach 2Go. In the end, a synchronous hand disinfection was carried out in the hospital using Visirub, by separating it into a group without (n = 191; with and without HH questionnaire) and a group with (n = 31; with HH questionnaire) previously completed self-training. For the eHL, the respondents tended to have a positive self-assessment of finding, using and critically evaluating health information. The voluntary participants of the practical hand disinfection who had received self-training were able to achieve significantly better results (p = 0.0047), resulting in fewer wetting gaps in a subsequent performance with Visirub than those who had not received digital self-training. The survey showed that healthcare-related participants belonging to the "digital native" generation have above-average knowledge on HH and profit by digitally guided self-training.

67 Ga-PSMA I&T for Radioguided Surgery of Lymph Node Metastases in Patients With Biochemical Recurrence of Prostate Cancer.

PURPOSE: Radioguided lymph node dissection in patients with prostate cancer, and suffering from biochemical recurrence has been described thoroughly during the past few years. Several prostate-specific membrane antigen (PSMA)-directed ligands labeled with 111 In, 99m Tc, and 68 Ga have been published; however, limitations regarding availability, short half-life, high costs, and unfavorable high energy might restrict frequent use. This study aims at introducing 67 Ga as a promising radionuclide for radioguided surgery. METHODS: Retrospective analysis was performed on 6 patients with 7 PSMA-positive lymph node metastases. 67 Ga-PSMA I&T (imaging and therapy) was synthesized in-house and intravenously applied according to §13 2b of the German Medicinal Products Act. Radioguided surgery was performed 24 hours after injection of 67 Ga-PSMA I&T using a gamma probe. Patient urine samples were collected. Occupational and waste dosimetry was performed to describe hazards arising from radiation. RESULTS: 67 Ga-PSMA application was tolerated without adverse effects. Five of 7 lymph nodes were detected on 22-hour SPECT/CT in 4 of 6 patients. During surgery, all 7 lymph node metastases were identified by positive gamma probe signal. Relevant accumulation of 67 Ga was observed in lymph node metastases (32.1 ± 15.1 kBq). Histology analysis of near-field lymph node dissection revealed more lymph node metastases than PET/CT (and gamma probe measurements) identified. Waste produced during inpatient stay required decay time of up to 11 days before reaching exemption limits according to German regulations. CONCLUSIONS: Radioguided surgery using 67 Ga-PSMA I&T is a safe and feasible option for patients suffering from biochemical recurrence of prostate cancer. 67 Ga-PSMA I&T was successfully synthesized according to Good Manufacturing Practice guidelines. Radioguided surgery with 67 Ga-PSMA I&T does not lead to relevant radiation burden to urology surgeons and represents a novel interdisciplinary approach in nuclear medicine and urology.

Preparation and labelling of red blood cells with [68Ga]Ga-oxine for PET/CT imaging of the human spleen.

INTRODUCTION: With the introduction of automated synthetization methods, the in-house production of several 68Ga-based tracers became feasible in hospital laboratories. We describe a possible standard operating procedure (SOP) for [68Ga]Ga-oxine-labeled heat-denaturated erythrocytes, which can be used for selective imaging in patients with splenic disorders. METHODS: Heat-denaturated erythrocytes were labeled with [68Ga]Ga-oxine, which was produced from 68Ga and 8-hydroxyquinoline on an automated synthesizer. The workflow was validated in a good manufacturing/good radiopharmaceutical practice (GMP/GRP) certified laboratory. A patient underwent [68Ga]Ga-oxine-erythrocyte PET/CT for differentiation of an intrapancreatic mass. RESULTS: [68Ga]Ga-oxine and [68Ga]Ga-oxine-labeled erythrocytes could be synthesized reproducibly and reliably. The products met GMP quality standards. The tracer showed high accumulation in the intrapancreatic mass, consistent with an accessory spleen. CONCLUSIONS: PET/CT imaging with [68Ga]Ga-oxine-labeled, heat-denaturated erythrocytes can be a backup method for the differentiation of functioning splenic tissue from tumors. An SOP for the production of the tracer in a clinical setting could be established.

Liver PET Reloaded: Automated Synthesis of [68Ga]Ga-BP-IDA for Positron Imaging of the Hepatobiliary Function and First Clinical Experience.

Hepatobiliary scintigraphy is a well-established nuclear imaging method for evaluating liver function and displaying the biliary system, but the spatial and temporal resolution is limited, and, there is still no established PET equivalent. Adapted from the work of Schuhmacher et al. in 1983, the production of a 68Gallium-labeled substitute, tetrabromophthalein ([68Ga]Ga-BP-IDA), was undertaken according to current Good Manufacturing Practice (GMP) standards and proved feasible and reproducible. PET/CT with the radiotracer was performed in two complex patients with hepatocellular carcinoma in preparation for transarterial radioembolization. Due to its high spatial and temporal resolution, localization of areas with impaired liver function and visualization of the biliary system were possible. We could demonstrate that this 68Gallium-labeled, IDA-based PET tracer is feasible and could advance hepatic and biliary function PET imaging.

Optimization of Thyroid Volume Determination by Stitched 3D-Ultrasound Data Sets in Patients with Structural Thyroid Disease.

Ultrasound (US) is the most important imaging method for the assessment of structural disorders of the thyroid. A precise volume determination is relevant for therapy planning and outcome monitoring. However, the accuracy of 2D-US is limited, especially in cases of organ enlargements and deformations. Software-based "stitching" of separately acquired 3D-US data revealed precise volume determination in thyroid phantoms. The purpose of this study is to investigate the feasibility and accuracy of 3D-US stitching in patients with structural thyroid disease. A total of 31 patients from the clinical routine were involved, receiving conventional 2D-US (conUS), sensor-navigated 3D-US (3DsnUS), mechanically-swept 3D-US (3DmsUS), and I-124-PET/CT as reference standard. Regarding 3DsnUS and 3DmsUS, separately acquired 3D-US images (per thyroid lobe) were merged to one comprehensive data set. Subsequently, anatomical correctness of the stitching process was analysed via secondary image fusion with the I-124-PET images. Volumetric determinations were conducted by the ellipsoid model (EM) on conUS and CT, and manually drawn segmental contouring (MC) on 3DsnUS, 3DmsUS, CT, and I-124-PET/CT. Mean volume of the thyroid glands was 44.1 ± 25.8 mL (I-124-PET-MC = reference). Highly significant correlations (all p < 0.0001) were observed for conUS-EM (r = 0.892), 3DsnUS-MC (r = 0.988), 3DmsUS-MC (r = 0.978), CT-EM (0.956), and CT-MC (0.986), respectively. The mean volume differences (standard deviations, limits of agreement) in comparison with the reference were -10.50 mL (±11.56 mL, -33.62 to 12.24), -3.74 mL (±3.74 mL, -11.39 to 3.78), and 0.62 mL (±4.79 mL, -8.78 to 10.01) for conUS-EM, 3DsnUS-MC, and 3DmsUS-MC, respectively. Stitched 3D-US data sets of the thyroid enable accurate volumetric determination even in enlarged and deformed organs. The main limitation of high time expenditure may be overcome by artificial intelligence approaches.