The accurate detection of hyperfunctioning parathyroid tissue (HFPT) is pivotal in the preoperative assessment of primary hyperparathyroidism (PHPT). PET/CT using [¹⁸F]fluorocholine ([¹⁸F]FCH) showed superior diagnostic performance compared to conventional functional imaging modalities. We aimed to evaluate the diagnostic performance of [¹⁸F]FCH PET/CT as a first-line functional imaging approach in patients with clinically diagnosed PHPT. The imaging and clinical data of 321 PHPT patients, including 271 overt PHPT and 50 mild PHPT, who underwent [¹⁸F]FCH PET/CT as first-line imaging were analysed in this retrospective study. Histopathology was the reference standard. In case of no available histopathology evaluation (conservative management), imaging and clinical follow-ups were considered reference standards. In the overt group (n = 271), [¹⁸F]FCH PET/CT showed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 0.99, 0.91, 1.00, 0.80, and 0.99, respectively. Regarding the correlation of the index lesions and initial laboratory data, all [¹⁸F]FCH PET/CT parameters (SUVs, SULs, and mSAD) were significantly correlated with the serum iPTH level. Additionally, SUVmax, SULpeak, and mSAD were significantly associated with the serum calcium level. In the mild group (n = 50), [¹⁸F]FCH PET/CT showed a sensitivity, specificity, PPV, NPV, and accuracy of 0.93, 0.75, 0.95, 0.67, and 0.90. In conclusion, [¹⁸F]FCH PET/CT revealed high diagnostic performance in the detection of HFPTs and the potential to be considered as a first-line imaging modality in the assessment of PHPT, including both overt and mild types. However, its cost–benefit concerning the clinical impact of early PHPT detection should be investigated in future studies.

The aim of the study was to evaluate the clinical impact of pre-ablation rhTSH-stimulated fluorine-18 fluorodeoxyglucose (F-18 FDG) PET/CT in addition to post-therapeutic whole body radioiodine scanning in patients with intermediate to high risk differentiated thyroid carcinoma (DTC). This was a retrospective single center study including 73 patients with thyroid cancer (44 females, mean age 43.2±16.2 years, 62% papillary, 31% follicular, 7% poorly differentiated). All patients underwent ablative radioiodine treatment (mean activity: 3661±673 MBq I-131) using rhTSH after thyroidectomy and lymph node (LN) dissection (01/2013–10/2016) and TSH-stimulated F-18 FDG PET/CT (4 MBq/kg body weight, low dose CT). Post-treatment I-131 whole body scan (I-131 WBS) was obtained 9 days afterwards in planar technique and in case of equivocal or abnormal findings using SPECT/CT. Thirty-one patients (42%) showed F-18 FDG avid lesions, 14 patients showed more FDG than iodine positive lesions and 5 patients more iodine positive lesions in I-131 WBS, respectively. Fifty-three patients showed identical F-18 FDG PET/CT and I-131 WBS. The initial treatment plan was changed from follow-up to therapy (surgery, systemic therapy using tyrosine-kinase inhibition) in 11 patients (15%) on the basis of F-18 FDG PET/CT imaging. Six of these 11 patients had papillary thyroid cancer. Three patients with histologically proven LN metastases had stimulated thyroglobulin-levels<2.0 ng/ml. Our study demonstrated a clinical benefit of pre-ablation rhTSH-stimulated F-18 FDG PET/CT imaging in about 20% of patients with intermediate to high risk DTC, leading to change in patient management in 15%.

[⁶⁸Ga]Ga-FAP-2286 is a new peptide-based radiopharmaceutical for positron-emission tomography (PET) that targets fibroblast activation protein (FAP). This article describes in detail the automated synthesis of [⁶⁸Ga]Ga-FAP-2286 using a commercially available synthesis tool that includes quality control for routine clinical applications. The synthesis was performed using a Scintomics GRP-3V module and a GMP grade ⁶⁸Ge/⁶⁸Ga generator. A minor alteration for transferring the eluate to the module was established, eliminating the need for new method programming. Five batches of [⁶⁸Ga]Ga-FAP-2286 were tested to validate the synthesis. A stability analysis was conducted up to 3 h after production to determine the shelf-life of the finished product. The automated synthesis on the Scintomics GRP-3V synthesis module was found to be compliant with all quality control requirements. The shelf-life of the product was set to 2 h post-production based on the stability study. A patient suffering from cholangiocellular carcinoma that could not be clearly detected by conventional imaging, including a [¹⁸F]FDG-PET/CT, highlights the potential use of [⁶⁸Ga]Ga-FAP-PET/CT.

Background: Myocardial perfusion imaging (MPI) plays a crucial role in diagnosing coronary artery disease (CAD), with single-photon emission computed tomography (SPECT) being a widely accepted method. The accuracy of MPI relies on image quality and the expertise of physicians. While CZT-SPECT cameras offer advantages, they can be susceptible to attenuation artifacts. Therefore, our objective was to evaluate the diagnostic accuracy of CZT-SPECT and SPECT/CT in a clinical setting. Method: We conducted a prospective single-center study involving patients with known or suspected stable ischemic heart disease who underwent SPECT-MPI using CZT-SPECT and SPECT/CT scanners, and the latter was equipped with cardiofocal collimation. Experienced physicians performed analysis and reporting based on automated quantification and visual image interpretation. Results: A total of 77 patients (32 women (41.6%) and 45 men (58.4%) with an average age of 71.9 ± 8.9 years) were included. The agreement between readers regarding the final conclusion based on imaging reporting using both devices was very high (Kappa 0.87–0.93). Per-vessel analysis revealed a trend suggesting that CZT-SPECT was superior to conventional SPECT/CT in terms of sensitivity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, although the difference did not reach statistical significance. Conclusion: Our study demonstrated that CZT-SPECT imaging offers comparable diagnostic accuracy, improved patient comfort, and eliminates CT-induced radiation compared to SPECT/CT. These findings suggest that cardiac CZT-SPECT imaging has the potential to become a valuable imaging modality in clinical practice.

Background: High-performance time-of-flight (TOF) positron emission tomography (PET) systems have the capability for rapid data acquisition while preserving diagnostic image quality. However, determining a reliable and clinically applicable cut-off of the acquisition time plays an important role in routine practice. This study aimed to assess the diagnostic equivalence of short acquisition time of 57 with routine 75 seconds per bed position (s/BP) of [¹⁸F]-fluoro-deoxy-glucose (FDG) PET. Phantom studies applying EARL criteria suggested the feasibility of shortened acquisition time in routine clinical imaging by 3D TOF PET/CT scanners. Ninety-six patients with melanoma, lung or head and neck cancer underwent a standard whole-body, skull base-to-thigh or vertex-to-thigh [¹⁸F]-FDG PET/CT examination using the 3D TOF Ingenuity TF PET/CT system (Philips, Cleveland, OH). The [¹⁸F]-FDG activity applied was equal to 4MBq per kg body weight. Retrospectively, PET list-mode data were used to calculate a second PET study per patient with a reduced acquisition time of 57 s instead of routine 75 s/BP. PET/CT data were reconstructed using a 3D OSEM TOF algorithm. Blinded patient data were analysed by two nuclear medicine physicians. The number of [¹⁸F]-FDG-avid lesions per body region (head&neck, thorax, abdomen, bone, extremity) and image quality (grade 1–5) were evaluated. Semiquantitative analyses were performed by standardized uptake value (SUV) measurements using 3D volume of interests (VOI). The visual and semiquantitative diagnostic equivalence of 214 [¹⁸F]-FDG-avid lesions were analysed in the routine standard (75 s/BP) as well as the calculated PET/CT studies with short acquisition time. Statistical analyses were performed by equivalence testing and Bland–Altman plots. Results: Lesion detection rate per patient’s body region agreed in > 98% comparing 57 s/BP and 75 s/BP datasets. Overall image quality was determined as equal or superior to 75 s in 80% and 69%, respectively. In the semiquantitative lesion-based analyses, a significant equivalence was found between the 75 s/BP and 57 s/BP PET/CT images both for SUV_max (p = 0.004) and SUV_mean (p = 0.003). Conclusion: The results of this study demonstrate significant clinical and semiquantitative equivalence between short acquisition time of 57 s/BP and standard 75 s/BP 3D TOF [¹⁸F]-FDG PET/CT scanning, which may improve the patient’s workflow in routine practice.

Objectives: Primary hyperparathyroidism (PHPT) is associated with normal or elevated calcium levels and affects bone mineral density. The proportion of cases predisposed to metabolic bone disease is unknown in patients with PHPT. The aim of this study was to assess bone mineral density and bone quality in patients with normo- or hypercalcemic primary hyperparathyroidism undergoing baseline parathyroid gland assessment with [¹⁸F]fluorocholine PET/CT imaging. Methods: A total of 140 consecutive patients were enrolled in this observational study. All patients with normo- or hypercalcemic primary hyperparathyroidism underwent dual-energy X-ray absorptiometry (DXA) for assessment of bone mineral density (BMD) and trabecular bone score (TBS). [¹⁸F]fluorocholine PET/CT was performed in all patients for the detection and localization of parathyroid adenoma. Hyper- and normocalcemic patients were compared with regard to the proportion of osteoporosis and osteopenia, T-Score, TBS, serum calcium, phosphorus and parathyroid hormone levels, the maximum standardized uptake value (SUVmax) in PET/CT imaging, and laboratory results. Results: The majority of patients was female (88.57%) and had a pathologic bone mineral density (52.86%). Overall, 33 patients had osteoporosis and 41 osteopenia. The mean lumbar T-Score was −1.48 (SD 1.37) and the T-Score of the femoral neck was −1.21 (SD 0.92). Mean TBS was also decreased (−2.13). No difference was found between normo- or hypercalcemic patients regarding bone metabolism and imaging parameters. Conclusions: More than half of patients with normo- or hypercalcemic PHPT showed abnormal BMD. First-line [¹⁸F]fluorocholine PET/CT identified parathyroid adenoma in a high proportion of patients, even in patients with normocalcemic PHPT. The early evaluation of metabolic bone disease seems desirable in clinical management of females with PHPT.