This study evaluated the performance of the Biograph Vision digital PET/CT system according to the NEMA NU 2-2012 standard (published by the National Electrical Manufacturers Association [NEMA]) to allow for a reliable, reproducible, and intersystemcomparable performance measurement. Methods: The new digital PET/CT system features silicon photomultiplier-based detectors with 3.2-mm lutetium oxyorthosilicate crystals and full coverage of the scintillator area. The PET components incorporate 8 rings of 38 detector blocks, and each block contains 4 • 2 mini blocks. Each mini block consists of a 5 • 5 lutetium oxyorthosilicate array of 3.2 • 3.2 • 20 mm crystals coupled to a silicon photomultiplier array of 16 • 16 mm, resulting in an axial field of view of 26.1 cm. In this study, PET/CT system performance was evaluated for conformation with the NEMA NU 2-2012 standard, with additional measurements described in the new NEMA NU 2-2018 standard. Spatial resolution, sensitivity, count-rate performance, accuracy of attenuation and scatter correction, image quality, coregistration accuracy, and time-of-flight performance were determined. Measurements were directly compared with results from its predecessor, the Biograph mCT Flow, using existing literature. Moreover, feasibility to comply with the European Association of Nuclear Medicine Research Ltd. (EARL) criteria was evaluated, and some illustrative patient PET images were obtained. Results: The Biograph Vision showed a transverse and axial spatial resolution of 3.6 and 3.5 mm, respectively, in full width at half maximum at a 1-cm offset from the center of the field of view (measured with a 22 Na 0.25-mm point source), a NEMA sensitivity of 16.4 kcps/MBq, and a NEMA peak noise-equivalent count-rate of 306 kcps at 32 kBq/mL. Time-of-flight resolution varied from 210 to 215 as count-rate increased up to the peak noise-equivalent count-rate. The overall image contrast seen with the NEMA image quality phantom ranged from 77.2% to 89.8%. Furthermore, the system was able to comply with the current and future EARL performance criteria. Conclusion: The Biograph Vision outperforms the analog Biograph mCT Flow, and the system is able to meet European harmonizing performance standards.

Bone scintigraphy with (99m)Tc-HDP may detect cardiac involvement in patients with ATTR amyloidosis prior to echocardiographic evidence of cardiac involvement. Cardiac uptake on bone scintigraphy correlates with severity of cardiac involvement using echocardiography, ECG and cardiac biomarkers. Visual grading and calculation of H/S ratio on planar imaging are the preferred methods to assess cardiac uptake.

Purpose To assess the value of baseline and restaging fluorine 18 (F) fluorodeoxyglucose (FDG) positron emission tomography (PET) radiomics in predicting pathologic complete response to neoadjuvant chemotherapy and radiation therapy (NCRT) in patients with locally advanced esophageal cancer. Materials and Methods In this retrospective study, 73 patients with histologic analysis-confirmed T1/N1-3/M0 or T2-4a/N0-3/M0 esophageal cancer were treated with NCRT followed by surgery (Chemoradiotherapy for Esophageal Cancer followed by Surgery Study regimen) between October 2014 and August 2017. Clinical variables and radiomic features from baseline and restaging F-FDG PET were selected by univariable logistic regression and least absolute shrinkage and selection operator. The selected variables were used to fit a multivariable logistic regression model, which was internally validated by using bootstrap resampling with 20 000 replicates. The performance of this model was compared with reference prediction models composed of maximum standardized uptake value metrics, clinical variables, and maximum standardized uptake value at baseline NCRT radiomic features. Outcome was defined as complete versus incomplete pathologic response (tumor regression grade 1 vs 2-5 according to the Mandard classification). Results Pathologic response was complete in 16 patients (21.9%) and incomplete in 57 patients (78.1%). A prediction model combining clinical T-stage and restaging NCRT (post-NCRT) joint maximum (quantifying image orderliness) yielded an optimism-corrected area under the receiver operating characteristics curve of 0.81. Post-NCRT joint maximum was replaceable with five other redundant post-NCRT radiomic features that provided equal model performance. All reference prediction models exhibited substantially lower discriminatory accuracy. Conclusion The combination of clinical T-staging and quantitative assessment of post-NCRTF-FDG PET orderliness (joint maximum) provided high discriminatory accuracy in predicting pathologic complete response in patients with esophageal cancer. RSNA, 2018 Online supplemental material is available for this article.

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The first Siemens Biograph Vision PET/CT system (Siemens Healthineers, Knoxville, USA) was installed at the University Medical Center Groningen. Improved performance of this system could allow for a reduction in activity administration and/or scan duration. This study evaluates the effects of reduced scan duration in oncological 18 F-FDG PET imaging on quantitative and subjective imaging parameters and its influence on clinical image reading. Methods: Patients referred for a clinical PET/CT scan were enrolled in this study, received a weightbased 18 F-FDG injected activity, and underwent a 180 seconds per bed position (s/bp) list-mode PET acquisition. Acquired PET data were reconstructed using the clinically vendor recommended reconstruction protocol (hereinafter referred to as Clinical), using the Clinical protocol with additional 2 mm Gaussian filtering (hereinafter referred to as Clinical+G2) as well as conform European Association of Nuclear Medicine Research Ltd (EARL) specifications using different scan durations per bed position (180, 120, 60, 30, and 10 s). Reconstructed images were quantitatively assessed for comparison of standardized uptake values (SUVs) and noise. In addition, Clinically reconstructed images were qualitatively evaluated by three nuclear medicine physicians. Results: In total, 30 oncological patients (22 men, 8 women; age 48-88, mean ± SD 67 ± 9.6 years) received a single weight-based (3 MBq/kg) 18 F-FDG injected activity (weight 45-123 kg, mean ± SD 81 ± 15; activity 135-380 MBq, mean ± SD 241 ± 46.5). Significant differences in lesion SUVmax were found between the 180 s/bp images and the 30 and 10 s/bp images reconstructed using the Clinical protocols, whereas no differences were found in lesion SUVpeak. EARL compliant images did not show differences in lesion SUVmax or SUVpeak between scan durations. Quantitative parameters showed minimal deviation (~5%) in the 60 s/bp images. Further subjective image quality assessment was therefore conducted using the 60 s/bp images. Qualitative assessment revealed the influence of personal by on September 17, 2020. For personal use only. jnm.snmjournals.org Downloaded from 3 preference on physicians' willingness to adopt the 60 s/bp images in clinical practice. Although quantitative PET parameters differed minimally, an increase in noise was observed. Conclusions: Using the Biograph Vision PET/CT for oncological 18 F-FDG imaging, scan duration and/or activity administration could be reduced by a factor of three or more when using the Clinical+G2 or the EARL compliant reconstruction protocol, respectively.

In May 2018, the Biograph Vision PET/CT system was installed at the University Medical Center Groningen. This study evaluated the initial experiences with this new PET/CT system in terms of perceived image quality and semiquantitative analysis in comparison to the Biograph mCT as a reference. Methods: In total, 20 oncologic patients were enrolled and received a single 3 MBq/kg injected dose of 18 F-FDG followed by a dual-imaging PET scan. Ten patients were scanned on the Biograph mCT first, whereas the other 10 patients were scanned on the Biograph Vision first. The locally preferred clinically reconstructed images were blindly reviewed by 3 nuclear medicine physicians and scored (using a Likert scale of 1-5) on tumor lesion demarcation, overall image quality, and image noise. In addition, these clinically reconstructed images were used for semiquantitative analysis by measurement of SUVs in tumor lesions. Images acquired using reconstructions conform with the European Association of Nuclear Medicine Research Ltd. (EARL) specifications were also used for measurements of SUV in tumor lesions and healthy tissues for comparison between systems. Results: The 18 F-FDG dose received by the 14 men and 6 women (age range, 36-84; mean ± SD, 61 ± 16 y) ranged from 145 to 405 MBq (mean ± SD, 268 ± 59.3). Images acquired on the Biograph Vision were scored significantly higher on tumor lesion demarcation, overall image quality, and image noise than images acquired on the Biograph mCT (P , 0.001). The overall interreader agreement showed a Fleiss κ of 0.61 (95% confidence interval, 0.53-0.70). Furthermore, the SUVs in tumor lesions and healthy tissues agreed well (within 95%) between PET/CT systems, particularly when EARL-compliant reconstructions were used on both systems. Conclusion: In this initial study, the Biograph Vision showed improved image quality compared with the Biograph mCT in terms of lesion demarcation, overall image quality, and visually assessed signal-to-noise ratio. The 2 systems are comparable in semiquantitatively assessed image biomarkers in both healthy tissues and tumor lesions. Improved quantitative performance may, however, be feasible using the clinically optimized reconstruction settings.

Pre-treatment MR-IBMs were associated to radiation-induced xerostomia, which supported the hypothesis that the amount of predisposed fat within the parotid glands is associated with Xer. In addition, xerostomia prediction was improved with MR-IBMs compared to the reference model.

Successful treatment of cancer patients requires balancing of the dose, timing, and type of therapeutic regimen. Detection of increased cell death may serve as a predictor of the eventual therapeutic success. Imaging of cell death may thus lead to early identification of treatment responders and nonresponders, and to “patient‐tailored therapy.” Cell death in organs and tissues of the human body can be visualized, using positron emission tomography or single‐photon emission computed tomography, although unsolved problems remain concerning target selection, tracer pharmacokinetics, target‐to‐nontarget ratio, and spatial and temporal resolution of the scans. Phosphatidylserine exposure by dying cells has been the most extensively studied imaging target. However, visualization of this process with radiolabeled Annexin A5 has not become routine in the clinical setting. Classification of death modes is no longer based only on cell morphology but also on biochemistry, and apoptosis is no longer found to be the preponderant mechanism of cell death after antitumor therapy, as was earlier believed. These conceptual changes have affected radiochemical efforts. Novel probes targeting changes in membrane permeability, cytoplasmic pH, mitochondrial membrane potential, or caspase activation have recently been explored. In this review, we discuss molecular changes in tumors which can be targeted to visualize cell death and we propose promising biomarkers for future exploration.