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Purpose: We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies.Materials and Methods: A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation).Results: For the first evaluation, the score for T2WI (4.68 +/- 0.65) was significantly higher than that for CT (3.54 +/- 1.02) or T1WI (3.71 +/- 0.97) (P < 0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74 +/- 0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06 +/- 0.68) or T1WI (2.23 +/- 0.61) (P < 0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72 +/- 0.54) localized the lesion significantly more convincingly than PET/CT (2.23 +/- 0.50) or PET/T1WI (2.29 +/- 0.53) (P < 0.01).Conclusion: PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies. [ABSTRACT FROM AUTHOR]

Purpose: We developed a new type of scintillation detector ring for positron emission tomography (PET). In this device the scintillation detectors were connected with 2.6 m length optic fibers to transport scintillation light to a photomultiplier (PMT) located apart from the detector rings. The present study aimed to test the possibility of simultaneous imaging with PET and magnetic resonance imaging (MRI) by means of the present PET device in ex vivo rat brain.Materials and Methods: The scintillation detector ring of 4 cm diameter was located in a magnetic field of 0.15 T open MRI. Simultaneous measurements of PET and MRI were performed in ex vivo rat brain after injection of (18)F-fluorodeoxyglucose ((18)F-FDG) 37 MBq and (18)F-NaF 37 MBq. Simultaneous data acquisition was performed for 10 min for PET and 5 min for T1-weighted MRI.Results: Simultaneous imaging of PET and MRI was possible without noticeable image distortion in the PET and MRI scans. In the fusion images, high uptake of (18)F-FDG was identified in the Harderian glands and striatum. High uptake of (18)F-NaF was found in the skull base and vault.Conclusions: The present study indicated the possibility of simultaneous imaging of PET and MRI by means of optic fiber-based scintillation detectors. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the diagnostic accuracy of positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) for staging/restaging, evaluating the treatment response, and screening of recurrence in patients with malignant lymphoma (ML) during long-term follow-up, and to compare that with computer tomography (CT)/magnetic resonance imaging (MRI). Methods: The study was conducted in 59 ML patients who underwent whole-body 18F-FDG-PET examinations three times or more from October 1998 to August 2006. The location of the lesions in the patients with positive findings on 18F-FDG-PET and/or the corresponding CT/MRI was classified into supradiaphragmatic (n = 10), infradiaphragmatic (n = 7), and extranodal sites (n = 20), and the findings were compared on a site basis according to the gold standard, which consisted of all clinical information available, including follow-up results. Results: A total of 156 18F-FDG-PET examinations for which the corresponding CT/MRI images were also available were evaluated, and a total of 305 sites showed positive findings on 18F-FDG-PET and/or CT/MRI. Concordant positive findings were obtained in 76% for staging/restaging, 34% for evaluation of the treatment response, and 50% for screening of recurrence. The accuracy of 18F-FDG-PET versus CT/MRI was 92% versus 84% (P = 0.06) for staging/restaging, 84% versus 50% (P < 0.05) for the evaluation of the treatment response, and 83% versus 72% (P = 0.21) for the screening of recurrence. At pathologic sites with discrepant findings between 18F-FDG-PET and CT/MRI (n = 122), the frequency of accurate diagnosis by 18F-FDG-PET (76%) was higher than that by CT/MRI (24%), especially for the evaluation of the treatment response. Conclusions: 18F-FDG-PET is expected to play a significant role in the management of ML patients even after effective treatment is initiated. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to prospectively investigate the relationship between high accumulation of 2-deoxy-2-[(18)F] fluoro-D: -glucose (FDG) in the oral cavity and dental infections on positron emission tomography/computed tomography (PET/CT). Methods: FDG-PET/CT scans of 103 patients who underwent a health screening were evaluated. The dental examination was performed prior to each PET/CT scan, and dental infections were assessed. Dental infections were classified into six blocks. The severity of dental caries was classified into five grades, and periodontal disease and apical periodontitis were classified into three grades. Two radiologists classified the PET images in the same manner as the dental examination. They evaluated the intensity of FDG uptake by a four-point visual PET image score for each block. The comparison of the dental examination, as a gold standard, and the visual PET image score was performed on a patient or block basis. Results: On a patient-based analysis, 21 of 103 patients (20.4%) showed PET positive findings in the oral cavity; 18 of the 21 patients (85.7%) had dental infections. On a block-based analysis, 25 of 605 blocks (4.1%) showed PET positive findings in the oral cavity; 22 of the 25 blocks (88.0%) had dental infections. On a detailed block-based analysis, a significant difference was observed between the presence of periodontal disease, or apical periodontitis and the positivity of the visual PET image findings (P < 0.01). Their severity correlated with the visual PET image score (P < 0.05). Conclusions: Periodontal disease or apical periodontitis, but not dental caries, caused FDG accumulation in the oral cavity. This finding should be taken into account when a head and neck FDG-PET study is interpreted. [ABSTRACT FROM AUTHOR]

Objective: A planar positron imaging system (PPIS) enables whole-body dynamic imaging of radiopharmaceuticals labeled with positron-emitting nuclides. We evaluated the difference in the brain and whole-body pharmacokinetics of (11)C-diphenylhydantoin ((11)C-DPH) between intravenous and duodenal administration in rats. Methods: Male Wistar rats (8 weeks old, mean body weight 250 g) were examined under anesthesia. A tracer amount of (11)C-DPH (2 microg or less; about 5 MBq) was injected into the tail vein (n = 3) or duodenum (n = 3). Immediately following the administration, PPIS scans were obtained for 20 min. Regions of interest (ROIs) were set on the brain, heart, liver, intestinal field, and urinary bladder, identified on the integrated images. The relative uptake value (RUV, %) was calculated as the regional count divided by the whole-body count multiplied by 100. Sequential changes in the RUV for each ROI were analyzed for the brain and other organs. Results: Following intravenous injection of (11)C-DPH, the RUV in the brain was 1.59 +/- 0.07%, 1.53 +/- 0.09%, 1.40 +/- 0.09%, and 1.38 +/- 0.08% at 5 min, 10 min, 15 min, and 20 min after the injection, respectively. After duodenal administration, the corresponding values were 0.54 +/- 0.16%, 1.01 +/- 0.12%, 1.43 +/- 0.24%, and 1.52 +/- 0.06%, respectively. The (11)C-DPH distribution was significantly lower at 5 min and 10 min following duodenal administration than after intravenous injection (P < 0.01). Radioactivity in the urinary bladder was identified by 20 min after both intravenous injection and duodenal administration. Conclusions: The present study demonstrated a difference in the brain distribution of (11)C-DPH between intravenous and duodenal administration in rats. Use of the PPIS is feasible for the evaluation of the pharmacokinetics in both the target organ and the whole body in small animals. [ABSTRACT FROM AUTHOR]

Cerebral blood flow (CBF) and mean transit time (MTT) can be determined by dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) and deconvolution with an arterial input function (AIF). However, deconvolution with a singular value decomposition (SVD) method is sensitive to the tracer delay that often occurs in patients with cerebrovascular disease. We developed a delay correction method that determines tracer delay by means of least-squares fitting pixel-by-pixel. The corrected CBF was determined by SVD deconvolution after time-shifting of the measured concentration curve. The simulations showed that the corrected CBF was insensitive to tracer delay irrespective of the vascular model, although CBF fluctuation increased slightly. We applied the delay correction to the CBF and MTT images acquired for a patient with hyperacute stroke and unilateral occlusion of the middle cerebral artery. The delay correction modulated the contrast of perfusion images. For hyperacute stroke patients, tracer delay correction is essential to obtain reliable CBF and MTT images when SVD deconvolution is used. [Copyright &y& Elsevier]

BACKGROUND: This study evaluated the usefulness of positron emission tomography with 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET) in monitoring the response to continuous arterial infusion chemotherapy (CAI) combined with external radiation therapy (ERT) for unresectable pancreatic carcinomas. METHODS: Ten patients with unresectable pancreatic cancer were enrolled in this study. Computed tomography (CT) and FDG-PET were done before and after CAI (5-fluorouracil [FU], 500 mg/body per day) combined with ERT (50.4 Gy total dose). Tumor regression was evaluated by standardized uptake value (SUV) with FDG-PET, tumor size on CT, and changes in blood levels of carbohydrate antigen (CA) 19-9. The three methods of evaluation were compared. RESULTS: The ten patients were classified in three categories. In category I, tumor changes evident on CT and FDG-PET were consistent. In category II, CT could not accurately detect the area of the tumor. However, tumor uptake on FDG-PET decreased markedly after the treatment in category II patients. In category III, both CT and FDG-PET detected the tumor, as in category I. Although there was no definite change in tumor size on CT, FDG-PET uptake was markedly reduced immediately after the treatment. Reduction in tumor size did not appear on CT until 2 months later. CONCLUSIONS: FDG-PET aids in analysis of the effectiveness of chemotherapy and/or radiotherapy. [ABSTRACT FROM AUTHOR]

In quantitative functional neuroimaging with positron emission tomography (PET) and magnetic resonance imaging (MRI), cerebral blood volume (CBV) and its three components, arterial, capillary, and venous blood volumes are important factors. The arterial fraction for systemic circulation of the whole body has been reported to be 20-30%, but there is no report of this fraction in the brain. In the present study, we estimated the arterial fraction of CBV with PET in the living human brain. C(15)O and dynamic H2(15)O PET studies were performed in each of seven healthy subjects to determine the CBV and arterial blood volume (Va), respectively. A two-compartment model (influx: K1, efflux: k2) that takes Va into account was applied to describe the regional time-activity curve of dynamic H2(15)O PET. K1, k2 and Va were calculated by a non-linear least squares fitting procedure. The Va and CBV values were 0.011 +/- 0.004 ml/ml and 0.031 +/- 0.003 ml/ml (mean +/- SD), respectively, for cerebral cortices. The arterial fraction of CBV was 37%. Considering the limited first-pass extraction fraction of H2(15)O, the true arterial fraction of CBV is estimated to be about 30%. The estimated arterial fraction of CBV was quite similar to that of the systemic circulation, whereas it was greater than that (16%) widely used for the measurement of cerebral metabolic rate of oxygen (CMRO2) using PET. The venous plus capillary fraction of CBV was 63-70% which is a important factor for the measurement of CMRO2 with MRI. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to investigate the association between very late-onset schizophrenia-like psychosis (VLOSLP), a schizophrenia spectrum disorder with an onset of ≥60 years, and Alzheimer's disease (AD) using biomarkers., Design: Retrospective cross-sectional study., Setting: Neuropsychology clinic of Osaka University Hospital in Japan., Participants: Thirty-three participants were classified into three groups: eight AD biomarker-negative VLOSLP (VLOSLP-AD), nine AD biomarker-positive VLOSLP (VLOSLP+AD), and sixteen amnestic mild cognitive impairment due to AD without psychosis (aMCI-P+AD) participants., Measurements: Phosphorylated tau levels in the cerebrospinal fluid and 18 F-Florbetapir positron emission tomography results were used as AD biomarkers. Several scales (e.g. the Mini-Mental State Examination (MMSE), Wechsler Memory Scale-Revised (WMS-R) Logical Memory (LM) I and II, and Neuropsychiatric Inventory (NPI)-plus) were conducted to assess clinical characteristics., Results: Those in both VLOSLP-AD and +AD groups scored higher than those in aMCI-P+AD in WMS-R LM I. On the other hand, VLOSLP+AD participants scored in between the other two groups in the WMS-R LM II, with only VLOSLP-AD participants scoring significantly higher than aMCI-P+AD participants. There were no significant differences in sex distribution and MMSE scores among the three groups or in the subtype of psychotic symptoms between VLOSLP-AD and +AD participants. Four VLOSLP-AD and five VLOSLP+AD participants harbored partition delusions. Delusion of theft was shown in two VLOSLP-AD patients and five VLOSLP+AD patients., Conclusion: Some VLOSLP patients had AD pathology. Clinical characteristics were different between AD biomarker-positive and AD biomarker-negative VLOSLP, which may be helpful for detecting AD pathology in VLOSLP patients.

Glypican-1 (GPC1) is overexpressed in several solid cancers and is associated with tumor progression, whereas its expression is low in normal tissues. This study aimed to evaluate the potential of an anti-GPC1 monoclonal antibody (GPC1 mAb) labeled with 89 Zr or 211 At as a theranostic target in pancreatic ductal adenocarcinoma. Methods: GPC1 mAb clone 01a033 was labeled with 89 Zr or 211 At with a deferoxamine or decaborane linker, respectively. The internalization ability of GPC1 mAb was evaluated by fluorescence conjugation using a confocal microscope. PANC-1 xenograft mice ( n = 6) were intravenously administered [ 89 Zr]GPC1 mAb (0.91 ± 0.10 MBq), and PET/CT scanning was performed for 7 d. Uptake specificity was confirmed through a comparative study using GPC1-positive (BxPC-3) and GPC1-negative (BxPC-3 GPC1-knockout) xenografts (each n = 3) and a blocking study. DNA double-strand breaks were evaluated using the γH2AX antibody. The antitumor effect was evaluated by administering [ 211 At]GPC1 mAb (∼100 kBq) to PANC-1 xenograft mice ( n = 10). Results: GPC1 mAb clone 01a033 showed increased internalization ratios over time. One day after administration, a high accumulation of [ 89 Zr]GPC1 mAb was observed in the PANC-1 xenograft (SUV max , 3.85 ± 0.10), which gradually decreased until day 7 (SUV max , 2.16 ± 0.30). The uptake in the BxPC-3 xenograft was significantly higher than in the BxPC-3 GPC1-knockout xenograft (SUV max , 4.66 ± 0.40 and 2.36 ± 0.36, respectively; P = 0.05). The uptake was significantly inhibited in the blocking group compared with the nonblocking group (percentage injected dose per gram, 7.3 ± 1.3 and 12.4 ± 3.0, respectively; P = 0.05). DNA double-strand breaks were observed by adding 150 kBq of [ 211 At]GPC1 and were significantly suppressed by the internalization inhibitor (dynasore), suggesting a substantial contribution of the internalization ability to the antitumor effect. Tumor growth suppression was observed in PANC-1 mice after the administration of [ 211 At]GPC1 mAb. Internalization inhibitors (prochlorperazine) significantly inhibited the therapeutic effect of [ 211 At]GPC1 mAb, suggesting an essential role in targeted α-therapy. Conclusion: [ 89 Zr]GPC1 mAb PET showed high tumoral uptake in the early phase after administration, and targeted α-therapy using [ 211 At]GPC1 mAb showed tumor growth suppression. GPC1 is a promising target for future applications for the precise diagnosis of pancreatic ductal adenocarcinoma and GPC1-targeted theranostics., (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)

Purpose: To identify qualitative MRI features of non-(contrast)-enhancing tumor (nCET) in glioblastoma's T2-FLAIR hyperintense lesion., Methods: Thirty-three histologically confirmed glioblastoma patients whose T1-, T2- and contrast-enhanced T1-weighted MRI and 11 C-methionine positron emission tomography (Met-PET) were available were included in this study. Met-PET was utilized as a surrogate for tumor burden. Imaging features for identifying nCET were searched by qualitative examination of 156 targets. A new scoring system to identify nCET was established and validated by two independent observers., Results: Three imaging features were found helpful for identifying nCET; "Bulky gray matter involvement", "Around the rim of contrast-enhancement (Around-rim)," and "High-intensity on T1WI and low-intensity on T2WI (HighT1LowT2)" resulting in an nCET score = 2 × Bulky gray matter involvement - 2 × Around-rim + HighT1LowT2 + 2. The nCET score's classification performances of two independent observers measured by AUC were 0.78 and 0.80, with sensitivities and specificities using a threshold of four being 0.443 and 0.771, and 0.916 and 0.768, respectively. The weighted kappa coefficient for the nCET score was 0.946., Conclusion: The current investigation demonstrated that qualitative assessments of glioblastoma's MRI might help identify nCET in T2/FLAIR high-intensity lesions. The novel nCET score is expected to aid in expanding treatment targets within the T2/FLAIR high-intensity lesions., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose of the Report: L-type amino acid transporter-1 (LAT1) is a tumor-specific transporter expressed in various tumor types, with minimal expression in normal organs. We previously demonstrated 18F-fluoro-borono-phenylalanine (18F-FBPA) as a selective PET probe for LAT1 in a preclinical study. Herein, we evaluated LAT1 expression in preoperative patients with lung or mediastinal tumors using 18F-FBPA PET and immunofluorescence staining., Patients and Methods: The study population included patients with histopathological diagnosis (n = 55): primary lung cancers (n = 21), lung metastases (n = 6), mediastinal tumors (n = 15), and benign lesion (n = 13). PET scanning was performed 1 hour after the injection of 18F-FBPA (232 ± 32 MBq). Immunofluorescence staining was performed on the resected tumor sections using LAT1 antibody. LAT1 staining was graded on a 4-grade scale and compared with the SUVmax on 18F-FBPA PET., Results: A positive correlation was observed between the SUVmax of 18F-FBPA PET and LAT1 expression by immunofluorescence staining (r = 0.611, P < 0.001). The SUVmax of 18F-FBPA was 3.92 ± 1.46 in grade 3, 3.21 ± 1.82 in grade 2, 2.33 ± 0.93 in grade 1, and 1.50 ± 0.39 in grade 0 of LAT1 expression. Although 18F-FBPA PET showed variable uptake in lung cancers and mediastinal tumors, benign lesions showed significantly lower SUVmax than those in malignant lesions (P < 0.01)., Conclusions: Uptake on 18F-FBPA PET reflected the expression level of LAT1 in lung and mediastinal tumors. It was suggested that 18F-FBPA PET can be used for the precise characterization of the tumor in pretreatment evaluation., Competing Interests: Conflicts of interest and sources of funding: The authors declare no potential conflicts of interest relevant to this study. This study was funded by the QiSS program of OPERA (grant number: JPMJOP1721) from the Japan Science and Technology Agency., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: Integrin α v is a key regulator in the pathophysiology of hepatic fibrosis. In this study, we evaluated the potential utility of an integrin α v β 3 positron emission tomography (PET) radiotracer, 18 F-labeled cyclic arginine-glycine-aspartic acid penta-peptide ([ 18 F]F-FPP-RGD 2 ), for detecting hepatic integrin α v and function in nonalcoholic steatohepatitis (NASH) model rats using integrin α v siRNA., Methods: NASH model rats were produced by feeding a choline-deficient, low-methionine, high-fat diet for 8 weeks. PET/computerized tomography imaging and quantification of integrin α v protein, serum aspartate aminotransferase, and alanine aminotransferase were performed 1 week after single intravenous injection of integrin α v siRNA., Results: Integrin α v siRNA (0.1 and 0.5 mg/kg) dose-dependently decreased hepatic integrin α v protein concentrations in control and NASH model rats. The hepatic mean standard uptake value of [ 18 F]F-FPP-RGD 2 was decreased dose-dependently by integrin α v siRNA. The mean standard uptake value was positively correlated with integrin α v protein levels in control and NASH model rats. Serum aspartate aminotransferase and alanine aminotransferase concentrations were also decreased by siRNA injection and correlated with liver integrin α v protein expression levels in NASH model rats., Conclusion: This study suggests that [ 18 F]F-FPP-RGD 2 PET imaging is a promising radiotracer for monitoring hepatic integrin α v protein levels and hepatic function in NASH pathology., Competing Interests: Conflict of InterestShuichi Hiroyama, Keiko Matsunaga, Miwa Ito, Hitoshi Iimori, Ippei Morita, Jun Nakamura, Eku Shimosegawa, and Kohji Abe declare that they have no competing interests., (© The Author(s), under exclusive licence to Korean Society of Nuclear Medicine 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Objective: 11 C-PHNO is a PET radioligand most specific to dopamine D 3 receptor (D 3 R). The long scan duration of 120 min used in quantification of 11 C-PHNO binding to D 3 R in previous studies is challenging to subjects. The main objective of this study was to investigate the effects of shorter scan times on the binding of 11 C-PHNO to D 3 R and test-retest reliability using the latest digital whole-body PET system., Methods: Two 120-min 11 C-PHNO brain scans were performed in 7 healthy subjects using a digital whole-body PET/CT. The binding potential relative to non-displaceable tracer in the tissue (BP ND ) of D 3 R-rich regions: the pallidum, ventral striatum (VST), substantia nigra (SN) and hypothalamus, were quantified using the simplified reference tissue model. The bias, correlation, and test-retest reliability of BP ND , which includes the test-retest variability (TRV) and intraclass correlation coefficient (ICC), were evaluated and compared between scans of shorter durations (40-110 min post-injection) and the original 120-min scan acquisitions., Results: Progressively, shorter scan durations were associated with underestimation of BP ND , slightly decreased correlation with 120-min derived BP ND , and decrease in test-retest reliability. The BP ND values of the pallidum, VST and SN from the shortened 90-min scans showed excellent correlation with those derived from the 120-min scans (determination coefficients > 0.98), and the bias within 5%. The test-retest reliability of BP ND in these regions derived from 90-min scan (TRV of 3% in the VST and pallidum, 7% in the SN and the ICC exceeded 0.88) was comparable to those obtained in previous 120-min studies using brain-dedicated PET scanners. In the hypothalamus, the BP ND values obtained from scan-time less than 110 min showed bias larger than 5% and the TRV more than 9%., Conclusion: The scan-time shortening causes bias and decreasing test-retest reliability of 11 C-PHNO BP ND . However, in the whole-body PET system, 90-min scan duration was sufficient for estimating the 11 C-PHNO BP ND in the D 3 R-rich striatum and SN with small bias and at the test-retest reliability comparable to those derived from 120-min scans using the brain-dedicated PET systems., (© 2023. The Author(s).)

Purpose: Integrins α v are key molecules in the pathogenesis of fibrosis in multiple organs. To assess the potential utility of integrin α v β 3 imaging for idiopathic pulmonary fibrosis (IPF), we evaluated an 18 F-FPP-RGD 2 PET probe in a rat model of bleomycin-induced lung fibrosis., Methods: Pulmonary fibrosis was induced by single intratracheal instillation of bleomycin (3 mg/rat). Positron emission tomography (PET)/computerized tomography scans were performed 4 weeks after bleomycin administration using 18 F-FPP-RGD 2 . Total distribution volume (V T ) was estimated using one-tissue/two-compartment, two-tissue/three-compartment models, and Logan graphical analysis (Logan plot; t* = 30 min). Plasma-free fractions were estimated from images of the left ventricle. Correlation between Logan V T and lung pathology was assessed by Spearman's rank correlation., Results: Histopathological evaluation demonstrated the development of fibrosis in IPF-model group. Integrin α v protein expression and lung radioactivity were higher in IPF-model group compared with control group. The lung radioactivity of 18 F-FPP-RGD 2 rapidly reached the peak after administration and then gradually decreased, whereas left ventricular radioactivity rapidly disappeared. Logan graphical analysis was found to be suitable for 18 F-FPP-RGD 2 kinetic analysis in the IPF-model lung. Logan V T values for 18 F-FPP-RGD 2 were significantly higher in IPF rats compared with control rats and strongly correlated with lung fibrosis, pathology, integrin α v protein expression, and oxygen partial pressure., Conclusion: Our findings demonstrate that the integrin α v β 3 PET probe 18 F-FPP-RGD 2 can detect pathophysiological changes in lungs, including fibrosis accompanying upregulated integrin α v of IPF-model rats. These findings support the utility of 18 F-FPP-RGD 2 PET imaging for the pathophysiological evaluation of pulmonary fibrosis., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To investigate whether whole-body dynamic positron emission tomography (PET) is useful for differentiating benign and malignant lesions., Methods: In this retrospective study, data from a cohort of 146 lesions from 187 patients who consecutively underwent whole-body dynamic PET scans at our hospital for suspected lesions in the lung, lymph nodes, liver, bone, esophagus, and colon were analyzed. Patients with malignant lymphomas, accumulations > 5 cm in length along the long axis of the esophagus, or lesions in the colon in which the site of accumulation moved during the imaging period were excluded. Patients were administered 3.7 MBq/kg of fluorine-18-fluorodeoxyglucose (F-18 FDG), and dynamic imaging was initiated 60 min after administration. We defined the 60-65, 65-70, 70-75, and 75-80 min time mark as the first, second, third, and fourth pass, respectively. The static image is the summed average of all the four pass images. We measured the accumulation in the mean image of the whole-body dynamic PET scan, which was arithmetically similar to the maximum standardized uptake value (SUVmax) throughout the whole-body static images obtained during 20 min of imaging (S-SUVmax). The ratio of SUVmax in the dynamic first pass(60-65 min after FDG administration) and fourth pass(75-80 min after FDG administration) was calculated as R-SUVmax., Results: The S-SUVmax in the lung, lymph nodes, and bone did not differ significantly between the benign and malignant groups. However, there was a significant difference in R-SUVmax, which was > 1 in most malignant lesions indicating an increase in accumulation during routine scan time. Significant differences were observed between benign and malignant lesions of the liver in both S-SUVmax and R-SUVmax values, with the latter being > 1 in most malignant lesions., Conclusions: Whole-body dynamic PET for 20 min starting 1 h after FDG administration improved the accuracy of malignant lesion detection in the liver, lymph nodes, lung, and bone. The incremental improvement was small, and the FDG dynamics in the distribution of values between benign and malignant overlapped. Additional information from whole-body dynamic imaging can help detect malignant lesions in these sites without increasing patient burden or prolonging imaging time., (© 2022. The Author(s) under exclusive licence to The Japanese Society of Nuclear Medicine.)

Background: This study aimed to identify cases of potential prodromal DLB in very late-onset schizophrenia-like psychosis (VLOSLP), using indicative biomarkers of dementia with Lewy bodies (DLB), and to evaluate the characteristics of psychosis as prodromal DLB., Methods: Data of patients with VLOSLP without dementia and Parkinsonism, who underwent testing for at least one indicative biomarker of DLB, were retrospectively collected from the database of the psychiatry clinic at the Osaka University Hospital. Patients were divided into two groups based on the positive (VLOSLP+LB) and negative (VLOSLP-LB) results of the indicative biomarkers of DLB. Age, gender, cognitive battery scores, prevalence of each type of delusions and hallucinations, cerebral volume, and cerebral perfusion were compared between the two groups., Results: Eleven VLOSLP+LB and 23 VLOSLP-LB participants were enrolled. There were no significant differences in age, proportion of females, and MMSE scores between the two groups. The standardized score of the digit symbol substitution test was significantly lower in the VLOSLP+LB than in VLOSLP-LB group (6.9 [3.1] vs. 10.0 [2.7], p = 0.005). The prevalence of visual hallucinations was significantly higher in the VLOSLP+LB group than in the VLOSLP-LB group (81.8% vs. 26.1%, p = 0.003). Auditory hallucinations were prevalent in both groups (43.5% in VLOSLP-LB, and 45.5% in VLOSLP+LB). Among patients with auditory hallucinations, auditory hallucinations without coexistent visual hallucinations tended to be more prevalent in VLOSLP-LB (7 out of 10) than in VLOSLP+LB patients (1 out of 5). Although cerebral volume was not different in any region, cerebral perfusion in the posterior region, including the occipital lobe, was significantly lower in the VLOSLP+LB group., Conclusions: Psychomotor slowing, visual hallucinations, and reduced perfusion in the occipital lobe may be suggestive of prodromal DLB in VLOSLP patients, even though the clinical manifestations were similar in many respects between VLOSLP+LB and VLOSLP-LB. Although auditory hallucinations were prevalent in both groups, most patients in VLOSLP+LB complained of auditory hallucinations along with visual hallucinations. Future studies with a larger number of patients without selection bias are desirable., (© 2022. The Author(s).)

Astatine ( 211 At) is an alpha-emitter with a better treatment efficacy against differentiated thyroid cancer compared with iodine ( 131 I), a conventional beta-emitter. However, its therapeutic comparison has not been fully evaluated. In this study, we compared the therapeutic effect between [ 211 At]NaAt and [ 131 I]NaI. In vitro analysis of a double-stranded DNA break (DSB) and colony formation assay were performed using K1-NIS cells. The therapeutic effect was compared using K1-NIS xenograft mice administered with [ 211 At]NaAt (0.4 MBq (n = 7), 0.8 MBq (n = 9), and 1.2 MBq (n = 4)), and [ 131 I]NaI (1 MBq (n = 4), 3 MBq (n = 4), and 8 MBq (n = 4)). The [ 211 At]NaAt induced higher numbers of DSBs and had a more reduced colony formation than [ 131 I]NaI. In K1-NIS mice, dose-dependent therapeutic effects were observed in both [ 211 At]NaAt and [ 131 I]NaI. In [ 211 At]NaAt, a stronger tumour-growth suppression was observed, while tumour regrowth was not observed until 18, 25, and 46 days after injection of 0.4, 0.8, and 1.2 MBq of [ 211 At]NaAt, respectively. While in [ 131 I]NaI, this was observed within 12 days after injection (1, 3, and 8 MBq). The superior therapeutic effect of [ 211 At]NaAt suggests the promising clinical applicability of targeted alpha therapy using [ 211 At]NaAt in patients with differentiated thyroid cancer refractory to standard [ 131 I]NaI treatment.