Dataset Information

Evaluating [⁶⁸Ga]Ga-p14-032 as a Novel PET Tracer for Diagnosis Cerebral Amyloid Angiopathy.

ABSTRACT: Objective: We aimed to investigate the distribution of [⁶⁸Ga]Ga-p14-032, a novel PET ligand that binds to vascular amyloid, in patients diagnosed clinically with probable cerebral amyloid angiopathy (CAA) compared with patients with Alzheimer's disease (AD) and normal controls (NC). Methods: This longitudinal cohort study was composed of 10 subjects (three probable CAA patients, two AD patients, five NC subjects), recruited from a clinic in China. CAA patients had a history of lobar intracerebral hemorrhage (ICH) and met modified Boston criteria for probable CAA. All participants were aged at least 55 years and underwent [⁶⁸Ga] Ga-p14-032 PET/CT or/and PET/MRI, and the Montreal Cognitive Assessment on initial assessment. Demographics were measured at baseline (diabetes, hypertension, hypercholesterolemia, ischemic stroke, and ICH). Two PET imaging experts reviewed the PET images with cortical standardized uptake value ratio (SUVr) displayed on a color scale and visually classified the images as positive or negative. The mean of SUVr was calculated using the pons as reference. Results: In CAA patients, PET scans were positive in regions with higher numbers of CMBs. No significant signal was seen in AD subjects or controls. The relative [⁶⁸Ga]Ga-p14-032 retention in the cortex was stronger in patients with CAA than AD and NC (median SUVr 2.68 ± 1.53 vs. 1.77 ± 0.08 and 0.83 ± 0.24). Conclusions: Our results provide early evidence that the [⁶⁸Ga] Ga-p14-032 PET probe binds preferentially to vascular amyloid and may be a useful tracer for diagnosing CAA.

SUBMITTER: Zhang Q

PROVIDER: S-EPMC8580011 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature

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Publications

Evaluating [68Ga]Ga-p14-032 as a Novel PET Tracer for Diagnosis Cerebral Amyloid Angiopathy.

Zhang Qihui Q Zhao Xiaobin X Lei Peng P Kung Hank F HF Yang Zhi Z Zhu Lin L Wang Shujing S Zhu Hua H Meng Xiangxi X Duan Yunyun Y Sun Li L Pan Jianwei J Ma Ruixue R Hong Haiyan H Zhao Xingquan X Demchuk Andrew A Smith Eric E EE Wang Yongjun Y

Frontiers in neurology 20211027

Objective: We aimed to investigate the distribution of [68Ga]Ga-p14-032, a novel PET ligand that binds to vascular amyloid, in patients diagnosed clinically with probable cerebral amyloid angiopathy (CAA) compared with patients with Alzheimer's disease (AD) and normal controls (NC). Methods: This longitudinal cohort study was composed of 10 subjects (three probable CAA patients, two AD patients, five NC subjects), recruited from a clinic in China. CAA patients had a hist ...[more]

PMID: 34777194

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Project description:Rationale: Early discovery, accurate diagnosis, and staging of lung cancer is essential for patients to receive appropriate treatment. PET/CT has become increasingly recognized as a valuable imaging modality for these patients, but there remains room for improvement in PET tracers. We aimed to evaluate the feasibility of using [68Ga]Ga-FAPI-RGD, a dual-targeting heterodimeric PET tracer that recognizes both fibroblast activation protein (FAP) and integrin αvβ3 for detecting lung neoplasms, by comparing it with [18F]FDG and single-targeting tracers [68Ga]Ga-RGD and [68Ga]Ga-FAPI. Methods: This was a pilot exploratory study of patients with suspected lung malignancies. All 51 participants underwent [68Ga]Ga-FAPI-RGD PET/CT, of which: 9 participants received dynamic scans, 44 participants also underwent [18F]FDG PET/CT scan within two weeks, 9 participants underwent [68Ga]Ga-FAPI PET/CT scan and 10 participants underwent [68Ga]Ga-RGD PET/CT scan. The final diagnosis was made based on histopathological analyses and clinical follow-up reports. Results: Among those who underwent dynamic scans, the uptake of pulmonary lesions increased over time. The optimal timepoint for a PET/CT scan was identified to be 2 h post-injection. [68Ga]Ga-FAPI-RGD had a higher detection rate of primary lesions than [18F]FDG (91.4% vs. 77.1%, p < 0.05), higher tumor uptake (SUVmax, 6.9 ± 5.3 vs. 5.3 ± 5.4, p < 0.001) and higher tumor-to-background ratio (10.0 ± 8.4 vs. 9.0 ± 9.1, p < 0.05), demonstrated better accuracy in mediastinal lymph node evaluation (99.7% vs. 90.9%, p < 0.001), and identified more metastases (254 vs. 220). There was also a significant difference between the uptake of [68Ga]Ga-FAPI-RGD and [68Ga]Ga-RGD of primary lesions (SUVmax, 5.8 ± 4.4 vs. 2.3 ± 1.3, p < 0.001). Conclusion: In our small scale cohort study, [68Ga]Ga-FAPI-RGD PET/CT gave a higher primary tumor detection rate, higher tracer uptake, and improved detection of metastases compared with [18F]FDG PET/CT, and [68Ga]Ga-FAPI-RGD also had advantages over [68Ga]Ga-RGD and was non-inferior to [68Ga]Ga-FAPI. We thus provide proof-of-concept for using [68Ga]Ga-FAPI-RGD PET/CT for diagnosing lung cancer. With the stated advantages, the dual-targeting FAPI-RGD should also be explored for therapeutic use in future studies.

Project description:68Ga-NODAGA-exendin-4 is a promising tracer for β-cell imaging using PET/CT. Possible applications include preoperative visualization of insulinomas and discrimination between focal and diffuse forms of congenital hyperinsulinism. There is also a significant role for this tracer in extending our knowledge on the role of β-cell mass in the pathophysiology of type 1 and type 2 diabetes by enabling noninvasive quantification of tracer uptake as a measure for β-cell mass. Calculating radiation doses from this tracer is important to assess its safety for use in patients (including young children) with benign diseases and healthy individuals. Methods: Six patients with hyperinsulinemic hypoglycemia were included. After intravenous injection of 100 MBq of the tracer, 4 successive PET/CT scans were obtained at 30, 60, 120, and 240 min after injection. Tracer activity in the pancreas, kidneys, duodenum, and remainder of the body were determined, and time-integrated activity coefficients for the measured organs were calculated. OLINDA/EXM software, version 1.1, was applied to calculate radiation doses using the reference adult male and female models and to estimate radiation doses to children. Results: The mean total effective dose for adults was very low (0.71 ± 0.07 mSv for a standard injected dose of 100 MBq). The organ with the highest absorbed dose was the kidney (47.3 ± 10.2 mGy/100 MBq). The estimated effective dose was 2.32 ± 0.32 mSv for an injected dose of 20 MBq in newborns. This dose decreased to 0.77 ± 0.11 mSv/20 MBq for 1-y-old children and 0.59 ± 0.05 mSv for an injected dose of 30 MBq in 5-y-old children. Conclusion: Our human PET/CT-based dosimetric calculations show that the effective radiation doses from the novel tracer 68Ga-NODAGA-exendin-4 are very low for adults and children. The doses are lower than reported for other polypeptide tracers such as somatostatin analogs (2.1-2.6 mSv/100 MBq) and are beneficial for application as a research tool, especially when repeated examinations are needed.

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Dataset Information

Evaluating [⁶⁸Ga]Ga-p14-032 as a Novel PET Tracer for Diagnosis Cerebral Amyloid Angiopathy.

Publications

Evaluating [<sup>68</sup>Ga]Ga-p14-032 as a Novel PET Tracer for Diagnosis Cerebral Amyloid Angiopathy.

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