Digital Solid-State SPECT/CT Quantitation of Absolute 177Lu Radiotracer Concentration: In Vivo and In Vitro Validation
| Autor: | Zohar Keidar, John A. Kennedy, Ronit Gill, Rachel Lugassi |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
business.industry Solid-state Imaging phantom Confidence interval 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine In vivo 030220 oncology & carcinogenesis Linear regression Image acquisition Radiology Nuclear Medicine and imaging Nuclear medicine business Urine sample Membrane antigen |
| Zdroj: | Journal of Nuclear Medicine. 61:1381-1387 |
| ISSN: | 2159-662X 0161-5505 |
| Popis: | The accuracy of 177Lu radiotracer concentration measurements using quantitative clinical software was determined by comparing in vivo results for a digital solid-state cadmium-zinc-telluride SPECT/CT system with in vitro sampling. Methods: First, image acquisition parameters were assessed for an International Electrotechnical Commission body phantom emulating clinical count rates loaded with a lung insert and 6 hot spheres with a 12:1 target-to-background ratio of 177Lu solution. Then, the data of 28 whole-body SPECT/CT scans of 7 patients who underwent 177Lu prostate-specific membrane antigen radioligand therapy were retrospectively analyzed. Three users analyzed SPECT/CT images for in vivo urinary bladder radiotracer uptake using quantitative software. In vitro radiopharmaceutical concentrations were calculated using urine sampling obtained immediately after each scan, scaled to SUVs. Any in vivo or in vitro identity relations were determined by linear regression (ideally, slope = 1 and intercept = 0), within a 95% confidence interval. Results: Phantom results demonstrated lower quantitative error for acquisitions using the 113-keV 177Lu energy peak rather than including the 208-keV peak, given that only low-energy collimation was available in this camera configuration. In the clinical study, 24 in vivo–in vitro pairs were eligible for further analysis, with 4 having been rejected as outliers (via Cook distance calculations). All linear regressions (R2 ≥ 0.82, P |
| Databáze: | OpenAIRE |
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