Green Michael V, Seidel Jurgen, Williams Mark R, Wong Karen J, Ton Anita, Basuli Falguni, Choyke Peter L, Jagoda Elaine M
Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD; Contractor to Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD.
Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD; Contractor to Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD.
Nucl Med Biol. 2017 Oct;53:29-36. doi: 10.1016/j.nucmedbio.2017.06.004. Epub 2017 Jun 30.
Quantitative small animal radionuclide imaging studies are often carried out with the intention of estimating the total radioactivity content of various tissues such as the radioactivity content of mouse xenograft tumors exposed to putative diagnostic or therapeutic agents. We show that for at least one specific application, positron projection imaging (PPI) and PET yield comparable estimates of absolute total tumor activity and that both of these estimates are highly correlated with direct well-counting of these same tumors. These findings further suggest that in this particular application, PPI is a far more efficient data acquisition and processing methodology than PET.
Forty-one athymic mice were implanted with PC3 human prostate cancer cells transfected with prostate-specific membrane antigen (PSMA (+)) and one additional animal (for a total of 42) with a control blank vector (PSMA (-)). All animals were injected with [F] DCFPyl, a ligand for PSMA, and imaged for total tumor radioactivity with PET and PPI. The tumors were then removed, assayed by well counting for total radioactivity and the values between these methods intercompared.
PET, PPI and well-counter estimates of total tumor radioactivity were highly correlated (R>0.98) with regression line slopes near unity (0.95<slope≤1.02) and intercepts near zero (-0.001MBq≤intercept ≤0.004MBq).
Total mouse xenograft tumor radioactivity can be measured with PET or PPI with an accuracy comparable to well counting if certain experimental and pharmacokinetic conditions are met. In this particular application, PPI is significantly more efficient than PET in making these measurements.
定量小动物放射性核素成像研究通常旨在估计各种组织的总放射性含量，例如暴露于假定的诊断或治疗剂的小鼠异种移植肿瘤的放射性含量。我们表明，对于至少一种特定应用，正电子投影成像（PPI）和PET对肿瘤绝对总活性的估计具有可比性，并且这两种估计与这些相同肿瘤的直接活度计计数高度相关。这些发现进一步表明，在这种特定应用中，PPI是一种比PET更有效的数据采集和处理方法。
将41只无胸腺小鼠植入转染了前列腺特异性膜抗原（PSMA(+)）的PC3人前列腺癌细胞，并将另外一只动物（共42只）植入对照空白载体（PSMA(-)）。所有动物均注射PSMA的配体[F]DCFPyl，并通过PET和PPI对肿瘤总放射性进行成像。然后切除肿瘤，通过活度计计数测定总放射性，并比较这些方法之间的值。
PET、PPI和活度计对肿瘤总放射性的估计高度相关（R>0.98），回归线斜率接近1（0.95<斜率≤1.02），截距接近0（-0.001MBq≤截距≤0.004MBq）。
如果满足某些实验和药代动力学条件，小鼠异种移植肿瘤的总放射性可以用PET或PPI进行测量，其准确性与活度计计数相当。在这种特定应用中，PPI在进行这些测量时比PET明显更有效。
