Eary J F, Appelbaum F L, Durack L, Brown P
University of Washington Hospital, Division of Nuclear Medicine RC-70, Seattle 98195.
Med Phys. 1989 May-Jun;16(3):382-7. doi: 10.1118/1.596347.
We perform gamma camera imaging to generate data for estimation of internal radiation dose in our radioimmunotherapy candidates. Because of the inability of single photon emission computed tomography (SPECT) to account for patient attenuation variability without serious error, quantitative planar imaging was performed to estimate the radioactive content of normal organs. We undertook the following studies to further validate this method. A realistic fillable human phantom was used to determine the accuracy of I-131 filled organ estimation. A transmission scan of the unfilled phantom was produced with an I-131 filled flat flood source. Anterior and posterior planar images of the filled organs were acquired with region of interest determination of the activity in the organ. Correction by the attenuation factor and a camera calibration factor yielded the MBq in the organ. The procedure was also performed in a simple phantom. Three dogs were imaged and sacrificed to validate the technique in vivo. A high degree of accuracy in estimation of organ radioactive content was found to be present using the phantom and dog models. Use of this method requires further validation but provides a solid basis for estimation of internal radiation dosimetry in radioimmunotherapy planning.
我们进行γ相机成像，以生成数据用于估算接受放射免疫治疗的患者的体内辐射剂量。由于单光子发射计算机断层扫描（SPECT）无法在不产生严重误差的情况下考虑患者衰减变异性，因此进行了定量平面成像以估算正常器官的放射性含量。我们开展了以下研究以进一步验证该方法。使用一个逼真的可填充人体模型来确定填充I-131的器官估算的准确性。用一个填充I-131的平面泛源对未填充的模型进行透射扫描。获取填充器官的前后平面图像，并确定器官内活性的感兴趣区域。通过衰减因子和相机校准因子进行校正后得出器官中的兆贝可（MBq）。该程序也在一个简单模型中进行。对三只狗进行成像并宰杀，以在体内验证该技术。使用模型和狗模型发现，在估算器官放射性含量方面具有高度准确性。使用该方法需要进一步验证，但为放射免疫治疗计划中体内辐射剂量测定的估算提供了坚实基础。
