Koral K F, Zasadny K R, Kessler M L, Luo J Q, Buchbinder S F, Kaminski M S, Francis I, Wahl R L
Internal Medicine Department, University of Michigan Medical Center, Ann Arbor 48109-0552.
J Nucl Med. 1994 Oct;35(10):1714-20.
A method for performing 131I quantitative SPECT imaging is described which uses the superimposition of markers placed on the skin to accomplish fusion of computed tomography (CT) and SPECT image sets.
To calculate mean absorbed dose after administration of one of two 131I-labeled monoclonal antibodies (Mabs), the shape of the time-activity curve is measured by daily diagnostic conjugate views, the y-axis of that curve is normalized by a quantitative SPECT measurement (usually intra-therapy), and the tumor mass is deduced from a concurrent CT volume measurement. The method is applied to six B-cell non-Hodgkin's lymphoma patients.
For four tumors in three patients treated with the MB1 Mab, a correlation appears to be present between resulting mean absorbed dose and disease response. Including all dosimetric estimates for both antibodies, the range for the specific absorbed dose is within that found by others in treating B-cell lymphoma patients. Excluding a retreated anti-B1 patient, the tumor-specific absorbed dose during anti-B1 therapy is from 1.4 to 1.7 mGy/MBq. For the one anti-B1 patient, where quantitative SPECT and conjugate-view imaging was carried out back to back, the quantitative SPECT-measured activity was somewhat less for the spleen and much less for the tumor than that from conjugate views.
The quantitative SPECT plus conjugate views method may be of general utility for macro-dosimetry of 131I therapies.
描述了一种进行¹³¹I定量单光子发射计算机断层扫描（SPECT）成像的方法，该方法使用放置在皮肤上的标记物叠加来实现计算机断层扫描（CT）和SPECT图像集的融合。
为了计算两种¹³¹I标记的单克隆抗体（Mab）之一给药后的平均吸收剂量，通过每日诊断性共轭视图测量时间-活性曲线的形状，该曲线的y轴通过定量SPECT测量（通常在治疗期间）进行归一化，并且肿瘤体积从同期CT体积测量中推导得出。该方法应用于6例B细胞非霍奇金淋巴瘤患者。
对于3例接受MB1 Mab治疗患者的4个肿瘤，所得平均吸收剂量与疾病反应之间似乎存在相关性。包括两种抗体的所有剂量学估计，比吸收剂量范围在其他治疗B细胞淋巴瘤患者中发现的范围内。排除一名接受再次治疗的抗B1患者，抗B1治疗期间肿瘤比吸收剂量为1.4至1.7 mGy/MBq。对于一名抗B1患者，在连续进行定量SPECT和共轭视图成像的情况下，定量SPECT测量的脾脏活性略低于共轭视图测量的活性，而肿瘤活性则远低于共轭视图测量的活性。
定量SPECT加共轭视图方法可能对¹³¹I治疗的宏观剂量学具有普遍实用性。
