Ak I, Aslan V, Vardareli E, Gülbaş Z
Department of Nuclear Medicine, Osmangazi University Medical Faculty, Eskişehir, Turkey.
Nucl Med Commun. 2003 Apr;24(4):397-402. doi: 10.1097/00006231-200304000-00009.
The ability of cancer cells to become simultaneously resistant to different drugs is a significant impediment to successful chemotherapy. 99mTc-MIBI has been reported to be a transport substrate for P-glycoprotein (Pgp). The aim of the study was to ascertain the relationship between the degree of 99mTc-MIBI uptake and the level of Pgp expression in patients with newly diagnosed leukaemia. A total of 26 patients (12 female and 14 male; mean age 46.8+/-3.7 years) with newly diagnosed leukaemia were included in the study. None of the patients had been previously treated with chemotherapy. Images were obtained 20 min post-injection of 740 MBq 99mTc-MIBI. Whole-body and planar spot images of the pelvis and thorax were acquired. The uptake of the MIBI in the bone marrow was evaluated using a qualitative and also a quantitative scoring system with determination of the tumour-to-background (T/B) ratios. Flow cytometry was performed for determining the Pgp expression of the blast cells in the bone marrow aspiration samples. There was a statistically significant inverse relationship between the Pgp level in numeric values and both mean qualitative (P<0.001; r=-0.665) and quantitative (P=0.001; r=-0.606) results of 99mTc-MIBI imaging. Both the mean qualitative score and the T/B ratios were higher in patients who were Pgp negative than in those who were Pgp positive (P<0.001 and P<0.001, respectively). These data indicate that an increased level of Pgp expression is correlated with a low accumulation of 99mTc-MIBI in bone marrow of patients with leukaemia. 99mTc-MIBI bone marrow imaging, as a method of functional imaging, can give in vivo information concerning the functional expression of the MDR phenotype in patients with untreated leukaemia.
癌细胞同时对不同药物产生耐药性的能力是成功进行化疗的重大障碍。据报道，99mTc-MIBI是P-糖蛋白（Pgp）的转运底物。本研究的目的是确定新诊断白血病患者99mTc-MIBI摄取程度与Pgp表达水平之间的关系。共有26例新诊断的白血病患者（12例女性，14例男性；平均年龄46.8±3.7岁）纳入本研究。所有患者此前均未接受过化疗。注射740MBq 99mTc-MIBI后20分钟获取图像。采集全身以及骨盆和胸部的平面点状图像。使用定性和定量评分系统评估骨髓中MIBI的摄取情况，并测定肿瘤与本底（T/B）比值。通过流式细胞术检测骨髓穿刺样本中原始细胞的Pgp表达。Pgp数值水平与99mTc-MIBI成像的平均定性结果（P<0.001；r=-0.665）和定量结果（P=0.001；r=-0.606）之间均存在统计学显著负相关。Pgp阴性患者的平均定性评分和T/B比值均高于Pgp阳性患者（分别为P<0.001和P<0.001）。这些数据表明，白血病患者骨髓中Pgp表达水平升高与99mTc-MIBI低蓄积相关。99mTc-MIBI骨髓显像作为一种功能显像方法，能够提供未经治疗的白血病患者体内多药耐药表型功能表达的信息。
