OtherBASIC SCIENCE INVESTIGATIONS

First Evaluation of a 99mTc-Tricarbonyl Complex, 99mTc(CO)3(LAN), as a New Renal Radiopharmaceutical in Humans

Malgorzata Lipowska, Haiyang He, Eugene Malveaux, Xiaolong Xu, Luigi G. Marzilli and Andrew Taylor
Journal of Nuclear Medicine June 2006, 47 (6) 1032-1040;

Article Figures & Data

Figures

  • FIGURE 1. 
    FIGURE 1. 

    Comparison of 99mTc-EC and 99mTc(CO)3(LAN), 2 agents with 2-carboxylate structural features.

  • FIGURE 2. 
    FIGURE 2. 
    FIGURE 2. 

    (A) 99mTc(CO)3(LAN) images and curves obtained from 27-y-old female volunteer who received an intravenous injection containing 62.9 MBq (1.7 mCi) of 99mTc(CO)3(meso-LAN) and 7.03 MBq (0.19 mCi) of 131I-OIH before 24 min of data acquisition. Demographics and renogram data—relative uptake (% uptake), time to maximum counts [Tmax (min)], time to half-maximum counts [T1/2 (min)], and ratio of counts at 20 min to maximum counts (20/max) for whole-kidney region of interest—are displayed in upper left panel. Upper middle panel shows flow images at 2 s per frame. Image containing injection site in volunteer's arm (upper right panel) showed no infiltration. Center panel shows good uptake by kidneys bilaterally and prompt excretion into bladder. Whole-kidney renogram curves are shown in lower left panel, and cortical renogram curves are shown in lower right panel. (B) 131I-OIH images and renogram curves obtained from volunteer described in A by use of identical regions of interest over whole kidney and cortex. 131I-OIH renogram curves are much noisier than 99mTc(CO)3(LAN) renogram curves because of lower dose of 131I-OIH and because camera was not optimized to image high-energy photons of 131I.

  • FIGURE 3. 
    FIGURE 3. 

    Urine samples from human volunteers injected with 99mTc(CO)3(meso-LAN) (A) and 99mTc(CO)3(dd,ll-LAN) (B) were subjected to γ-radioactive reversed-phase HPLC analysis. Corresponding reference HPLC traces show that both complexes were excreted unchanged in urine.

  • FIGURE 4. 
    FIGURE 4. 

    Schematic drawing of spatial relationships of carboxylate groups (CO2) to each other and to plane defined by donor atoms in 99mTc-EC and 99mTc(CO)3(LAN) complexes.

Tables

  • TABLE 1

    Percentage Injected Dose in Rats of 99mTc(CO)3(meso-LAN) and 99mTc(CO)3(dd,ll-LAN) Compared with 131I-OIH in Blood, Urine, and Selected Organs at 10 and 60 Minutes (n = 5)

    BloodKidneysUrineLiverBowel
    Isomer99mTc131I-OIH99mTc131I-OIH99mTc131I-OIH99mTc/131I-OIH ratio99mTc131I-OIH99mTc131I-OIH
    meso-LAN
     10 min4.1 ± 0.43.3 ± 0.56.5 ± 2.84.9 ± 3.541.0 ± 7.359.9 ± 11.569 ± 64.2 ± 0.62.0 ± 0.21.2 ± 0.31.0 ± 0.2
     60 min0.6 ± 0.10.5 ± 0.11.2 ± 0.30.7 ± 0.377.9 ± 3.287.5 ± 8.289 ± 61.2 ± 0.50.8 ± 0.51.7 ± 0.10.9 ± 0.2
    dd,ll-LAN
     10 min5.7 ± 0.74.0 ± 0.69.5 ± 0.94.6 ± 1.033.4 ± 3.959.2 ± 3.656 ± 43.9 ± 0.52.3 ± 0.21.7 ± 0.41.1 ± 0.2
     60 min0.7 ± 0.20.4 ± 0.11.2 ± 0.30.3 ± 0.176.4 ± 7.288.0 ± 7.887 ± 40.8 ± 0.30.5 ± 0.34.6 ± 0.70.9 ± 0.1

    • Data are mean ± SD.

  • TABLE 2

    Clearance, Protein Binding, Erythrocyte Binding, and Urine Excretion of 99mTc(CO)3(LAN) Complexes Compared with 131I-OIH in Humans (n = 3)

    Isomer99mTc(CO)3(LAN) clearance (mL/min)131I-OIH clearance (mL/min)99mTc(CO)3(LAN)/ 131I-OIH clearance ratio (%)Protein binding (%)Erythrocyte binding (%)99mTc(CO)3(LAN)/131I-OIH 30-min urine excretion ratio (%)99mTc(CO)3(LAN)/ 131I-OIH 180-min urine excretion ratio (%)
    meso-LAN228 ± 33548 ± 3742 ± 510 ± 0.624 ± 3.657 ± 685 ± 6
    dd,ll-LAN176 ± 8528 ± 1333 ± 22 ± 0.021 ± 8.645 ± 377 ± 6

    • Data are mean ± SD.

  • TABLE 3

    Renogram Parameters for Whole-Kidney Regions of Interest with 99mTc(CO)3(meso-LAN) and 99mTc(CO)3(dd,ll-LAN) Compared with 131I-OIH in Humans (n = 3)

    Left kidneyRight kidneyLeft kidneyRight kidney
    Isomer% 99mTc% 131I-OIHTTP (min) for 99mTcTTP (min) for 131I-OIHTTP (min) for 99mTcTTP (min) for 131I-OIH20 min/max for 99mTc20 min/max for 131I-OIH20 min/max for 99mTc20 min/max for 131I-OIH
    meso-LAN47 ± 8.146 ± 7.04.66 ± 2.492.65 ± 0.533.58 ± 0.323.08 ± 0.590.35 ± 0.100.12 ± 0.090.29 ± 0.030.07 ± 0.02
    dd,ll-LAN60 ± 2.162 ± 4.23.17 ± 0.623.15 ± 0.753.01 ± 0.573.55 ± 0.190.39 ± 0.070.12 ± 0.060.33 ± 0.080.08 ± 0.04

    • TTP = time to peak height of renogram curve; 20 min/max = ratio of counts in kidney at 20 min after injection to maximum counts.

    • Data are mean ± SD.

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