Núñez Eutimio Gustavo Fernández, Faintuch Bluma Linkowski, Teodoro Rodrigo, Wiecek Danielle Pereira, Martinelli Jose Roberto, da Silva Natanael Gomes, Castanheira Claudia E, Filho Renato Santos de Oliveira, Pasqualini Roberto
Radiopharmacy Center, Institute of Energetic and Nuclear Research, Sao Paulo, SP 05508-000, Brazil.
Nucl Med Biol. 2009 Oct;36(7):741-7. doi: 10.1016/j.nucmedbio.2009.04.009. Epub 2009 Jul 9.
Particle size of colloids employed for sentinel lymph node (LN) detection is not well studied. This investigation aimed to correlate particle size and distribution of different products with LN uptake.
All agents (colloidal tin, dextran, phytate and colloidal rhenium sulfide) were labeled with (99m)Tc according to manufacturer's instructions. Sizing of particles was carried out on electron micrographs using Image Tool for Windows (Version 2.0). Biodistribution studies in main excretion organs as well as in popliteal LN were performed in male Wistar rats [30 and 90 min post injection (p.i.)]. The injected dose was 0.1 ml (37 MBq) in the footpad of the left posterior limb. Dynamic images (0-15 min p.i.) as well as static ones (30 and 90 min) were acquired in gamma camera.
Popliteal LN was clearly reached by all products. Nevertheless, particle size remarkably influenced node uptake. Colloidal rhenium sulfide, with the smallest diameter (5.1 x 10(-3)+/-3.9 x 10(-3) microm), permitted the best result [2.72+/-0.64 percent injected dose (%ID) at 90 min]. Phytate displayed small particles (<15 microm) with favorable uptake (1.02+/-0.14%ID). Dextran (21.4+/-12.8 microm) and colloidal tin (39.0+/-8.3 microm) were less effective (0.55+/-0.14 and 0.06+/-0.03%ID respectively). Particle distribution also tended to influence results. When asymmetric, it was associated with biphasic uptake which increased over time; conversely, symmetric distribution (colloidal tin) was consistent with a constant pattern.
The results are suggesting that particle size and symmetry may interfere with LN radiopharmaceutical uptake.
用于前哨淋巴结（SLN）检测的胶体颗粒大小尚未得到充分研究。本研究旨在将不同产品的颗粒大小和分布与淋巴结摄取情况相关联。
所有试剂（胶体锡、葡聚糖、植酸盐和硫化铼胶体）均按照制造商的说明用（99m）Tc进行标记。使用适用于Windows的图像工具（版本2.0）在电子显微镜照片上对颗粒进行大小测量。在雄性Wistar大鼠中进行主要排泄器官以及腘窝淋巴结的生物分布研究[注射后（p.i.）30分钟和90分钟]。将0.1毫升（37兆贝克勒尔）注射到左后肢的足垫中。在γ相机中采集动态图像（注射后0 - 15分钟）以及静态图像（30分钟和90分钟）。
所有产品均能清晰地到达腘窝淋巴结。然而，颗粒大小对淋巴结摄取有显著影响。直径最小的硫化铼胶体（5.1×10⁻³±3.9×10⁻³微米）取得了最佳结果[90分钟时为2.72±0.64%注射剂量（%ID）]。植酸盐显示出小颗粒（<15微米）且摄取良好（1.02±0.14%ID）。葡聚糖（21.4±12.8微米）和胶体锡（39.0±8.3微米）效果较差（分别为0.55±0.14%ID和0.06±0.03%ID）。颗粒分布也倾向于影响结果。当不对称时，与随时间增加的双相摄取相关；相反，对称分布（胶体锡）与恒定模式一致。
结果表明颗粒大小和对称性可能会干扰淋巴结放射性药物的摄取。
