Centre for Molecular Imaging and Translational Research Laboratory, Peter MacCallum Cancer Centre, Victoria, Australia.
J Nucl Med. 2010 Mar;51(3):441-7. doi: 10.2967/jnumed.109.070060. Epub 2010 Feb 11.
The aim of this study was to evaluate the novel probe (18)F-6-fluoro-N-[2-(diethylamino)ethyl] pyridine-3-carboxamide ((18)F-MEL050) for the imaging of primary and metastatic melanoma.
PET using (18)F-MEL050 was performed in murine models of melanoma. The specificity of (18)F-MEL050 was studied by comparing its accumulation in pigmented B16-F0 allograft tumors with that of human amelanotic A375 xenografts using PET and high-resolution autoradiography. (18)F-MEL050 PET results were compared with (18)F-FDG PET, the current standard in melanoma molecular imaging. To test the ability of (18)F-MEL050 to assess the metastatic spread of melanoma, a murine model of lung metastasis was imaged by PET/CT, and results correlated with physical assessment of tumor burden in the lungs.
In pigmented B16-F0 grafts, (18)F-MEL050 PET yielded a tumor-to-background ratio of approximately 20:1 at 1 h and greater than 50:1 at 2 and 3 h. In the B16-F0 melanoma allograft model, tumor-to-background ratio was more than 9-fold higher for (18)F-MEL050 than for (18)F-FDG (50.9 +/- 6.9 vs. 5.8 +/- 0.5). No uptake was observed in the amelanotic melanoma xenografts. Intense uptake of (18)F-MEL050 was evident in metastatic lesions in the lungs of B16-BL6 tumor-bearing mice on PET at 2 h after tracer injection, with high concordance between (18)F-MEL050 accumulation on PET/CT and tumor burden determined at necroscopy.
(18)F-MEL050 has a rapid tumor uptake and high retention with specificity for melanin, suggesting great potential for noninvasive clinical evaluation of suspected metastatic melanoma.
本研究旨在评估新型探针（18）F-6-氟-N-[2-（二乙氨基）乙基]吡啶-3-甲酰胺（（18）F-MEL050）在原发性和转移性黑色素瘤成像中的应用。
在黑色素瘤的鼠模型中进行了（18）F-MEL050 的 PET 研究。通过 PET 和高分辨率放射自显影比较其在色素性 B16-F0 同种异体移植瘤中的积累与人类无色素性 A375 异种移植物中的积累，研究了（18）F-MEL050 的特异性。将（18）F-MEL050 的 PET 结果与黑色素瘤分子成像的当前标准（18）F-FDG PET 进行了比较。为了测试（18）F-MEL050 评估黑色素瘤转移扩散的能力，通过 PET/CT 对肺转移的鼠模型进行了成像，并将结果与肺部肿瘤负担的物理评估进行了相关。
在色素性 B16-F0 移植物中，（18）F-MEL050 的 PET 在 1 小时时产生了约 20:1 的肿瘤与背景比，在 2 和 3 小时时大于 50:1。在 B16-F0 黑色素瘤同种异体移植模型中，（18）F-MEL050 的肿瘤与背景比是（18）F-FDG 的 9 倍以上（50.9 ± 6.9 比 5.8 ± 0.5）。在无色素性黑色素瘤异种移植物中未观察到摄取。在注射示踪剂后 2 小时，B16-BL6 荷瘤小鼠的肺部转移灶在（18）F-MEL050 的 PET 上显示出强烈的摄取，（18）F-MEL050 在 PET/CT 上的积累与尸检确定的肿瘤负担之间具有高度一致性。
（18）F-MEL050 具有快速的肿瘤摄取和高保留性，对黑色素具有特异性，表明其在非侵入性临床评估可疑转移性黑色素瘤方面具有巨大潜力。
