美國核醫(yī)學(xué)學(xué)會7月1日表示,，新出版的《核醫(yī)學(xué)雜志》報(bào)道了名為切倫科夫冷光成像（Cerenkov luminescence imaging）的新型光學(xué)成像技術(shù),。據(jù)文章作者介紹,，新技術(shù)有望幫助人們診治癌癥和其他疾病，以及更快和更有效地開發(fā)放射性藥物,。
研究負(fù)責(zé)人,、斯隆-凱特靈紀(jì)念癌癥中心教授簡·格林姆博士表示，新型多通道顯影劑和技術(shù)屬于醫(yī)學(xué)成像科學(xué)領(lǐng)域的研究前沿,，它可能為新的光學(xué)成像進(jìn)入臨床應(yīng)用開辟新途徑。格林姆小組認(rèn)為,，自己的研究屬于那些首次探討將切倫科夫輻射應(yīng)用于醫(yī)學(xué)成像的工作,。據(jù)悉，加州大學(xué)和斯坦福大學(xué)科學(xué)家參與了研究,。
當(dāng)光在水中傳播時(shí),，其速度會減慢。而此時(shí)速度超過光速的粒子如同突破聲障的音爆,，會產(chǎn)生 “震波”（或“沖擊波”）發(fā)出藍(lán)色可見光,，該現(xiàn)象被稱為切倫科夫輻射。
光學(xué)成像是一種分子成像過程,。在此過程中,，設(shè)計(jì)出來用于附著在特殊細(xì)胞和分子上的發(fā)光分子被注入人體血液中，并可為光學(xué)成像儀探測到,。通常,，為便于光學(xué)成像儀工作，這些發(fā)光分子需要通過體外光源或生物手段進(jìn)行激活,。
在新型光學(xué)成像技術(shù)中,，由于切倫科夫成像產(chǎn)生的光來源于輻射,，因此不再需要用體外光源照明。格林姆認(rèn)為,，這種將光學(xué)成像與核醫(yī)學(xué)的結(jié)合代表了醫(yī)學(xué)成像的新途徑,。他同時(shí)表示，目前多種核示蹤物被批準(zhǔn)用于醫(yī)學(xué)臨床,，它們與光學(xué)成像組成的切倫科夫冷光成像系統(tǒng)能夠很快得到應(yīng)用,，這與熒光染料截然不同。
在研究中,，科學(xué)家對有可能用于切倫科夫冷光成像系統(tǒng)的幾種放射性核素進(jìn)行了評估,。他們用切倫科夫冷光成像系統(tǒng)和正電子斷層掃描儀（PET）對患有腫瘤的實(shí)驗(yàn)鼠進(jìn)行了視覺化處理，結(jié)果表明,，切倫科夫冷光成像系統(tǒng)能夠?qū)z入到體內(nèi)的放射性示蹤物可視化,。生物谷新域名www.bioon.net
研究人員表示，切倫科夫冷光成像技術(shù)采用了過去無法可視化的輕同位素,，也就是說它能夠?qū)炔话l(fā)射正電子又不發(fā)射伽瑪射線的放射性示蹤物進(jìn)行成像,，這個(gè)能力是目前核成像法所不具備的。此外,，光學(xué)成像技術(shù)將有助于內(nèi)窺檢查和外科手術(shù),，原因是它能將腫瘤的損害實(shí)現(xiàn)可視化，為手術(shù)等提供實(shí)時(shí)信息,。(生物谷Bioon.net)
生物谷推薦原文出處：
Journal of Nuclear Medicine doi: 10.2967/jnumed.110.076521
Cerenkov Luminescence Imaging of Medical Isotopes
Alessandro Ruggiero*,1, Jason P. Holland*,2, Jason S. Lewis2,3 and Jan Grimm1,3
1 Nuclear Medicine Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York; 2 Radiochemistry Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York; and 3 Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York
The development of novel multimodality imaging agents and techniques represents the current frontier of research in the field of medical imaging science. However, the combination of nuclear tomography with optical techniques has yet to be established. Here, we report the use of the inherent optical emissions from the decay of radiopharmaceuticals for Cerenkov luminescence imaging (CLI) of tumors in vivo and correlate the results with those obtained from concordant immuno-PET studies. Methods: In vitro phantom studies were used to validate the visible light emission observed from a range of radionuclides including the positron emitters 18F, 64Cu, 89Zr, and 124I; β-emitter 131I; and -particle emitter 225Ac for potential use in CLI. The novel radiolabeled monoclonal antibody 89Zr-desferrioxamine B [DFO]-J591 for immuno-PET of prostate-specific membrane antigen (PSMA) expression was used to coregister and correlate the CLI signal observed with the immuno-PET images and biodistribution studies. Results: Phantom studies confirmed that Cerenkov radiation can be observed from a range of positron-, β-, and -emitting radionuclides using standard optical imaging devices. The change in light emission intensity versus time was concordant with radionuclide decay and was also found to correlate linearly with both the activity concentration and the measured PET signal (percentage injected dose per gram). In vivo studies conducted in male severe combined immune deficient mice bearing PSMA-positive, subcutaneous LNCaP tumors demonstrated that tumor-specific uptake of 89Zr-DFO-J591 could be visualized by both immuno-PET and CLI. Optical and immuno-PET signal intensities were found to increase over time from 24 to 96 h, and biodistribution studies were found to correlate well with both imaging modalities. Conclusion: These studies represent the first, to our knowledge, quantitative assessment of CLI for measuring radiotracer uptake in vivo. Many radionuclides common to both nuclear tomographic imaging and radiotherapy have the potential to be used in CLI. The value of CLI lies in its ability to image radionuclides that do not emit either positrons or -rays and are, thus, unsuitable for use with current nuclear imaging modalities. Optical imaging of Cerenkov radiation emission shows excellent promise as a potential new imaging modality for the rapid, high-throughput screening of radiopharmaceuticals.
