Chemical Engineering, Arizona State University , Tempe, Arizona 85287-6106, United States.
Banner-MD Anderson Cancer Center , Gilbert, Arizona 85234, United States.
ACS Nano. 2015 Dec 22;9(12):11540-50. doi: 10.1021/acsnano.5b05113. Epub 2015 Nov 6.
Modern radiation therapy using highly automated linear accelerators is a complex process that maximizes doses to tumors and minimizes incident dose to normal tissues. Dosimeters can help determine the radiation dose delivered to target diseased tissue while minimizing damage to surrounding healthy tissue. However, existing dosimeters can be complex to fabricate, expensive, and cumbersome to operate. Here, we demonstrate studies of a liquid phase, visually evaluated plasmonic nanosensor that detects radiation doses commonly employed in fractionated radiotherapy (1-10 Gy) for tumor ablation. We accomplished this by employing ionizing radiation, in concert with templating lipid surfactant micelles, in order to convert colorless salt solutions of univalent gold ions (Au(1)) to maroon-colored dispersions of plasmonic gold nanoparticles. Differences in color intensities of nanoparticle dispersions were employed as quantitative indicators of the radiation dose. The nanoparticles thus formed were characterized using UV-vis absorbance spectroscopy, dynamic light scattering, and transmission electron microscopy. The role of lipid surfactants on nanoparticle formation was investigated by varying the chain lengths while maintaining the same headgroup and counterion; the effect of surfactant concentration on detection efficacy was also investigated. The plasmonic nanosensor was able to detect doses as low as 0.5 Gy and demonstrated a linear detection range of 0.5-2 Gy or 5-37 Gy depending on the concentration of the lipid surfactant employed. The plasmonic nanosensor was also able to detect radiation levels in anthropomorphic prostate phantoms when administered together with endorectal balloons, indicating its potential utility as a dosimeter in fractionated radiotherapy for prostate cancer. Taken together, our results indicate that this simple visible nanosensor has strong potential to be used as a dosimeter for validating delivered radiation doses in fractionated radiotherapies in a variety of clinical settings.
利用高度自动化直线加速器进行现代放射治疗是一个复杂的过程，它最大限度地提高肿瘤的剂量，同时最大限度地减少正常组织的入射剂量。剂量计可帮助确定施用于靶病变组织的辐射剂量，同时最大限度地减少对周围健康组织的损伤。然而，现有的剂量计可能制造复杂、昂贵且操作繁琐。在这里，我们展示了一种液相、可视评估的等离子体纳米传感器的研究，该传感器用于检测肿瘤消融的分割放射治疗（1-10Gy）中常用的辐射剂量。我们通过使用电离辐射，与模板化脂质表面活性剂胶束协同作用，将单价金离子（Au(1)）的无色盐溶液转化为等离子体金纳米粒子的栗红色分散体来实现这一点。纳米粒子分散体的颜色强度差异被用作辐射剂量的定量指标。使用紫外-可见吸收光谱、动态光散射和透射电子显微镜对形成的纳米粒子进行了表征。通过改变链长同时保持相同的头基和抗衡离子，研究了脂质表面活性剂对纳米粒子形成的作用；还研究了表面活性剂浓度对检测效果的影响。该等离子体纳米传感器能够检测低至 0.5Gy 的剂量，并表现出 0.5-2Gy 或 5-37Gy 的线性检测范围，具体取决于所使用的脂质表面活性剂的浓度。当与直肠内球囊一起施用于人体前列腺模型时，该等离子体纳米传感器还能够检测到辐射水平，表明其作为前列腺癌分割放射治疗中剂量计的潜在用途。总之，我们的结果表明，这种简单的可见纳米传感器具有很强的潜力，可用于验证各种临床环境中分割放射治疗中所给予的辐射剂量。
