Dubal Jigar, Arce Pedro, South Chris, Florescu Lucia
University of Surrey, Centre for Vision, Speech and Signal Processing, United Kingdom.
CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas), Madrid, Spain.
J Biomed Opt. 2025 May;30(5):055002. doi: 10.1117/1.JBO.30.5.055002. Epub 2025 May 29.
Cherenkov light emitted in the tissue during radiation therapy enables unprecedented approaches to tumor functional imaging for early treatment assessment. Cherenkov light-based tomographic imaging requires image reconstruction algorithms based on internal light sources that, in turn, require knowledge about the characteristics of the Cherenkov light within the patient.
We aim to investigate the spatial and spectral characteristics of Cherenkov light within the patient and at the patient's surface, and the origin within the tissue of light reaching the surface, to provide insight for the development of image reconstruction algorithms for Cherenkov light-based tomographic imaging.
Numerical experiments using clinical patient data and Monte Carlo simulations are performed for the radiation therapy of laryngeal cancer for intensity-modulated radiation therapy and volumetric-modulated arc radiation therapy.
The emitted Cherenkov light is concentrated in regions of high delivered dose, with the spatial distribution within the patient and at the patient's surface depending on the treatment type and patient anatomy. The Cherenkov light at the patient's surface is dominant in the near-infrared spectral region. Light emitted within the tumor emerges at the patient's surface on a well-defined radiation beam-independent region. The distribution within the patient of the emitted light that emerges on reduced areas on the patient's surface containing this region is similar to that of the light that emerges across the entire patient's surface.
Detailed information about the spectral and spatial characteristics of Cherenkov light is provided. In addition, these results suggest that surface light measurements restricted to smaller areas containing the region where the light emitted in the tumor emerges (that can be determined through simulations prior to the treatment) could enable probing the tumor while being easier to integrate with the radiotherapy system and while the effect of measurement data incompleteness on image reconstruction may not be too strong.
放射治疗期间组织中发出的切伦科夫光为肿瘤功能成像提供了前所未有的方法，用于早期治疗评估。基于切伦科夫光的断层成像需要基于内部光源的图像重建算法，而这又需要了解患者体内切伦科夫光的特性。
我们旨在研究患者体内和体表切伦科夫光的空间和光谱特性，以及到达体表的光在组织内的起源，为基于切伦科夫光的断层成像图像重建算法的开发提供见解。
针对喉癌的调强放射治疗和容积调强弧形放射治疗，使用临床患者数据和蒙特卡罗模拟进行数值实验。
发出的切伦科夫光集中在高剂量照射区域，患者体内和体表的空间分布取决于治疗类型和患者解剖结构。患者体表的切伦科夫光在近红外光谱区域占主导。肿瘤内发出的光在一个明确的与放射束无关区域出现在患者体表。在患者体表包含该区域的缩小区域上出现的发出光在患者体内的分布与在整个患者体表出现的光的分布相似。
提供了关于切伦科夫光的光谱和空间特性的详细信息。此外，这些结果表明，将表面光测量限制在包含肿瘤发出光出现区域的较小区域（可在治疗前通过模拟确定），既能探测肿瘤，又更容易与放射治疗系统集成，而且测量数据不完整对图像重建的影响可能不会太大。
