Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK.
F1000Res. 2023 May 22;12:526. doi: 10.12688/f1000research.130883.1. eCollection 2023.
Preclinical models of radiotherapy (RT) response are vital for the continued success and evolution of RT in the treatment of cancer. The irradiation of tissues in mouse models necessitates high levels of precision and accuracy to recapitulate clinical exposures and limit adverse effects on animal welfare. This requirement has been met by technological advances in preclinical RT platforms established over the past decade. Small animal RT systems use onboard computed tomography (CT) imaging to delineate target volumes and have significantly refined radiobiology experiments with major 3Rs impacts. However, the CT imaging is limited by the differential attenuation of tissues resulting in poor contrast in soft tissues. Clinically, radio-opaque fiducial markers (FMs) are used to establish anatomical reference points during treatment planning to ensure accuracy beam targeting, this approach is yet to translate back preclinical models.
We report on the use of a novel liquid FM BioXmark developed by Nanovi A/S (Kongens Lyngby, Denmark) that can be used to improve the visualisation of soft tissue targets during beam targeting and minimise dose to surrounding organs at risk. We present descriptive protocols and methods for the use of BioXmark in experimental male and female C57BL/6J mouse models.
These guidelines outline the optimum needle size for uptake (18-gauge) and injection (25- or 26-gauge) of BioXmark for use in mouse models along with recommended injection volumes (10-20 µl) for visualisation on preclinical cone beam CT (CBCT) scans. Injection techniques include subcutaneous, intraperitoneal, intra-tumoral and prostate injections.
The use of BioXmark can help to standardise targeting methods, improve alignment in preclinical image-guided RT and significantly improve the welfare of experimental animals with the reduction of normal tissue exposure to RT.
放射治疗 (RT) 反应的临床前模型对于 RT 在癌症治疗中的持续成功和发展至关重要。在小鼠模型中照射组织需要高精度和准确度，以重现临床暴露并限制对动物福利的不利影响。这一要求已经通过过去十年中建立的临床前 RT 平台的技术进步得到满足。小动物 RT 系统使用内置计算机断层扫描 (CT) 成像来描绘目标体积，并对放射生物学实验进行了重大的 3Rs 影响的改进。然而，CT 成像受到组织差异衰减的限制，导致软组织对比度差。在临床上，放射性不透射线的基准标记物 (FM) 用于在治疗计划中建立解剖参考点，以确保精确的光束靶向，这种方法尚未转化为临床前模型。
我们报告了一种新型液体 FM BioXmark 的使用，该 FM 由 Nanovi A/S（丹麦 Kongens Lyngby）开发，可用于改善光束靶向期间软组织目标的可视化效果，并最大限度地减少周围危及器官的剂量。我们介绍了在实验雄性和雌性 C57BL/6J 小鼠模型中使用 BioXmark 的描述性方案和方法。
这些指南概述了在小鼠模型中使用 BioXmark 的最佳摄取（18 号针）和注射（25 或 26 号针）针大小，以及推荐的注射量（10-20 µl）用于预临床锥形束 CT (CBCT) 扫描中的可视化。注射技术包括皮下、腹腔内、肿瘤内和前列腺内注射。
BioXmark 的使用有助于标准化靶向方法，改进临床前图像引导 RT 的对准，并通过减少正常组织对 RT 的暴露，显著改善实验动物的福利。
