Deng Zijian, Xu Xiangkun, Dehghani Hamid, Reyes Juvenal, Zheng Lei, Tran Phuoc T, Wang Ken Kang-Hsin
Biomedical Imaging and Radiation Technology Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21231, USA.
Biomed Opt Express. 2024 Jul 9;15(8):4525-4539. doi: 10.1364/BOE.523916. eCollection 2024 Aug 1.
Recent development of radiotherapy (RT) has heightened the use of radiation in managing pancreatic cancer. Thus, there is a need to investigate pancreatic cancer in a pre-clinical setting to advance our understanding of the role of RT. Widely-used cone-beam CT (CBCT) imaging cannot provide sufficient soft tissue contrast to guide irradiation. The pancreas is also prone to motion. Large collimation is unavoidably used for irradiation, costing normal tissue toxicity. We innovated a bioluminescence tomography (BLT)-guided system to address these needs. We established an orthotopic pancreatic ductal adenocarcinoma (PDAC) mouse model to access BLT. Mice underwent multi-projection and multi-spectral bioluminescence imaging (BLI), followed by CBCT imaging in an animal irradiator for BLT reconstruction and radiation planning. With optimized absorption coefficients, BLT localized PDAC at 1.25 ± 0.19 mm accuracy. To account for BLT localization uncertainties, we expanded the BLT-reconstructed volume with margin to form planning target volume(PTV) for radiation planning, covering 98.7 ± 2.2% of PDAC. The BLT-guided conformal plan can cover 100% of tumors with limited normal tissue involvement across both inter-animal and inter-fraction cases, superior to the 2D BLI-guided conventional plan. BLT offers unique opportunities to localize PDAC for conformal irradiation, minimize normal tissue involvement, and support reproducibility in RT studies.
放射治疗（RT）的最新进展增加了辐射在胰腺癌治疗中的应用。因此，有必要在临床前环境中研究胰腺癌，以加深我们对放疗作用的理解。广泛使用的锥形束CT（CBCT）成像无法提供足够的软组织对比度来指导放疗。胰腺也容易移动。放疗时不可避免地要使用大准直，这会导致正常组织毒性增加。我们创新了一种生物发光断层扫描（BLT）引导系统来满足这些需求。我们建立了一个原位胰腺导管腺癌（PDAC）小鼠模型以进行BLT研究。小鼠接受多投影和多光谱生物发光成像（BLI），然后在动物放疗机中进行CBCT成像，用于BLT重建和放射治疗计划。通过优化吸收系数，BLT定位PDAC的精度为1.25±0.19毫米。为了考虑BLT定位的不确定性，我们将BLT重建体积扩大一定边界以形成用于放射治疗计划的计划靶体积（PTV），覆盖了98.7±2.2%的PDAC。在动物间和分次治疗的情况下，BLT引导的适形计划可以在正常组织受影响有限的情况下覆盖100%的肿瘤，优于二维BLI引导的传统计划。BLT为PDAC的适形照射定位、最小化正常组织受影响以及支持放疗研究的可重复性提供了独特的机会。
