Quantitative MR imaging biomarkers for toxicity prediction in prostate cancer

本项目使用混合1.5 T MR-Linac系统，基于以下假设：前列腺癌中的在线自适应MR引导放疗（MRGRT）将提供新的定量成像生物标志物，用于预测泌尿生殖系统毒性，包括关键解剖子结构中基于MR的辐射剂量累积（尿道，三角，阴茎球和更多）以及它们的结构和功能的变化在分割RT。因此，在MR直线加速器的前瞻性II期研究（Mbase Pro，Mbase HyPro）中检查了两种分次方案（60戈伊/ 20 fx和78戈伊/ 39 fx）。预期的结果将成为未来生物个体化MRgRT干预的基础，例如前列腺癌的个体剂量和分次处方。对于该项目，将优化和验证在分割RT之前和期间在1.5 T MR-Linac上前列腺癌的结构和功能定量MRI（qMRI）的MR序列。MR信号的变化，在分割RT解剖泌尿生殖系统的子结构将被描述和相关的毒性和累积的辐射剂量在这些子结构，目的是产生新的毒性预测模型，个性化的RT。

This project using the hybrid 1.5 T MR-Linac system is based on the hypothesis that online adaptive MR-guided radiotherapy (MRgRT) in prostate cancer will provide novel quantitative imaging biomarkers for prediction of genitourinary toxicity including MR-based radiation dose accumulation in critical anatomical substructures (urethra, trigonum, penile bulb and more) as well as their structural and functional changes during fractionated RT. Therefore, two fractionated regimens (60 Gy/ 20 fx and 78 Gy/ 39 fx) are examined within prospective phase II studies (Mbase Pro, Mbase HyPro) at the MR-Linac. The expected results will form the basis for future biologically individualized MRgRT interventions such as individual dose and fractionation prescription in prostate cancer. For this project MR sequences for structural and functional quantitative MRI (qMRI) at the 1.5 T MR-Linac of prostate cancer before and during fractionated RT will be optimized and validated. MR signal changes during fractionated RT in anatomical genitourinary substructures will be described and associated with toxicity and accumulated radiation dose in those substructures with the aim to generate new toxicity prediction models for individualized RT.