Quantitative MR imaging biomarkers for toxicity prediction in prostate cancer

本项目采用混合1.5 T MR-Linac系统，基于以下假设：前列腺癌在线自适应磁共振引导放射治疗（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，包括关键解剖亚结构（尿道、三角区、阴茎球等）的磁共振辐射剂量积累及其在分块放射治疗期间的结构和功能变化。在MR-Linac的前瞻性II期研究（Mbase Pro、Mbase HyPro）中，研究了两种分级方案（60 Gy/ 20 fx和78 Gy/ 39 fx）。预期的结果将成为未来生物个体化MRgRT干预的基础，如前列腺癌的个体剂量和分离处方。本项目将优化和验证前列腺癌分级放疗前和分级放疗期间在1.5 T MR- linac上的结构和功能定量MRI （qMRI）的MR序列。将描述解剖性泌尿生殖系统亚结构分步放射治疗期间MR信号的变化，并将其与亚结构的毒性和累积辐射剂量联系起来，旨在为个体化放射治疗建立新的毒性预测模型。

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.