发表机构
University of California, San Francisco（加利福尼亚大学旧金山分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过87例脑转移瘤纵向MRI数据基准测试DIR方法，发现基于优化的DIR方法表现最佳，但现有DIR方法仍无法满足脑转移瘤再照射剂量累积的临床无人监督使用需求，需病例级质量控制。
AI 中文摘要
剂量累积在适应性放射治疗和再照射中愈发重要，但其临床有效性取决于可变形图像配准（DIR）的性能。采用立体定向放射外科（SRS）对脑转移瘤（BMs）进行再照射，是一个可控且具有临床意义的DIR测试案例：刚性配准后受试者脑内变形通常有限，但复发病变会出现刚性配准无法捕捉的显著局部形状和体积变化，进而影响剂量累积。我们在某机构BMs SRS再治疗队列的87例经人工筛选的纵向增强T1加权MRI病变配对数据上，对多种基于学习和基于优化的DIR方法进行了基准测试。对在健康脑MRI上预训练的基于学习的方法，我们评估了其零样本性能，以及经实例特异性优化（ISO）或肿瘤邻近目标特异性优化（TSO）后的性能。配准评估采用了病变重叠度（Dice）、表面距离指标（HD95和sASD）、目标体积恢复情况，以及运行时间和内存占用。预训练的基于学习的方法零样本性能存在差异，而ISO/TSO可改善所有测试的基于学习的方法家族的性能。不过，基于优化的方法仍是表现最佳的方法，同时保持了合理的运行时间。这些发现表明，即使是最先进的DIR方法，目前也无法提供足够准确和一致的配准，以用于脑转移瘤再照射剂量累积的无人监督使用。由于准确的配准是可变形剂量累积的前提，临床应用将需要病例级质量控制，并直接评估配准不确定性如何影响下游剂量指标。
英文摘要
Dose accumulation is increasingly important in adaptive radiation therapy and reirradiation, but its clinical validity depends on the performance of deformable image registration (DIR). Reirradiation of brain metastases (BMs) with stereotactic radiosurgery (SRS) provides a controlled but clinically meaningful DIR test case: intra-subject brain deformation is usually limited after rigid alignment, yet recurrent lesions can undergo substantial local shape and volume changes that rigid registration cannot capture and can affect dose accumulation. We benchmarked a wide range of learning-based and optimization-based DIR methods on 87 manually screened longitudinal contrast-enhanced T1-weighted MRI lesion pairs from an institutional BM SRS retreatment cohort. Learning-based methods pretrained on healthy-brain MRI were evaluated zero-shot and after instance-specific optimization (ISO) or tumor-proximity target-specific optimization (TSO). Registration was assessed using lesion overlap (Dice), surface distance metrics (HD95 and sASD), target-volume recovery, and runtime and memory. Pretrained learning-based methods showed variable zero-shot performance, while ISO/TSO improved all tested learning-based families. However, optimization-based methods remained the best-performing approach while maintaining reasonable runtime. These findings suggest that even state-of-the-art DIR methods do not yet provide sufficiently accurate and consistent registration for unmonitored use in brain metastasis reirradiation dose accumulation. Because accurate registration is a prerequisite for deformable dose accumulation, clinical application will require case-level quality control and direct assessment of how registration uncertainty affects downstream dose metrics.
