Section of Radiotherapy, Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Acta Oncol. 2022 Feb;61(2):239-246. doi: 10.1080/0284186X.2021.1974554. Epub 2021 Sep 17.
The prospective TEDDI protocol investigates the feasibility of radiotherapy delivery in deep inspiration breath-hold (DIBH) for pediatric patients. To secure optimal radiotherapy planning, a diagnostic baseline FDG PET/CT in free breathing (FB) and DIBH was acquired. The anatomical changes in the mediastinum and the effect on PET metrics between the two breathing conditions were assessed for pediatric patients with mediastinal lymphoma.
Ten patients aged 5-17 were included and had a PET/CT in FB and DIBH. Metabolic active lymphoma volumes were manually delineated with a visually based segmentation method and the PET metrics were extracted. The anatomical lymphoma, lung and heart volumes were delineated on CT.
The lung volume increased while the heart was displaced caudally and separated from the lymphoma in DIBH compared to FB. Both the anatomical and the metabolically active lymphoma volumes appeared different regarding shape and configuration in the two breathing conditions. The image quality of the DIBH PET was equal to the FB PET regarding interpretation and delineation of lymphoma lesions. All PET metrics increased on the DIBH PET compared to the FB PET with the highest increase observed for the maximum standardized uptake value (33%, range 7-56%).
Diminished respiratory motion together with anatomical changes within the lymphoma increased all PET metrics in DIBH compared to FB. The anatomical changes observed in DIBH compared to FB are expected to reduce radiation doses to the heart and lungs in pediatric patients with mediastinal lymphoma referred for radiotherapy delivery in DIBH and, thereby, reduce their risk of late effects.
The Danish Ethical Committee (H-16035870, approved November 24 2016), the Danish Data Protection Agency (2012-58-0004, approved 1 January 2017). Registered retrospectively at clinicaltrials.gov (NCT03315546, 20 October 2017).
前瞻性 TEDDI 方案旨在研究儿童患者深吸气屏气（DIBH）下放疗的可行性。为了确保最佳的放疗计划，在自由呼吸（FB）和 DIBH 下采集了诊断性基线 FDG PET/CT。评估了纵隔淋巴瘤患儿两种呼吸状态下纵隔的解剖变化及其对 PET 指标的影响。
纳入 10 例 5-17 岁患者，行 FB 和 DIBH PET/CT。采用基于视觉的分割方法手动勾画代谢活跃的淋巴瘤体积，并提取 PET 指标。在 CT 上勾画纵隔淋巴瘤、肺和心脏的解剖学体积。
与 FB 相比，DIBH 时肺容积增加，心脏向尾侧移位并与淋巴瘤分离。两种呼吸状态下，解剖学和代谢活跃的淋巴瘤体积在形状和结构上均有不同。DIBH PET 的图像质量与 FB PET 相当，对于淋巴瘤病变的解读和勾画均无影响。与 FB PET 相比，DIBH PET 的所有 PET 指标均升高，最大标准化摄取值（SUVmax）升高最明显（33%，范围 7-56%）。
与 FB 相比，DIBH 时呼吸运动减少以及纵隔内的解剖变化导致所有 PET 指标均升高。与 FB 相比，DIBH 时观察到的解剖变化有望降低纵隔淋巴瘤患儿放疗中 DIBH 时的心脏和肺剂量，从而降低其发生迟发性并发症的风险。
丹麦伦理委员会（H-16035870，2016 年 11 月 24 日批准），丹麦数据保护局（2012-58-0004，2017 年 1 月 1 日批准）。于 2017 年 10 月 20 日在临床试验.gov 上进行了回顾性注册（NCT03315546）。
