Department of Radiology, American University of Beirut Medical Center, Riad El-Solh 1107 2020, PO Box: 11-0236, Beirut, Lebanon.
Faculty of Health Sciences, American University of Beirut, Riad El-Solh 1107 2020, PO Box: 11-0236, Beirut, Lebanon.
Eur J Radiol. 2020 Mar;124:108855. doi: 10.1016/j.ejrad.2020.108855. Epub 2020 Jan 28.
To assess the value of using Apparent Diffusion Coefficient (ADC) mapping in Diffusion Weighted Imaging (DWI) when monitoring treatment response in pediatric Osteogenic and Ewing sarcomas and to correlate with level of necrosis on post-surgical excision pathology.
This retrospective study includes 7 Osteosarcoma and 8 Ewing sarcoma patients. Pre-treatment and post-treatment focal MRIs were evaluated for ADC values, tumor volumes and variability of both measurements. We also compared the measurement between Ewing and Osteosarcoma groups, as well as between good (=/>90 % necrosis post-excision) and poor (<90 % necrosis post-excision) responders.
All measurements except Maximum ADC (p = 0.20) showed a statistically significant difference when comparing them before and after treatment. When we segregated our population according to pathologic complete response, there was no difference in ADC measurements, volumetric measurements or either variability between good (8 Patients) and poor responders (7 Patients). When comparing the before-after changes in our measurement between the Ewing sarcoma and Osteosarcoma cases, there was no significant difference in the change between pre and post treatment (Δ) Mean or Maximum ADC, or in Δtumor-volume when measured on STIR or SPIR T1 post-contrast sequences. Only the ΔMinimum-ADC showed a statistically significant difference (p < 0.02) in this group.
ADC can potentially reflect cellular changes associated with chemotherapy use, reflecting a response to treatment. However, quantitative use of those parameters to dictate a change in management, treatment regimen or chemotherapy dose in order to target a good response (>/ = 90 % necrosis post-excision) needs further investigation.
评估在监测小儿成骨性和尤文肉瘤治疗反应时，在弥散加权成像（DWI）中使用表观扩散系数（ADC）图的价值，并将其与术后切除病理的坏死程度相关联。
本回顾性研究纳入了 7 例成骨肉瘤和 8 例尤文肉瘤患者。评估了治疗前后的局灶性 MRI 的 ADC 值、肿瘤体积及其变化。我们还比较了尤文肉瘤组和成骨肉瘤组之间的测量值，以及良好（切除后>90%坏死）和不良（切除后<90%坏死）反应者之间的测量值。
除最大 ADC 外（p=0.20），所有测量值在治疗前后的比较中均具有统计学差异。当我们根据病理完全缓解对我们的人群进行分类时，在良好（8 例）和不良（7 例）反应者之间，ADC 测量值、体积测量值或两者的变异性均无差异。当我们比较尤文肉瘤和成骨肉瘤病例之间测量值的治疗前后变化时，治疗前后（Δ）均值或最大 ADC 或 STIR 或 SPIR T1 增强后序列的肿瘤体积的变化没有显著差异。只有最小 ADC 的变化具有统计学意义（p<0.02）。
ADC 可能反映与化疗使用相关的细胞变化，反映治疗反应。然而，为了靶向良好反应（切除后>/=90%坏死），定量使用这些参数来改变管理、治疗方案或化疗剂量，还需要进一步研究。
