Zhang Xiaomeng, Chen Yen-Lin E, Lim Ruth, Huang Chuan, Chebib Ivan A, El Fakhri Georges
Gordon Center for Medical Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114.
Gordon Center for Medical Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114; Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114.
Magn Reson Imaging. 2016 Apr;34(3):276-9. doi: 10.1016/j.mri.2015.10.027. Epub 2015 Oct 31.
The primary objective of this study was to develop and validate simultaneous PET/MRI-MRS as a novel biological image-guided approach to neoadjuvant radiotherapy (RT) and/or chemoradiation (chemoRT) in soft tissue sarcomas (STS). A patient with sarcoma of the right thigh underwent PET/MRI scan before and after neoadjuvant (preoperative) radiotherapy. The magnetic resonance imaging (MRI) and 2-deoxy-2-[fluorine-18]-fluoro-D-glucose-Positron Emission Tomography ((18)F-FDG-PET) scans were performed simultaneously. In the post-radiation scan, magnetic resonance spectroscopy (MRS) was subsequently acquired with volume of interest positioned in a residual hyper-metabolic region detected by PET. Post-radiation PET/MRI showed a residual T2-hyperintense mass with significantly reduced (18)F-FDG-uptake, compatible with near complete response to radiotherapy. However, a small region of residual high (18)F-FDG uptake was detected at the tumor margin. MRS of this region had similar metabolite profile as normal tissue, and was thus considered false positive on PET scan. Pathology results were obtained after surgery for confirmation of imaging findings.
本研究的主要目的是开发并验证同步正电子发射断层扫描/磁共振成像-磁共振波谱（PET/MRI-MRS）作为一种用于软组织肉瘤（STS）新辅助放疗（RT）和/或放化疗（chemoRT）的新型生物图像引导方法。一名右大腿肉瘤患者在新辅助（术前）放疗前后接受了PET/MRI扫描。磁共振成像（MRI）和2-脱氧-2-[氟-18]-氟-D-葡萄糖正电子发射断层扫描（(18)F-FDG-PET）扫描同时进行。在放疗后扫描中，随后在PET检测到的残留高代谢区域放置感兴趣区进行磁共振波谱（MRS）采集。放疗后PET/MRI显示残留的T2高信号肿块，(18)F-FDG摄取显著降低，与放疗接近完全缓解相符。然而，在肿瘤边缘检测到一小片残留的高(18)F-FDG摄取区域。该区域的MRS代谢物谱与正常组织相似，因此在PET扫描中被认为是假阳性。术后获得病理结果以证实影像学发现。
