肿瘤内缺氧与头颈癌患者预后不良和治疗反应差有关。如果能够确定，可以增加对缺氧病灶亚区的放射剂量。18F-FMISO PET成像是金标准，但经多参数MRI定量分析也能显示肿瘤内缺氧状况。因此，在治疗前，对16名头颈癌患者进行了18F-FDG PET / CT、18F-FMISO PET / CT和多参数定量MRI(DCE、扩散和T1、T2松弛度技术)，并在同一位置进行了检查。利用PET和MRI分割肿瘤亚区，并将其分类为缺氧和非缺氧体积，比较了正常和缺氧体积之间的定量MRI参数。共有13名患者有缺氧病变。FDG PET和MRI测量的病灶体积之间的Dice、Jaccard和重叠分数相似指数分别为0.43、0.28和0.71，表明FDG PET肿瘤体积部分包含在MRI肿瘤体积之内。结果显示，FDG和FMISO PET中SUV参数，对于有和没有可测量缺氧病灶的患者之间存在显着差异。ADC、T1 max映射和T2 max映射的定量MRI参数在缺氧和正常亚区之间也是不同的。基于自由水扩散和T1、T2映射的定量MRI似乎能够为进一步的放射治疗剂量确定肿瘤内缺氧亚部位。

Intratumoral hypoxia is associated with a poor prognosis and poor response to treatment in head and neck cancers. Its identification would allow for increasing the radiation dose to hypoxic tumor subvolumes. 18F-FMISO PET imaging is the gold standard; however, quantitative multiparametric MRI could show the presence of intratumoral hypoxia. Thus, 16 patients were prospectively included and underwent 18F-FDG PET/CT, 18F-FMISO PET/CT, and multiparametric quantitative MRI (DCE, diffusion and relaxometry T1 and T2 techniques) in the same position before treatment. PET and MRI sub-volumes were segmented and classified as hypoxic or non-hypoxic volumes to compare quantitative MRI parameters between normoxic and hypoxic volumes. In total, 13 patients had hypoxic lesions. The Dice, Jaccard, and overlap fraction similarity indices were 0.43, 0.28, and 0.71, respectively, between the FDG PET and MRI-measured lesion volumes, showing that the FDG PET tumor volume is partially contained within the MRI tumor volume. The results showed significant differences in the parameters of SUV in FDG and FMISO PET between patients with and without measurable hypoxic lesions. The quantitative MRI parameters of ADC, T1 max mapping and T2 max mapping were different between hypoxic and normoxic subvolumes. Quantitative MRI, based on free water diffusion and T1 and T2 mapping, seems to be able to identify intra-tumoral hypoxic sub-volumes for additional radiotherapy doses.