Department of Radiation Oncology, St-Luc University Hospital, Brussels, Belgium; Department of Molecular Imaging, Radiotherapy and Oncology Unit, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium.
Section for Biomedical Physics, Department of Radiation Oncology, University of Tübingen, Tübingen, Germany.
Semin Radiat Oncol. 2018 Jan;28(1):35-45. doi: 10.1016/j.semradonc.2017.08.003.
With the routine use of intensity modulated radiation therapy for the treatment of head-and-neck squamous cell carcinoma allowing highly conformed dose distribution, there is an increasing need for refining both the selection and the delineation of gross tumor volumes (GTV). In this framework, molecular imaging with positron emission tomography and magnetic resonance imaging offers the opportunity to improve diagnostic accuracy and to integrate tumor biology mainly related to the assessment of tumor cell density, tumor hypoxia, and tumor proliferation into the treatment planning equation. Such integration, however, requires a deep comprehension of the technical and methodological issues related to image acquisition, reconstruction, and segmentation. Until now, molecular imaging has had a limited value for the selection of nodal GTV, but there are increasing evidences that both FDG positron emission tomography and diffusion-weighted magnetic resonance imaging has a potential value for the delineation of the primary tumor GTV, effecting on dose distribution. With the apprehension of the heterogeneity in tumor biology through molecular imaging, growing evidences have been collected over the years to support the concept of dose escalation/dose redistribution using a planned heterogeneous dose prescription, the so-called "dose painting" approach. Validation trials are ongoing, and in the coming years, one may expect to position the dose painting approach in the armamentarium for the treatment of patients with head-and-neck squamous cell carcinoma.
随着调强放射治疗技术在头颈部鳞状细胞癌治疗中的常规应用，能够实现高度适形的剂量分布，因此越来越需要对大体肿瘤体积（GTV）的选择和勾画进行精细化处理。在这种情况下，正电子发射断层扫描和磁共振成像的分子影像学为提高诊断准确性提供了机会，并将肿瘤生物学主要与肿瘤细胞密度、肿瘤缺氧和肿瘤增殖的评估相结合，纳入治疗计划方程。然而，这种整合需要深入了解与图像采集、重建和分割相关的技术和方法问题。到目前为止，分子影像学对于淋巴结 GTV 的选择仅有有限的价值，但越来越多的证据表明，氟代脱氧葡萄糖正电子发射断层扫描和弥散加权磁共振成像对于勾画原发肿瘤 GTV 具有潜在的价值，从而影响剂量分布。通过分子影像学来了解肿瘤生物学的异质性，多年来积累了越来越多的证据支持使用计划的不均匀剂量处方（所谓的“剂量描绘”方法）来进行剂量升级/剂量再分布的概念。验证性试验正在进行中，在未来几年内，人们可能会期望将剂量描绘方法应用于头颈部鳞状细胞癌患者的治疗中。
