New developments in Mill for target volume delineation in radiotherapy
New developments in Mill for target volume delineation in radiotherapy
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DOI：
10.1259/bjr/41321492
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发表时间：
2006-01-01
影响因子：
2.6
通讯作者：
Joon, D. L.
中科院分区：
文献类型：
--
作者：
Khoo, V. S.;Joon, D. L.
磁共振成像（MRI）在肿瘤学中越来越多地用于分期、评估肿瘤反应以及放射治疗计划的制定。适形放疗和调强放疗都需要更好的方法来确定治疗计划的靶区体积，以实现其预期效果。与计算机断层扫描（CT）相比，MRI能够更好地显示软组织特征，从而可为放射治疗计划（RTP）流程提供帮助。加上其多平面成像能力和增强的成像功能，这些在靶区勾画方面的优势超过了其缺乏电子密度信息和可能存在图像失真的缺点。有效的磁共振失真评估和校正算法以及图像配准和融合程序可以克服这些局限性，使其可用于放射治疗计划。利用新型造影剂（如用于识别异常淋巴结的超小超顺磁性氧化铁颗粒）的磁共振成像技术发展，以及动态对比增强磁共振成像和扩散磁共振成像等技术（用于更好地描述组织和肿瘤区域特征），还有超快容积或电影磁共振序列（用于确定靶区和危及器官变形的时间模式以及空间位置的变化），都增加了磁共振成像在放射治疗计划中的应用范围和实用性。这些磁共振成像技术发展所提供的信息可能有助于实现治疗个体化、剂量递增策略以及影像引导的放射治疗。本文将对这些技术发展进行综述，以评估它们目前以及在放射治疗计划和精确高剂量放射治疗中的潜在应用。（C）2006英国放射学会
MRI is being increasingly used in oncology for staging, assessing tumour response and also for treatment planning in radiotherapy. Both conformal and intensity-modulated radiotherapy requires improved means of defining target volumes for treatment planning in order to achieve its intended benefits. MRI can add to the radiotherapy treatment planning (RTP) process by providing excellent and improved characterization of soft tissues compared with CT. Together with its multiplanar capability and increased imaging functionality, these advantages for target volume delineation outweigh its drawbacks of lacking electron density information and potential image distortion. Efficient MR distortion assessment and correction algorithms together with image co-registration and fusion programs can overcome these limitations and permit its use for RTP. MRI developments using new contrast media, such as ultrasmall superparamagnetic iron oxide particles for abnormal lymph node identification, techniques such as dynamic contrast enhanced MRI and diffusion MRI to better characterize tissue and tumour regions as well as ultrafast volumetric or cine MR sequences to define temporal patterns of target and organ at risk deformity and variations in spatial location have all increased the scope and utility of MRI for RTP. Information from these MR developments may permit treatment individualization, strategies of dose escalation and image-guided radiotherapy. These developments will be reviewed to assess their current and potential use for RTP and precision high dose radiotherapy. (C) 2006 The British Institute of Radiology.