Taylor Alice, Sen Mehmet, Prestwich Robin J D
School of Medicine, Worsley Building, University of Leeds, Leeds LS2 9JT, UK.
Department of Clinical Oncology, St. James's University Hospital, Leeds Cancer Centre, Beckett Street, Leeds LS9 7TF, UK.
Healthcare (Basel). 2018 Nov 24;6(4):135. doi: 10.3390/healthcare6040135.
Aim of study was to assess impact of deformable registration of diagnostic MRI to planning CT upon gross tumour volume (GTV) delineation of oropharyngeal carcinoma in routine practice.
22 consecutive patients with oropharyngeal squamous cell carcinoma treated with definitive (chemo)radiotherapy between 2015 and 2016, for whom primary GTV delineation had been performed by a single radiation oncologist using deformable registration of diagnostic MRI to planning CT, were identified. Separate GTVs were delineated as part of routine clinical practice (all diagnostic imaging available side-by-side for each delineation) using: CT (GTV), MRI (GTV), and CT and MRI (GTV). Volumetric and positional metric analyses were undertaken using contour comparison metrics (Dice conformity index, centre of gravity distance, mean distance to conformity).
Median GTV volumes were 13.7 cm³ (range 3.5⁻41.7), 15.9 cm³ (range 1.6⁻38.3), 19.9 cm³ (range 5.5⁻44.5) for GTV, GTV and GTV respectively. There was no significant difference in GTV and GTV volumes; GTV was found to be significantly larger than both GTV and GTV. Based on positional metrics, GTV and GTV were the least similar (mean Dice similarity coefficient (DSC) 0.71, 0.84, 0.82 for GTV⁻GTV, GTV⁻GTV and GTV⁻GTV respectively).
These data suggest a complementary role of MRI to CT to reduce the risk of geographical misses, although they highlight the potential for larger target volumes and hence toxicity.
本研究的目的是评估在常规实践中，将诊断性磁共振成像（MRI）与计划计算机断层扫描（CT）进行可变形配准对口咽癌大体肿瘤体积（GTV）勾画的影响。
确定了2015年至2016年间连续接受根治性（化疗）放疗的22例口咽鳞状细胞癌患者，这些患者的原发性GTV勾画由一名放射肿瘤学家使用诊断性MRI与计划CT的可变形配准完成。作为常规临床实践的一部分（每次勾画时所有诊断成像并排可用），分别使用CT（GTV）、MRI（GTV）以及CT和MRI（GTV）勾画独立的GTV。使用轮廓比较指标（骰子一致性指数、重心距离、平均符合距离）进行体积和位置度量分析。
GTV、GTV和GTV的中位GTV体积分别为13.7 cm³（范围3.5⁻41.7）、15.9 cm³（范围1.6⁻38.3）、19.9 cm³（范围5.5⁻44.5）。GTV和GTV体积之间无显著差异；发现GTV显著大于GTV和GTV。基于位置度量，GTV和GTV最不相似（GTV⁻GTV、GTV⁻GTV和GTV⁻GTV各自的平均骰子相似系数（DSC）分别为0.71、0.84、0.82）。
这些数据表明MRI对CT具有互补作用，可降低遗漏肿瘤区域的风险，尽管它们也凸显了靶区体积更大从而导致毒性增加的可能性。
