Vieillevigne Laure, Vidal Marie, Izar Françoise, Rives Michel
Institut Claudius Regaud, Institut Universitaire du Cancer de Toulouse Oncopole, Radiotherapy Department, France.
Rep Pract Oncol Radiother. 2015 Jan 5;20(2):135-40. doi: 10.1016/j.rpor.2014.12.006. eCollection 2015 Mar-Apr.
To investigate the feasibility of dose escalation using rapid arc (RA) and Helical Tomotherapy (HT) for patients with upper, middle and distal esophageal carcinomas, even for large tumor volumes.
In esophageal cancer, for patients with exclusive radio-chemotherapy, local disease control remains poor. Planning study with dose escalation was done for two sophisticated modulated radiotherapy techniques: Rapid arc against Tomotherapy.
Six patients treated with a RA simultaneous integrated boost (SIB) of 60 Gy were re-planned for RA and HT techniques with a SIB dose escalated to 70 Gy. Dose volume histogram statistics, conformity indices and homogeneity indices were analyzed. For a given set of normal tissue constraints, the capability of each treatment modality to increase the GTV dose to 70 Gy was investigated.
Either HT or VMAT may be used to escalate the dose delivered in esophageal tumors while maintaining the spinal cord, lung and heart doses within tolerance. Adequate target coverage was achieved by both techniques. Typically, HT achieved better lung sparing and PTV coverage than did RA.
Dose escalation for esophageal cancer becomes clinically feasible with the use of RA and HT. This promising result could be explored in a carefully controlled clinical study which considered normal tissue complications and tumor control as endpoints.
探讨采用容积旋转调强放疗（RA）和螺旋断层放疗（HT）对食管上段、中段和下段癌患者，甚至是肿瘤体积较大的患者进行剂量递增的可行性。
在食管癌中，对于单纯接受放化疗的患者，局部疾病控制效果仍然较差。针对两种先进的调强放疗技术（容积旋转调强放疗与螺旋断层放疗）进行了剂量递增的计划研究。
对6例接受60 Gy容积旋转调强放疗同步整合加量（SIB）治疗的患者，重新制定容积旋转调强放疗和螺旋断层放疗计划，将同步整合加量剂量增至70 Gy。分析剂量体积直方图统计数据、适形指数和均匀性指数。在给定的一组正常组织限制条件下，研究每种治疗方式将大体肿瘤体积（GTV）剂量增至70 Gy的能力。
螺旋断层放疗或容积旋转调强放疗均可用于提高食管肿瘤的放疗剂量，同时将脊髓、肺和心脏的剂量维持在耐受范围内。两种技术均实现了足够的靶区覆盖。通常，螺旋断层放疗在保护肺组织和计划靶区（PTV）覆盖方面比容积旋转调强放疗效果更好。
使用容积旋转调强放疗和螺旋断层放疗使食管癌的剂量递增在临床上变得可行。这一有前景的结果可在一项精心控制的临床研究中进行探索，该研究将正常组织并发症和肿瘤控制作为终点指标。
