Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 1/F, Professorial Block, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong.
Radiat Oncol. 2012 Nov 26;7:199. doi: 10.1186/1748-717X-7-199.
We would like to investigate the if IMRT produced better target coverage and dose sparing to adjacent normal structures as compared with 3-dimensional conformal radiotherapy (3DCRT) and lateral opposing fields (LOF) for patients with Graves' ophthalmopathy treated with retro-orbital irradiation.
Ten consecutive patients diagnosed with Graves' ophthalmopathy were prospectively recruited into this study. An individual IMRT, 3DCRT and LOF plan was created for each patient. Conformity index (CI), homogeneity index (HI) and other dosimetric parameters of the targets and organs-at-risk (OAR) generated by IMRT were compared with the other two techniques.
Mann-Whitney U test demonstrated that CI generated by IMRT was superior to that produced by 3DCRT and LOF (p=0.005 for both respectively). Similarly HI with IMRT was proven better than 3DCRT (p=0.007) and LOF (p=0.005). IMRT gave rise to better dose sparing to some OARs including globes, lenses and optic nerves as compared with 3DCRT but not with LOF.
IMRT, as compared with 3DCRT and LOF, was found to have a better target coverage, conformity and homogeneity and dose sparing to some surrounding structures, despite a slight increase but clinically negligible dose to other structures. Dosimetrically it might be a preferred treatment technique and a longer follow up is warranted to establish its role in routine clinical use.
我们希望研究与 3 维适形放射治疗（3DCRT）和外侧对置野（LOF）相比，调强放射治疗（IMRT）是否能为眼眶放射治疗的格雷夫斯眼病患者提供更好的靶区覆盖和对相邻正常结构的剂量保护。
本研究前瞻性纳入 10 例连续确诊的格雷夫斯眼病患者。为每位患者创建了个体化的 IMRT、3DCRT 和 LOF 计划。比较了 IMRT 生成的靶区和危及器官（OAR）的适形指数（CI）、均匀性指数（HI）和其他剂量学参数与其他两种技术。
Mann-Whitney U 检验表明，IMRT 生成的 CI 优于 3DCRT 和 LOF（p 值分别为 0.005 和 0.005）。同样，IMRT 的 HI 也优于 3DCRT（p=0.007）和 LOF（p=0.005）。与 3DCRT 相比，IMRT 对一些 OAR （包括眼球、晶状体和视神经）的剂量保护更好，但与 LOF 相比则不然。
与 3DCRT 和 LOF 相比，IMRT 发现具有更好的靶区覆盖、适形性和均匀性，对一些周围结构具有更好的剂量保护作用，尽管对其他结构的剂量略有增加，但临床可忽略不计。从剂量学角度来看，它可能是一种首选的治疗技术，需要进行更长时间的随访，以确定其在常规临床应用中的作用。
