Gunma University Heavy Ion Medical Center, Japan.
Kanagawa Cancer Center, Japan.
Radiother Oncol. 2019 Aug;137:77-82. doi: 10.1016/j.radonc.2019.04.026. Epub 2019 May 9.
To determine whether bone matching (BM) or marker matching (MM) is the better positioning technique for carbon ion radiotherapy (CIRT) of primary hepatocellular carcinoma (HCC), we prospectively evaluated accumulated dose distributions with respect to intra- and inter-fractional anatomical changes.
The accumulated doses in ten patients with HCC were evaluated, with the doses being calculated with respect to inter-fractional changes (InterDose) on treatment-room CT images on day 1 or day 2 of therapy (RefCT). This was accomplished by warping 3-day CT dose distributions to the RefCT through deformable registration. The accumulated doses were also calculated with respect to intra-fractional change (IntraDose) calculated by warping dose distributions for three 4DCT phases to the RefCT. Each dose was evaluated using dose-volume parameters for the clinical target volume (CTV) percentages receiving greater than 95% of the prescription dose (V).
The InterDose CTV V values (mean [range]) were BM: 98.74% (95.62-100%), MM: 99.79% (98.55-100%), and the IntraDose values were BM: 99.46% (98.10-100%), MM: 99.74% (98.91-100%). Although all cases were acceptable with either matching method, MM provided better values than BM.
MM is a better positioning technique than BM for ensuring the target dose during and between fractions of CIRT. However, further analysis is required as our study included only a low number of cases.
为了确定在原发性肝细胞癌（HCC）的碳离子放射治疗（CIRT）中，骨匹配（BM）还是标记物匹配（MM）是更好的定位技术，我们前瞻性地评估了与分次内和分次间解剖变化相关的累积剂量分布。
评估了 10 例 HCC 患者的累积剂量，根据治疗室 CT 图像上第 1 天或第 2 天（RefCT）的分次内变化（InterDose）计算剂量，通过对 3 天 CT 剂量分布进行变形配准到 RefCT 来实现。还根据将三个 4DCT 相位的剂量分布变形配准到 RefCT 来计算分次内变化（IntraDose）来计算累积剂量。使用临床靶体积（CTV）接受处方剂量大于 95%的百分比（V）的剂量体积参数评估每个剂量。
InterDose CTV V 值（平均值[范围]）为 BM：98.74%（95.62-100%），MM：99.79%（98.55-100%），IntraDose 值为 BM：99.46%（98.10-100%），MM：99.74%（98.91-100%）。虽然两种匹配方法都可以接受所有病例，但 MM 提供的结果优于 BM。
在 CIRT 的分次内和分次间，MM 是一种比 BM 更好的定位技术，可确保目标剂量。然而，由于我们的研究仅包括少数病例，因此需要进一步分析。
