Research and Development Center, Bharathiar University, Coimbatore, India.
Department of Radiation Oncology, Healthcare Global Enterprises, Bangalore, India.
Asian Pac J Cancer Prev. 2020 Apr 1;21(4):1149-1154. doi: 10.31557/APJCP.2020.21.4.1149.
This study was conducted to dosimetrically compare plan quality of Simultaneous Integrated Boost - Stereotactic Body Radiotherapy (SIB-SBRT) generated for different techniques such as Cyberknife (CK), Helical Tomotherapy (HT) and RapidArc (RA) for carcinoma prostate with same treatment margins.
SIB-SBRT plans were generated for CK, HT and RA for thirteen CT data sets. The dose prescription was 45Gy in 5 fractions to GTV45 and 37.5Gy in 5 fractions to PTV37.5. The plan quality evaluation of the three techniques was done by comparing the DVH parameters, conformity index (CI) and gradient index (GI). For OAR's mean, maximum dose and dose volumes were compared for bladder, rectum and bilateral femoral heads. The number of Monitor Units (MU) delivered and Beam-on time (BOT) were also compared.
D2%, D50% and DMean to GTV45 was significantly higher in the CK compared to HT and RA (CK vs HT: p values, <0.001, 0.002 and 0.003; CK vs RA: p values, 0.001, 0.004 and 0.004) respectively. RA gives a better gradient index compared to CK and HT. Conformity indices of the RA plans were better than the CK plans (P<0.001). Normal tissue and integral dose delivered to the patient in HT and CK were found to be significantly higher than RA. The average number of MU's and BOT were significantly higher in CK (p<0.001).
Using the same treatment margins and dose constraints, RA achieved better target dose distribution and sparing of critical structures compared to CK and HT. RA seemed to be the optimal planning technique for SIB-SBRT treatment of carcinoma prostate.
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本研究旨在比较立体定向体部放射治疗（SBRT）同步推量（SIB）计划的剂量学，这些计划是为了治疗前列腺癌，使用的技术包括 Cyberknife（CK）、螺旋断层放疗（HT）和 RapidArc（RA），同时使用相同的治疗靶区边界。
对 13 套 CT 数据集生成 CK、HT 和 RA 的 SIB-SBRT 计划。处方剂量为 45Gy/5f 至 GTV45 和 37.5Gy/5f 至 PTV37.5。通过比较剂量体积直方图（DVH）参数、适形指数（CI）和梯度指数（GI）来评估三种技术的计划质量。比较膀胱、直肠和双侧股骨头的 OAR 平均值、最大剂量和剂量体积。还比较了每个计划的机器跳数（MU）和射束开启时间（BOT）。
与 HT 和 RA 相比，CK 组 GTV45 的 D2%、D50%和 DMean 明显更高（CK 与 HT 相比：p 值均<0.001、0.002 和 0.003；CK 与 RA 相比：p 值均<0.001、0.004 和 0.004）。RA 的梯度指数优于 CK 和 HT。RA 计划的适形指数优于 CK 计划（P<0.001）。HT 和 CK 中患者接受的正常组织和积分剂量明显高于 RA。CK 的平均 MU 和 BOT 明显更高（p<0.001）。
在使用相同的治疗靶区边界和剂量约束的情况下，RA 与 CK 和 HT 相比，能更好地实现靶区剂量分布，同时保护关键结构。RA 似乎是 SIB-SBRT 治疗前列腺癌的最佳计划技术。
