Toya Ryo, Saito Tetsuo, Kai Yudai, Shiraishi Shinya, Matsuyama Tomohiko, Watakabe Takahiro, Sakamoto Fumi, Tsuda Noriko, Shimohigashi Yoshinobu, Yamashita Yasuyuki, Oya Natsuo
Department of Radiation Oncology, Kumamoto University Hospital, Kumamoto, Japan.
Department of Radiological Technology, Kumamoto University Hospital, Kumamoto, Japan.
Dose Response. 2019 Mar 4;17(1):1559325819832149. doi: 10.1177/1559325819832149. eCollection 2019 Jan-Mar.
To evaluate the impact of Tc-labeled diethylene triamine pentaacetate-galactosyl human serum albumin (Tc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning on the dose-function histogram (DFH) parameters for stereotactic body radiation therapy planning in patients with hepatocellular carcinoma (HCC).
Eleven patients were enrolled in this study. The functional liver structure (FLS) was derived from SPECT thresholds of 60% to 80% of the maximum pixel value. Two treatment plans optimized without FLS (plan C) and with FLS (plan F) were designed for 50 Gy to the planning target volume (PTV). The DFH parameters were calculated as follows: = (sum of the counts within the liver volume receiving a dose > Gy/sum of the counts within the whole liver volume) × 100. Other parameters for the PTV included D, mean dose, conformity index (CI), and homogeneity index (HI).
Compared with plan C, plan F significantly reduced DFH parameters of F to F ( < .05). There were no significant differences in the parameters of the PTV of D, mean dose, CI, and HI and organs at risks (stomach, duodenum, spinal cord, and kidneys) between plans C and F.
DFH analyses revealed that Tc-GSA SPECT image-guided inverse planning provided dosimetric benefits related to sparing of liver function and may reduce hepatic toxicities.
评估锝标记的二乙烯三胺五乙酸 - 半乳糖基人血清白蛋白（Tc - GSA）单光子发射计算机断层扫描（SPECT）图像引导的逆向计划对肝细胞癌（HCC）患者立体定向体部放射治疗计划中剂量 - 功能直方图（DFH）参数的影响。
本研究纳入11例患者。功能性肝结构（FLS）源自SPECT阈值为最大像素值的60%至80%。针对计划靶区（PTV）50 Gy设计了两个治疗计划，一个不使用FLS进行优化（计划C），另一个使用FLS进行优化（计划F）。DFH参数计算如下：=（接受剂量> Gy的肝体积内的计数总和/全肝体积内的计数总和）×100。PTV的其他参数包括D、平均剂量、适形指数（CI）和均匀性指数（HI）。
与计划C相比，计划F显著降低了F至F的DFH参数（<0.05）。计划C和F之间，PTV的D、平均剂量、CI和HI参数以及危及器官（胃、十二指肠、脊髓和肾脏）方面无显著差异。
DFH分析表明，Tc - GSA SPECT图像引导的逆向计划在肝功能保留方面提供了剂量学益处，并可能降低肝毒性。
