Huang He-Fa, Gao Xing-Xin, Li Qiang, Ma Xiao-Yun, Du Lan-Ning, Sun Peng-Fei, Li Sha
Department of Irradiation Oncology, the 940th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army, Lanzhou, China.
School of Nuclear Science and Technology, Lanzhou University, Lanzhou, China.
Quant Imaging Med Surg. 2023 Oct 1;13(10):6965-6978. doi: 10.21037/qims-23-340. Epub 2023 Sep 22.
Prostate cancer rates have been steadily increasing in recent years. As high-precision radiation therapy methods, stereotactic body radiation therapy (SBRT) and carbon-ion radiation therapy (CIRT) have unique advantages. Analyzing the dosimetric differences between SBRT and CIRT in the treatment of localized prostate cancer can help provide patients with more accurate, individualized treatment plans.
We selected computed tomography positioning images and the contours of target volumes of 16 patients with localized prostate cancer who received radiotherapy. We delineated the organs at risk (OARs) on the CyberKnife (CK) treatment planning system (TPS) MultiPlan4.0, which were imported into the CIRT uniform scanning TPS HIMM-1 ci-Plan. Two treatment plans, SBRT and CIRT, were designed for the same patient, and we used SPSS 22.0 for the statistical analysis of data.
Both SBRT and CIRT plans met the prescribed dose requirements. In terms of target volume exposure dose, D2 (P<0.001), D5 (P<0.001), D50 (P<0.001), D90 (P=0.029), D95 (P<0.001), D98 (P<0.001), and D (P<0.001) under SBRT were significantly higher than those under CIRT; the conformity index (CI) under SBRT was significantly better than that under CIRT (P<0.001); the target volume coverage rate (V95%) and dose homogeneity index (HI) under CIRT were significantly better than those under SBRT (P<0.001). In terms of OAR exposure dosage, the D of the bladder and rectum under SBRT was significantly lower than that under CIRT (P<0.001), but D was in the other direction; the exposure dose of the intestinal tract under CIRT was significantly lower than that under SBRT (P<0.05); D of the femoral head under CIRT was significantly lower than that under SBRT (P<0.05), and there was no statistical difference between them at other doses.
In this study, we found that when CIRT was used for treating localized prostate cancer, the dose distribution in target volume was more homogeneous and the coverage rate was higher; the average dose of OARs was lower. SBRT had a better CI and higher dose in target volume; the dose hotspot was lower in OARs. It is important to comprehensively consider the dose relationship between local tumor and surrounding tissues when selecting treatment plans.
近年来前列腺癌发病率一直在稳步上升。作为高精度放射治疗方法，立体定向体部放射治疗（SBRT）和碳离子放射治疗（CIRT）具有独特优势。分析SBRT和CIRT在局限性前列腺癌治疗中的剂量学差异有助于为患者提供更准确、个性化的治疗方案。
我们选取了16例接受放射治疗的局限性前列腺癌患者的计算机断层扫描定位图像和靶区轮廓。在射波刀（CK）治疗计划系统（TPS）MultiPlan4.0上勾画危及器官（OARs），并导入CIRT均匀扫描TPS HIMM-1 ci-Plan。为同一患者设计SBRT和CIRT两种治疗计划，并用SPSS 22.0对数据进行统计分析。
SBRT和CIRT计划均满足规定剂量要求。在靶区暴露剂量方面，SBRT下的D2（P<0.001）、D5（P<0.001）、D50（P<0.001）、D90（P=0.029）、D95（P<0.001）、D98（P<0.001）和D（P<0.001）显著高于CIRT；SBRT下的适形指数（CI）显著优于CIRT（P<0.001）；CIRT下的靶区覆盖率（V95%）和剂量均匀性指数（HI）显著优于SBRT（P<0.001）。在OAR暴露剂量方面，SBRT下膀胱和直肠的D显著低于CIRT（P<0.001），但D则相反；CIRT下肠道的暴露剂量显著低于SBRT（P<0.05）；CIRT下股骨头的D显著低于SBRT（P<0.05），其他剂量下两者无统计学差异。
在本研究中，我们发现当使用CIRT治疗局限性前列腺癌时，靶区内的剂量分布更均匀且覆盖率更高；OARs的平均剂量更低。SBRT具有更好的CI且靶区内剂量更高；OARs中的剂量热点更低。选择治疗方案时综合考虑局部肿瘤与周围组织的剂量关系很重要。
