容积旋转调强计划遮挡技术应用于早期鼻腔NK/T细胞淋巴瘤的剂量学研究-《中国医学物理学杂志》

文章信息/Info

Title:: Avoidance technique applied in volumetric modulated arc therapy for early-stage nasal natural killer/T-cell lymphoma: a dosimetric study

作者:: 徐婷婷1; 靳富2; 杨含2; 1.重庆市丰都县人民医院放射科，重庆 408299； 2.重庆大学附属肿瘤医院/重庆市肿瘤研究所/重庆市肿瘤医院肿瘤放射治疗中心，重庆 400030

Author(s):: XU Tingting1; JIN Fu2; YANG Han2; 1. Department of Radiology, Fengdu Peoples Hospital of Chongqing, Chongqing 408299, China 2. Department of Radiation Oncology, Chongqing University Cancer Hospital/Chongqing Cancer Institute Chongqing Cancer Hospital, Chongqing 400030, China

Keywords:: Keywords: natural killer/T-cell lymphoma volumetric modulated arc therapy lens avoidance radiotherapy

摘要:: 目的：比较3种容积旋转调强计划（VMAT）的剂量学差异，探讨VMAT遮挡技术对早期鼻腔NK/T细胞淋巴瘤的剂量学影响。方法：选取20例早期鼻腔NK/T细胞淋巴瘤患者，分别设计无晶体遮挡（VMAT-OFF）计划、晶体半遮挡（VMAT-E）计划和晶体全遮挡（VMAT-E&E）计划，评估3组计划的计划靶区体积（PTV）和危及器官（OARs）剂量学参数，评估机器跳数（MU）和SCIMOCA通过率（3%/2 mm）。结果：3种计划的靶区剂量分布均能满足临床要求，PTV的D2%、D98%、V95%、均匀性指数、适形度指数均无统计学差异；在MU方面，VMAT-OFF<0.05）；在oars晶体（dmax、dmean）方面，vmat-e&e><0.05），vmat-e&e>

Abstract:: Abstract: Objective To compare the dosimetric differences among 3 different volumetric modulated arc therapy (VMAT) plans, and to explore the dosimetric effects of VMAT avoidance technique on early-stage nasal natural killer/T-cell lymphoma. Methods Twenty patients with early-stage nasal natural killer/T-cell lymphoma were enrolled in the study, and 3 kinds of plans, namely no lens avoidance plan (VMAT-OFF), lens half-avoidance (VMAT-E) and lens avoidance plan (VMAT-E&E), were designed for each patients. The dosimetric parameters of planning target volume (PTV) and organs-at-risk were compared among 3 kinds of groups, and meanwhile, monitor units (MU) and SCIMOCA passing rate (3%/2 mm) were evaluated. Results The target dose distribution in 3 kinds of plans all met the prescribed dose requirements. There was no statistically difference in the D2%, D98%, V95%, homogeneity index and conformity index of PTV. MU was highest in VMAT-E&E, followed by VMAT-E and VMAT-OFF (P<0.05). The Dmax and Dmean to lens in VMAT-E&E were lower than those in VMAT-OFF (P<0.05) and VMAT-E (P<0.05), and no statistically difference was found in the Dmax and Dmean to other OAR. The SCIMOCA passing rate (3%/2 mm) of PTV, lens and plans were all higher than 95%, without statistical differences. Conclusion Although VMAT-E&E has relatively higher MU, it has more advantages in lens sparing.