UASSIGNED:自适应放射治疗(ART)基于重复计算机断层扫描(CT)成像和调强放射治疗(IMRT)期间的重新计划,可实时校正目标和剂量,对于局部晚期鼻咽癌(NPC)很重要。然而,重复CT成像和重新计划是耗时的并且阻碍ART的广泛应用。重新计划时间的最佳剂量和频率已在以前的报告中公布。这项研究的目的是确定诱导化疗(IC)是否减少IMRT期间的靶体积漂移,有可能减少重新规划的工作量。
UNASSIGNED:从2012年1月至2017年12月,40例局部晚期患者,在第一附属医院放射肿瘤科治疗的非转移性III-IVa期NPC,医学院,浙江大学,参加了这项研究。在40名患者中,20例同步放化疗前接受2-3个周期的IC(IC+CCRT),其余20例患者接受CCRT联合辅助化疗(CCRT+AC)治疗。在CCRT期间,所有患者均接受每周模拟CT检查,共6周.总肿瘤体积(GTV),临床目标体积(CTV),每周测量体重,并比较两组之间的差异。
UNASSIGNED:与基线相比,25个部分后的平均失重为7.0kg(13.6%;范围,在CCRTAC组中为3.9-25.5%)和5.7kg(8.3%;范围,3.6-20%)在IC+CCRT组中。GTV和CTV平均减少16.55mL(15.7%;范围,6.1-33.7%)和61.25mL(9.33%;范围,4.4-17.0%),分别,在IC+CCRT组中,和39.86毫升(38.79%;范围,25.3-50.7%)和87.72mL(12.7%;范围,6.7-22.9%),分别,在CCRT+AC组中。IC+CCRT组GTV周降低程度不显著高于CCRT+AC组,与前5周相比,每个百分比降低的P值如下,分别为:P<0.001,P=0.015,P=0.01,P=0.01,P<0.001。在IC+CCRT组中,每周CTV减少仅与体重减轻显著相关(P=0.005)。
UNASSIGNED:IC显着降低了体重减轻的程度,GTV收缩,和CCRT期间的CTV减少,因此,在IMRT的适应性重新计划过程中减少了解剖和目标剂量漂移。这可能导致局部晚期NPC的复发减少,尤其是颈部淋巴结转移大的患者,有可能提高生存率。该结果提供了有利的证据,表明IC可改善局部区域晚期NPC患者的局部区域无复发生存率(LRFS)和总体生存率(OS)。
UNASSIGNED: Adaptive radiotherapy (ART) provides real-time correction of the target and dose of radiation based on repeat computed tomography (CT) imaging and replanning during intensity-modulated radiation therapy (IMRT) and is important for locoregionally advanced nasopharyngeal carcinoma (NPC). However, repeat CT imaging and replanning are time-consuming and hinder the broader application of ART. The optimum dose and frequency of replanning time have been published in previous reports. The purpose of this
study was to determine whether induction chemotherapy (IC) reduces target volume drift during IMRT, potentially reducing the replanning workload.
UNASSIGNED: From January 2012 to December 2017, 40 patients with locoregionally advanced, nonmetastatic stage III-IVa NPC treated in the Department of Radiation Oncology in the First Affiliated Hospital, College of Medicine, Zhejiang University, were enrolled into this
study. Of the 40 patients, 20 received 2-3 cycles of IC before concurrent chemoradiotherapy (IC + CCRT), and the other 20 patients were treated with CCRT plus adjuvant chemotherapy (CCRT + AC). During CCRT, all patients underwent weekly simulated CT for 6 weeks. The gross tumor volume (GTV), clinical target volume (CTV), and body weight were measured weekly and compared between the 2 groups.
UNASSIGNED: Compared with the baseline, the mean weight loss after 25 fractions was 7.0 kg (13.6%; range, 3.9-25.5%) in the CCRT + AC group and 5.7 kg (8.3%; range, 3.6-20%) in the IC + CCRT group. The mean GTV and CTV decreased by 16.55 mL (15.7%; range, 6.1-33.7%) and 61.25 mL (9.33%; range, 4.4-17.0%), respectively, in the IC + CCRT group, and by 39.86 mL (38.79%; range, 25.3-50.7%) and 87.72 mL (12.7%; range, 6.7-22.9%), respectively, in the CCRT + AC group. The degree of weekly reduction in the GTV of the IC + CCRT group was not significantly higher than that of the CCRT + AC group, with the following P values of each percentage reduction in comparison with the previous week over 5 weeks, respectively: P<0.001, P=0.015, P=0.01, P=0.01, and P<0.001. The weekly CTV reduction only significantly correlated with weight loss (P=0.005) in the IC + CCRT group.
UNASSIGNED: IC significantly decreased the degree of weight loss, GTV shrinkage, and CTV reduction during CCRT, consequently decreasing the anatomical and target dose drift during the adaptive replanning of IMRT. This may lead to a reduction in the recurrence of locoregionally advanced NPC, especially among patients with large metastatic cervical lymph nodes, potentially improving survival. This result provides favorable evidence that IC improves locoregional recurrence-free survival (LRFS) and overall survival (OS) in patients with locoregionally advanced NPC.