Shi Julia J, Meduri Krithi, Liao Chien-Yi, Moon Dominic H, Avkshtol Vladimir, Parsons David, Zhong Xinran, Chen Liyuan, Lin Mu-Han, Sher David J
Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas.
Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas.
Int J Radiat Oncol Biol Phys. 2025 Jul 15;122(4):917-925. doi: 10.1016/j.ijrobp.2025.03.050. Epub 2025 Mar 30.
Data are limited on the feasibility and dosimetric advantages of cone beam computed tomography-based online adaptive radiation therapy (oART) in head and neck squamous cell carcinoma. In this retrospective analysis, we assessed the dosimetric outcomes in patients receiving definitive radiation therapy and treated with oART at least once during their treatment course.
We retrospectively analyzed 69 patients with head and neck squamous cell carcinoma who received definitive-intent treatment and oART using the Varian Ethos system at a single tertiary care institution between September 2021 and March 2024. Dosimetric outcomes were compared using a t test. The coverage and mean doses of the planning target volumes (PTVs) and the dose to organs-at-risk (OARs) was analyzed. Conformality and heterogeneity were compared with the conformality index, maximum hotspot, and the absolute volume receiving 103%, 105%, and 107% of the maximum prescribed dose. Treatment delivery time was also recorded for each fraction.
The cohort was primarily comprised of patients diagnosed with oropharynx (n = 46, 66.7%) and larynx/hypopharynx (n = 15, 21.7%) cancers. Adapted plans had significantly improved coverage when using the V100 as the coverage metric (95.83% vs 89.58%, P < .001) for all PTVs and improved D95% (99.63% vs 95.69%, P < .001) and D99% (95.64% vs 87.82%, P < .001) of the PTV70. The adapted plans also had a substantially smaller volume receiving above 103% of the prescription (-19.04 cc, P = .007). There was no significant difference in the dose distributions of any salivary glands, and the differences in other OARs were clinically insignificant. The mean total adaptive workflow time was 17 (SD, 1.9) minutes, and the mean total in-room time was 36 minutes (SD, 2.3 minutes).
Online ART is associated with significantly improved coverage and dose homogeneity but not superior OAR sparing. Additional research is needed to optimally select patients for oART and determine the clinical benefits of these dosimetric advantages.
关于基于锥形束计算机断层扫描的在线自适应放射治疗（oART）在头颈部鳞状细胞癌中的可行性和剂量学优势的数据有限。在这项回顾性分析中，我们评估了接受根治性放射治疗且在治疗过程中至少接受一次oART治疗的患者的剂量学结果。
我们回顾性分析了2021年9月至2024年3月期间在一家三级医疗机构使用瓦里安Ethos系统接受根治性治疗和oART的69名头颈部鳞状细胞癌患者。使用t检验比较剂量学结果。分析了计划靶体积（PTV）的覆盖范围和平均剂量以及危及器官（OAR）的剂量。通过适形指数、最大热点以及接受最大处方剂量103%、105%和107%的绝对体积比较适形性和异质性。还记录了每个分次的治疗交付时间。
该队列主要由诊断为口咽癌（n = 46，66.7%）和喉/下咽癌（n = 15，21.7%）的患者组成。当使用V100作为覆盖指标时，所有PTV的适应性计划的覆盖范围显著改善（95.83%对89.58%，P <.001），PTV70的D95%（99.63%对95.69%，P <.001）和D99%（95.64%对87.82%，P <.001）也有所改善。适应性计划中接受超过处方剂量103%的体积也显著更小（-19.04 cc，P =.007）。任何唾液腺的剂量分布均无显著差异，其他OAR的差异在临床上无显著意义。平均总自适应工作流程时间为17（标准差，1.9）分钟，平均总室内时间为36分钟（标准差，2.3分钟）。
在线ART与显著改善的覆盖范围和剂量均匀性相关，但在保护OAR方面并不优越。需要进一步研究以优化选择oART患者并确定这些剂量学优势的临床益处。
