目的 肺部恶性肿瘤立体定向放射治疗(stereotactic radiation therapy,SRT)后计算机断层扫描(computed tomography,CT)图像的动态变化是一个复杂而连续的过程,容易引起误诊.探讨SRT后肿瘤及其周边正常肺组织的CT图像动态变化的规律.方法 回顾性分析2018-2021年在南京医科大学附属肿瘤医院接受SRT的104例肺部恶性肿瘤患者的临床资料,根据纳入条件,由研究者诊断小组对每次CT图像进行评估和动态比较,记录SRT后肿瘤本身及周边正常肺组织形态学变化和时序特征.结果 104例患者共109个病变.94个(86.2%)病灶呈现残存病灶与周边放射性肺损伤融合形成肿块样实变,可分为3个阶段.发生期:治疗后3个月(范围为1~9个月),胸部CT呈病灶周围絮状渗出性改变.发展期:治疗后4.5个月(范围为1.5~15.5个月),呈密度更高的斑片条索影和/或纤维化实变影.影像稳定前期:治疗后13个月(范围为5.5~39个月),呈纤维化实变逐渐吸收、固结或收缩并与病灶融合形成最终的肿块样实变,伴或不伴随纤维化移动,最终趋于稳定.15例(14.4%)患者周围肺组织无明显改变,仅表现为病灶本身变化,达到影像学稳定的中位时间为治疗后10个月(范围为2.5~15.5个月).65个(59.6%)病灶影像稳定期肿块样实变长径比初始病变增加了20%以上.进入发展期时间越短,影像稳定阶段肿块样实变长径可能越大(P = 0.021).结论 SRT后肿瘤本身及周边正常肺组织通常会出现连续动态影像学改变,最终多数患者残存病灶与周边肺组织纤维化融合形成肿块样实变.多数患者肿块样实变长径较SRT前增加20%以上.
Objective Following stereotactic radiation therapy(SRT)for pulmonary malignancy,the dynamic changes in computed tomography(CT)imaging constitute a complex and continuous process,posing challenges that may lead to misdiagnosis.To investigate dynamic CT imaging changes in tumors and adjacent normal lung tissue post-SRT in this study.Method Retros-pectively analyzed 104 patients with pulmonary malignancies treated with SRT from 2018 to 2021 in the Affiliated Cancer Hospital of Nanjing Medical University.A total of 109 pulmonary lesions from 104 patients met the inclusion criteria.A diagnostic team assessed and compared post-SRT CT images,observing changes in tumor morphology and surrounding lung tissue over time.Result Upon analyzing the dynamic changes in CT images of 104 patients whit 109 lesions,it was found that 94 lesions(86.2%)exhibited mass-like consolidations,indicating a fusion of residual lesions with radiation-induced lung damage,which evolved in three distinct phases.Onset:3 months post-treatment(range:1-9 months)showing perilesional fluffy exudative alterations on chest CT.Progressive:4.5 months post-treatment(range:1.5-15.5 months)depicting increased density of patchy striations and/or fibrotic changes.Stabilization:13 months post-treatment(range:5.5-39 months)with fibrotic changes gradually resolving,consolidating,or retracting,and merging with lesions to form the final mass-like consolidations,which may or may not be accompanied by migratory fibrosis,ultimately reaching stabilization.In 15 cases(14.4%),peripheral pulmonary tissues displayed no significant alterations,showing only intrinsic lesion changes,reaching imaging stabilization at a median time of 10 months post-treatment(range:2.5-15.5 months).During the stabilisation phase,65 lesions(59.6%)exhibited mass-like consolidations with a longitudinal diameter that increased by more than 20%from the initial lesion.The shorter the duration to enter the development phase,the potential for a larger long-axis dimension of the mass-like consolidation during the stable imaging phase(P = 0.021).Conclusion Post-SRT,tumors and adjacent normal pulmonary tissues typically manifest sequential dynamic radiological alterations,culminating in the majority of patients having residual lesions merging with pulmonary tissue fibrosis to form mass-like consolidations.In most patients,the longitudinal diameter of mass-like consolidations increased by more than 20%compared to pre-SRT measurements.