Abstract: Objective To explore the correlation between the dose segmentation pattern of stereotactic radiotherapy (SRT) and the local control rate,and analyze the factors affecting the local control rate,so as to provide a scientific and reasonable dose segmentation scheme reference for the clinical treatment of brain metastases. Methods Data of 90 patients with brain metastases who underwent SRS and SRT in the Radiotherapy Department,the First Affiliated Hospital of Hebei Northern University from February 2023 to February 2025 were retrospective reviewed.According to the different radiotherapy dose segmentation patterns,patients were divided into group A (single high dose group,single 18 Gy irradiation),group B (hypofractionated less high dose group,4 fraction,7.5 Gy,total dose of 30 Gy),and Group C (multiple low dose group,10fraction,3.5 Gy,total dose of 35 Gy).After regular follow-up after the completion of treatment,the tumor local control was evaluated by MRI examination and the local control rate was calculated.At the same time,general data,clinical characteristics,and radiotherapy related data were collected,and univariate and multivariate analysis were used to explore the correlation and local control rate. Results Local control rates varied significantly in different dose segmentation modes (P＜0.05),and group B had the highest local control rate.Univariate analysis showed that tumor volume,radiotherapy dose segmentation pattern,KPS score,primary tumor type,and whether combined systemic therapy were associated with local control rate (P＜0.05).The results of binary Logistic regression analysis showed that tumor volume,primary tumor type,and whether combined systemic treatment were all independent factors affecting the local control rate (P＜0.05).The ROC curve showed that the AUC of tumor volume,primary tumor type,and general treatment were 0.746,0.680,0.640,indicating that the above factors have some predictive value for local control rate (P＜0.05). Conclusion The dose segmentation pattern of stereotactic radiotherapy for brain metastases is closely related to the local control rate,and the effect of local control is more prominent,and factors such as tumor volume and KPS score have an important influence on the local control rate.These factors should be taken into account in clinical treatment,and an individualized radiotherapy regimen should be developed to improve the local control rate and patient quality of life of brain metastases.There were differences in BED among the groups in this study,and the radiotherapy fractionation mode should be further optimized under the premise of equal biological dose.

Key words: Brain metastases, Stereotactic radiotherapy, Dose segmentation pattern, Local control rate, Impact factor

摘要： 目的 探究脑转移瘤立体定向放疗(SRT)剂量分割模式与局部控制率的相关性,并分析影响局部控制率的因素,为临床治疗脑转移瘤提供科学合理的剂量分割方案参考。方法 回顾性分析2023年2月至2025年2月在河北北方学院附属第一医院放射治疗科接受SRS、SRT的90例脑转移瘤患者资料。依据放疗剂量分割模式不同,将患者分为A组(单次大剂量组,给予单次18 Gy照射)、B组(低分次大剂量组,分4次照射,每次7.5 Gy,总剂量30 Gy)、C组(多次小剂量组,分10次照射,每次3.5 Gy,总剂量35 Gy)。治疗结束后定期随访,通过MRI检查评估肿瘤局部控制情况,计算局部控制率。同时收集患者一般资料、临床特征、放疗相关数据等,采用单因素及多因素分析探讨脑转移瘤立体定向放疗剂量分割模式与局部控制率的相关性及影响因素。结果 不同剂量分割模式下患者局部控制率存在显著差异(P＜0.05),B组局部控制率最高。单因素分析显示,肿瘤体积、放疗剂量分割模式、KPS评分、原发肿瘤类型、是否联合全身治疗与局部控制率相关(P＜0.05)。二元 Logistic 回归分析结果显示,肿瘤体积、原发肿瘤类型、是否联合全身治疗为影响局部控制率的独立因素(P＜0.05)。ROC曲线结果显示,肿瘤体积、原发肿瘤类型、是否联合全身的AUC为0.746、0.680、0.640,表明上述指标对局部控制率均有一定预测价值(P＜0.05)。结论 脑转移瘤立体定向放射治疗剂量分割模式与局部控制率紧密相关,低分次大剂量分割模式的局部控制效果更为突出,且肿瘤体积、原发肿瘤类型等因素对局部控制率有着重要影响。临床治疗时应综合考虑这些因素,制定个体化放疗方案,以提高脑转移瘤的局部控制率和患者生存质量。本研究各组BED存在差异,后续应在等效生物剂量统一的前提下进一步优化放疗分割模式。

关键词: 脑转移瘤, 立体定向放射治疗, 剂量分割模式, 局部控制率, 影响因素