Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, BC, Canada.
Int J Radiat Oncol Biol Phys. 2012 Jul 1;83(3):872-7. doi: 10.1016/j.ijrobp.2011.08.019. Epub 2011 Dec 28.
To investigate predictive factors in the development of symptomatic radiation injury after treatment with linear accelerator-based stereotactic radiosurgery for intracerebral arteriovenous malformations and relate the findings to the conclusions drawn by Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC).
Archived plans for 73 patients who were treated at the British Columbia Cancer Agency were studied. Actuarial estimates of freedom from radiation injury were calculated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used for analysis of incidence of radiation injury. Log-rank test was used to search for dosimetric parameters associated with freedom from radiation injury.
Symptomatic radiation injury was exhibited by 14 of 73 patients (19.2%). Actuarial rate of symptomatic radiation injury was 23.0% at 4 years. Most patients (78.5%) had mild to moderate deficits according to Common Terminology Criteria for Adverse Events, version 4.0. On univariate analysis, lesion volume and diameter, dose to isocenter, and a V(x) for doses ≥8 Gy showed statistical significance. Only lesion diameter showed statistical significance (p < 0.05) in a multivariate model. According to the log-rank test, AVM volumes >5 cm(3) and diameters >30 mm were significantly associated with the risk of radiation injury (p < 0.01). The V(12) also showed strong association with the incidence of radiation injury. Actuarial incidence of radiation injury was 16.8% if V(12) was <28 cm(3) and 53.2% if >28 cm(3) (log-rank test, p = 0.001).
This study confirms that the risk of developing symptomatic radiation injury after radiosurgery is related to lesion diameter and volume and irradiated volume. Results suggest a higher tolerance than proposed by QUANTEC. The widely differing findings reported in the literature, however, raise considerable uncertainties.
研究基于线性加速器立体定向放射外科治疗颅内动静脉畸形后出现症状性放射性损伤的预测因素，并将这些发现与定量分析临床正常组织效应（QUANTEC）得出的结论进行比较。
对在不列颠哥伦比亚癌症署接受治疗的 73 例患者的存档计划进行了研究。使用 Kaplan-Meier 法计算无放射性损伤的累积生存率。采用单变量和多变量 Cox 比例风险模型分析放射性损伤的发生率。对数秩检验用于寻找与无放射性损伤相关的剂量学参数。
73 例患者中有 14 例（19.2%）出现症状性放射性损伤。4 年时，有症状性放射性损伤的累积发生率为 23.0%。根据通用不良事件术语标准，版本 4.0，大多数患者（78.5%）存在轻度至中度的缺陷。单变量分析显示，病变体积和直径、等中心点剂量以及剂量≥8 Gy 的 V(x)具有统计学意义。只有病变直径在多变量模型中具有统计学意义（p < 0.05）。根据对数秩检验，AVM 体积>5 cm(3)和直径>30 mm 与放射性损伤的风险显著相关（p < 0.01）。V(12)也与放射性损伤的发生率有很强的关联。如果 V(12) <28 cm(3)，则放射性损伤的累积发生率为 16.8%；如果 V(12) >28 cm(3)，则累积发生率为 53.2%（对数秩检验，p = 0.001）。
本研究证实，放射外科治疗后发生症状性放射性损伤的风险与病变直径和体积以及照射体积有关。结果表明，其耐受程度高于 QUANTEC 提出的水平。然而，文献中报告的差异很大的结果存在相当大的不确定性。
