We critically examined the damaging affects of therapeutic irradiation by comparing results from cross-disciplinary studies of early- and late-delayed radiotherapy effects. Focus is attained by concentrating on clinical treatment issues (volume of brain, dose, timing of effects, age, modality types, and stereotactic treatment techniques), rather than on methodological means or problems, which is necessary to understand the mechanisms and characteristics of radiotherapy-induced behavioral dysfunction including cognition. We make observations and hypotheses about the actual risks from radiotherapy that could be informative in the treatment decision process, and which may lessen the concerns of some patients and their families about the risks they take when receiving radiation. Conditions that predispose to radiation injury are reviewed: (1) higher doses even to part of the brain versus lower doses to the whole brain, (2) combined treatment modalities, (3) malignancy itself, (4) radiation early during postnatal brain development, and (5) late-delayed effects (more than 3 years posttreatment). Current neurocognitive frameworks for understanding cognitive change over time in children and adults are summarized, along with the literature on effects of brain tumors and treatment on depression. No studies have as yet identified candidate brain regions that are more sensitive to radiotherapy. Two studies have provided early, preliminary evidence for a specific vulnerability of visual attention/memory to the early stage of late radiation damage. Furthermore, radiation effects appear severe only in a minority of patients. Risk is related to direct and indirect effects of cancer type, concurrent clinical factors, and premorbid risk factors.

中文翻译：

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对脑部治疗性放射损伤的临床效果的重要评论：争议的根源。

我们通过比较早期和晚期延迟放疗效果的跨学科研究结果，严格审查了治疗性放射的有害影响。通过集中于临床治疗问题（大脑的体积，剂量，作用时间，年龄，方式类型和立体定向治疗技术）来获得焦点，而不是集中于了解放射疗法的机制和特征所必需的方法论手段或问题。引起的行为功能障碍，包括认知。我们对放疗的实际风险进行观察和假设，这些信息可能会在治疗决策过程中提供有益的信息，并可能减轻某些患者及其家人对他们接受放射线治疗时所面临风险的担忧。回顾了易受辐射伤害的条件：（1）甚至对部分大脑而言剂量较高，而对整个大脑而言剂量较低；（2）联合治疗方式；（3）恶性肿瘤本身；（4）出生后大脑发育早期的放射，以及（5）延迟效应（治疗后3年以上）。总结了目前用于理解儿童和成人随着时间的推移认知变化的神经认知框架，以及有关脑肿瘤和抑郁症治疗的文献。尚无研究确定对放射疗法更敏感的候选大脑区域。两项研究提供了早期的初步证据，证明视觉注意力/记忆在晚期放射损伤的早期阶段特别脆弱。此外，仅少数患者出现严重的放射效应。风险与癌症类型的直接和间接影响有关，