Department of Radiation Oncology, E-Da Hospital, Kaohsiung, Taiwan.
Int J Radiat Oncol Biol Phys. 2010 Jul 1;77(3):722-6. doi: 10.1016/j.ijrobp.2009.06.080. Epub 2010 Jan 13.
To evaluate the effects of radiation therapy (RT) on neurocognitive function in patients with nasopharyngeal carcinoma (NPC).
Thirty patients with NPC treated with intensity-modulated RT were included. Dose-volume histograms of the temporal lobes were obtained in every patient. Neurocognitive tests were administered individually to each patient 1 day before initiation of RT and at least 12 months after completion of RT. Cognitive functioning status was evaluated as change in scores over time.
Among the total of 30 patients, 23 patients (76.7%) had significantly lower post-RT cognitive functioning scores compared with their pre-RT scores (p = 0.033). The cognitive functioning scores had significantly declined in the domains of short-term memory, language abilities, and list-generating fluency (p = 0.020, 0.023, and 0.001, respectively). Compared with patients with a mean dose to the temporal lobes of 36 Gy or less, patients with a mean dose of greater than 36 Gy had a significantly greater reduction in cognitive functioning scores (p = 0.017). Patients in whom V60 of the temporal lobes (i.e., the percentage of the temporal lobe volume that had received >60 Gy) was greater than 10% also had a greater reduction in cognitive functioning scores than those in whom V60 was 10% or less (p = 0.039).
The results of our study indicated that RT could have deleterious effects on cognitive function in patients with NPC. Efforts should be made to reduce the radiation dose and irradiated volume of temporal lobes without compromising the coverage of target volume.
评估鼻咽癌（NPC）患者放射治疗（RT）对神经认知功能的影响。
纳入 30 例接受调强放疗的 NPC 患者。为每位患者获得颞叶的剂量-体积直方图。每位患者在 RT 开始前 1 天和 RT 完成后至少 12 个月接受单独的神经认知测试。认知功能状态通过随时间的评分变化进行评估。
在 30 例患者中，共有 23 例（76.7%）患者的 RT 后认知功能评分明显低于 RT 前评分（p=0.033）。在短期记忆、语言能力和列表生成流畅性方面，认知功能评分明显下降（p=0.020、0.023 和 0.001）。与颞叶平均剂量为 36Gy 或更低的患者相比，颞叶平均剂量大于 36Gy 的患者认知功能评分下降更明显（p=0.017）。颞叶 V60（即颞叶体积中接受>60Gy 的百分比）大于 10%的患者的认知功能评分下降也大于 V60 为 10%或更低的患者（p=0.039）。
我们的研究结果表明，RT 可能对 NPC 患者的认知功能产生有害影响。应努力降低颞叶的辐射剂量和照射体积，同时不影响靶区的覆盖范围。
