Grau C, Møller K, Overgaard M, Overgaard J, Elbrønd O
Department of Oto-rhino-laryngology and Audiology, University of Aarhus, Denmark.
Int J Radiat Oncol Biol Phys. 1991 Aug;21(3):723-8. doi: 10.1016/0360-3016(91)90692-w.
The present investigation has been carried out to evaluate the sensitivity of the inner ear to irradiation. Cochlear function was tested in a cohort of 22 patients before and 7-84 months after receiving external irradiation for nasopharyngeal carcinoma. The pre-irradiation sensori-neural hearing threshold at 500, 1000, 2000, and 4000 Hz was used as a baseline for the individual patient, and the observed sensori-neural hearing loss (SNHL) was calculated as the difference between pre- and post-irradiation values. The pre-irradiation hearing level or patient age was not correlated with the actual SNHL. In contrast, there was a significant correlation between the total radiation dose to the inner ear and the observed hearing impairment. SNHL was most pronounced in the high frequencies, with values up to 35 dB (4000 Hz) and 25 dB (2000 Hz) in some patients. The latent period for the complication appeared to be 12 months or more. The deleterious effect of irradiation on the hearing should be kept in mind both in treatment planning and in the follow-up after radiotherapy.
本研究旨在评估内耳对辐射的敏感性。对22例鼻咽癌患者在接受外照射之前以及照射后7至84个月进行了耳蜗功能测试。将每个患者在500、1000、2000和4000Hz的照射前感觉神经性听力阈值作为基线，并计算观察到的感觉神经性听力损失（SNHL），即照射前后值之间的差异。照射前听力水平或患者年龄与实际SNHL无关。相反，内耳的总辐射剂量与观察到的听力损害之间存在显著相关性。SNHL在高频最为明显，部分患者在4000Hz时高达35dB，在2000Hz时高达25dB。并发症的潜伏期似乎为12个月或更长时间。在治疗计划和放疗后的随访中，都应牢记辐射对听力的有害影响。
