Prospective study of inner ear radiation dose and hearing loss in head-and-neck cancer patients
Prospective study of inner ear radiation dose and hearing loss in head-and-neck cancer patients
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DOI：
10.1016/j.ijrobp.2004.08.019
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发表时间：
2005-04-01
影响因子：
7
通讯作者：
Kileny, PR
中科院分区：
文献类型：
--
作者：
Pan, CC;Eisbruch, A;Kileny, PR
目的：确定内耳辐射剂量与长期听力损失之间的关系。方法和材料：符合条件的患者包括接受头颈癌根治性放射治疗（RT）的患者。入组后，患者接受了适合其疾病部位和阶段的三维适形放疗计划和实施（180-200 cGy/分次）。在轴向 CT 规划图像上绘制内耳轮廓。计算剂量体积直方图以及每个结构的平均和最大剂量。患者在基线（治疗前）以及 RT 后 1、6、12、24 和 36 个月接受纯音测听。记录 250、500、1000、2000、4000 和 8000 Hz 的阈值水平（值越大，听力损失越严重）（以分贝为单位）。对于主要接受单侧放疗的患者，对侧耳作为事实上的对照。计算同侧和对侧耳朵之间的阈值水平差异，并使用统计方法分析听力损失的时间模式和剂量反应关系，该方法考虑到同一受试者的两只耳朵之间的相关性以及每个受试者的重复、连续测量。 结果：在参加本研究的 40 名患者中，35 名符合分析资格。分别对四例接受同步化疗和放疗的患者进行分析。 31 名单侧治疗患者的同侧内耳接受的中位剂量为 47.4 Gy（范围：14.1-68.8 Gy），对侧内耳接受的中位剂量为 4.2 Gy（范围：0.5-31.3 Gy）。听力损失与内耳接收的辐射剂量有关（在接收 >= 45 Gy 的耳朵中观察到损失 210dB），并且在较高频率（>= 2000 Hz）中最为明显。对于双耳既往没有听力损失的 60 岁患者，根据我们的临床模型，接受 45 Gy 后，同侧耳在 8000 Hz 和 1000 Hz 频率下，与对侧耳相比，听力下降 19.3 dB（95% 置信区间 [CI]，15.5-23.0）和 5.4 dB（95% CI，3.5-7.5）。分别为赫兹。年龄和一对耳朵内的初始听力差异也会影响听力损失。基线轴承阈值与辐射引起的听力损失呈负相关。听力损失的程度取决于测试的频率、年龄、基线听力以及患者两耳听力的基线差异。结论：RT 后高频（>= 2000 Hz）听力敏锐度以剂量依赖性方式显着恶化。需要研究更多的患者来验证这些结果。这些知识可用于制定有关未来接受头颈 RT 的患者听觉器官剂量限制的指南。 (c) 2005 年爱思唯尔公司。
Purpose: To determine the relationship between the radiation dose to the inner ear and long-term hearing loss.Methods and Materials: Eligible patients included those receiving curative radiotherapy (RT) for head-and-neck cancer. After enrollment, patients underwent three-dimensional conformal RT planning and delivery (180-200 cGy/fraction) appropriate for their disease site and stage. The inner ear was contoured on axial CT planning images. Dose-volume histograms, as well as the mean and maximal dose for each structure, were calculated. Patients underwent pure tone audiometry at baseline (before treatment) and 1, 6, 12, 24, and 36 months after RT. The threshold level (the greater the value, the more hearing loss) in decibels was recorded for 250, 500, 1000, 2000, 4000, and 8000 Hz. For patients receiving predominantly unilateral RT, the contralateral ear served as the de facto control. The differences in threshold level between the ipsilateral and contralateral ears were calculated, and the temporal pattern and dose-response relation of hearing loss were analyzed using statistical methods that take into account the correlation between two ears in the same subject and repeated, sequential measurements of each subject.Results: Of the 40 patients enrolled in this study, 35 qualified for analysis. Four patients who received concurrent chemotherapy and RT were analyzed separately. The 31 unilaterally treated patients received a median dose of 47.4 Gy (range, 14.1-68.8 Gy) to the ipsilateral inner ear and 4.2 Gy (range, 0.5-31.3 Gy) to the contralateral inner ear. Hearing loss was associated with the radiation dose received by the inner ear (loss of 210dB was observed in ears receiving >= 45 Gy) and was most appreciable in the higher frequencies (>= 2000 Hz). For a 60-year-old patient with no previous hearing loss in either ear, after receiving 45 Gy, the ipsilateral ear, according to our clinical model, would have a 19.3-dB (95% confidence interval [CI], 15.5-23.0) and 5.4-dB (95% CI, 3.5-7.5) hearing decrement compared with the contralateral ear for 8000 Hz and 1000 Hz, respectively. Age and an initial hearing difference within an ear pair also affected hearing loss. The baseline bearing threshold was inversely related to radiation-induced hearing loss. The degree of hearing loss was dependent on the frequency tested, age, baseline hearing, and baseline difference in hearing between a patient's two ears.Conclusion: High-frequency (>= 2000 Hz) hearing acuity worsens significantly after RT in a dose-dependent fashion. A larger number of patients needs to be studied to validate these results. This knowledge can be applied to create guidelines regarding future dose limits to the auditory apparatus for patients undergoing head-and-neck RT. (c) 2005 Elsevier Inc.