St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.
Br J Ophthalmol. 2021 May;105(5):648-652. doi: 10.1136/bjophthalmol-2019-314802. Epub 2020 Jun 25.
Uveal melanoma is most commonly treated with radiotherapy, destroying the tumour cells with adequate safety margins and limiting collateral damage to surrounding structures to preserve maximal vision. We used optical coherence tomography (OCT) to study the effects of radiotherapy on the retina.
Patients with posteriorly located choroidal melanoma treated with proton beam radiotherapy (PBR) and ruthenium-106 brachytherapy between January 2010 and June 2014 underwent spectral domain OCT.
Images of 32 patients following ruthenium-106 brachytherapy and 44 patients following proton beam teletherapy were analysed. Following plaque brachytherapy, an early marked disruption of the outer retinal layers could be observed in 30 cases (94%) with retinal atrophy evident in 26 cases (81%). In contrast, the images from patients who underwent PBR showed subtle outer retinal layer change with 16 cases (36%) showing some inner-outer segment junction disruption by 6 months and 63% by 24 months with minimal atrophy. In cases with tumours <2 mm from the fovea, the visual loss was significantly less at 6 and 12 months in the proton beam group.
In comparison to ruthenium-106 plaque brachytherapy, PBR leads to more subtle and slower changes in the outer retinal layers enabling retention of visual function for longer. The difference in dosing regime and dose distribution across the tumour is likely to be causative for this structural differential.
葡萄膜黑色素瘤最常采用放射疗法治疗，通过在肿瘤细胞周围保留足够的安全边界，以限制对周围结构的附带损伤，从而达到消灭肿瘤细胞并保留最大视力的效果。我们使用光学相干断层扫描（OCT）来研究放射疗法对视网膜的影响。
2010 年 1 月至 2014 年 6 月期间，我们对接受质子束放射疗法（PBR）和钌-106 近距离放射疗法治疗的、位于眼后段的脉络膜黑色素瘤患者进行了光谱域 OCT 检查。
对 30 例（94%）接受钌-106 近距离放射治疗和 44 例（100%）接受质子束远距离放射治疗的患者的图像进行了分析。在接受敷贴器近距离放射治疗后，在 30 例（94%）患者中可以观察到早期明显的外视网膜层破坏，26 例（81%）患者出现明显的视网膜萎缩。相比之下，接受 PBR 的患者的图像显示外视网膜层的细微变化，16 例（36%）在 6 个月时出现一些内-外节连接中断，63%在 24 个月时出现中断，且萎缩程度最小。对于距黄斑<2mm 的肿瘤，在质子束组中，6 个月和 12 个月时的视力丧失明显较少。
与钌-106 敷贴器近距离放射治疗相比，PBR 导致外视网膜层的变化更细微、更缓慢，从而使更长时间保留视觉功能。肿瘤内的剂量方案和剂量分布的差异可能是造成这种结构差异的原因。
