St. Erik Eye Hospital, Stockholm, Sweden
Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Br J Ophthalmol. 2021 Jan;105(1):57-62. doi: 10.1136/bjophthalmol-2019-315722. Epub 2020 May 19.
Episcleral brachytherapy is the most common treatment for medium-sized choroidal melanomas. Although controversial, inadequate brachytherapy dose and dose rates have at least a hypothetical implication on patient survival.
All patients who received ruthenium-106 or iodine-125 brachytherapy for choroidal melanoma at St. Erik Eye Hospital 1996 to 2016 were included (n=1238). Cox regression hazard ratios for melanoma-related mortality across deciles, quartiles and individual integers of apex radiation doses (Gy) and dose rates (Gy/hour) were calculated, adjusted for tumour size and location.
The average radiation dose at the tumour apex ranged from 73.0 Gy in the first decile to 108.6 Gy in the tenth. Decreasing apex dose by 1 Gy increments or by decile or quartile group was not associated with melanoma-related mortality (p>0.2) The average radiation dose rate at the tumour apex ranged from 0.5 Gy/hour in the first decile to 2.8 Gy/hour in the tenth. Similarly, decreasing apex dose rate by 1 Gy/hour increments or by decile or quartile groups was not associated with melanoma-related mortality (p>0.5).
There are no increased hazards for choroidal melanoma-related mortality after brachytherapy with decreasing doses between 108.6 and 73.0 Gy, or with decreasing dose rates between 2.8 and 0.5 Gy/hour.
巩膜敷贴放疗是治疗中等大小脉络膜黑色素瘤最常用的方法。尽管存在争议，但放疗剂量和剂量率不足至少在假设上对患者的生存有影响。
本研究纳入了 1996 年至 2016 年期间在圣埃里克眼科医院接受钌-106 或碘-125 巩膜敷贴放疗的所有脉络膜黑色素瘤患者（n=1238）。通过 Cox 回归风险比计算了肿瘤顶点剂量（Gy）和剂量率（Gy/小时）的十个等分位数、四分位数和个别整数水平与黑色素瘤相关死亡率之间的关系，调整了肿瘤大小和位置。
肿瘤顶点的平均放射剂量范围从第一分位数的 73.0 Gy 到第十分位数的 108.6 Gy。每次递增 1 Gy 或按分位数或四分位数组减少顶点剂量与黑色素瘤相关死亡率无关（p>0.2）。肿瘤顶点的平均剂量率范围从第一分位数的 0.5 Gy/小时到第十分位数的 2.8 Gy/小时。同样，每次递增 1 Gy/小时或按分位数或四分位数组减少顶点剂量率与黑色素瘤相关死亡率无关（p>0.5）。
在 108.6 Gy 至 73.0 Gy 之间降低剂量，或在 2.8 Gy/小时至 0.5 Gy/小时之间降低剂量率进行巩膜敷贴放疗后，不会增加与脉络膜黑色素瘤相关的死亡风险。
