Visual Outcomes after Proton Beam Irradiation for Choroidal Melanomas Involving the Fovea

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• 作者：Avni V. Patel ; MD ; MBA¹ ; Anne Marie Lane ; MPH¹ ; Margaux A. Morrison ; MPH² ; Alexei V. Trofimov ; PhD³ ; Helen A. Shih ; MD³ ; Evangelos S. Gragoudas ; MD¹ ; Ivana K. Kim ; MD¹ ; ^{ivana_kim@meei.harvard.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：BLVA ; baseline visual acuity ; CF ; counting fingers ; DD ; disc diameter ; FAZ ; foveal avascular zone ; Gy ; gray ; NLP ; no light perception ; RBE ; relative biological effectiveness
• 刊名：Ophthalmology
• 出版年：2016
• 出版时间：February 2016
• 年：2016
• 卷：123
• 期：2
• 页码：369-377
• 全文大小：1349 K

文摘

To report visual outcomes in patients undergoing proton beam irradiation of tumors located within 1 disc diameter of the fovea.

Design

Retrospective review.

Participants

Patients with choroidal melanoma involving the fovea treated with proton beam therapy between 1975 and 2009.

Methods

Three hundred fifty-one patients with choroidal melanomas located 1 disc diameter (DD) or less from the fovea and more than 1 DD away from the optic nerve were included in this study. In a subgroup of 203 of the patients with small and medium choroidal melanomas, the effect of a reduced dose of radiation, 50 Gy (relative biological effectiveness [RBE]) versus 70 Gy (RBE), on visual outcomes was analyzed. The Kaplan-Meier method and Cox regression analysis were performed to calculate cumulative rates of vision loss and to assess risk factors for vision loss, respectively.

Main Outcome Measures

Visual acuity and radiation complications, which included radiation maculopathy, papillopathy, retinal detachment, and rubeosis, were assessed.

Results

Three hundred fifty-one patients were included in this study with a mean follow-up time of 68.7 months. More than one-third of patients (35.5%) retained 20/200 or better vision 5 years after proton beam irradiation. For those patients with a baseline visual acuity of 20/40 or better, 16.2% of patients retained this level of vision 5 years after proton beam irradiation. Tumor height less than 5 mm and baseline visual acuity 20/40 or better were associated significantly with a better visual outcome (P < 0.001). More than two-thirds (70.4%) of patients receiving 50 Gy (RBE) and nearly half (45.1%) of patients receiving 70 Gy (RBE) retained 20/200 or better vision 5 years after treatment, but this difference was not significant. Approximately 20% of patients with these smaller macular tumors retained 20/40 vision or better 5 years after irradiation.

Conclusions

The results of this retrospective analysis demonstrate that despite receiving a full dose of radiation to the fovea, many patients with choroidal melanoma with foveal involvement maintain useful vision. A radiation dose reduction from 70 to 50 Gy (RBE) did not seem to increase the proportion of patients who retain usable vision.