Robotic CyberKnife Radiosurgery for Choroidal and Ciliary Body Melanoma
By Lynda Seminara
Selected by Richard K. Parrish II, MD
Journal Highlights
American Journal of Ophthalmology, June 2023
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As experience with stereotactic radiosurgery has grown, treatment algorithms have been modified to optimize outcomes. However, the literature has not always kept pace with these changes, especially for choroidal melanoma. To close the gap, Liegl et al. reviewed 15 years of experience treating choroidal and ciliary body melanomas with the CyberKnife (Accuray). They found good rates of local control and eye retention through five years post-op and affirmed that these rates have improved in the past decade.
Patients enrolled in this interventional case series had been referred to the department of ophthalmology of Ludwig-Maximilians University and European CyberKnife Center in Munich for the treatment of choroidal or ciliary body melanoma during a 15-year period, ending in 2019. Patients treated before 2012 usually received a radiation dose below 21 Gy, whereas those treated after 2012 typically received 21 Gy at the 70% isodose.
Altogether, 594 patients and tumors were included (22.7% stage I, 57.9% stage II, 18.9% stage III, 0.5% stage IV). Median apical tumor height was 5.8 mm, and median base diameter was 11.4 mm. The mean follow-up time was 41.7 months. Rates of local tumor control varied significantly by radiation dose. Among patients who received 21 to 22 Gy, local control was observed for 92.0% at three years and 84.3% at five years. For those who received ≤20 Gy, the rate of local control was 86.9% at year 3 and 77.7% at year 5. Three- and five-year rates of eye retention also varied by radiation dose: 89.9% and 81.0% (respectively) in the higher dose group and 85.9% and 80.0% (respectively) in the lower dose group. The main reasons for enucleation were tumor recurrence (59%) and secondary glaucoma (38%). Overall disease-specific survival rates were 93.1% at three years, 89.8% at five years, and 87.8% at seven years. Tumor size had little effect on outcomes.
The authors noted that the rate of local control achieved with 21 Gy—an adjustment made based on their experience—is similar to that with other treatments such as brachytherapy. They consider CyberKnife therapy to be a viable option for small and large melanomas of the choroid or ciliary body.
The original article can be found here.