The immediate results of choroidal melanoma treatment using stereotactic radiosurgery

Abstract

The aim of this study was to evaluate the immediate results of the stereotactic radiosurgery (SRS) application in patients with choroid melanoma.Material and methods. The prospective study included 43 patients who were diagnosed with choroidal melanoma cT1–3N0M0.SRS was performed on a Gamma Knife gamma therapeutic unit, Perfexion (Elekta, Sweden). Under local anesthesia, the eyeball was immobilized using frenulum sutures on the rectus muscles. The median prescribed dose per tumor margin at 50% isodose was 30 Gy. The immediate effect of the treatment was assessed as positive (local control) in all cases, except increased blood flow according to Doppler ultrasound, an increase in tumor size by more than 20% of the previously determined lesion according to MRI.Results. During the follow-up period (median follow-up — 16 months), there were no cases of negative outcome in terms of local tumor control.A statistically significant gradual decrease in tumor thickness was revealed during the entire observation period (6.6±2.1 mm before treatment, 5.3±2.1 mm 12 months after treatment, p<0.001), stabilization of the tumor base (12.25±3.26 mm before treatment, 11.4±2.5 mm 12 months after treatment, p=0.355). Contrast-enhanced MRI also showed a progressive statistically significant decrease in tumor volume (635.21±328.32 mm3 before treatment, 376.0±267.6 mm3 15 months after treatment, p><0.001). The eyeball was saved in 90.1%. Post-radiation optical retinopathy developed in 9.3% of >˂0.001), stabilization of the tumor base (12.25±3.26 mm before treatment, 11.4±2.5 mm 12 months after treatment, p=0.355). Contrast-enhanced MRI also showed a progressive statistically significant decrease in tumor volume (635.21±328.32 mm3 before treatment, 376.0±267.6 mm3 15 months after treatment, p<0.001). The eyeball was saved in 90.1%. Post-radiation optical retinopathy developed in 9.3% of>˂0.001). The eyeball was saved in 90.1%. Post-radiation optical retinopathy developed in 9.3% of cases, progression of retinal detachment was registered in 13.9% of cases. The one-year metastatic-free survival rate was 96.3±3.6%, the two-year survival rate was 81.3±8.6%.Conclusions. In the present study, the use of stereotactic radiosurgery with a prescribed marginal dose of up to 35 Gy allowed achieving sustainable local control of primary choroidal melanoma cT1–3 in 100% of cases over a median follow-up period of 16 months.