Gamma Knife Perfexion® radiosurgery and endo diode laser thermotherapy for choroidal melanoma with technical analysis: A case report

Radiosurgery serves an important function in the treatment of patients with intraocular tumors and preserves visual function via organ conservation. Therefore, it is important to ensure the safety and precision of GK-SRS as a primary treatment for intraocular tumors. The present case study described a 57-year-old female with uveal melanoma treated with GK-SRS. Retrobulbar anesthesia following fixation of the treated eye, via the suture of two of the extraocular muscles to the stereotactic frame, was performed to immobilize the eye during treatment. Computed tomography (CT) scans were performed following eye fixation, immediately prior to and following GK-SRS, to validate the accuracy of the tumor localization. The eye movement analysis revealed that the gravity center point deviations of the tumor and lens during treatment were <0.110 mm. At least 95% of the tumor volume was covered by the prescription dose according to three sets of CT images. The patient underwent a trans pars plana vitrectomy owing to a right eye vitreous hemorrhage. A 37-month follow-up assessment revealed tumor shrinkage, and the disappearance of the serous retinal detachments was noted on the basis of ophthalmoscopy and orbital magnetic resonance imaging. No major complications developed during the follow-up period. Using our treatment protocol, GK-SRS is a non-invasive procedure which is used as a brief single fraction treatment for intraocular tumor. The eye fixation method used in the present study has high accuracy.