title: Development of a streamlined, non-invasive robotic radiosurgery method for treatment of uveal melanoma.
abstract: To analyze the feasibility and safety of frameless, image-guided robotic radiosurgery against uveal melanoma, we developed a streamlined procedure that is completed within 3 hours under retrobulbar anesthesia without immobilization. Twenty patients (10 men and 10 women) with medium (3-5-mm prominence) and large (>5-mm prominence) unilateral uveal melanomas were treated with a frameless robotic radiosurgery system. Median age was 61 years (range 32-78 years). All patients underwent a single-session procedure beginning with retrobulbar anaesthesia, followed by computerized tomography (CT) scanning that was used in the generation of a treatment plan, and then the delivery of a radiosurgical tumor dose between 18 and 22 Gy to the 70% isodose line. Three-dimensional treatment planning was aimed at securing the optical lens and the optic disc as much as possible. Follow-up occurred at 3, 6, 12, and 18 months after the radiosurgery with clinical, ultrasound, and CT studies. We were able to treat all patients in the frameless setup within 3 hours. In five patients with lateral and dorsal tumors, the dose to the optic lens could be kept below 2 Gy. The clinical response was evaluated for the first seven patients treated with a follow-up of at least 6 months. No local recurrences occurred with any of the clinically evaluated patients for a mean 13-month follow-up (range 6-22 months). Maximum median apical tumor height according to standardized A-scan ultrasound evaluations decreased from 7.7 to 5.6 mm (p < 0.1). The median reflectivity increased from 41% to 70% (p < 0.01). None of the patients developed a secondary glaucoma during the short-term follow-up period. Frameless, single-session, image-guided robotic radiosurgery is a feasible, safe and comfortable treatment option for patients with uveal melanoma. Longer follow-up and analysis of a larger patient series is required for definitive clinical recommendations.
authors.affiliation: European CyberKnife Center Munich, Max-Lebsche-Platz 31, 81377 Munich, Germany. Alexander.Muacevic@cyber-knife.net
authors.forename: Alexander
authors.initials: A
authors.lastname: Muacevic
authors.forename: Martin
authors.initials: M
authors.lastname: Nentwich
authors.forename: Berndt
authors.initials: B
authors.lastname: Wowra
authors.forename: Sibylle
authors.initials: S
authors.lastname: Staerk
authors.forename: Anselm
authors.initials: A
authors.lastname: Kampik
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schaller
mesh_terms: D000328:Adult; D000368:Aged; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000379:methods; D008545:Melanoma / Q000601:surgery*; D008875:Middle Aged; D016634:Radiosurgery / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012371:Robotics; D016896:Treatment Outcome; D014604:Uveal Neoplasms / Q000601:surgery*