Cureus | Preliminary Results of Fractionated Cyberknife Radiosurgery for Uveal Melanoma

Preliminary Results of Fractionated Cyberknife Radiosurgery for Uveal Melanoma



Abstract

Objective(s): We report our clinical experience of a hypofractionated Cyberknife Radiosurgery schedule for uveal melanoma treatment.

Methods: Between April 2014 and March 2016 14 patients (pts), mean age 65 years (range 36 – 83 years) suffering from uveal melanoma (11 choroidal melanoma and 1 ciliary body melanoma) were treated at Cyberknife Center, Centro Diagnostico Italiano, Milan. All of the pts had received a diagnosis and referral from an ophthalmologist. Cyberknife radiosurgery was performed delivering a total dose of 54 - 60 Gy (mean 60 Gy) given in 3 or 4 fractions (mean 3) of 15 - 20 Gy (mean 20 Gy) prescribed to the 79 - 82% (mean 80%) isodose surface. All pts underwent orbit MRI with gadolinium for coregistration with the planning CT scans. The planning target volume (PTV) included the contrast-enhancing lesion on MRI plus a 2.5 mm margins in all directions. All pts were irradiated eyelids closed, using a contention with a thermoplastic mask. The mean PTV volume was 2037 mm³ (range 701.82 – 5792 mm³), mean tumor base measured ultrasonographically 11.36 mm (range 7-15 mm), mean thickness 4.79 mm (range 2.5 – 10 mm), with a mean distance of 5.25 mm (range 0 – 15 mm) from fovea and 5.55 mm (range 0 – 13 mm) from optic nerve.

Results: After a mean follow-up of 17 months (range 7 – 30) local control was achieved in 100% of pts. No patient underwent enucleation and none developed distant metastases (all pts underwent abdomen ultrasound and liver blood examination once every six months and chest CT once a year). We observed a reduction of 13% in median base and of 44% in median thickness that were respectively 10 mm (range 4.8 – 13 mm) and 2.45 mm (range 0.5 – 5 mm) at last follow-up. Visual acuity was reduced in 64 % of pts, while in the others no change was found. Four pts suffered of radiation maculopathy, associated in one case with atrophy and in three cases with cystoids macular edema. Moreover radiation-induced optic neuropathy and radiation vasculopathy occurred respectively in 3 and 4 cases. 7 pts developed choroidal ischemia and 3 retinal detachment. At the last follow-up none had corneal anomalies.

Conclusion(s): These initial results of our Cyberknife schedule are consistent with data in literature and show a safe, minimally invasive and well tolerated method for treating uveal melanoma. Further follow-up is necessary.

Related content

abstract
non-peer-reviewed

Preliminary Results of Fractionated Cyberknife Radiosurgery for Uveal Melanoma


Author Information

Isa Bossi Zanetti Corresponding Author

Unit of Diagnostic Imaging and Stereotactic Radiotherapy, Centro Diagnostico Italiano, Milano, ITA

Marco Pellegrini

Eye Clinic, Luigi Sacco Hospital, University of Milan, Milano, ITA

Giancarlo Beltramo

Radiation Oncology, Cyberknife Center, Centro Diagnostico Italiano, Milano, ITA

Achille Bergantin

Medical Physics, Cyberknife Center, Centro Diagnostico Italiano, Milano, ITA

Pantaleo Romanelli

Neurosurgery, Cyberknife Center, Centro Diagnostico Italiano, Milano, ITA


PDF Share