Abstract
Purpose:
Radiotherapy offers patients with malignant melanoma of the choroid a vision-sparing alternative to enucleation. The most commonly used forms of radiotherapy are ophthalmic plaque brachytherapy and external beam irradiation such as proton beam and stereotactic radiotherapy that typically involves a column of radiation directing through the anterior structures in order to reach the intraocular tumor causing complications like eyelash loss, eyelid excoriation, corneal neovascularization and ulceration, dry eye, neovascular glaucoma.<br /> Varian Truebeam Stereotactic Radiotherapy is a new option using a non filtered photons rapidarc VMAT (Volumetric Modulated Arc Therapy) dynamically delivered that shortens the irradiation time.We report our experience with this technique in the treatment of choroidal melanoma.
Methods:
Between February 2012 and November 2012, 15 patients affected by choroidal melanoma were treated with stereotactic radiotherapy (SRT) with VMAT with flattening filter-free (FFF) on a VarianTM TrueBeamSTx. Acute toxicity was recorded. Local control evaluation was scored by means of Ocular A and B scan ultrasound examination, anterior segment and fundus examination, fluorescein and indocianine angiography, intraocular pressure measurement and CT /PET scan.
Results:
Patients were 5 males and 10 females, with a median age of 71.3 years (range, 65-78 years). The mean sizes of the lesions were base: 12.67 mm (range 10-16.1 mm) and high: 8.25 mm (range 4-12.5mm). The prescribed radiation dose was 27 Gy in 1 fraction to CTV. The median follow-up was 10.5 months (range: 5-22 months).<br /> All patients completed the treatment. Until today there were no cases of local progression and no enucleations. Up to now complications were 1 cataract, 1 hemovitreous and 1 retinal ischemia.
Conclusions:
Data of dosimetrical findings and acute toxicity are excellent for patients with choroidal melanoma treated with SRT with VMAT using FFF beams. Preliminary clinical results showed a high rate of local control in irradiated patients with a low incidence of toxicity. The VMAT is delivered in a dynamic way with the radiation source in motion during dispensing thus allowing greater speed of delivery of dose, focusing radiation on tumor tissues and reducing the risk of collateral damage to healthy organs. Further data and longer follow up are needed to assess late toxicity and definitive clinical outcomes.<br />