Abstract
Purpose: :
To report the status of a safety and feasibility study of a new ocular brachytherapy device designed to treat exudative age–related macular degeneration.
Methods: :
The TheraSight® Safety and Feasibility Study is a multicenter randomized study of three doses of radiation (12, 14, 16 Gy) delivered by the TheraSight® System in patients with choroidal neovascularization due to AMD. The TheraSight® System consists of a high dose rate 103 Pd applicator, a sterile sheath, and an articulating arm to stabilize the device after it is inserted into the retrobulbar space and aligned flush with the sclera behind the macula. Eligible patients have active subfoveal CNV due to AMD with classic, occult or mixed characteristics up to 7.5mm in greatest linear dimension and Snellen visual acuity <20/100. Patients are evaluated for acute safety effects at 1, 7 and 30 days, and followed over a 3 year post–treatment interval. The feasibility of properly placing the device is assessed by treating ophthalmologist and, after placement, ultrasound is used to verify that the device is aligned flush with the sclera behind the macula.
Results: :
A total of 16 patients were treated at 5 clinical centers from October 2004 through October 2005 when enrollment ended. The study population consists of 9 females and 7 males with mean age of 79 years at the time of treatment. The TheraSight® device was successfully positioned with ultrasound verification in all cases. One serious adverse event (SAE) was reported in which a patient experienced a 6 line visual acuity loss. This SAE was reviewed by an independent Clinical Events Committee (CEC) that concluded the vision loss resulted from natural disease progression and not from the procedure. There have been 4 other non–ocular SAEs that were reviewed by the CEC and found not to be related to the device or the surgical procedure. A total of 20 other (non–serious) adverse events in 13 patients have been reported. Among the 12 patients followed for >3 months, visual acuity has been stable (within 15 letters from baseline) in 10 patients, improved (>15 letters) in 1, and worse (>15 letters) in 1.
Conclusions: :
The TheraSight® brachytherapy device has not been associated with any serious, related adverse events to date. The device has been effectively positioned and the procedure has been generally well tolerated in this study. Further study will be required to determine efficacy.
Keywords: age-related macular degeneration • radiation therapy