Stereotactic radiosurgery in intraocular malignant melanoma--retrospective study.

OBJECTIVE: One day session linear accelerator based stereotactic radiosurgery of intraocular malignant melanoma is a method of "conservative" attitude to treat posterior uveal melanoma. MATERIAL AND METHODS: Retrospective clinic-based study of patients with posterior uveal melanoma in stage T2/T3 who underwent stereotactic radiosurgery at linear accelerator in period 2001-2011. Immobilization of the affected eye was achieved by mechanical fixation to the stereotactic Leibinger frame. The stereotactic treatment planning after fusion of computed tomography and magnetic resonance imaging was optimized according to the critical structures (lenses, optic nerves, chiasm). RESULTS: In group of 96 patients with posterior uveal melanoma treated with one day session stereotactic radiosurgery, patient age ranged from 25 to 80 years with a median of 54 years. Median tumor volume at baseline was 0.6 cm(3) (with range from 0.2 to 1.0 cm(3)). Median maximal dose applied was 49.0 Gy (range from 37.0 to 52.0 Gy). Secondary enucleation was necessary in 11 patients (11.5%) due to complications like irradiation neuropathy and secondary glaucoma. Tumor local control was successful in 95% of patients in 3 years interval after stereotactic radiosurgery and in 85% of patients in 5 years interval after stereotactic radiosurgery. CONCLUSION: One step LINAC based stereotactic radiosurgery with a single dose 35.0 Gy is one of treatment options to treat T2 or T3 stage posterior uveal melanoma.

Clinical experience of stereotactic radiosurgery at a linear accelerator for intraocular melanoma.

Long-term results with linear accelerator LINAC-based stereotactic radiosurgery for intraocular uveal malignant melanoma were assessed. A retrospective study was carried out of patients with uveal melanoma after a 1-day session stereotactic radiosurgery at LINAC in Slovakia. In the period 2001-2015, a group of 150 patients with uveal melanoma (139 choroidal melanoma, 11 ciliary body melanoma) was treated. The median tumor volume at baseline was 0.5 cm (with range from 0.2 to 1.6 cm). Tumors ranged in size from 2.4 to 20.8 mm in basal diameter and from 2.0 to 18.3 mm in thickness. The therapeutic dose was 35.0 Gy by 99% of dose volume histogram. Older age at treatment was correlated with the largest basal tumor diameter, tumor thickness, and TNM stage. The survival after stereotactic irradiation was 96% in 1 year, 93% in 2 years, 84% in 5 years, 80% in 7 years, and 53% in 11 years. In 20 (13.3%) patients, secondary enucleation was necessary because of complications (secondary glaucoma). Enucleation-free interval ranged from 1 to 6 years. The median age at death was lower (65.7 years) for patients who died from metastatic disease than for those who died from any other cause (75.0 years). Survival rates at 5-year intervals and the need for secondary enucleation because of complications after linear accelerator irradiation are comparable to other techniques.

Protective effects of black tea extract against oxidative DNA damage in human lymphocytes.

The aim of the present study was to examine the genoprotective and radioprotective effects of black tea extract (BTE) against the induction of single strand DNA breaks in human lymphocytes subjected to hydrogen peroxide (H2O2) or gamma-rays (2 Gy dose). Lymphocytes were incubated with or without different concentrations of BTE (0.005-500 µg/ml) for 30 min, followed by treatment with or without H2O2 (0.088 µmol/l) for 5 min. To examine the radioprotective effect of BTE, the lymphocytes were incubated with or without BTE for 30 and 60 min prior to and following in vitro irradiation. Oxidative damage to DNA was monitored using a comet assay. BTE at lower concentrations prevented H2O2-induced DNA damage. An increase in BTE concentrations resulted in increased formation of single strand DNA breaks. BTE also exerted significant protective effects against gamma radiation-induced total DNA damage in healthy lymphocytes during their 30 or 60 min incubation with BTE prior to or following irradiation. Therefore, the protective effect of BTE against irradiation was time-dependent. The results contribute to the research on potential beneficial effects of natural compounds, such as BTE, in cancer and its protective effects of normal tissue during radiation therapy.