Episcleral Iodine-125 radioactive plaque brachytherapy as a salvage treatment for retinoblastoma in the era of intraarterial chemotherapy.

BACKGROUND: Retinoblastoma shows high rates of recurrence after initial chemotherapy (systemic or intraarterial). Our aim was to evaluate the effectiveness of iodine-125 radioactive plaque brachytherapy as a salvage treatment with globe-preserving attributes after initial chemotherapy in patients with intraocular retinoblastoma. METHODS: The effect of brachytherapy was investigated retrospectively in 17 eyes of 17 patients who were followed up due to retinoblastoma between May 2012 and June 2018 and who received iodine-125 radioactive plaque brachytherapy as a salvage treatment after systemic or intra-arterial chemotherapy. The regression, ocular toxicity, and enucleation rates were evaluated at the end of the follow-up period. RESULTS: The tumor locations were post equator, macular, anterior to the equator, and peripapillary in 5, 3, 7, and 2 patients, respectively. Regression was initially and rapidly observed in 17 of the 17 eyes that underwent brachytherapy. Enucleation was performed in 5 (29.42%) of these patients due to recurrence with diffuse tumor involvement, and 4 of the tumors were located anterior to the equator. In 12 (70.58%) patients, the eyes were protected from enucleation following local brachytherapy. CONCLUSIONS: Radioactive plaque brachytherapy can be applied as an effective salvage therapy with successful results in retinoblastoma patients who have received initial systemic or intra-arterial chemotherapy. Post equator-located solitary tumors have the highest success rate.

Effects of topical application of methotrexate on nasal mucosa in rats: a preclinical assessment study.

OBJECTIVE: The aim of this study is to investigate dose-dependent effect of the topical application of methotrexate (MTX) in rats on the normal nasal mucosa, liver tissue, liver enzymes, and hemoglobin levels. STUDY DESIGN: Preclinical animal study. SETTING: Twenty male adult wistar albino rats were randomly divided into 4 groups (n=5). A single puff of MTX (2.5 microg) was applied to both nasal cavities 2 times a day. The animals were given MTX 1 day a week in group 1, 3 days a week in group 2, and 5 days a week in group 3. Control group animals were given 1 puff of physiologic saline to both nasal cavities 5 days a week and 2 times a day. After 28 days, liver biopsies, blood samples, and 5 nasal mucosal biopsies were taken. Histological examination was made with respect to certain parameters semiquantitatively (grade 0-3). The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and hemoglobin counts were studied from blood samples. RESULTS: There are no statistically significant differences with respect to histopathological parameters between the control group and the groups 1-3 (P>0.05). Histopathological examination of liver tissue did not reveal any evident difference between the control and study groups. Mean AST and ALT as liver function tests and hemoglobin counts were within normal limits. Topical application of MTX at these doses has no toxic effect on the nasal mucosa, the liver tissue, AST and ALT levels, and hemoglobin level. CONCLUSIONS: These results have been encouraging to investigate use of the topical application of MTX in nasal manifestation of autoimmune disease or addition of the topical application of MTX to the steroid treatment in cases with massive nasal polyposis resistant to steroids and prone to recurrence.