Optical Coherence Tomography — Angiography in Revealing Predictors of Small Choroidal Melanoma Transpupillary Thermotherapy Efficiency

Abstract

Purpose. To reveal predictors of small choroidal melanoma transpupillary thermotherapy efficiency using optical coherence tomography-angiography.Patients and methods. 34 patients with small choroidal melanoma at an average age of 55.0 ± 2.9 years were examined. Optical coherence tomography-angiography was performed on an OCT-Angiography Software for RS-3000 Advance Optical Coherent Tomograph, Nidek, Japan, before and 4 months after 1 session of transpupillary thermotherapy. Transpupillary thermotherapy (TTT) was performed with a Nidec DC 3300 diode laser.Results. Prior to TTT — a loop-shaped, cranked-convoluted with an uneven lumen heterogeneous nature of the vasculature of the tumor with numerous bends and interlacing, located under the vessels of the retina in the central zone; the area of neovascular vasculature is 32.82 mm2, the density is 12.42 %. The limiting avascular zone is on the periphery. Around melanoma is a homogeneous hyperreflective rim of dilated choriocapillaries. 4 months after 1 session of TTT in 24 (70.6 %) of 34 cases — occlusion of the choriocapillaries in the central and peripheral zone of the tumor (avascular regions), expansion of the large and medium vessels of the choroid around the focus — predictors of complete tumor devitalization (chorioretinal scar). In 6 (17.6 %) of 34 patients, occlusion of the choriocapillaries in the central zone, expansion of large and medium vessels of the choroid around the tumor, along its periphery and in the paracentral region, retinochoroidal anastamoses along the periphery and in the paracentral zone, heterogeneous neovascularization of the choriocapillaries around; decrease in the area of vasculature — 12.44 mm2, density — 6.15 %, (p < 0.05) — predictors of partial devitalization of small choroidal melanoma (residual tumor). In 4 (11.8 %) of 34 cases, tumor vessels in the tumor area, large and medium vessels of the choroid around, along its periphery and in the central zone, occlusion of the choriocapillaries in the central zone, retinochoroidal anastamoses in the periphery and in the central zone, heterogeneous neovascularization choriocapillaries around; vascular network area — 29.13 mm2, density — 10.17 %, (p > 0.05), lack of devitalization (continued growth).Conclusion. The introduction of optical coherence tomography-angiography revealed the predictors of the effectiveness of transpupillary thermotherapy of the initial melanoma of the choroid, which are various types of tumor vascularization, indicating its about complete, partial or absence devitalization after treatment.