Khomiakova O. Blockexcision efficiency for patients with uveal melanoma iridociliary and ciliochoroidal localization by radio wave surgery method and its combination with previous brachytherapy with reduced doses.

Thesis for a candidate’s degree by speciality 14.01.18 «Ophthalmology». – SI «The Filatov Institute of Eye Diseases and Tissue Therapy of NAMS of Ukraine», Odesa, 2023. The dissertation is devoted to increasing the effectiveness of the treatment of patients with melanoma of iridociliary and ciliochoroidal localization by the method of radio wave surgery and its combination with preliminary brachytherapy with reduced doses. It was found that melanoma of iridociliary and ciliochoroidal localization is more often observed in men (57.1 %) aged 52.3-55.7 years with localization in the lower lateral region (31.1 %), pigmented (63.45 %) with a nodular form growth (69%), mixed cell type (50.5 %) and those with T2v stage of the tumor process (45.0 %). For the first time in the experiment, the histomorphological features of the eye tissues (sclera, iris, ciliary body, choroid) of rabbits after using a radio wave knife were established. It has been established that in the immediate vicinity of the incision site, pronounced necrotic and dystrophic changes develop in them (zones of homogenization, dry necrosis of the stroma and pigment epithelium), which spread over a certain distance. Around the zones of homogenization and necrosis, there is a pronounced inflammatory reaction with lymphocytic infiltration. These changes are stable and persist for 30 days, during which a protective barrier is formed to delimit the surrounding tissues. An analysis was made of the effectiveness of the treatment of patients with melanoma of iridociliary and ciliochoroidal localization. It was found that in patients with UM of iridociliary localization during surgery with a radio wave knife, there were no complications, while when using a cutting microsurgical instrument, hyphema and lens dislocation were observed equally often (11.1 %). In the postoperative period, in patients with UM of iridociliary localization, when using a radio wave knife, the frequency of such complications as hyphema and hemophthalmos was significantly less than in the control group, by 6.3 and 17.7 times, respectively. Local relapses in patients with UM of iridociliary localization when using a radio wave knife occurred 4.2 times less often than when using a cutting microsurgical instrument. During the observation period from 62 to 108 months, no cases of metastasis were registered. A method for the treatment of melanomas of ciliochoroidal localization has been developed, which consists in the use of radiation therapy with reduced doses followed by block excision with a radio wave knife (Patent of Ukraine No. 143392, 2020, Bull. No. 14), which allows to reduce the interchange of tension by 1.5-2 times and increase the effectiveness of exaltation of ailments up to 85.7%. In 64.3% of cases, the early treatment changes the vitality of plump cells and affects their types of healthy tissues. Blockexcision of melanomas of ciliochoroidal localization using a radio wave knife with preliminary brachytherapy with reduced doses made it possible to reduce the number of intraoperative (hyphema - by 2.3, subretinal hemorrhage - by 2.5 times) and postoperative complications (retinal detachment by 3.6 times), as well as to reduce the number of enucleations by 1.7 times. The recurrence rate in patients with ciliochoroidal melanoma was 14.3%, which is comparable with the literature data. According to a histomorphological study, the use of reduced doses of radiation therapy at the first stage of combined treatment of melanomas of ciliochoroidal localization helps to reduce the invasion of surrounding tissues, and blockexcision with a radio wave knife allows maximum preservation of healthy tissues that remain without the risk of transferring tumor cells to healthy areas. It has been proven that the use of reduced doses of radiation therapy at the first stage of combined treatment of melanoma of ciliochoroidal localization helps to reduce the invasion of surrounding tissues, and block excision with a radio wave knife allows to preserve the remaining healthy tissues as much as possible, without the risk of transferring tumor cells to healthy areas. The use of combined treatment (block excision with a radio wave knife with previous brachytherapy with reduced doses) allows to obtain a fairly good functional and aesthetic result (preserving the eye and initial visual acuity), which improves the quality of life of patients with ciliochoroidal melanoma. Key words: melanoma of iridociliary and ciliochorioidal localization, radiowave surgery, blockexcision, brachytherapy.