Work

Photodynamic therapy with chlorine e6 in the treatment of choroidal melanoma

Year: 2025

Type: article

Abstract: The relevance of the search for effective methods of treating uveal melanoma (UM) is determined by its high frequency in the structure of intraocular malignant neoplasms and the progressive nature of its course. Purpose . To present the results of using photodynamic therapy (PDT) with chlorin e6 in the treatment of uveal melanoma (UM). Material and methods . 210 patients, follow-up time = 88 (12;49) months. Treatment was carried out in various modes of exposure (“ALOD-01”, 662 nm), chlorine PS “Photolon”/”Photoran”, 1.0 mg/kg. As an independent treatment method, PDT: transpupillary (n=47), hybrid (n=13), transscleral (n=6). As a component of combination treatment: brachytherapy Ru-106/Rh-106 (n = 124), proton therapy (n = 20). Results. The use of PDT with chlorin e6 in the treatment of patients with UM promotes rapid tumor regression and a decrease in intra-tumor vascularization due to antiangiogenic and direct cytotoxic effects on the tumor substrate. Conclusions. The results obtained expand the possibilities and open up prospects for organ-preserving treatment of this pathology, including large tumors. Key words . Choroidal melanoma, uveal melanoma, photodynamic therapy, lasers in ophthalmology, predictors of the effectiveness of photodynamic therapy. The relevance of the search for effective methods of treating uveal melanoma (UM) is determined by its high frequency in the structure of intraocular malignant neoplasms, the progressive nature of the course associated with metastasis and the possibility of death [1]. One of the promising areas in the organ-preserving treatment of UM, including large tumors, is photodynamic therapy (PDT) with photosensitizers (PS) of the chlorine series, which can be used either alone or in combination with radiation treatment methods [2-7]. Laser irradiation with a wavelength of 0.66 nm makes it possible to influence the intraocular lesion not only from the apex (transpupillary), but also from the base of the tumor (transscleral), which is especially important when localization of UM in the peripheral zone [8, 9]. Purpose. To present the results of using PDT with chlorine e6 in the organ-preserving treatment of UM. Material and methods. Since 2017, 210 patients with UM aged from 28 to 87 years (59.5 ± 13.5) have been treated with PDT. Follow-up period ranged from 1 month to 156 months (13 years), median follow-up time = 88 (12;49) months. In accordance with the TNM grading system, the distribution was as follows: T 1 N 0 M 0 – (n=39), T 2 N 0 M 0 – (n=69), T 3 N 0 M 0 – (n=85), T 4 N 0 M 0 – (n=17). Diagnosis was carried out on the basis of a clinical and instrumental examination, including a comprehensive ultrasonography with assessment of the degree of tumor vascularization (PHILIPS Affinity 50). PDT was carried out on a laser system "ALOD-01", 662 nm (Alkom Medica, Russia), chlorine PS "Photolon"/"Photoran", 1.0 mg/kg body weight. Treatment was carried out in various treatment options. As an independent treatment method: isolated transpupillary PDT (n=47), isolated hybrid PDT (n=13), isolated transscleral PDT (n=6). As a component of combination treatment: with brachytherapy (BT) Ru-106/Rh-106 (n = 124), with proton therapy (PT) (n=20). BT and PT were performed up to 1 month after PDT. Results. The effectiveness of transpupillary PDT in the isolated treatment of UM small and medium-sized tumors is determined by the ability to achieve complete tumor regression in 84% of cases, use in hypo/hypervascular tumors (p = 0.001), and initial thickness of the tumor up to 4.5 mm (p = 0.0001) and weak/moderate severity of UM pigmentation (p=0.012). The use of combined organ-preserving treatment, including PDT followed by brachytherapy, helps accelerate the rate of tumor regression at periods of 3, 6 and 12 months (p <0.05), achieve complete tumor regression in 86% of patients, as well as a significant reduction in signs of intratumor vascularization (p<0.05). The possibility of using transscleral and hybrid PDT in the treatment of UM is determined by preliminary results demonstrating the expansion of possibilities for organ-preserving treatment of large tumors due to direct cytotoxic, antiangiogenic effects on the tumor substrate, as well as potentiation of the effect of radiation therapy. Conclusions. The use of PDT with chlorine e6 in the treatment of patients with UM expands the possibilities and opens up prospects in the organ-preserving treatment of this pathology, including large tumors. It seems promising to further improve laser methods using modern production technologies, process automation, precise dosimetry with the study of the threshold of safe laser radiation, as well as an individual selection of parameters and the development of modern instruments.

Source: Photodiagnosis and Photodynamic Therapy

DOI: 10.1016/j.pdpdt.2025.105026

Authors: E.V. Boiko, E.V. Samkovich, I.E. Panova, A.A. Ivanov

Institutions: St Petersburg University, Intersectoral Research and Technology Complex Eye Microsurgery, North-Western State Medical University named after I.I. Mechnikov

Language: English

Topic: Ocular Oncology and Treatments

Subfield: Ophthalmology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,610