Page 155 - SRPSKO DRUŠTVO ISTRAŽIVAČA RAKA

SDIRSACR Oncology Insights

P63

First experience of using intraluminal photodynamic therapy with pulse-mode radiation of
gastrointestinal tract and respiratory system tumors

Albina Avanesyan, Alina Akkalaeva, Aleksey Bogdanov, Vladimir Moiseyenko

N.P Napalkov Saint Petersburg Clinical Research and Practical Centre for Specialized Types of Medical Care (Oncological), Saint
Petersburg, Russia

Keywords: photodynamic therapy, pulse-mode radiation, gastrointestinal tract and respiratory system tumors

Background: For patients with inoperable tumor gastro-intestinal tract and respiratory system tumors using
intraluminal photodynamic therapy and calculated regime of pulse-mode radiation shows a higher antitumor
effect compared to the standard persistent irradiation by reducing photo-induced hypoxia of the tumor tissue.
Materials and methods: From August, 2019 to May 2025, two groups (I and II group) of patients underwent the
treatment. Group I consisted of three subgroups: 33 patients with gastrointestinal tract tumor. Nineteen patients in
Group I had stenosing inoperable gastrointestinal tumors and complaints of dysphagia of grade 2–3 (subgroup I(a));
six patients had inoperable gastrointestinal tumors without signs of stenosis (subgroup I(b)); and eight patients had
stage I gastrointestinal tumors (subgroup I(c)). Group II included 7 patients with bronchial tumors: two patients had
stenosing inoperable lung cancer with grade 2–3 respiratory failure; one patient underwent non-radical resection of
a lung tumor; three patients had grade I bronchial tumors; and one patient had a local recurrence of a laryngeal
oropharyngeal tumor after a radical course of external beam radiation therapy.
Results: In Group I subgroup I (a) in 15 of 19 patients (79%) with a stenotic gastrointestinal tumor, 2-3 days after
intraluminal photodynamic therapy during pulse-mode radiation, experienced relief from dysphagia, and independent
feeding with solid food became possible. Control esophagogastroduodenoscopy showed partial tumor regression and
3-9 mm expansion. In the subgroup I (b) in 5 cases (83 %) endoscopically observed partial regression, in 1 patient (17
%) – complete regression. In Group II: in 1 of 3 cases with a tumor of the tracheo-bronchial tree of the bronchus of
the 1st stage, a complete regression occurred. In the remaining 2 cases – partial regression was observed. 1 Patient
with respiratory failure of 2-3 degrees observed a clinical significant partial effect. In one patient after non-radical lung
tumor resection, a single session on the stump area prevented tumor relapse for 7 months.
Conclusions: Photodynamic therapy during pulse-mode radiation allows to restore the patency of hollow organs in
stenosing cancers of the gastrointestinal tract and bronchus in a short period of time and improves the quality of life.
We can observe a radical effect and long-term remission in cases of patients with stage I tumors.

P64
Discovery and evaluation of a novel phthalazine-based vascular endothelial growth factor receptor 2
inhibitor in glioblastoma cell lines

Selma Zukic , Larisa Ivanova , Eva Zusinaite , Andres Merits , Uko Maran 1
2
2
1
1
1Institute of Chemistry, University of Tartu, Tartu, Estonia
2Institute of Bioengineering, University of Tartu, Tartu, Estonia
Background: Cancer is among the leading causes of mortality, and new targeted therapies protecting off-target cells
and tissues ungenrtly needed. Vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitors are among the first
clinically approved drug substances for the treatment of tumour-induced angiogenesis. Glioblastoma multiforme
(GBM) is one of the most aggressive forms of aggressive brain tumour which is also regulated via vascular endothelial
growth factor (VEGF) and its receptor 2 (VEGFR-2). Objectives: (i) to test the hypothesis that in the structurally diverse
biochemical space of VEGFR-2 inhibitors with favourable interaction pharmacophores, there is a relationship between
chemical structure and activity that can be described by a mathematical model; (ii) to design, screen and in vitro
evaluate new active VEGFR-2 inhibitors based only on structural information of the ligands; (iii) to test promising
inhibitor(s) in vitro in glioblastoma cell lines.
Materials and methods: Over two hundred VEGFR-2 inhibitors with highly diverse chemical structures were manually
collected and curated. Original chemical space was analyzed using machine learning (ML) methodology within the

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