THE ROLE OF RADIATION THERAPY IN THE TREATMENT OF PTCL-NOS.

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders, accounting for about 10 % of all non-Hodgkin lymphomas. The most common subtype is peripheral T-cell lymphoma, unclassified (PTCL-NOS), accounting for about 26 % of all PTCLs. PTCL-NOS is associated with less favorable overall survival (OS) and progression-free survival (PFS) compared with aggressive B-cell lymphomas. The role of radiation therapy in the treatment of PTCL-NOS is still not definitively defined. The results of many studies show that the addition of radiation therapy to the treatment regimen is associated with a significant improvement in survival in patients with early-stage PTCL-NOS, but in the later stages, the benefit of radiation therapy is not obvious.

Objective: peripheral T-cell lymphoma, unspecified is a clinically and biologically heterogeneous disease with a poor prognosis. Since the role of radiation therapy is still unclear, a study was conducted to evaluate the effectiveness of radiation therapy in peripheral T-cell lymphoma, unspecified.

Materials and methods: The work is based on clinical observations and treatment results of patients who were diagnosed between 2013 and 2023 at the National Cancer Institute (in the period from 2020 to 2023, patients were observed and treated as part of research). 56 patients were included in the study.

Results: The work analyzed the immediate results of the treatment of patients with peripheral T-cell lymphoma, unspecified depending on the stage and type of treatment, as well as the overall survival of these patients. When analyzing the overall response to the treatment of patients with I/II stages of the disease, it was proven that this indicator is higher in the group of patients who received chemoradiotherapy, compared to patients who received only chemotherapy (100 % versus 83.3 %), and this indicator was higher due to patients who demonstrated a complete response to therapy (75 % vs. 50 %). Analyzing the response to treatment of patients with III/IV stages of the pathological process, it was established that there was no difference in the overall response to treatment, the level of complete and partial response to treatment. Analysis of the overall survival of patients with I/II stages of the disease, with a median follow-up of 60 months, demonstrated a significant improvement in overall survival in the group of patients who received chemoradiotherapy compared to the group of patients who received only radiation therapy (median 48 vs. 22 months). Overall 1-year (78 % vs. 69 %), 3-year (64 % vs. 40 %), and 5-year (48 % vs. 35 %) were also higher in the chemoradiotherapy group. In the group of patients with III/IV stages of the disease, there was no difference in overall survival between patients who received chemoradiotherapy and patients who received only chemotherapy (median 16 vs. 13 months, 1-year survival 54 vs. 52, 3-year survival 33 vs. 30 and 5-year overall survival of 23 vs. 20 %.

Conclusions: The addition of radiation therapy to the treatment plan demonstrated a significant improvement in the overall response and overall survival of patients with peripheral T-cell lymphomas, unspecified with I and II stages of the pathological process, but in III and IV stages of the disease, the benefit of radiation therapy has not been proven.