ESTRO 2025 - Abstract Book

S1420

Clinical - Lung

ESTRO 2025

regional in 25 & distant in 27 patients. Thirty-four patients received salvage treatment on progression. The overall incidence of brain metastasis was 6.6%.

Conclusion: Our study demonstrated comparable survival outcomes with real-world practice in LS-SCLC treated with CTRT. Intensification of CTRT with maintenance immunotherapy might further improve survival outcomes in LS-SCLC.

Keywords: Small cell Lung Cancer, PCI, real-world data

References: 1. Concurrent once-daily versus twice-daily chemoradiotherapy in patients with limited-stage small-cell lung cancer (CONVERT): an open-label, phase 3, randomized, superiority trial. Lancet Oncol. 2017 Aug;18(8):1116-1125 2. Twice-daily compared with once-daily thoracic radiotherapy in limited small-cell lung cancer treated concurrently with cisplatin and etoposide. N Engl J Med. 1999 Jan 28;340(4):265-71. 3. Prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission. Prophylactic Cranial Irradiation Overview Collaborative Group. N Engl J Med. 1999 Aug 12;341(7):476-84.

3950

Digital Poster Value of Systemic Inflammatory Markers to Predict Treatment Response in Non-Small Cell Lung Cancer

Patients Treated with Definitive Chemoradiation Melisa Bagci Kilic, Ece Ercan, Hilal Alkis, Mustafa Adli Radiation Oncology, Marmara University, Istanbul, Turkey

Purpose/Objective: Systemic inflammatory markers are useful to predict treatment response, prognosis, and survival in cancer patients. The aim of this study was to evaluate the correlation between inflammatory markers and treatment response in NSCLC patients treated with definitive chemoradiation (dCRT). Material/Methods: A total of 72 NSCLC patients treated with dCRT were included in the study. Median age was 63 years (40-90). Male/female ratio was 65/7. Radiation dose was 60 Gy in 30 fractions to the primary tumor and pathological lymph nodes. All patients received concurrent chemotherapy (carboplatin+paclitaxel or cisplatin+etoposide). Response to CRT was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST 1.1) and categorized as complete response (CR) and non-complete response (nCR). Pretreatment absolute values of neutrophil (N) (/L), monocyte (M) (/L), lymphocyte (L) (/L), platelets (P) (/L), hemoglobin (H) (g/L), and albumin (ALB) (g/L) and lactate dehydrogenase (LDH) (U/L) were recorded. Pretreatment systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), hemoglobin, albumin, lymphocyte, platelet (HALP) score, pan immune inflammation value (PIV), LANR, and platelet-to-albumin ratio (PAR) were calculated by using the formula: SII= P x N /L, SIRI= NxM/L, HALP=(H x ALB x L)/P, LANR= L x ALB/N, PAR= P/ALB, PIV=(NxPxM)/L. GRIm scores were defined as low and high by using ALB, LDH, and N/L ratio. To compare the variables between groups, Independent T-Test and Mann Whitney U Test for continuous variables and Chi-square test for categorical variables were used. Results: Patients with lower GRIm score were found to have significantly higher CR rates compared to nCR group (p=0.024). While SII was not significantly different between CR and nCR groups (p<0.05), HALP, LANR, SIRI, PAR, and PIV were statistically significantly higher in patients with CR compared to nCR (Table).