ESTRO 2025 - Abstract Book

S1419

Clinical - Lung

ESTRO 2025

Conclusion: This single-institution experience suggests that concurrent encephalic radiotherapy and TKIs therapy is safe and effective in NSCLC patients with CNS metastases. Although neurological symptoms are typically associated with poor survival, in this cohort, survival was more strongly influenced by systemic disease progression than by intracranial factors. The high intracranial response rate (64.3%) in contrast with the short overall survival, suggests the potential benefit of an earlier WBRT or SRS. Considering the retrospective design, limited sample size, and patient heterogeneity, further studies are needed to investigate these findings and to determine optimal timing for encephalic radiotherapy in brain-metastatic NSCLC patients receiving TKIs.

Keywords: Oncogene-driven NSCLC, brain metastases

3921

Digital Poster Long-term Survival Outcomes of Limited Stage Small Cell Lung Cancer – Experience from the Tertiary Cancer Center of India ANIL RAMAKANT TIBDEWAL 1 , RENU NABARIYA 1 , Guncha Maheshwari 1 , Megha Madhavi 1 , Kumar Prabhash 2 , Vanita Noronha 2 , Nandini Menon 2 , Minit Shah 2 , Rajiv Kaushal 3 , Amit Janu 4 , Jai Prakash Agarwal 1 1 RADIATION ONCOLOGY, TATA MEMORIAL HOSPITAL, HOMI BHABHA NATIONAL INSTITUTE, MUMBAI, India. 2 Medical Oncology, TATA MEMORIAL HOSPITAL, HOMI BHABHA NATIONAL INSTITUTE, Mumbai, India. 3 Pathology, TATA MEMORIAL HOSPITAL, HOMI BHABHA NATIONAL INSTITUTE, Mumbai, India. 4 Radiology, TATA MEMORIAL HOSPITAL, HOMI BHABHA NATIONAL INSTITUTE, Mumbai, India Purpose/Objective: Small cell lung cancer (SCLC) is an aggressive malignancy with a dismal prognosis. Concurrent chemoradiation therapy (CTRT) is the standard treatment for limited-stage SCLC (LS-SCLC). In this retrospective study, we analyzed the long term survival outcomes of LS-SCLC treated at our institute with CTRT. Material/Methods: From Jan 2011 to Sept 2023, we retrospectively audited consecutive patients treated at our institute of LS-SCLC with CTRT and Prophylactic Cranial Irradiation (PCI). Patient demographics, treatment, and outcome details were collected from electronic medical records and case files. Median follow-up (FU) was calculated using the reverse Kaplan-Meier method. Overall survival (OS) & progression-free survival (PFS) were calculated using Kaplan-Meier method. Acute & late toxicities were documented as per CTCAE v5.0. Results: A total of 106 consecutive patients were included in this analysis. The median age was 58 years (range, 36-88) with predominantly males (87%) & smokers (73%). Sixty-five percent had KPS of >70 and 44% had co-morbidities. The majority underwent staging PET-CT and MRI brain. The majority received 1-2 chemotherapy (CT) cycles before thoracic RT (TRT) and almost all received concurrent CTRT with the platinum-doublet regimen. The median CT cycles received were 4 (range, 1-6) with a median TRT dose of 60 Gy in 30 fractions once daily (range, 8.25-60 Gy) and median PCI dose of 25 Gy in 10 fractions. 3D-CRT and IMRT techniques were used in 33% and 56%, respectively. Seventy-one percent received PCI. The median time from start of any treatment to end of radiotherapy was 62 days (10-252 days). At the time of analysis, 23 patients were alive. The median follow-up of surviving patients was 62 months (44.68 – 79.63 months). The median PFS was 9 months (95% CI, 6.2-11.6 months) and OS was 17 months (95% CI, 11.99 – 21.98 months), respectively. The 3-yr & 5-yr PFS were 20% & 13% and 3-yr & 5-yr OS were 30% & 20% respectively. Acute grade II skin toxicity was observed in 5.6%, ≥ grade II pneumonitis in 8.5% & ≥ grade II esophagitis in 19% of patients. Late ≥ grade 2 pneumonitis in 6% of patients. Forty percent had disease progression with local recurrence in 11,