High-Dose Twice-Daily Thoracic Radiotherapy for Limited-Stage Small-Cell Lung Cancer: A Real-World Retrospective Experience from Two Tertiary Centers

Background: Hyperfractionated thoracic radiotherapy (RT) is a standard component of curative treatment for limited-stage small-cell lung cancer (LS-SCLC). While 45 Gy in 30 twice-daily fractions remains the most validated regimen, recent Phase II data suggest that dose-escalated RT using 60 Gy in 40 fractions may improve outcomes. However, real-world data on this intensified regimen remain scarce. Methods: We conducted a retrospective cohort study of LS-SCLC patients treated with 60 Gy in 40 twice-daily fractions and concurrent platinum-etoposide chemotherapy at two tertiary centers. Modern radiation techniques were employed. Key outcomes included overall survival (OS), progression-free survival (PFS), patterns of failure, and treatment-related toxicity. Results: Thirteen patients were included in the analysis. The median age at diagnosis was 59 years; 61.5% were female. At a median follow-up of 15 months, the 2-year OS rate was 71.4%, and the median OS was 30.9 months. The overall response rate was 60%. Most failures were distant; only one local failure was observed. Acute grade ≥ 3 esophagitis occurred in 7.6%, and no patients experienced grade ≥ 2 pneumonitis. Hematologic toxicity, particularly neutropenia, was frequent but manageable. No treatment-related deaths occurred. Conclusion: In this cohort, delivery of dose-escalated twice-daily thoracic radiotherapy using contemporary techniques was feasible and associated with acceptable toxicity in routine clinical practice. Survival outcomes were comparable to those reported in phase II studies of this approach. These findings warrant confirmation in larger, multi-institutional, or registry-based studies. Plain Language Summary: Small-cell lung cancer is a fast-growing type of lung cancer that often spreads quickly. When it is found early and is still confined to one area of the chest, it is called “limited-stage” disease. In these cases, doctors treat patients with a combination of chemotherapy and radiation. A common approach is to give radiation twice a day for 3 weeks, which has been shown to help patients live longer. However, some recent studies suggest that giving a higher total dose of radiation over 4 weeks might work even better, without adding more side effects. In this study, we looked at 13 patients with small-cell lung cancer who were treated at two major hospitals. All patients received the higher radiation dose (60 Gy) twice a day, along with standard chemotherapy. We aimed to see how well this treatment worked in real-world settings and whether it was safe. We found that this treatment approach was generally well tolerated and showed promising results: most patients responded to the treatment, and serious side effects were uncommon. After 2 years, more than 70% of the patients were still alive, which is similar to results seen in clinical trials. Most cancer recurrences happened in other parts of the body, not in the thorax. These findings suggest that giving a higher dose of radiation twice a day is a practical and effective option for treating limited-stage small-cell lung cancer outside of clinical trials. This approach could help improve survival in some patients without causing more harm.