Efficacy and safety of omitting the clinical target volume in limited-stage small cell lung cancer: a large-scale multicenter real-world study
In brief
Skipping CTV halves severe lung toxicity while preserving survival in limited-stage SCLC
In a propensity-matched analysis of 530 patients, omitting the clinical target volume did not change response rates, progression-free or overall survival, but reduced grade 3 or higher radiation pneumonitis from 8.3% to 3.4% and severe esophagitis from 9.1% to 5.7%. The benefit was especially pronounced in those receiving immunotherapy, suggesting a safer radiotherapy approach that merits prospective testing.
- Journal
- Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Q1)
- Published
- 19 September 2026
- Study design
- Prospective / inception cohort
- Evidence level
- Level 2, Moderate (CEBM 2b)
- Authors
- Xiaolong Wang, Xinrui Yu, Xiaoli Liu, Kaikai Zhao, Yankang Li, Hong Feng, et al.
- PMID
- 42763051
- DOI
- 10.1016/j.radonc.2026.111784
Why clinicians should know about it
- Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (paper of the day, 22 September 2026): Omitting CTV in LS‑SCLC impacts efficacy and toxicity
- Picked for Radiation Oncology (paper of the day, 20 September 2026): Omit CTV shows similar efficacy, lower toxicity
Abstract
PURPOSE: Routine Clinical Target Volume (CTV) coverage in limited-stage small cell lung cancer (LS-SCLC) aims to address microscopic extension but often increases toxicity without necessarily translating to improved disease control. Our objective was to determine whether omitting the CTV could preserve efficacy while reducing toxicity compared with conventional delineation, with exploratory contemporary immunotherapy subgroup analysis. METHODS AND MATERIALS: This study enrolled 946 LS-SCLC patients between February 2016 and February 2025. According to radiotherapy strategy, patients were classified into an Omit-CTV (n = 403) group and a CTV group (n = 543). Subsequently, propensity score matching yielded 265 patients per group for the final analysis. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Secondary endpoints included first-failure patterns and treatment-related toxicity. RESULTS: With a median follow-up of 33.2 months, response rates were similar between groups (ORR: 69.4% with CTV vs. 72.8% with Omit-CTV). Median PFS was 11.6 months in the CTV group versus 11.8 months in the Omit-CTV group (HR, 0.93; 95% CI, 0.76-1.14; P = 0.500), while median OS was 30.7 months and 35.8 months, respectively (HR, 0.85; 95% CI, 0.66-1.10; P = 0.220). Furthermore, no statistically significant difference was observed in local recurrence patterns (P = 0.561). Omit-CTV was associated with lower rates of radiation pneumonitis (Grade 1-2: 20.0% vs. 27.2%; Grade ≥ 3: 3.4% vs. 8.3%; P = 0.004) and esophagitis (Grade 1-2: 32.1% vs. 39.2%; Grade ≥ 3: 5.7% vs. 9.1%; P = 0.037). Among patients receiving immunotherapy, median PFS was not reached in the Omit-CTV group and 15.2 months in the CTV group (HR, 0.48; 95% CI, 0.24-0.96; P = 0.033), and median OS was not reached and 26.9 months, respectively (HR, 0.31; 95% CI, 0.11-0.85; P = 0.018). CONCLUSIONS: In this large-scale LS-SCLC cohort, Omit-CTV was associated with similar efficacy and lower rates of treatment-related toxicity, with a promising survival signal in patients receiving immunotherapy, warranting further prospective validation.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.