Multi-Institutional Experience of Stereotactic Ablative Radiation Therapy for Stage I Small Cell Lung Cancer

Int J Radiat Oncol Biol Phys. 2017 Feb 1;97(2):362-371. doi: 10.1016/j.ijrobp.2016.10.041. Epub 2016 Nov 2.

Abstract

Purpose: For inoperable stage I (T1-T2N0) small cell lung cancer (SCLC), national guidelines recommend chemotherapy with or without conventionally fractionated radiation therapy. The present multi-institutional cohort study investigated the role of stereotactic ablative radiation therapy (SABR) for this population.

Methods and materials: The clinical and treatment characteristics, toxicities, outcomes, and patterns of failure were assessed in patients with histologically confirmed stage T1-T2N0M0 SCLC. Kaplan-Meier analysis was used to evaluate the survival outcomes. Univariate and multivariate analyses identified predictors of outcomes.

Results: From 24 institutions, 76 lesions were treated in 74 patients (median follow-up 18 months). The median age and tumor size was 72 years and 2.5 cm, respectively. Chemotherapy and prophylactic cranial irradiation were delivered in 56% and 23% of cases, respectively. The median SABR dose and fractionation was 50 Gy and 5 fractions. The 1- and 3-year local control rate was 97.4% and 96.1%, respectively. The median disease-free survival (DFS) duration was 49.7 months. The DFS rate was 58.3% and 53.2% at 1 and 3 years, respectively. The median, 1-year, and 3-year disease-specific survival was 52.3 months, 84.5%, and 64.4%, respectively. The median, 1-year, and 3-year overall survival (OS) was 17.8 months, 69.9%, and 34.0% respectively. Patients receiving chemotherapy experienced an increased median DFS (61.3 vs 9.0 months; P=.02) and OS (31.4 vs 14.3 months; P=.02). The receipt of chemotherapy independently predicted better outcomes for DFS/OS on multivariate analysis (P=.01). Toxicities were uncommon; 5.2% experienced grade ≥2 pneumonitis. Post-treatment failure was most commonly distant (45.8% of recurrence), followed by nodal (25.0%) and "elsewhere lung" (20.8%). The median time to each was 5 to 7 months.

Conclusions: From the findings of the largest report of SABR for stage T1-T2N0 SCLC to date, SABR (≥50 Gy) with chemotherapy should be considered a standard option.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Antineoplastic Agents / therapeutic use
  • Combined Modality Therapy / methods
  • Cranial Irradiation / statistics & numerical data
  • Disease-Free Survival
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology
  • Lung Neoplasms / radiotherapy*
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Radiation Pneumonitis / etiology
  • Radiosurgery / adverse effects
  • Radiosurgery / methods*
  • Radiotherapy Dosage
  • Small Cell Lung Carcinoma / drug therapy
  • Small Cell Lung Carcinoma / mortality
  • Small Cell Lung Carcinoma / pathology
  • Small Cell Lung Carcinoma / radiotherapy*
  • Treatment Outcome
  • Tumor Burden

Substances

  • Antineoplastic Agents