Kiri A Sandler1, Fereidoun Abtin2, Robert Suh2, Ryan R Cook3, Carol Felix1, Jay M Lee4, Edward B Garon5, Jeffrey Wu1, Elaine M Luterstein1, Nzhde Agazaryan1, Stephen E Tenn1, Chul Lee1, Michael L Steinberg1, Percy Lee6. 1. Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California. 2. Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California. 3. Department of Epidemiology, Fielding School of Public Health at UCLA, Los Angeles, California. 4. Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California. 5. Department of Medicine, Division of Medical Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California. 6. Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California. Electronic address: percylee@mednet.ucla.edu.
Abstract
PURPOSE: Stereotactic body radiation therapy (SBRT) and heat-based ablation (HBA) are both potentially safe and effective treatments for primary and metastatic lung tumors. Both are suboptimal for centrally located tumors, with SBRT having a higher risk of significant toxicity and HBA having lower efficacy. This study evaluates the safety and efficacy of combination SBRT-HBA to determine whether combined treatment can result in superior outcomes to each treatment alone. METHODS AND MATERIALS: Patients with 1 or 2 primary or metastatic lung tumors ≤ 5 cm in size were enrolled in a prospective phase 2 trial and treated with SBRT in 3 fractions followed by HBA. Tumors < 1 cm from the central bronchial tree received a total of 36 Gy, and tumors 1 to 2 cm away received 42 Gy. HBA was delivered within 10 days after SBRT. The primary endpoints were local control, toxicity, and degree of decline in lung function. The secondary endpoints were progression-free survival and overall survival. RESULTS: We treated 16 patients with 17 tumors. The median follow-up time was 26 months. Fifteen tumors were evaluable for local control. The 1- and 2-year actuarial local control rates were 93% and 81%, respectively. Three patients had grade ≥ 3 toxicity: bronchial stenosis, pain, and pulmonary hemorrhage. The percent predicted forced expiratory volume in 1 second and functional vital capacity decreased by 8% and 8.5%, respectively, at 3 months after treatment (P < .001 for both). CONCLUSIONS: Combining SBRT and HBA for centrally located lung tumors offers reasonable local control and toxicity despite the anatomic challenges of this location. HBA may be a reasonable supplement to SBRT when trachea and bronchus, large vessel, or esophageal constraints cannot be met with full-dose SBRT and a biologically effective dose < 100 Gy is delivered because of an ultra-central location or large tumor size.
PURPOSE: Stereotactic body radiation therapy (SBRT) and heat-based ablation (HBA) are both potentially safe and effective treatments for primary and metastatic lung tumors. Both are suboptimal for centrally located tumors, with SBRT having a higher risk of significant toxicity and HBA having lower efficacy. This study evaluates the safety and efficacy of combination SBRT-HBA to determine whether combined treatment can result in superior outcomes to each treatment alone. METHODS AND MATERIALS: Patients with 1 or 2 primary or metastatic lung tumors ≤ 5 cm in size were enrolled in a prospective phase 2 trial and treated with SBRT in 3 fractions followed by HBA. Tumors < 1 cm from the central bronchial tree received a total of 36 Gy, and tumors 1 to 2 cm away received 42 Gy. HBA was delivered within 10 days after SBRT. The primary endpoints were local control, toxicity, and degree of decline in lung function. The secondary endpoints were progression-free survival and overall survival. RESULTS: We treated 16 patients with 17 tumors. The median follow-up time was 26 months. Fifteen tumors were evaluable for local control. The 1- and 2-year actuarial local control rates were 93% and 81%, respectively. Three patients had grade ≥ 3 toxicity: bronchial stenosis, pain, and pulmonary hemorrhage. The percent predicted forced expiratory volume in 1 second and functional vital capacity decreased by 8% and 8.5%, respectively, at 3 months after treatment (P < .001 for both). CONCLUSIONS: Combining SBRT and HBA for centrally located lung tumors offers reasonable local control and toxicity despite the anatomic challenges of this location. HBA may be a reasonable supplement to SBRT when trachea and bronchus, large vessel, or esophageal constraints cannot be met with full-dose SBRT and a biologically effective dose < 100 Gy is delivered because of an ultra-central location or large tumor size.