Stereotactic body radiation therapy for early-stage primary lung cancer, is an active breath coordinator necessary? An audit from a tertiary cancer care center.

CONTEXT: The hypofractionated stereotactic body radiation therapy (SBRT) has emerged as a safe and effective treatment modality for early-stage nonsmall cell lung carcinoma.

AIMS: An audit SBRT in primary lung cancer treated in our center with and without an active breath coordinator (ABC) was undertaken to evaluate its impact on target volumes and clinical outcomes.

SETTINGS AND DESIGN: This was an observational study.

MATERIALS AND METHODS: Nine patients with lung carcinoma were treated from January 2014 to August 2016. Five patients were simulated using ABC and four patients with free breathing. Volumetric modulated arc therapy plans were generated using Monaco treatment planning software. Three patients were treated with a dose of 54 Gy in three fractions and six patients with a dose of 48 Gy in four fractions.

STATISTICAL ANALYSIS USED: The statistical analysis was performed using Kaplan-Meier survival.

RESULTS: The mean planning target volumes (PTV) in ABC and free breathing groups were 42.19cc and 60.17cc, respectively. The mean volume of lung receiving 20, 10, and 5 Gy (V20, V10and V5) in ABC group were 5.37cc, 10.49cc, and 18.45cc whereas in free breathing 6.63cc, 12.74cc, and 20.64cc, respectively. At a median follow-up of 18 months, there were three local recurrences. No significant toxicity occurred in our series.

CONCLUSION: Our initial results show that SBRT is well tolerated with good local control. Although the PTV volume and irradiated normal lung volume was higher in this group compared to ABC group, this did not translate to any added clinical toxicity.