Is there Any Impact of Tumor Volume in Stereotactic Body Radiation Therapy for Lung Cancer? A Cohort for T1, 2 Non-small Cell Lung Cancer Cases.

PURPOSE/AIM: The aim of the study was to assess the impact of tumor size on dose-volume histograms (DVHs) and clinical outcomes in patients with early-stage non-small cell lung cancer (NSCLC) undergoing stereotactic body radiation therapy (SBRT) using the CyberKnife M6 System with a lung-optimized treatment module.

MATERIALS AND

METHODS

Retrospective analysis was performed on 12 patients diagnosed with NSCLC receiving SBRT treatment. Analysis of cumulative DVHs was done to evaluate dose distribution in the planning target volume (PTV) and surrounding organs at risk. The patient population was divided according to tumor size; one group was patients with PTV <12 cc and the other group was patients with PTV >12 cc. Statistical analysis was performed using SPSS software.

RESULTS

All treatment plans achieved adequate target coverage with sharp dose gradients. There was slight improvement in terms of dose distribution and response rate for smaller tumors (PTV <12 cc); however, these differences did not show statistical significance.

CONCLUSIONS

There were no statistically significant differences between tumor volume and DVH parameters or clinical response in SBRT treatment of NSCLC. Most of the patients received biological effective dose (α/β =10) values above 100 Gy, with some of them receiving >120 Gy, which has been associated with improved treatment outcomes.