Objectives: To assess response rate with regards to SUV of patients treated with SBRT using the CyberKnife Robotic Radiosurgery system.

Methods: 45 lesions were able to be evaluated that had both a pre and post PET/CT scan treated with SBRT from Jan. 2013 – Dec. 2016. Response rate was determined by reduction or stabilization of SUV at first follow-up imaging. First post treatment PET/CT was usually obtained 3-4 months after treatment. A sub-analysis was performed on T2b or greater lung cancers assessed by tumor size response rate determined by reduction or stabilization of size after first follow-up imaging.

Results: In our examination of 45 lesions treated with SBRT, the median pre-treatment max SUV was 7.9 (range of 0 – 27.0, n = 45) and post-treatment median max SUV measured at 3.4 (range of 0 – 7.2, n = 45) at first follow-up. Response rate as measured by SUV was 82% (37/45). Sub-analysis of nine T2b or greater primary pulmonary tumors showed a response rate of 77% (7/9).

Conclusions: Treatment of lung cancers with SBRT using the CyberKnife system has excellent response as measured by max SUV. The assessment of treating T2b or greater pulmonary lesions showed promising response rates with regards to tumor size. Further study of the effectiveness in treating T2b or greater lung tumors needs to be studied to assess SBRT’s role.