Abstract

INTRODUCTION

Our aim is to determine treatment response to Cyberknife based on follow-up MRI in patients with pituitary adenoma.

METHODS

We retrospectively identified the patients with pituitary adenoma treated with Cyberknife between 2010 – 2014. Patients with postreatment eligible follow-up MRI scan after at least 6 months of Cyberknife treatment were included in this study. Pre- and posttreatment MRI scans of 38 patients (male/female=1) were retrospectively analysed to evaluate tumor response. Volumetric changes of the tumors, local control rate, volumetric changes over time and signal alterations on the surrounding brain parenchyma were assessed.

RESULTS

The mean follow-up time of 38 patients was 25 months (range, 6-51 months). Significant mean tumor volume reduction was found between pre- and posttreatment mean tumor volumes, which were 4722 mm3 and 3475 mm3, respectively. There were 2 cases with radiological progression, 18 cases with stable disease and 18 cases with regression. Thus, tumor local control rate was calculated as 94.7% in our study. There was also a significant follow-up time difference between stable and radiological regression groups which indicates that increased follow-up time may be related with better volume decrease. Patient gender, additional medical treatment, age, the number of previous surgeries did not affect treatment response. Lastly, there was no case with signal alteration on the surrounding brain parenchyma.

DISCUSSION AND CONCLUSION

Cyberknife is a known and effective treatment method in patients with pituitary adenoma. Our results also support that Cyberknife provides excellent local tumor control without any radiological obvious side effects on surrounding tissues.