Tumoral reduction in patients with intra-abdominal tumors treated with CyberKnife: a single center's experience

Abstract

Introduction: to estimate tumoral reduction and overall survival at one year in a series of patients with abdominal tumors treated with body fractionated stereotactic radiotherapy (SBRT). Methods: retrospective descriptive study of a series of patients with abdominal tumors (solid or hollow viscus), treated with image-guided SBRT using a CyberKnife system and who had post-treatment follow-up and control images. The study was completed at the XXXXXXX in a five-year period from January 2013 to January 2018, in XXXXXXX. Results: 16 patients were included. 75% of the cases were under 65 years of age. The treated lesions were located in the pancreas (37.5%), abdomino-pelvic lymph nodes (25%), liver (25%) and retroperitoneum (12.5%). Most of the treated patients required up to two fiduciary markers (93.7%). The SBRT dose applied ranged from 24 to 60 Gy, mostly in 3 fractions (81.3%). Mean tumoral reduction after treatment was of 15.6 mm (SD ±13.5), being statistically significant (p <0.0003). According to RECIST 1.1 criteria, a complete response was achieved in 6.2% (n=1) of the cases, a partial response in 56.3% (n=9), and stable disease in 37.5% (n=6). No disease progression was documented in any patient during the follow-up period. The one-year overall survival rate was 93.7%. Conclusion: experience at this center shows that Cyberknife radiosurgery in both primary and metastatic abdominal tumors provides, in the short term, an adequate local control rate and improved one-year overall survival.