Acute gastrointestinal toxicity after robotic stereotactic ablative radiotherapy for treatment of metastatic gynecological malignancies.

Aims: The aim of this study was to assess acute and subacacute gastrointestinal toxicity after fractionated stereotactic ablative radiotherapy (SABR) in women having recurrent gynecological cancers in the upper abdomen. Materials & methods: In total, 34 women underwent upper abdominal SABR (24 Gy/three divided 8 Gy consecutive daily doses) using a robotic Cyberknife (R) (Accuray, CA, USA) platform. Volumes of the duodenum receiving 10% increments of the prescription dose were associated to post-therapy gastrointestinal toxicities using binary logistic regression analyses. Results: Median clinical follow-up was 10 months. In total, 14 (41%) of the 34 women manifested grade 2 or higher post-therapy gastrointestinal adverse events. The duodenal volume, receiving 80% of a 24-Gy dose, was significantly associated with gastrointestinal toxicity (p = 0.03). However, in a multivariate ana-lysis, only patient age at SABR adjusted the odds of experiencing gastrointestinal toxicity (p = 0.02). Conclusion: The duodenal volume receiving 80% of 24 Gy dose may be associated with gastrointestinal toxicity from upper abdominal SABR.