Celiac plexus radiosurgery: A new palliative modality for upper gastrointestinal malignancies—Final results of a proof-of-concept clinical trial.

10098Background: Many patients with upper-abdominal malignancies suffer from severe lower back pain radiating to the epigastrium, caused by infiltration of the celiac plexus. The celiac plexus is a network of nociceptive nerves, located along the aorta. Contemporary approaches (opioids, celiac plexus chemical neurolysis, systemic chemotherapy) are often inadequate. The celiac plexus has not previously been targeted using radiation. We hypothesized that ablative radiation targeted to the celiac plexus would alleviate pain. Methods: We conducted a single arm prospective clinical trial. Eligible patients had celiac-pain > 4/10 on Numerical Rating Scale (NRS), ECOG ≤ 3, no previous abdominal RT, and were evaluable if they completed treatment per protocol with at least one post-treatment visit. The celiac plexus was irradiated from D12 to L2. Radiation was given as either five fractions of 9 Gy or a single-fraction 25 Gy. The primary endpoint was NRS pain 3 weeks post-treatment. Secondary endpoints were toxici...