Abstract CT147: Celiac plexus radiosurgery a new palliative modality for upper gastrointestinal malignancies - final quality of life results from a proof-of-concept clinical trial

Background: Many patients with upper-abdominal malignancies suffer from severe low back / epigastric pain 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 and improve quality of life (QOL). Methods: We conducted a single arm prospective clinical trial. Eligible patients had celiac-pain > 4/10 on Numerical Rating Scale (NRS) and 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 toxicity, pain at 6w, analgesic use, and pain interference with daily activities as evaluated by ‘Brief pain assessment short-form’. Analgesic use was not restricted. Here we report results from those who received single fraction treatment. Results: 19 patients were evaluable. The median age of the study population was 67 yr with a median ECOG of 2, 89% had pancreatic cancer. Patients were a median 8 months from diagnosis, and had received a median of one systemic treatment. Toxicity was limited to grade 1-2. Average pain decreased from 5.9/10 at baseline, to 3.1/10 at 3w, and to 1.8/10 (both p Conclusions: Single fraction celiac plexus radiosurgery alleviates pain, and improves quality of life among patients with advanced upper-GI cancer. An international phase II trial is accruing. Citation Format: Yaacov R. Lawrence, Liat Hammer, Ofir Morag, Maoz Ben-Ailan, Dror Alezra, Ofer Margalit, Naama Halpern, Ben Boursi, Einat Shacham Shmueli, Galia Jacobson, Uri Amit, Tamar Katzman, Kinneret Shefer, Ilana Weiss, Inessa Yanovsky, Adam P. Dicker, Talia Golan, Zvi Symon, David Hausner. Celiac plexus radiosurgery a new palliative modality for upper gastrointestinal malignancies - final quality of life results from a proof-of-concept clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT147.