In a phase II study reported in The Lancet Oncology, Lawrence et al found that celiac plexus radiosurgery showed promise in the alleviation of retroperitoneal pain syndrome in patients with pancreatic cancer or other tumors involving the celiac axis.
Study Details
Between January 2018 and December 2021, 125 patients enrolled in the study from eight sites in Israel, Poland, Canada, the United States, and Portugal received a single fraction of 25 Gy of external-beam photons to the celiac plexus. A total of 90 patients were evaluable for efficacy; of these, 92% had pancreatic cancer and 86% had metastatic disease. Patients had an average pain level of 5 to 10 on the Brief Pain Inventory short form (BPI-SF). The primary outcome measure was complete or partial pain response based on reduction in BPI-SF average pain score of ≥ 2 points from baseline to 3 weeks after treatment.
Key Findings
Among the 90 evaluable patients, the median baseline BPI-SF average pain score was 6 (interquartile range = 5–7). At 3 weeks, 48 patients (53%, 95% confidence interval [CI] = 42%–64%) had at least a partial pain response.
Median average pain scores were reduced from baseline (6) by 2.5 points at 3 weeks and 3.2 points at 6 weeks. Mean changes in worst pain scores were –2.5 at 3 weeks and –3.4 at 6 weeks.
A total of 84 patients were using opioids for pain control at baseline. Median daily opioid use at baseline was 30.9 mg of intravenous morphine equivalents. At 3 weeks, patients with pain response had a mean decrease in daily opioid use of 5.3 mg, and those without response had a mean increase of 5.4 mg.
Among the 125 treated patients, the most common grade 3 or 4 adverse events seen with celiac plexus radiosurgery were abdominal pain (28%), fatigue (18%), and nausea (4%). Grade ≥ 3 serious adverse events considered probably or possibly related to treatment included grade 3 abdominal pain (n = 3), duodenal hemorrhage (n = 2), nausea (n = 1), and bilirubin increase (n = 1) and grade 5 gastrointestinal bleeding (n = 1).
The investigators concluded, “Celiac plexus radiosurgery could potentially be a noninvasive palliative option for patients with retroperitoneal pain syndrome. Further investigation by means of a randomized comparison with conventional celiac block or neurolysis is warranted.”
Yaacov R. Lawrence, MBBS, FASTRO, of the Department of Radiation Oncology, Sheba Medical Center, Ramat Gan, Israel, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by the Gateway for Cancer Research and Israel Cancer Association. For full disclosures of the study authors, visit thelancet.com.
