Groove thing.

One of the biggest challenges with dose-escalated pancreas radiation is that the tumor is often in close proximity to the duodenum. This pilot study evaluated the feasibility of injecting and then identifying a contrast-enhanced hydrogel spacer between the pancreatic head and duodenum. Eligible patients (n=6) had locally-advanced pancreatic adenocarcinoma and were planned to receive 33 Gy in 5 fractions SBRT. They had to have a 1 mm or greater tissue plan between tumor and the duodenal wall. The spacer gel procedure was incorporated into fiducial placement and performed with endoscopic ultrasound. The gel solution was typically diluted with saline and then multiple 1 cc blebs were deposited in the soft tissue interface between the pancreas and duodenum. The idea here was to inject a small volume of hydrogel to see how well it was tolerated and if it was visible for radiation planning and delivery. Indeed, blebs were visible for treatment planning and on image guidance during SBRT with stable size and location. TBL: Ongoing trials are evaluating the feasibility of injecting larger volumes of hydrogel spacer between the duodenum and pancreas. | Dholakia, Pract Radiat Oncol 2020