Radiation esophageal stent

• Published in: Journal of clinical oncology Vol. 35; no. 15_suppl; p. e15514
• Main Authors: Herskovic, Arnold M., Rivard, Mark, Rothstein, Richard I, Hussein, Zella, Saunders, Jennifer, Corcoran, Kathleen, Clerc, Claude, Favreau, John
• Format: Journal Article
• Language: English
• Published: 20.05.2017
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2017.35.15_suppl.e15514

Abstract only e15514 Baclground:Self-expanding metal stents (SEMS) produce palliative dysphagia relief for esophageal cancers (EC) which is enhanced by brachytherapy. We present a brachytherapy stent designed to deliver radiation to ECs with brachytherapy sources in the porcine esophagus. Methods: A radioactive carrier stent containing I 125 seeds was designed to deliver 60 Gy to 5mm depth over 2 months. One dummy,non-radioactive seeds, and 3 radioactive stents were implanted into the esophagus of Yucatan minipigs. Stents were left in place for up to 43 days after implant, and one pig survived 10 weeks after stent removal. Animals were monitored biweekly via endoscopy and fluoroscopic imaging throughout the study collecting tissue at necropsy. Results: Swine esophageal tissue received doses ranging from 39-48 Gy at the prescription depth of 5mm and 132-160 Gy at the mucosal surface. Tissues were assessed pathologically at 0, 1, and 10 weeks after stent removall. Endoscopic assessment of all irradiated animals found increasingly pronounced and permanent infolding of the proximal stent flare over time, eventually resulting in early stent removal. At stent removal, all animals had numerous benign mucosal polyps ( < 5mm) at both stent flares which mostly resolved. within 6 weeks of removal, At gross necropsy, small amounts of necrotic tissue as well as mucosal polyps were observed along the entire length of the tissue adjacent to the radioactive stent (mostly adjacent to the stent flares). No systemic effects related to radiation were observed. Conclusions: We demonstrated that brachytherapy stent delivery is feasible and reasonably safe for irradiated healthy tissue. Although irradiation > 130 Gy affected the mucosal tissue, stent-related injury appeared to cause more substantial damage to the tissue. Both experimental and control animals showed the most marked tissue reaction at the non radiative stent flares. Tissue reactions along the stent body were consistent with stent related tissue erosion possibly enhanced by radiation exposure, . One animal, assessed up to 10 weeks after stent removal showed nearly complete healing of the esophageal tissue. Future studies will assess safety in a larger cohort of animals with escalated RT doses and different radionuclides.