Radiation field feature of 188Re esophageal stent

OBJECTIVE: To evaluate the radiation field feature of Re esophageal stent and provide scientific basis for clinical application. METHODS: We measure the beta-ray, gamma-ray and bremssfrahlung dose of every selected point on the bionics esophageal stent and then draw out computer software by mathematical formula. RESULTS: The radiation field of Re esophageal stent has its own feature: the max range of beta-ray is 11 mm, 90% dose construction field is within 1.5 mm, 95% dose range is within 2.5 mm, and only 4.21% of total energy of gamma-ray and bremssfrahlung is out of 6.5 mm range. The absorption dose of every direction in same point of the esophageal model was similar (P>0.05). CONCLUSION: Beta ray is the major radiation of Re esophageal stent while gamma-ray and bremssfrahlung are 4.21% among the radiation field. The max dose construction field is within 0.5-1.5 mm, just short at the depth of esophagus mucosa within 0.5-1.5 mm range. So Re stent is a good choice of palliative intracavitary radiotherapy of esophageal carcinoma.