Objective　: To investigate the protective effects of different types of lead collars on the thyroid during radio- therapy after breast-conserving surgery.  Methods: Forty breast cancer patients undergoing radiotherapy after breast-con- serving surgery were randomly divided into four groups to wear different lead collars for thyroid protection: control group (0 mm Pb), common material group (0.5 mm Pb), common material group (2 mm Pb), and new radiation-shielding material group (2 mm Pb). Radiation doses inside and outside lead collars were monitored. A questionnaire survey was conducted to acquire information on patient acceptance of the lead collars. Results: All the groups (except the control group) showed significant differences between scattered radiation doses inside and outside lead collars (P < 0.05). The scattered radiation was attenuated by 33.64% on average in the 2-mm new material group, which was significantly higher than in the other groups (P < 0.05). After radiotherapy, there was no significant change in the color and appearance of skin under lead collars in any group. All the patients were normal at the first thyroid ultrasound re-examination. The 2-mm new material lead collar was the most acceptable. Conclusion　 The lead collar made of the new radiation-shielding material has a good protective effect on the thyroid gland, and is easily accepted by patients, which can be promoted for application.

A 60-year-old man presented with severe watery diarrhea for 2 months complicated with weight loss and acute kidney injury.He did not respond well to antidiarrheal medicines,empirical antibiotics and dietary exclusion of gluten or even complete bowel rest.The final diagnosis of autoimmune enteropathy (AIE) was made based on histopathologic findings of endoscopic biopsy from duodenal mucosa after excluding neoplastic disease,inflammatory bowel disease,and infectious diarrhea,etc.Chronic diarrhea and oliguria alleviated after the administration of corticosteroids.