In patients with medullary thyroid carcinoma (MTC), calcitonin (Ctn) and carcinoembryonic antigen (CEA) were the most important serum biomarkers for diagnosis, evaluation and follow-up. Approximately 0.3% to 5.9% of the thyroid nodule population could present with elevated Ctn on screening, and a diagnosis of MTC can be basically confirmed when serum Ctn > 100 pg/ml.. Ctn and CEA levels could reflect tumor burden and help determine the extent and timing of surgery. When preoperative serum Ctn >200 pg/mL or CEA >30 ng/mL, nearly more than one-third of patients had lateral neck lymph node metastasis. Few patients developed distant metastasis when Ctn<500 pg/mL, however the proportion of distant metastasis could reach 75% when CEA>100 ng/mL. In inherited MTC patients, tumors with Ctn<30 pg/mL were usually localized in the gland without metastasis. The time to normalization of serum Ctn and CEA postoperatively was one month in most patients. According to the response to initial therapy, patients with undetectable Ctn and normal CEA had a low risk of relapse and death in the follow-up period. The risk of local recurrence, LNM and distant metastasis increased as Ctn levels rose. The Ctn/CEA doubling time could predict the disease prognosis, and when it was less than 0.5 years, most patients would die.

A set of new operational quantities for external radiation protection was proposed in ICRU Report 95. The new operational quantities were designed to overcome the conceptual and technical shortcomings of the existing operational quantities, and to achieve a better estimation of the protection quantities. This paper introduces the development of operational quantities, and the changes in their definitions, calculation phantoms and the application scopes, so as to fully understand the significance of the changes in the new operational quantities, which can be used as a reference for the relevant professionals.

Objective To investigate effect of high dose irradiation on the performances of thermolumines-cence detectors (LiF:Mg, Cu, P). Methods The high-dose irradiated thermoluminescence detector was annealed by a thermoluminescence annealing furnace until the annealing was completed, and then the annealed thermoluminescent detector was irradiated 0.5Gy by 137Cs irradiator to verify the accuracy of the thermoluminescentdetector. Results The thermoluminescence detector after high-dose irradiation could not be completely annealed under the temperature condition of 240 ℃, and it could be completely annealed at a high temperature as 400℃. After 0.5 Gy irradiation by 137Cs irradiator, the measurement results of the annealed thermoluminescence detector were significantly smaller, and the dose response and dispersion of the detector were also changed significantly. Conclusions After a more than 5 Gy irradiation, the crystal structure of the thermoluminescence detector has changed, and a high temperature peak above 240 ℃ has appeared, which leads to the failure to completely anneal at normal temperature. Therefore, the thermoluminescence detector can no longer be used for dosimetry after high-dose irradiation.