BACKGROUND Reconstruction and analysis of low doses received by the occupationally exposed medical radiation workers, especially nuclear medicine staff dealing with radioisotopes may significantly contribute to the understanding of radiation impact on individuals, assess and predict radiation related risks for the development of cancer or other specific diseases. METHODS A pool of 2059 annual effective doses corresponding to 272 job's positions occupied by nuclear medicine and radiology workers for a certain time period over 26 years in five Lithuanian hospitals was investigated in order to analyze the occupational exposure tendencies to medical staff. Requested data, measured in terms of whole body dose, personal dose equivalent Hp(10), was obtained from the National Register of Sources of Ionizing Radiation and Occupational Exposure. Considering that nuclear medicine staff is dealing with open sources/radioisotopes, doses to extremities, Hp(0.07), were measured using thermoluminescent dosimeters (TLD) of LiF:Mg, Ti type. Lifetime risk estimations for the development of specific cancer (thyroid cancer and leukemia) for exposed radiation workers were performed using risk models included in BEIR VII report (BEIR VII, 2006). The conservative assessment of the thyroid exposure was performed using RadRAT 4.1.1 tool. RESULTS Doses to radiology technologists and radiology nurses were found to be highest over the years. However, their annual doses never exceeded dose limit of 20 mSv and were following the same decreasing tendency as the doses of other personnel. There was no increase of doses to nuclear medicine staff observed after installation of two new PET/CT machines, indicating increased radiation protection culture and application of relevant technical and protective measures by the staff. Measured fingertip doses were 2-3 times higher than the hand doses measured with TLD ring and were dependent on the type and frequency of the nuclear medicine examination procedure and on the type and activity of isotopes used for examination. CONCLUSIONS For the first time, retrospective dose evaluation for the cohort of medical radiation workers was performed in the country. It enabled estimation of lifetime attributable risk for the development of two cancer types: thyroid and leukemia cancer among occupationally exposed medical radiation staff. Projected risk was low, ~10-5, however it was found that the risk of thyroid cancer for female staff was 5.7 times higher than for the males. Obtained results will be used for the predictive assessment of possible radiation induced health effects to occupationally exposed medical radiation workers.

中文翻译：

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卫生专业人员的职业辐射照射和立陶宛核医学工作者的癌症风险评估。

背景技术职业暴露的医学放射工作者，特别是从事放射性同位素工作的核医学工作者所接受的低剂量的重建和分析，可能对理解辐射对个人的影响，评估和预测与癌症或其他特定疾病发展相关的辐射风险具有重要意义。 。方法调查了立陶宛五家医院在26年内的一定时期内，核医学和放射工作者在一定时期内所占的272个职位的2059个年度有效剂量，以分析医务人员的职业暴露倾向。要求的数据以全身剂量，个人剂量当量Hp（10）的形式从国家电离辐射和职业暴露源登记处获得。考虑到核医学工作人员正在处理开放源/放射性同位素，使用LiF：Mg，Ti型热发光剂量计（TLD）测量了四肢的剂量Hp（0.07）。使用BEIR VII报告（BEIR VII，2006年）中包括的风险模型，对暴露的放射线工作者发展为特定癌症（甲状腺癌和白血病）的终生风险评估。使用RadRAT 4.1.1工具对甲状腺暴露进行保守评估。结果发现，多年来放射技术人员和放射护士的剂量最高。但是，他们的年剂量从未超过20 mSv的剂量极限，并且遵循与其他人员相同的下降趋势。在安装了两台新的PET / CT机器后，没有观察到核医学人员的剂量增加，表明工作人员加强了辐射防护文化并采取了相关的技术和防护措施。测量的指尖剂量比使用TLD环测量的手部剂量高2-3倍，并且取决于核医学检查程序的类型和频率以及检查所用同位素的类型和活性。结论在该国首次进行了医疗辐射工作者队列的回顾性剂量评估。它可以估算职业暴露的医疗放射工作人员中两种癌症类型的终生归因风险：甲状腺癌和白血病。预计的风险很低，约为10-5，但是发现女性员工患甲状腺癌的风险是男性的5.7倍。