非均整模式下早期左侧乳腺癌患者放疗后辐射致癌风险性研究

Risk study of radiation-induced carcinogenesis under flattening-filter free mode in patients with early left breast cancer after radiotherapy

目的探讨早期左侧乳腺癌患者放疗后应用6MV光子线高剂量非均整模式对辐射致癌的风险。方法选取2017年8月至2018年9月我院收治的早期左侧乳腺癌患者38例为研究对象,随机将其等分为对照组和试验组,对照组采用均整模式,试验组采用非均整模式,比较两组患者治疗计划右侧乳腺、肺、甲状腺、肝脏等危及器官的辐射致癌风险。结果两组患者计划靶区均达到临床处方量的要求。试验组治疗计划中右侧乳腺、肺、甲状腺及肝脏等器官的当量值和超额绝对风险均低于对照组(P <0. 05)。结论将6MV光子线高剂量非均整模式应用在早期左侧乳腺癌患者中,靶区和危及器官受照剂量均可以满足治疗的要求,同时降低右侧乳腺、肺、甲状腺及肝脏等器官的超额风险。

Objective To investigate the risk of radiation-induced carcinogenesis in patients with early left breast cancer treated with 6 MV photon beam under high dose flattening-filter free( FFF) mode after radiotherapy. Methods We selected 38 cases of patients with early left breast cancer treated in our hospital from August 2017 to September 2018 as the study subjects,and they were randomly divided into a control group and a test group. The control group used the flattening-filter( FF) mode,and the test group used the FFF mode. The risk of radiation-induced carcinogenesis of right breast,lung,thyroid,liver and other organs that were treated as planned target areas,which was compared between patients of the two groups. Results The target areas planned of patients met the requirements of clinical prescriptions. In the treatment plan of the test group,the equivalent values and excess absolute risks of the right breast,lung,thyroid,liver and other organs were lower than those in the control group( P < 0. 05). Conclusion When the 6 MV photon beam under high-dose FFF model was applied to early patients with left breast cancer,the target area and exposure dose of threatened organ could meet the treatment requirements,and then it reduced the excess risk of right breast,lung,thyroid,liver and other organs.