Reiners C, Demidchik Y E, Drozd V M, Biko J
Clinic and Policlinic of Nuclear Medicine, University of Wuerzburg, Wuerzburg, Germany.
Minerva Endocrinol. 2008 Dec;33(4):381-95.
Studies in children medically exposed to external irradiation more than 50 years ago revealed a considerably increased risk for thyroid cancer. Similarly, a strongly age-dependent risk for thyroid cancer was observed in the Japanese population after the atomic bomb explosions with the highest risk in the group of children below age of 10. After the Chernobyl accident, children from Belarus living in highly exposed regions received mean thyroid doses by radioactive fallout higher by a factor of approximately 2 as compared to the survivors of the atomic bomb explosions. This lead to a radiation related increase of thyroid cancer incidence in children and adolescents with the highest incidence in age group 0-4 years up to now totally amounting to approximately 5 000 cases. For screening of thyroid cancer in children, high resolution ultrasound is the method of choice which has to be complemented by fine-needle aspiration biopsy in suspicious cases. Diagnostic criteria for malignancy in childhood thyroid cancer by ultrasound are hypoechogenicity and irregularity of the outline, subcapsular location of lesions and increased peri-intranodular vascularisation. The treatment strategy for thyroid cancer in children does not differ substantially from the approach used in adults. Primary treatment consists of thyroidectomy and lymph node dissection. Careful and complete removal of the lymph nodes is of great clinical relevance in children because of very frequent node involvement (between 40% and 90%). Because of the high prevalence of lymph node metastases, ablation of thyroid remnants is mostly indicated in children with thyroid cancer. Distant metastases which need higher activities of radioiodine are less frequent with 10-20%. Even in advanced cases of childhood thyroid cancer, long-lasting remissions can be achieved. A specific finding in children is disseminated, milliary lung metastases with intense radioiodine uptake. In this situation, pulmonary fibrosis may be a severe side-effect so that the indication for repeated courses of radioiodine therapy has to be decided thoroughly. With respect to side-effects of radioiodine therapy, the risk of developing breast cancer has to be taken into account seriously since especially the female breast is exposed to a relatively high radiation dose. Generally, young patients treated with high activities of radioiodine should be carefully followed up during their whole lifespan.
对50多年前受到外部辐射医学照射的儿童进行的研究显示，甲状腺癌风险大幅增加。同样，在原子弹爆炸后的日本人群中观察到甲状腺癌风险与年龄密切相关，10岁以下儿童组风险最高。切尔诺贝利事故后，生活在高暴露地区的白俄罗斯儿童通过放射性沉降物接受的甲状腺平均剂量比原子弹爆炸幸存者高出约2倍。这导致儿童和青少年甲状腺癌发病率因辐射而增加，0至4岁年龄组发病率最高，目前总计约5000例。对于儿童甲状腺癌的筛查，高分辨率超声是首选方法，可疑病例需辅以细针穿刺活检。儿童甲状腺癌超声诊断恶性的标准为低回声、轮廓不规则、病变位于包膜下以及结节内血管增多。儿童甲状腺癌的治疗策略与成人基本相同。主要治疗方法包括甲状腺切除术和淋巴结清扫术。由于淋巴结受累非常频繁（40%至90%），在儿童中仔细彻底清除淋巴结具有重要临床意义。由于淋巴结转移发生率高，甲状腺癌患儿大多需要切除甲状腺残余组织。需要更高剂量放射性碘的远处转移较少见，为10%至20%。即使是儿童甲状腺癌晚期病例，也可实现长期缓解。儿童的一个特殊表现是弥漫性粟粒状肺转移且放射性碘摄取强烈。在这种情况下，肺纤维化可能是严重的副作用，因此必须慎重决定是否进行重复放射性碘治疗。关于放射性碘治疗的副作用，必须认真考虑患乳腺癌的风险，因为尤其是女性乳房会受到相对较高的辐射剂量。一般来说，接受高剂量放射性碘治疗的年轻患者在其整个生命周期都应仔细随访。
