Vinchon Matthieu, Leblond Pierre, Caron Sabine, Delestret Isabelle, Baroncini Marc, Coche Bernard
Department of Pediatric Neurosurgery, University Hospital, Lille, France.
Childs Nerv Syst. 2011 Mar;27(3):445-53. doi: 10.1007/s00381-011-1390-4. Epub 2011 Jan 14.
Radiation-induced tumors (RIT) are increasingly recognized as delayed complications of brain irradiation during childhood. However, the true incidence is not established, their biology is poorly understood, and few guidelines exist regarding the long-term follow-up of irradiated children.
We studied retrospectively patients irradiated for brain tumor under 18 years and followed in our institution since 1970. RIT were defined as new masses, different from the original tumor, occurring after delay in irradiated areas, and not related to phacomatosis.
Among 552 irradiated patients, 42 (7.6%) developed one or more RIT, 26 months to 29 years after irradiation (mean 12.8 years). The cumulated incidence was 2.0% at 5 years and 8.9% at 10 years. Of the patients, 73.8% were adult at the time of diagnosis of RIT, and 75% were diagnosed within 18.1 years after irradiation. We identified 60 cavernomas, 26 meningiomas, 2 malignant gliomas, 1 meningosarcoma, and 6 thyroid tumors. Compared with meningiomas, cavernomas appeared earlier, in children irradiated at an older age, and with a male predominance. Although RIT were correlated with higher irradiation doses, 80.9% of these occurred at some distance from the maximum irradiation field. Twenty-five lesions were operated in 20 patients; three patients died because of progression of the RIT.
A significant number of patients undergoing irradiation for brain tumor during childhood develop a RIT, often during adulthood. Our data suggest that radiation-induced cavernomas result from angiogenetic processes rather than true tumorigenesis. Protracted follow-up with MRI is warranted in children irradiated for brain tumor.
辐射诱发肿瘤（RIT）日益被认为是儿童期脑部放疗的迟发并发症。然而，其真实发病率尚未确定，生物学特性了解甚少，关于接受放疗儿童的长期随访指南也很少。
我们回顾性研究了1970年以来在本机构接受脑肿瘤放疗且年龄在18岁以下的患者。RIT定义为在放疗区域延迟出现的、与原发肿瘤不同的新肿块，且与错构瘤无关。
在552例接受放疗的患者中，42例（7.6%）在放疗后26个月至29年（平均12.8年）出现了一个或多个RIT。5年时累积发病率为2.0%，10年时为8.9%。这些患者中，73.8%在诊断RIT时已成年，75%在放疗后18.1年内被诊断。我们识别出60例海绵状血管瘤、26例脑膜瘤、2例恶性胶质瘤、1例脑膜肉瘤和6例甲状腺肿瘤。与脑膜瘤相比，海绵状血管瘤出现得更早，见于年龄较大时接受放疗的儿童，且男性居多。虽然RIT与较高的放疗剂量相关，但其中80.9%发生在距最大放疗野一定距离处。20例患者的25个病灶接受了手术；3例患者因RIT进展死亡。
大量儿童期接受脑肿瘤放疗的患者会发生RIT，通常在成年期。我们的数据表明，辐射诱发的海绵状血管瘤是由血管生成过程而非真正的肿瘤发生所致。对接受脑肿瘤放疗的儿童进行长期MRI随访是必要的。
