Fletcher B D, Hanna S L, Kun L E
Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
Magn Reson Imaging. 1990;8(6):771-7. doi: 10.1016/0730-725x(90)90013-r.
Increased MR signal intensity was observed on T2-weighted, STIR, and Gadolinium-DTPA-enhanced T1-weighted images of subcutaneous and muscular soft tissue in 9 of 10 children treated with combination chemotherapy and radiation therapy (RT) for malignancy in the pelvis or an extremity. Total radiation doses ranged from 59.5 to 65 Gy. Eight of the patients with these changes received hyperfractionated RT (seven for Ewing sarcoma and one for perineal rhabdomyosarcoma); one was treated for pelvic hemangiopericytoma with once-daily fractions. Evidence of soft tissue damage became apparent as early as the sixth week of RT and was seen for up to 69 wk post-RT. There was no clear MR evidence of RT-induced soft tissue damage in one patient, who underwent hyperfractionated RT for pelvic rhabdomyosarcoma. Other MR findings in this group included evidence of bladder wall thickening in three of the seven patients given pelvic RT and increased T1-weighted signal of irradiated marrow in nine patients. All patients had clinical evidence of skin, soft tissue, or epithelial radiation effects. Increased MR signal intensity secondary to RT-induced damage can be differentiated from widespread tumor by geometric borders that conform to the margins of the radiation field.
在接受盆腔或四肢恶性肿瘤联合化疗和放射治疗（RT）的10名儿童中，有9名儿童的皮下和肌肉软组织在T2加权、短T1反转恢复序列（STIR）以及钆喷酸葡胺增强T1加权图像上观察到磁共振信号强度增加。总放射剂量范围为59.5至65戈瑞。出现这些变化的患者中有8名接受了超分割放疗（7名患有尤因肉瘤，1名患有会阴横纹肌肉瘤）；1名盆腔血管外皮细胞瘤患者接受了每日1次的分割放疗。软组织损伤的证据早在放疗第6周就很明显，并且在放疗后长达69周都可见。1名因盆腔横纹肌肉瘤接受超分割放疗的患者没有明显的磁共振证据表明存在放疗引起的软组织损伤。该组中的其他磁共振表现包括：7名接受盆腔放疗的患者中有3名出现膀胱壁增厚的证据，9名患者照射部位的骨髓T1加权信号增加。所有患者都有皮肤、软组织或上皮放疗效应的临床证据。放疗引起的损伤继发的磁共振信号强度增加可通过符合放疗野边缘的几何边界与广泛的肿瘤相鉴别。
