T1/T2 Matching to Differentiate Tumor Growth From Radiation Effects After Stereotactic Radiosurgery
T1/T2 Matching to Differentiate Tumor Growth From Radiation Effects After Stereotactic Radiosurgery
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DOI：
10.1227/01.neu.0000360391.35749.a5
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发表时间：
2010-03-01
期刊：
影响因子：
4.8
通讯作者：
Lunsford, L. Dade
中科院分区：
文献类型：
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作者：
Kano, Hideyuki;Kondziolka, Douglas;Lunsford, L. Dade
目的：我们定义了磁共振成像（MRI）和临床标准，区分放射效应（RE）从肿瘤进展后立体定向放射外科手术（SRS）。方法：我们相关的术后影像学和组织病理学数据，在68例患者接受延迟切除脑转移后SRS。这些患者需要手术切除，因为SRS后0.3至27.7个月有病变进展的临床和影像学证据。SRS时，中位靶体积为7.1 mL（范围：0.5-26 mL），手术时增加至14 mL（范围：1.3-81 mL）。初始SRS后，常规对比增强MRI用于评估肿瘤反应并检测潜在的不良辐射效应。我们回顾性地将这些系列MRI与术后组织病理学相关联，以确定是否有任何常规MRI特征可以区分肿瘤进展与RE。结果：从SRS到手术切除的中位时间为6.9个月（范围为0.3-27.7个月）。从SRS到切除的间隔时间越短，肿瘤复发率越高（P = 0.014）。T1加权像上的对比增强体积与T2加权像上的低信号定义的病变边缘之间的对应关系（“T1/T2匹配”）与组织病理学上的肿瘤进展相关（P <0.0001）。与T1加权像上的造影剂摄取边缘相比，T2加权像上缺乏清晰和明确的病变边缘（“T1/T2不匹配”）与病理标本中较高的RE率显著相关（P < .0001）。T1/T2不匹配诊断RE的敏感性为83.3%，特异性为91.1%。结论：T1/T2不匹配和进展时间可鉴别RE与肿瘤进展。当怀疑RE时，如果患者对保守措施有反应，则可能不需要手术。当怀疑肿瘤进展时，切除或重复放射外科手术可能有效，这取决于肿块效应的程度。
OBJECTIVE: We define magnetic resonance imaging (MRI) and clinical criteria that differentiate radiation effect (RE) from tumor progression after stereotactic radiosurgery (SRS).METHODS: We correlated postoperative imaging and histopathological data in 68 patients who underwent delayed resection of a brain metastasis after SRS. Surgical resection was required in these patients because of clinical and imaging evidence of lesion progression 0.3 to 27.7 months after SRS. At the time of SRS, the median target volume was 7.1 mL (range, 0.5-26 mL), which increased to 14 mL (range, 1.3-81 mL) at the time of surgery. After initial SRS, routine contrast-enhanced MRI was used to assess tumor response and to detect potential adverse radiation effects. We retrospectively correlated these serial MRIs with the postoperative histopathology to determine if any routine MRI features might differentiate tumor progression from RE.RESULTS: The median time from SRS to surgical resection was 6.9 months (range, 0.3-27.7 months). A shorter interval from SRS to resection was associated with a higher rate of tumor recurrence (P = .014). A correspondence between the contrast-enhanced volume on T1-weighted images and the low signal-defined lesion margin on T2-weighted images ("T1/T2 match") was associated with tumor progression at histopathology (P < .0001). Lack of a clear and defined lesion margin on T2-weighted images compared to the margin of contrast uptake on T1-weighted images ("T1/T2 mismatch") was significantly associated with a higher rate of RE in pathological specimens (P < .0001). The sensitivity of the T1/T2 mismatch in identifying RE was 83.3%, and the specificity was 91.1%.CONCLUSIONS: We found that time to progression and T1/T2 mismatch were able to differentiate tumor progression from RE in most patients. When REs are suspected, surgery may not be necessary if patients respond to conservative measures. When tumor progression is suspected, resection or repeat radiosurgery can be effective, depending on the degree of mass effect.