Donahue Bernadine R, Goldberg Judith D, Golfinos John G, Knopp Edmond A, Comiskey Jessica, Rush Stephen C, Han Kerry, Mukhi Vandana, Cooper Jay S
Department of Radiation Oncology, New York Medical Center, New York, NY 10016, USA.
Neuro Oncol. 2003 Oct;5(4):268-74. doi: 10.1215/S1152851703000048.
We investigated how frequently the imaging procedure we use immediately prior to radiosurgery--triple-dose gadolinium-enhanced MR performed with the patient immobilized in a nonrelocatable head frame and 1-mm-thick MPRAGE (magnetization-prepared rapid gradient echo) images (SRS3xGado)-identifies previously unrecognized cerebral metastases in patients initially imaged by conventional MR with single-dose gadolinium (1xGado). Between July 1998 and July 2000, the diagnoses established for 47 patients who underwent radio-surgical procedures for treatment of cerebral metastases at The Gamma Knife Center of New York University were based initially on the 1xGado protocol. In July 1998, we began using SRS3xGado as our routine imaging protocol in preparation for targeting lesions for radio-surgery, using triple-dose gadolinium and acquisition of contiguous 1-mm Tl-weighted axial images. Because our SRS3xGado scans sometimes unexpectedly revealed additional metastases, we sought to learn how frequently the initial 1xGado scans would underestimate the number of metastases. We therefore reviewed the number of brain metastases identified on the SRS3xGado studies and compared the results to the number found by the 1xGado protocol, which had initially identified the brain metastases. Additional metastases, ranging from 1 to 23 lesions per patient, were identified on the SRS3xGado scan in 23 of 47 patients (49%). In 57% of the 23 patients, only one additional lesion was identified. The mean time interval between the 1xGado and the SRS3xGado scans was 20.6 days (range, 4-83 days), and the number of additional lesions detected and the time interval between two scans were negatively correlated (-0.11). The number of lesions detected on the SRS3xGado was associated only with the number of lesions on the 1xGado and not with any other patient or tumor pretreatment characteristics such as age, gender, largest tumor volume on the 1xGado, or number of days between the 1xGado and the SRS3xGado or prior surgery. The identification of additional lesions with SRS3xGado MR may have implications for patients who are treated with stereotactic radiosurgery alone (without whole-brain irradiation) with single-dose gadolinium imaging, in that unidentified lesions may go untreated. As a result of these findings we continue to use and advocate SRS3xGado scans for radiosurgery.
我们研究了在放射外科手术前即刻使用的成像程序——对固定于不可重新定位的头架中的患者进行的三倍剂量钆增强磁共振成像以及1毫米厚的磁化准备快速梯度回波（MPRAGE）图像（SRS3xGado）——能够发现多少最初通过常规单剂量钆增强磁共振成像（1xGado）进行初次成像的患者中先前未被识别的脑转移瘤。1998年7月至2000年7月期间，纽约大学伽马刀中心对47例因脑转移瘤接受放射外科手术治疗的患者所做出的诊断最初基于1xGado方案。1998年7月，我们开始将SRS3xGado作为常规成像方案用于为放射外科手术靶向病变做准备，采用三倍剂量钆并采集连续的1毫米厚T1加权轴向图像。由于我们的SRS3xGado扫描有时会意外发现额外的转移瘤，我们试图了解最初的1xGado扫描低估转移瘤数量的频率。因此，我们回顾了SRS3xGado研究中发现的脑转移瘤数量，并将结果与最初识别出脑转移瘤的1xGado方案所发现的数量进行比较。在47例患者中的23例（49%）的SRS3xGado扫描中发现了额外的转移瘤，每位患者的额外转移瘤数量从1个到23个不等。在这23例患者中，57%的患者仅发现了一个额外的病灶。1xGado和SRS3xGado扫描之间的平均时间间隔为20.6天（范围为4 - 83天），检测到的额外病灶数量与两次扫描之间的时间间隔呈负相关（-0.11）。SRS3xGado上检测到的病灶数量仅与1xGado上的病灶数量相关，而与任何其他患者或肿瘤治疗前特征无关，如年龄、性别、1xGado上最大肿瘤体积、1xGado和SRS3xGado之间的天数或既往手术情况。使用SRS3xGado磁共振成像发现额外病灶可能对仅接受立体定向放射外科手术（不进行全脑照射）且采用单剂量钆成像的患者有影响，因为未识别的病灶可能得不到治疗。基于这些发现，我们继续使用并提倡将SRS3xGado扫描用于放射外科手术。
