Greene G M, Hitchon P W, Schelper R L, Yuh W, Dyste G N
Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City.
J Neurosurg. 1989 Oct;71(4):494-7. doi: 10.3171/jns.1989.71.4.0494.
Twenty-seven patients underwent 29 computerized tomography (CT)-guided stereotactic biopsy procedures for untreated or recurrent malignant astrocytomas. Biopsies were obtained from the hypodense center, enhancing margin, and hypodense periphery as seen on contrast-enhanced CT scans, with diagnostic yields of (number of biopsies yielding tumor/number of biopsies obtained): 34/61 (56%), 68/101 (67%), and 8/22 (36%) from these three zones, respectively. Although tumor was identified in all three zones, diagnostic yield was significantly higher in the hypodense center and enhancing margin. Comparison of patients with untreated tumors to those with recurrent tumors demonstrated no statistical difference in tumor distribution, although there was a trend toward a higher yield from the hypodense periphery in the recurrent tumor group. Tumor was found up to 15 mm beyond the CT-enhancing margin, in addition to extending beyond the area of abnormality on T2-weighted magnetic resonance images. These findings suggest that serial stereotactic biopsies should be targeted to the hypodense center and enhancing margin for improved diagnostic yield. Biopsy material obtained from the hypodense periphery that demonstrates tumor also indicates that a tumor volume beyond the confines of the CT-enhancing margin should be considered when calculating dosimetry for interstitial radiation.
27例患者因未治疗或复发性恶性星形细胞瘤接受了29次计算机断层扫描（CT）引导下的立体定向活检手术。活检取材于增强CT扫描所见的低密度中心、强化边缘及低密度周边区域，这三个区域的诊断阳性率（取材活检发现肿瘤的数量/取材活检的总数）分别为：34/61（56%）、68/101（67%）和8/22（36%）。尽管在所有三个区域均发现了肿瘤，但低密度中心和强化边缘的诊断阳性率显著更高。将未治疗肿瘤患者与复发肿瘤患者进行比较，结果显示肿瘤分布无统计学差异，不过复发肿瘤组的低密度周边区域取材阳性率有升高趋势。除了在T2加权磁共振图像上超出异常区域外，在CT强化边缘以外达15毫米处也发现了肿瘤。这些发现提示，为提高诊断阳性率，系列立体定向活检应针对低密度中心和强化边缘。从低密度周边区域取材活检发现肿瘤也表明，在计算组织间放疗剂量时应考虑超出CT强化边缘范围的肿瘤体积。
