Department of Morphological-Biomedical Sciences, Section of Anatomy and Histology, University of Verona, Italy.
Br J Radiol. 2011 Mar;84(999):271-8. doi: 10.1259/bjr/10315979. Epub 2010 Nov 2.
Delineation of clinical target volume (CTV) is still controversial in glioblastomas. In order to assess the differences in volume and shape of the radiotherapy target, the use of pre-operative vs post-operative/pre-radiotherapy T(1) and T(2) weighted MRI was compared.
4 CTVs were delineated in 24 patients pre-operatively and post-operatively using T(1) contrast-enhanced (T1(PRE)CTV and T1(POST)CTV) and T(2) weighted images (T2(PRE)CTV and T2(POST)CTV). Pre-operative MRI examinations were performed the day before surgery, whereas post-operative examinations were acquired 1 month after surgery and before chemoradiation. A concordance index (CI) was defined as the ratio between the overlapping and composite volumes.
The volumes of T1(PRE)CTV and T1(POST)CTV were not statistically different (248 ± 88 vs 254 ± 101), although volume differences >100 cm(3) were observed in 6 out of 24 patients. A marked increase due to tumour progression was shown in three patients. Three patients showed a decrease because of a reduced mass effect. A significant reduction occurred between pre-operative and post-operative T(2) volumes (139 ± 68 vs 78 ± 59). Lack of concordance was observed between T1(PRE)CTV and T1(POST)CTV (CI = 0.67 ± 0.09), T2(PRE)CTV and T2(POST)CTV (CI = 0.39 ± 0.20) and comparing the portion of the T1(PRE)CTV and T1(POST)CTV not covered by that defined on T2(PRE)CTV images (CI = 0.45 ± 0.16 and 0.44 ± 0.17, respectively).
Using T(2) MRI, huge variations can be observed in peritumoural oedema, which are probably due to steroid treatment. Using T(1) MRI, brain shifts after surgery and possible progressive enhancing lesions produce substantial differences in CTVs. Our data support the use of post-operative/pre-radiotherapy T(1) weighted MRI for planning purposes.
在胶质母细胞瘤中，临床靶区（CTV）的勾画仍存在争议。为了评估放疗靶区体积和形状的差异，比较了术前与术后/放疗前 T1 增强（T1（PRE）CTV 和 T1（POST）CTV）和 T2 加权 MRI 的应用。
24 例患者分别在术前和术后勾画 4 个 CTV，使用 T1 增强（T1（PRE）CTV 和 T1（POST）CTV）和 T2 加权图像（T2（PRE）CTV 和 T2（POST）CTV）。术前 MRI 检查在手术前一天进行，而术后检查则在手术后 1 个月和放化疗前进行。定义一致性指数（CI）为重叠和复合体积的比值。
T1（PRE）CTV 和 T1（POST）CTV 的体积无统计学差异（248 ± 88 比 254 ± 101），尽管 24 例患者中有 6 例体积差异>100cm3。3 例患者由于肿瘤进展而显示明显增加。3 例患者由于质量效应减小而减少。术前和术后 T2 体积有显著差异（139 ± 68 比 78 ± 59）。T1（PRE）CTV 和 T1（POST）CTV 之间（CI = 0.67 ± 0.09）、T2（PRE）CTV 和 T2（POST）CTV 之间（CI = 0.39 ± 0.20）以及比较 T1（PRE）CTV 和 T1（POST）CTV 未被 T2（PRE）CTV 图像定义的部分之间（CI = 0.45 ± 0.16 和 0.44 ± 0.17）均观察到一致性不佳。
使用 T2 MRI 可观察到肿瘤周围水肿的巨大变化，这可能是由于类固醇治疗所致。使用 T1 MRI，手术后的脑移位和可能的进展性强化病变会导致 CTV 产生显著差异。我们的数据支持使用术后/放疗前 T1 加权 MRI 进行计划。
