Chang Eric L, Akyurek Serap, Avalos Tedde, Rebueno Neal, Spicer Chris, Garcia John, Famiglietti Robin, Allen Pamela K, Chao K S Clifford, Mahajan Anita, Woo Shiao Y, Maor Moshe H
Department of Radiation Oncology, The University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA.
Int J Radiat Oncol Biol Phys. 2007 May 1;68(1):144-50. doi: 10.1016/j.ijrobp.2006.12.009. Epub 2007 Feb 15.
To evaluate the spatial relationship between peritumoral edema and recurrence pattern in patients with glioblastoma (GBM).
Forty-eight primary GBM patients received three-dimensional conformal radiotherapy that did not intentionally include peritumoral edema within the clinical target volume between July 2000 and June 2001. All 48 patients have subsequently recurred, and their original treatment planning parameters were used for this study. New theoretical radiation treatment plans were created for the same 48 patients, based on Radiation Therapy Oncology Group (RTOG) target delineation guidelines that specify inclusion of peritumoral edema. Target volume and recurrent tumor coverage, as well as percent volume of normal brain irradiated, were assessed for both methods of target delineation using dose-volume histograms.
A comparison between the location of recurrent tumor and peritumoral edema volumes from all 48 cases failed to show correlation by linear regression modeling (r(2) = 0.0007; p = 0.3). For patients with edema >75 cm(3), the percent volume of brain irradiated to 46 Gy was significantly greater in treatment plans that intentionally included peritumoral edema compared with those that did not (38% vs. 31%; p = 0.003). The pattern of failure was identical between the two sets of plans (40 central, 3 in-field, 3 marginal, and 2 distant recurrence).
Clinical target volume delineation based on a 2-cm margin rather than on peritumoral edema did not seem to alter the central pattern of failure for patients with GBM. For patients with peritumoral edema >75 cm(3), using a constant 2-cm margin resulted in a smaller median percent volume of brain being irradiated to 30 Gy, 46 Gy, and 50 Gy compared with corresponding theoretical RTOG plans that deliberately included peritumoral edema.
评估胶质母细胞瘤（GBM）患者瘤周水肿与复发模式之间的空间关系。
2000年7月至2001年6月期间，48例原发性GBM患者接受了三维适形放疗，临床靶区未特意纳入瘤周水肿。所有48例患者随后均复发，其原始治疗计划参数用于本研究。根据放射治疗肿瘤学组（RTOG）的靶区勾画指南，为同一48例患者制定了新的理论放射治疗计划，该指南规定要纳入瘤周水肿。使用剂量体积直方图对两种靶区勾画方法的靶区体积、复发肿瘤覆盖情况以及正常脑照射体积百分比进行评估。
对所有48例病例复发肿瘤位置与瘤周水肿体积进行线性回归建模比较，未显示相关性（r² = 0.0007；p = 0.3）。对于水肿体积>75 cm³的患者，特意纳入瘤周水肿的治疗计划中，照射至46 Gy的脑体积百分比显著高于未纳入者（38%对31%；p = 0.003）。两组计划的失败模式相同（40例中心复发、3例野内复发、3例边缘复发和2例远处复发）。
基于2 cm边界而非瘤周水肿进行临床靶区勾画，似乎并未改变GBM患者的中心复发模式。对于瘤周水肿体积>75 cm³的患者，与特意纳入瘤周水肿的相应理论RTOG计划相比，采用恒定的2 cm边界导致照射至30 Gy、46 Gy和50 Gy的脑体积中位数更小。
