Bokstein Felix, Kovner Felix, Blumenthal Deborah T, Ram Zvi, Templehoff Haim, Kanner Andrew A, Corn Benjamin W
Neuro-Oncology Service, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Int J Radiat Oncol Biol Phys. 2008 Nov 1;72(3):900-4. doi: 10.1016/j.ijrobp.2008.01.053. Epub 2008 Apr 11.
Irradiation remains the cornerstone of management for glioblastoma multiforme. The Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer advocate encompassing the primary tumor plus a 2-cm margin in the high-dose volume. One shortcoming of this approach is the exposure of critical structures to radiation doses that could exceed organ tolerance. We investigated whether the temporal bone (rather than the aforementioned 2-cm radius) would serve as a barrier to tumor spread when regarded as the anterior margin for temporal lobe lesions. We hypothesized that by using the temporal bone as the radiation field margin, toxicity could be reduced without compromising tumor control.
Between 2003 and 2007, 342 patients with newly diagnosed glioblastoma multiforme were treated with surgery and primary irradiation at our institution. Of these 342 patients, 50 had lesions confined to the temporal lobe. The clinical target volume included the primary lesion, the area of edema when present, and a 2-cm margin, except in the direction of the temporal bone.
Of the 50 patients, 40 were available for evaluation. At a median follow-up of 12.95 months, 8 patients had not yet shown signs of tumor progression, 24 had local failure, 7 had distant or mixed (local plus distant) failure, and only 1 patient had failure in the infratemporal fossa.
The results of the study have demonstrated an acceptable level of recurrence when the temporal bone, rather than a 2-cm margin, is used as the anterior border of the clinical target volume. The strategy we have proposed achieves tumor control and respects optic tolerance without resorting to complex, expensive approaches such as intensity-modulated radiotherapy.
放射治疗仍是多形性胶质母细胞瘤治疗的基石。放射治疗肿瘤学组和欧洲癌症研究与治疗组织主张在高剂量照射区域内包括原发性肿瘤及2厘米的边缘区域。这种方法的一个缺点是关键结构会受到可能超过器官耐受剂量的辐射。我们研究了将颞骨（而非上述2厘米半径范围）视为颞叶病变的前缘时，其是否能作为肿瘤扩散的屏障。我们假设通过将颞骨用作放射野边缘，可以在不影响肿瘤控制的情况下降低毒性。
2003年至2007年间，我院对342例新诊断的多形性胶质母细胞瘤患者进行了手术和初次放疗。在这342例患者中，50例病变局限于颞叶。临床靶区包括原发性病变、存在水肿时的水肿区域以及2厘米的边缘区域，但在颞骨方向除外。
50例患者中，40例可供评估。中位随访12.95个月时，8例患者尚未出现肿瘤进展迹象，24例出现局部失败，7例出现远处或混合（局部加远处）失败，仅1例患者在颞下窝出现失败。
研究结果表明，将颞骨而非2厘米边缘用作临床靶区的前缘时，复发水平可接受。我们提出的策略在不采用强度调制放疗等复杂、昂贵方法的情况下实现了肿瘤控制并尊重了视神经耐受性。
