Nakamatsu Kiyoshi, Suzuki Minoru, Nishimura Yasumasa, Kanamori Shuichi, Koike Ryuta, Shibata Toru, Shintani Naoya, Okumura Masahiko, Okajima Kaoru, Akai Fumiharu
Department of Radiation Oncology, Kinki University School of Medicine, Osaka, Japan.
Int J Clin Oncol. 2008 Feb;13(1):48-53. doi: 10.1007/s10147-007-0722-6. Epub 2008 Feb 29.
The aim of this article is to report the treatment outcomes, toxicities, and dosimetric feasibility of our simultaneous-boost intensity-modulated radiotherapy (SIB-IMRT) protocol.
Thirteen patients with malignant gliomas treated between December 2000 and September 2004 were enrolled in this study. Two planning target volumes (PTVs) were defined in the present study. Our IMRT regimen delivered 70 Gy/28 fractions (fr)/daily; 2.5 Gy to the gross tumor volume (GTV) with a 0.5-cm margin, defined as the PTV-G, and 56 Gy/28 fr/daily, with 2.0 Gy to the surrounding edema, defined as the planning target volume annulus (PTV-a). Eleven of the 13 patients received one or two courses of nimustine hydrochloride (ACNU) (100 mg/m(2)) and vincristine (1.2 mg/body) and interferon-beta (3 x 10(6) units) three times weekly during the period of radiotherapy. Adjuvant chemotherapy, ACNU (100 mg/m(2)) and vincristine (1.2 mg/body), was repeated every 6 weeks and interferon-beta was repeated every 2 weeks. The treatment outcomes, toxicity, and dosimetric feasibility were assessed.
All the patients experienced tumor recurrence. The median progression-free survival times for patients with grade III tumors and glioblastome were 7.5 and 8.0 months, respectively. The 1-year and 2-year overall survival rates for all the patients were 77% and 31%, respectively. Four patients experienced acute grade 1/2 toxicities during the treatment. No late toxicity related to radiotherapy has been seen. Analyses with dose-volume histograms confirmed excellent conformity of dose distributions in the two target volumes, PTV-G and PTV-a, with the sparing of organs at risk.
Our IMRT regimen did not prevent tumor progression. However, the ability of IMRT to deliver highly conformative doses to two contiguous targets, GTV and the surrounding edema, justifies its application to malignant gliomas.
本文旨在报告同步推量调强放射治疗（SIB-IMRT）方案的治疗效果、毒性反应及剂量测定的可行性。
本研究纳入了2000年12月至2004年9月期间接受治疗的13例恶性胶质瘤患者。本研究定义了两个计划靶体积（PTV）。我们的调强放射治疗方案为每天70 Gy/28次分割（f）；给予大体肿瘤体积（GTV）边缘外放0.5 cm的区域，即PTV-G，2.5 Gy/次，以及每天56 Gy/28 f，给予周围水肿区域，即计划靶体积环（PTV-a）2.0 Gy/次。13例患者中有11例在放疗期间接受了1或2个疗程的盐酸尼莫司汀（ACNU）（100 mg/m²）、长春新碱（1.2 mg/体）和干扰素-β（3×10⁶单位），每周3次。辅助化疗，ACNU（100 mg/m²）和长春新碱（1.2 mg/体）每6周重复一次，干扰素-β每2周重复一次。评估了治疗效果、毒性反应及剂量测定的可行性。
所有患者均出现肿瘤复发。Ⅲ级肿瘤和胶质母细胞瘤患者的无进展生存期的中位数分别为7.5个月和8.0个月。所有患者的1年和2年总生存率分别为77%和31%。4例患者在治疗期间出现急性1/2级毒性反应。未观察到与放疗相关的晚期毒性反应。剂量体积直方图分析证实，在两个靶体积PTV-G和PTV-a中剂量分布具有良好的适形性，同时危及器官得到了保护。
我们的调强放射治疗方案未能阻止肿瘤进展。然而，调强放射治疗能够向两个相邻靶区，即GTV和周围水肿区域，提供高度适形剂量的能力，证明了其在恶性胶质瘤治疗中的应用价值。
