Treatment outcomes and dose-volume histogram analysis of simultaneous integrated boost method for malignant gliomas using intensity-modulated radiotherapy
Tóm tắt
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/m2) and vincristine (1.2 mg/body) and interferon-β (3 × 106 units) three times weekly during the period of radiotherapy. Adjuvant chemotherapy, ACNU (100 mg/m2) and vincristine (1.2 mg/body), was repeated every 6 weeks and interferon-β 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.
Tài liệu tham khảo
Laperriere N, Zuraw L, Cairncross G, et al. (2002) Radiotherapy for newly diagnosed malignant glioma in adults: a systematic review. Radiother Oncol 64:259–273
Pollack A, Hanlon AL, Horwitz EM, et al. (2006) Dosimetry and preliminary acute toxicity in the first 100 men treated for prostate cancer on a randomized hypofractionation dose escalation trial. Int J Radiat Oncol Biol Phys 64:518–526
Zelefsky MJ, Chan H, Hunt M, et al. (2006) Long-term outcome of high dose intensity modulated radiation therapy for patients with clinically localized prostate cancer. J Urol 176:1415–1419
Wolden SL, Chen WC, Pfister DG, et al. (2006) Intensity-modulated radiation therapy (IMRT) for nasopharynx cancer: update of the Memorial Sloan-Kettering experience. Int J Radiat Oncol Biol Phys 64:57–62
Lee N, Xia P, Fischbein NJ, et al. (2003) Intensity-modulated radiation therapy for head-and-neck cancer: the UCSF experience focusing on target volume delineation. Int J Radiat Oncol Biol Phys 57:49–60
Suzuki M, Nakamatsu K, Kanamori S, et al. (2003) Feasibility study of the simultaneous integrated boost (SIB) method for malignant gliomas using intensity-modulated radiotherapy (IMRT). Jpn J Clin Oncol 33:271–277
Iuchi T, Hatano K, Narita Y, et al. (2006) Hypofractionated high-dose irradiation for the treatment of malignant astrocytomas using simultaneous integrated boost technique by IMRT. Int J Radiat Oncol Biol Phys 64:1317–1324
Sultanem K, Patrocinio H, Lambert C, et al. (2004) The use of hypofractionated intensity-modulated irradiation in the treatment of glioblastoma multiforme: preliminary results of a prospective trial. Int J Radiat Oncol Biol Phys 58:247–252
Floyd NS, Woo SY, The BS, et al. (2004) Hypofractionated intensity-modulated radiotherapy for primary glioblastoma multiforme. Int J Radiat Oncol Biol Phys 58:721–726
Narayana A, Yamada J, Berry S, et al. (2006) Intensity-modulated radiotherapy in high-grade gliomas: clinical and dosimetric results. Int J Radiat Oncol Biol Phys 64:892–897
International Commission on Radiation Units and Measurements (ICRU) (1993) Report number 50: prescribing, recording and reporting photon beam therapy. ICRU, Washington, DC
Suzuki M, Nakamatsu K, Kanamori S, et al. (2004) Comparison of outcomes between overlapping structure-based and non-overlapping structure-based optimization for simultaneous integrated boost IMRT for malignant gliomas. Int J Clin Oncol 9:491–497
IMRT CWG: intensity-modulated radiotherapy: current status and issues of interest. (2001) Int J Radiat Oncol Biol Phys 51:880–914
Chan MF, Schupak K, Burman C, et al. (2003) Comparison of intensity-modulated radiotherapy with three-dimensional conformal radiation therapy planning for glioblastoma multiforme. Med Dosim 28:261–265
Gutin PH, Prados MD, Phillips TL, et al. (1991) External irradiation followed by an interstitial high activity iodine-125 implant “boost” in the initial treatment of malignant gliomas: NCOG study 6G-82-2. Int J Radiat Oncol Biol Phys 21:601–606