Feasibility and Outcomes of Hypofractionated Simultaneous Integrated Boost-Intensity Modulated Radiotherapy for Malignant Gliomas: A Preliminary Report.
- Author:
Jihye CHA
1
;
Chang Ok SUH
;
Kwangwoo PARK
;
Jong Hee CHANG
;
Kyu Sung LEE
;
Se Hoon KIM
;
Jee Suk CHANG
;
Joo Ho KIM
;
Yang Gun SUH
;
Jun Won KIM
;
Jaeho CHO
Author Information
- Publication Type:Original Article
- Keywords: Radiotherapy; intensity-modulated; malignant glioma; hypofractionation; simultaneous integrated boost
- MeSH: Adult; Aged; Female; Glioma/*radiotherapy; Humans; Male; Middle Aged; Radiotherapy, Intensity-Modulated/*methods; Retrospective Studies; Young Adult
- From:Yonsei Medical Journal 2014;55(1):70-77
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: The aim of this study was to assess the feasibility and efficacy of hypofractionated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) using three-layered planning target volumes (PTV) for malignant gliomas. MATERIALS AND METHODS: We conducted a retrospective analysis of 12 patients (WHO grade IV-10; III-2) postoperatively treated with SIB-IMRT with concurrent temozolomide. Three-layered PTVs were contoured based on gadolinium-enhanced magnetic resonance imaging as follows; high risk PTV (H-PTV) as the area of surgical bed including residual gross tumor with a 0.5 cm margin; low risk PTV (L-PTV) as the area surrounding the high risk PTV with 1.5 cm margin; moderate risk PTV (M-PTV) as a line at one-third the distance from high risk PTV to low risk PTV. Total dose to high risk PTV was 70 Gy in 8 and 62.5 Gy in 4 patients. RESULTS: The median follow-up time was 52 months in surviving patients. The 2- and 5-year overall survival (OS) rates were 66.6% and 47.6%, respectively. The 2- and 5-year progression-free survival (PFS) rates were 57.1% and 45.7%, respectively. The median OS and PFS were 48 and 31 months, respectively. Six patients (50%) progressed: in-field only in one, out-field or disseminated in 4, and both in one patient. All patients completed planned treatments without a toxicity-related gap. Asymptomatic radiation necrosis was observed in 4 patients at post-radiotherapy 9-31 months. CONCLUSION: An escalated dose of hypofractionated SIB-IMRT using three-layered PTVs can be safely performed in patients with malignant glioma, and might contribute to better tumor control and survival.
