Email this article 
Post a Comment 
Hide
Show all
Intensity Modulated Radiation Therapy (IMRT) Versus Three Dimensional Conformal Radiation Therapy (3DCRT) for the Treatment of High Grade Glioma: A Dosimetric Comparison
Abstract
ABSTRACT
Purpose: This study was undertaken to perform a dosimetric comparison of IMRT versus 3DCRT techniques in patients treated for high-grade glioma.
Materials and Methods: Twenty patients underwent computed tomography (CT) treatment planning in conjunction with magnetic resonance imaging (MRI) fusion. Prescription dose and normal tissue constraints were identical for both 3DCRT and IMRT plans. The prescribed dose was 59.4 Gy delivered at 1.8 Gy per fraction using 4-10 MV photons. Normal tissue dose constraints were 50-54 Gy for optic chiasm/nerves and 55-60 Gy for brainstem.
Results: IMRT resulted in superior target coverage compared to 3DCRT. Specifically, minimum and mean planning target volume cone down (PTVcd) doses were 54.52 and 61.74 Gy for IMRT and 50.56 and 60.06 Gy for 3DCRT, respectively (p≤0.01). IMRT reduced the percent volume of brainstem receiving dose greater than 45 Gy by 31% (p=0.004), and the percent volumes of brain above 18, 24 and 45 Gy by 10% (p=0.059), 14% (p=0.015) and 40% (p≤0.0001), respectively. Percent volume of optic chiasm receiving above 45 Gy was also reduced with IMRT by 30.40% (p=0.047). Compared to 3DCRT, IMRT significantly increased TCP (p≤0.005) and lowered NTCP for brain and brainstem (p
Purpose: This study was undertaken to perform a dosimetric comparison of IMRT versus 3DCRT techniques in patients treated for high-grade glioma.
Materials and Methods: Twenty patients underwent computed tomography (CT) treatment planning in conjunction with magnetic resonance imaging (MRI) fusion. Prescription dose and normal tissue constraints were identical for both 3DCRT and IMRT plans. The prescribed dose was 59.4 Gy delivered at 1.8 Gy per fraction using 4-10 MV photons. Normal tissue dose constraints were 50-54 Gy for optic chiasm/nerves and 55-60 Gy for brainstem.
Results: IMRT resulted in superior target coverage compared to 3DCRT. Specifically, minimum and mean planning target volume cone down (PTVcd) doses were 54.52 and 61.74 Gy for IMRT and 50.56 and 60.06 Gy for 3DCRT, respectively (p≤0.01). IMRT reduced the percent volume of brainstem receiving dose greater than 45 Gy by 31% (p=0.004), and the percent volumes of brain above 18, 24 and 45 Gy by 10% (p=0.059), 14% (p=0.015) and 40% (p≤0.0001), respectively. Percent volume of optic chiasm receiving above 45 Gy was also reduced with IMRT by 30.40% (p=0.047). Compared to 3DCRT, IMRT significantly increased TCP (p≤0.005) and lowered NTCP for brain and brainstem (p
Keywords
High-Grade Glioma; Intensity Modulated Radiation Therapy (IMRT), Conformal Radiation Therapy (3DCRT)