Tim Schakel1, Johannes M Hoogduin2, Chris H J Terhaard1, Marielle E P Philippens1. 1. Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. 2. Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
Abstract
PURPOSE: Diffusion-weighted (DW) MRI, showing high contrast between tumor and background tissue, is a promising technique in radiotherapy for tumor delineation. However, its use for head-and-neck patients is hampered by poor geometric accuracy in conventional echo planar imaging (EPI) DW-MRI. An alternative turbo spin echo sequence, DW-SPLICE, is implemented and demonstrated in patients. METHODS: The DW-SPLICE sequence was implemented on a 3.0 T system and evaluated in 10 patients. The patients were scanned in treatment position, using a customized head support and immobilization mask. Image distortions were quantified at the gross tumor volume (GTV) using field map analysis. The apparent diffusion coefficient (ADC) was evaluated using an ice water phantom. RESULTS: The DW images acquired by DW-SPLICE showed no image distortions. Field map analysis at the gross tumor volumes resulted in a median distortion of 0.2 mm for DW-SPLICE, whereas for the conventional method this was 7.2 mm. ADC values, measured using an ice water phantom were in accordance with literature values. CONCLUSIONS: The implementation of DW-SPLICE allows for diffusion-weighted imaging of patients in treatment position with excellent geometrical accuracy. The images can be used to facilitate target volume delineation in RT treatment planning.
PURPOSE: Diffusion-weighted (DW) MRI, showing high contrast between tumor and background tissue, is a promising technique in radiotherapy for tumor delineation. However, its use for head-and-neck patients is hampered by poor geometric accuracy in conventional echo planar imaging (EPI) DW-MRI. An alternative turbo spin echo sequence, DW-SPLICE, is implemented and demonstrated in patients. METHODS: The DW-SPLICE sequence was implemented on a 3.0 T system and evaluated in 10 patients. The patients were scanned in treatment position, using a customized head support and immobilization mask. Image distortions were quantified at the gross tumor volume (GTV) using field map analysis. The apparent diffusion coefficient (ADC) was evaluated using an ice water phantom. RESULTS: The DW images acquired by DW-SPLICE showed no image distortions. Field map analysis at the gross tumor volumes resulted in a median distortion of 0.2 mm for DW-SPLICE, whereas for the conventional method this was 7.2 mm. ADC values, measured using an ice water phantom were in accordance with literature values. CONCLUSIONS: The implementation of DW-SPLICE allows for diffusion-weighted imaging of patients in treatment position with excellent geometrical accuracy. The images can be used to facilitate target volume delineation in RT treatment planning.
Authors: Mischa de Ridder; Cornelis P J Raaijmakers; Frank A Pameijer; Remco de Bree; Floris C J Reinders; Patricia A H Doornaert; Chris H J Terhaard; Marielle E P Philippens Journal: Cancers (Basel) Date: 2022-06-20 Impact factor: 6.575
Authors: Hans Ligtenberg; Tim Schakel; Jan Willem Dankbaar; Lilian N Ruiter; Boris Peltenburg; Stefan M Willems; Nicolien Kasperts; Chris H J Terhaard; Cornelis P J Raaijmakers; Marielle E P Philippens Journal: Cureus Date: 2018-04-11
Authors: Tim Schakel; Boris Peltenburg; Jan-Willem Dankbaar; Carlos E Cardenas; Michalis Aristophanous; Chris H J Terhaard; Johannes M Hoogduin; Marielle E P Philippens Journal: Phys Imaging Radiat Oncol Date: 2018-01-30
Authors: Carri K Glide-Hurst; Eric S Paulson; Kiaran McGee; Neelam Tyagi; Yanle Hu; James Balter; John Bayouth Journal: Med Phys Date: 2021-07 Impact factor: 4.071