Polymer gel dosimetry utilizing a 2D (SE) and a 2D (HASTE) multiple echo sequences

Abstract

Abstract. Two pulse sequences were used for the estimation of dosimetric characteristics of VIPET polymer gels. The first one, multi-echo spin echo (MESE) is the well-established method for T2 measurements. The other method is a new multi-echo single shot turbo spin echo pulse sequence, MEHASTE that reduces the acquisition time significantly. Both techniques showed a linear R2-dose response. With MESE sequence, the dose sensitivity was slightly enhanced as compared to MEHASTE. The linear portion of the R2-dose curve was restricted using the MEHASTE sequence. For doses above 7 Gy both methods fulfill the 2% ICRU criterion limit for dose resolution estimations (95% confidence level). Finally, for a time period of one month the temporal stability of R2-dose response was maintained stable utilizing both MESE and MEHASTE pulse sequences. MEHASTE serves as an excellent means for fast 3D polymer gel dosimetry.

Examination of THPC as an oxygen scavenger impacting VIC dosimeter thermal stability and comparison of NVP-containing polymer gel dosimeters

“…The THPC concentration was expected to be rather over 5 mM, as it was shown elsewhere (Papoutsaki et al 2013a(Papoutsaki et al , 2013b) that for VIPET with 5 mM THPC, the threshold dose was about 2 Gy. However, due to a very short period of gelation time after addition of 4 mM THPC to VIC with 7.5% gelatine, the concentration of gelatine was reduced to 5%.…”

“…First proposed was VIPAR (Pappas et al 1999). The other NVP-containing gel dosimeters are as follows: VIPAR d ('d' denoting the doubled concentration of NVP) (Kozicki et al 2005), VIPAR nd ('nd' denoting normoxic-double, VIP, Kozicki et al 2007), modified VIPAR, VIPET, VIPET 1v, 2v (Papadakis et al 2007, Papoutsaki et al 2013a, 2013b, VIC (VIPAR CT ) (Kozicki et al 2017), VIP3-Pluronic (Jaszczak et al 2018), AQUAJOINT gel (Takanashi et al 2017), VIPET aqua (Maeyama et al 2018). All the modifications of the originally proposed VIPAR gel dosimeter are described in supplementary material (stacks.iop.org/PMB/64/035019/mmedia).…”

Whole Three-Dimensional Dosimetry of Carbon Ion Beams with an MRI-Based Nanocomposite Fricke Gel Dosimeter Using Rapid T1 Mapping Method

“…Vandecasteele and De Deene [ 36 ] quantified the relative contributions of error factors for dosimetry in polymer gel dosimeters, such as magnetic field strength, magnetic field inhomogeneity, and gel temperature during scanning. Papoutsaki et al [ 37 ] used a multi-echo single-shot turbo spin echo pulse sequence for T 2 measurements of polymer gel dosimeters to significantly reduce the imaging time. Cho et al [ 38 ] succeeded in shortening the imaging time by using a high-speed spin echo MR imaging sequence in order to detect signal intensity changes in the Fricke gel dosimeter for gamma rays of a gamma knife.…”

Radiological characteristics of MRI-based VIP polymer gel under carbon beam irradiation

“…VIP gel, one of representative polymer gel dosimeters, was originally introduced by a Greek group in 1999 (Pappas et al, 1999). Its characterization and improvement have been reported in numerous investigations, especially for low LET radiation (Karaiskos et al, 2005;Kipouros et al, 2001;Kozicki et al, 2007;Pantelis et al, 2008;Papagiannis et al, 2001;Papoutsaki et al, 2013aPapoutsaki et al, , 2013bPappas et al, 2003Pappas et al, , 2006Pappas et al, , 2008Pappas et al, , 2005Pappas et al, , 2001. With its wide range of linear dose response up to ca.…”