Specific phantom and tools were designed and manufactured for this study. The phantom was filled with a tissue-like solution and MR images were acquired with clinical protocols as per GEC-ESTRO recommendations. Images were obtained at 6 different orientations that mimic possible clinical settings and full-width-at-half-maximum (FWHM) was recorded at multiple locations/angles. The accuracy of detecting the centerline of the tandem was assessed using a novel radial-fiducials mount.
FWHM from all line profiles at all angles and all orientations was 6.14 ± 0.7 mm (compared to 6 mm of the actual DMBT tandem diameter). The in-plane spatial-shift observed at para-axial and para-sagittal views was less than 0.5 mm.
This work demonstrated that the novel DMBT tandem applicator prototype has minimal artifact in T2-weighted images employed in clinical practice, suggesting the applicator might be a good candidate for MRI-guided adaptive brachytherapy.