Quantitative MRI assessment of a novel direction modulated brachytherapy tandem applicator for cervical cancer at 1.5 T. Issue 3 (September 2016)

• Record Type: Journal Article
• Authors: Soliman, Abraam S.; Elzibak, Alyaa; Easton, Harry; Kim, James Y.; Han, Dae Yup; Safigholi, Habib; Mashouf, Shahram; Owrangi, Amir; Ravi, Ananth; Song, William Y.
• Is Part Of: Radiotherapy and oncology. Volume 120:Issue 3(2016:Sep.)
• Page Start: 500
• Page End: 506
• Publication Date: 2016-09
• Subjects: MRI -- Cervical cancer -- Brachytherapy -- DMBT -- Tandem applicator; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2016.07.006
• Languages: English
• ISSNs: 0167-8140

Abstract

Abstract: Background and purpose: The purpose of this work is to quantitatively investigate the artifacts and image distortions induced in the MR images by a recently proposed direction modulated brachytherapy (DMBT) tandem applicator prototype. This new MRI-compatible applicator allows better sparing of organs-at-risk (OAR) for cervical cancer patients, while providing conformal dose distributions to target volumes. Materials and methods: 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. Results: 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. Conclusions: 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.