Assessing the impact of distortion correction on Gamma Knife radiosurgery for multiple metastasis: Volumetric and dosimetric analysis

• Published in: Brain & spine Vol. 4; p. 102791
• Main Authors: Samanci, Yavuz, Askeroglu, M. Orbay, Düzkalir, Ali Haluk, Peker, Selcuk
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2024; Elsevier
• Subjects: Displacement; Distortion; Gamma Knife radiosurgery; Magnetic resonance imaging; Metastatic brain tumors; LPd; GKRS; MRI; Distortion; Displacement; CBCT; Metastatic brain tumors; LGK; CT; TE; Magnetic resonance imaging; SRS; DSC; Ld; Gamma Knife radiosurgery; MET; TR
• ISSN: 2772-5294; 2772-5294
• DOI: 10.1016/j.bas.2024.102791

Magnetic resonance imaging (MRI) is a robust neuroimaging technique and is the preferred method for stereotactic radiosurgery (SRS) planning. However, MRI data always contain distortions caused by hardware and patient factors. Can these distortions potentially compromise the effectiveness and safety of SRS treatments? Twenty-six MR datasets with multiple metastatic brain tumors (METs) used for Gamma Knife radiosurgery (GKRS) were retrospectively evaluated. A commercially available software was used for distortion correction. Geometrical agreement between corrected and uncorrected tumor volumes was evaluated using MacDonald criteria, Euclidian distance, and Dice similarity coefficient (DSC). SRS plans were generated using uncorrected tumor volumes, which were assessed to determine their coverage of the corrected tumor volumes. The median target volume was 0.38 cm3 (range,0.01–12.38 cm3). A maximum displacement of METs of up to 2.87 mm and a median displacement of 0.55 mm (range,0.1–2.87 mm) were noted. The median DSC between uncorrected and corrected MRI was 0.92, and the most concerning case had a DSC of 0.46. Although all plans met the optimization criterion of at least 98% of the uncorrected tumor volume (median 99.55%, range 98.1–100%) receiving at least 100% of the prescription dose, the percent of the corrected tumor volume receiving the total prescription dose was a median of 95.45% (range,23.1–99.5%). MRI distortion, though visually subtle, has significant implications for SRS planning. Regular utilization of corrected MRI is recommended for SRS planning as distortion is sometimes enough to cause a volumetric miss of SRS targets. •MRI distortion can compromise the effectiveness of stereotactic radiosurgery treatments.•Uncorrected MRI can lead to inadequate treatment planning and geometric miss.•Distortion correction should be a standard procedure for stereotactic radiosurgery planning.