A novel tool for motion-related dose inaccuracies reduction in 99mTc-MAA SPECT/CT images for SIRT planning. (June 2022)

• Record Type: Journal Article
• Authors: Santoro, Miriam; Della Gala, Giuseppe; Paolani, Giulia; Zagni, Federico; Strolin, Silvia; Civollani, Simona; Calderoni, Letizia; Cappelli, Alberta; Mosconi, Cristina; Lodi Rizzini, Elisa; Tabacchi, Elena; Morganti, Alessio Giuseppe; Fanti, Stefano; Golfieri, Rita; Strigari, Lidia
• Is Part Of: Physica medica. Volume 98(2022)
• Page Start: 98
• Page End: 112
• Publication Date: 2022-06
• Subjects: SPECT/CT -- Respiratory motion -- Hepatic dome -- Artifact -- Attenuation map; SIRT Selective Internal Radiation Therapy -- TARE Transarterial Radioembolization -- PLLA Poly-L-Lactic Acid -- CECT Contrast-Enhanced Computed Tomography -- MR Magnetic Resonance -- MAA Macro-Aggregated Albumin -- LSF Lung Shunt Fraction -- VOI Volume Of Interest -- OARs Organs At Risk -- DVH Dose Volume Histogram -- MC Monte Carlo -- μMap Attenuation Map -- PET Positron Emission Tomography -- CIRS Computerized Imaging Reference System -- OSEM Ordered Subset Expectation Maximization -- GUI Graphical User Interface -- LDM Local Deposition Method -- DD Dose Difference -- DTA Distance To Agreement -- LOA Limits Of Agreement -- SPECT Single Photon Emission Computed Tomography; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2022.04.017
• Languages: English
• ISSNs: 1120-1797

Abstract

Highlights: SPECT/CT reconstruction is affected by motion. Liver and tumor dosimetry in radioembolization may be improved by motion correction. A dedicated tool was implemented to realign the projection images. The tool was experimentally validated with an ad-hoc dynamic phantom. The correction improved the lung, liver and tumor dose estimation. Abstract: Introduction: In Selective Internal Radiation Therapy (SIRT), 90 Y is administered to primary/secondary hepatic lesions. An accurate pre-treatment planning using 99m Tc-MAA SPECT/CT allows the assessment of its feasibility and of the activity to be injected. Unfortunately, SPECT/CT suffers from patient-specific respiratory motion which causes artifacts and absorbed dose inaccuracies. In this study, a data-driven solution was developed to correct the respiratory motion. Methods: The tool realigns the barycenter of SPECT projection images and shifts them to obtain a fine registration with the attenuation map. The tool was validated using a modified dynamic phantom with several breathing patterns. We compared the absorbed dose distributions derived from uncorrected( D m )/corrected( D c ) images with static ones( D s ) in terms of γ-passing rates, 210 Gy isodose volumes, dose-volume histograms and percentage differences of mean doses (i.e., Δ D ¯ m and Δ D ¯ c, respectively). The tool was applied to twelve SIRT patients and the Bland-Altman analysis was performed on mean doses. Results: In the phantom study, the agreement between D c and D s was higher (γ-passing rates generally > 90%) than D m and D s . The isodose volumes in D c were closer than D m to D s, with differences up to 10% and 30% respectively. A reduction from a median Δ D ¯ m = -19.3% to Δ D ¯ c = -0.9%, from Δ D ¯ m = -42.8% to Δ D ¯ c = -7.0% and from Δ D ¯ m = 1586% to Δ D ¯ c = 47.2% was observed in liver-, tumor- and lungs-like structures. The Bland-Altman analysis on patients showed variations (±50 Gy) and (±4 Gy) between D ¯ c and D ¯ m of tumor and lungs, respectively. Conclusion: The proposed tool allowed the correction of 99m Tc-MAA SPECT/CT images, improving the accuracy of the absorbed dose distribution.