Assessment of unintended shifts during frame-based stereotactic radiosurgery using cone beam computed tomography image g
- PDF / 903,887 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 78 Downloads / 197 Views
CLINICAL STUDY
Assessment of unintended shifts during frame‑based stereotactic radiosurgery using cone beam computed tomography image guidance Danushka S. Seneviratne1 · Austin R. Hadley3 · Jennifer L. Peterson1,2 · Timothy D. Malouff1 · Ronald Reimer2 · Steve M. Herchko1 · Byron May1 · Stephen Ko1 · Daniel M. Trifiletti1,2 · Laura A. Vallow1 Received: 30 December 2019 / Accepted: 18 March 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Purpose To investigate the frequency, magnitude and possible causes of frame-shifts that may occur between treatment planning and treatment delivery when performing Gamma Knife radiosurgery with rigid frame-based immobilization. Methods Differences between computed tomography (CT) framed fiducial stereotactic coordinate reference and cone beam computed tomography stereotactic coordinates after image registration were recorded for 49 frame-based GK radiosurgery cases performed using the Gamma Knife Icon. Parameters recorded include rotational shifts, translational shifts, and the GK-computed Maximum Shot Displacement (MSD) between the two stereotactic coordinate spaces. Other patient-specific parameters were collected and linear regression analysis was performed to evaluate predictors of increased displacement. Results The median values of rotational shifts were: pitch 0.14°, yaw 0.17°, and roll 0.13°. The median absolute values of translational shifts were: left–right 0.39 mm, anteroposterior 0.14 mm, and superior-inferior 0. 22 mm. The median value of MSD was 0.71 mm. Twelve cases (24.5%) had a MSD of greater than 1.0 mm. Male gender was associated with increased MSD (p = 0.013) and translational shifts (root-mean-squared value, p = 0.017). Cases with large differences between right and left sided pin lengths were also associated with increased MSD (p = 0.011). Conclusions The use of CBCT image guidance in frame-based GK radiosurgery allows unintended frame shifts to be identified and corrected. A significant fraction (24.5%) of patients had large enough shifts to result in a MSD of greater than 1.0 mm. Male gender and eccentrically placed frames were associated with increased MSD, and particular care should be taken in these cases. Keywords Frame · Gamma-knife · Stereotactic shifts · Radiosurgery · Intracranial displacement
Introduction Radiosurgery has revolutionized the treatment of neurological disorders. The existing radiosurgery platforms, including Gamma Knife (GK, Elekta AB, Stockholm, Sweden), Cyberknife (Accuray, Sunnyvale, CA), and LINAC-based units, all allow for highly targeted delivery of radiation. To * Daniel M. Trifiletti [email protected] 1
Department of Radiation Oncology, Mayo Clinic, 4500 San Pablo Road South, Jacksonville, FL 32224, USA
2
Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, USA
3
Alaska Cancer Treatment Center, Anchorage, AK, USA
achieve this precise treatment while minimizing damage to adjacent normal tissues, target volumes must be well-defined and immobilized d
Data Loading...
