title: The use of dual vacuum stabilization device to reduce kidney motion for stereotactic radiotherapy planning.
abstract: Abdominal stereotactic ablative body radiotherapy is aided by motion management strategies to ensure accurate dose delivery as targets such as the kidney are easily influenced by breathing motion. Commercial devices such as compression plates and dual vacuum technology have been demonstrated to reduce the motion of lung and liver tumors. The aim of this study was to evaluate the effectiveness of a dual vacuum system in reducing kidney motion as well to investigate any relationship between abdominal wall motions with kidney motion. Ten healthy volunteers were set up with and without vacuum compression (Elekta BodyFIX(TM)) to simulate free and dampened breathing. Ultrasound imaging was used to visualize kidney motion at the same time an abdominal surface marker was monitored using infrared imaging (Varian, Real Time Position Management). The resulting kidney and abdominal motion tracks were imported into motion analysis (Physmo(TM)) and custom built software (Matlab) to calculate amplitude of motion independent of shifting baselines. Thirty-four kidney datasets were available for analysis, with six datasets unable to be retrieved. With vacuum compression six out of nine participants showed a mean reduction of kidney motion ranging between 1.6 and 8 mm (p < 0.050). One participant showed an increase in motion of 8.2 mm (p < 0.001) with vacuum compression. Two participants showed no significant change (<1 mm) in kidney motion. No relationship was observed for abdominal wall motion and motion changes in the left kidney (r = 0.345, p = 0.402) or right kidney (r = 0.527, p = 0.145). Vacuum compression reduced kidney motion in the majority of participants; however larger breathing motion can also result from its use. No pattern emerged regarding which patients may benefit from vacuum immobilization as abdominal wall motion was not found to be an adequate surrogate for kidney motion.
authors: Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia Daniel.pham@petermac.org.
authors: Daniel
authors: D
authors: Pham
authors: Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Tomas
authors: T
authors: Kron
authors: Barwon Health, Melbourne, Australia.
authors: Colin
authors: C
authors: Styles
authors: Department of Radiation Oncology, Royal Prince Alfred Hospital, Sydney, Australia.
authors: May
authors: M
authors: Whitaker
authors: Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Mathias
authors: M
authors: Bressel
authors: Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Farshad
authors: F
authors: Foroudi
authors: Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia.
authors: Michal
authors: M
authors: Schneider
authors: Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Thomas
authors: T
authors: Devereux
authors: Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Kim
authors: K
authors: Dang
authors: Division of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia.
authors: Shankar
authors: S
authors: Siva
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007103:Immobilization / Q000379:methods*; D007668:Kidney / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009068:Movement; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted; D014463:Ultrasonography; D014618:Vacuum; D055815:Young Adult
keywords: Abdominal compression; Kidney; Radiotherapy; Stereotactic body.