A. Bel et al., A computerized remote table control for fast on-line patient repositioning: Implementation and clinical feasibility, MED PHYS, 27(2), 2000, pp. 354-358
Citations number
20
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
A computerized remote control for a Siemens ZXT treatment couch was impleme
nted and its characteristics were investigated to establish its feasibility
for on-line setup corrections, using portal imagine. Communication with th
e table was obtained by connecting it via a serial line to a work station.
The treatment couch enables "goto" commands in the three main directions an
d around the isocenter. The accuracy of the movements after giving such a c
ommand was checked and the time for each movement was recorded. First, the
movements into a single direction were studied (range of -4 to +4 cm and -4
degrees to +-4 degrees). Each command was repeated four times. Second, the
table was moved into the three main directions simultaneously. For this ex
periment a clinically relevant three-dimensional (3-D) normal distribution
of shifts was used [N=200, standard deviation (SD) 5 mm in the three main d
irections]. This latter experiment was done twice: without and with rotatio
ns (a distribution with SD 1 degrees). During the first experiment, with sh
ifts into one direction, no systematic deviations were found. The overall a
ccuracy of the shifts was 0.6 mm (1 SD) in each direction and 0.04 degrees
(1 SD) for the rotations. The time required for a translation ranged betwee
n 4 and 13 s and for the rotation between 8 and 20 s. The second experiment
with the 3-D distribution of setup errors yielded an error in the 3-D vect
or length equal to 0.96 mm (1 SD), independent of rotations. Shifts were pe
rformed in less than 11 s for 95% of the cases without rotations. When rota
tions were also performed, 95% of the movements finished in less than 16 s.
In conclusion, the table movements are accurate and enable on-line setup c
orrections in daily clinical practice. (C) 2000 American Association of Phy
sicists in Medicine. [S0094-2405 (00)00502-2].