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ESTRO 36 2017
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In the standard group, the considered trigger point
percentages were 1.3 for neck, 13.8 for trapezium, 13.8
for scapula, 16.5 for pectoral muscle, 11.3 for arm and 5
for dorsal spine.
The corresponding values of the hypofractionated group
were respectively 6.5, 29, 19.4, 6.5, 12.9, 6.5%.
Results are summarized in table 1.
Conclusion
According to DASH score and trigger point evaluation, a
better ROM can be appreciated in patients who underwent
standard RT.
Pain is more common, both in terms of intensity and
trigger point frequency (scapula and trapezium on top), in
patients who underwent hypofractionated treatment.
A slight arm functional impairment can also be recognized
in this group.
These not statistically significant observations need to be
further validated in more homogeneous and numerous
samples in order to define an effective rehabilitation
program.
OC-0074 Analysis of diaphragm motion at various levels
of abdominal compression by dynamic MRI
K.F. Cheng
1
, P.H. Fok
1
, J. Yuan
2
, O.L. Wong
2
, G. Chiu
1
1
Hong Kong Sanatorium & Hospital, D epartment of
Radiotherapy, Happy Valley, Hong Kong SAR China
2
Hong Kong Sanatorium & Hospital, Medical Physics and
Research Department, Happy Valley, Hong Kong SAR China
Purpose or Objective
To investigate the effectiveness of abdominal compression
on diaphragm motion control.
Material and Methods
15 healthy volunteers were recruited. Volunteers were
positioned in Orfit stereotactic body radiation therapy
(SBRT) solution which included a short SBRT base plate, a
pressure system bridge, an adjustable screw and a
pressure plate. The pressure plate was placed on the
abdomen inferiorly to xiphoid process and rib cage to
apply abdominal compression force. Indexing numbers on
the adjustable screw indicated the pressure that was
applying to the volunteers. Four sets of MRI scans with four
levels of abdominal compression were performed on each
volunteer including, (i) free breathing (FB) representing
no abdominal compression force applied (screw just
touching pressure plate), (ii) high abdominal compression
(HAC) representing the maximum abdominal compression
force which the volunteer could tolerate, (iii) medium
abdominal compression (MAC) representing 80% of HAC
(80% of the screw reading difference between FB and
HAC), (iv) low abdominal compression (LAC) representing
50% of HAC (50% of the screw reading difference between
FB and HAC) .
Examinations were done in a MR-Simulator (Siemens
MAGNETOM RT Pro edition). Two six-channel
radiofrequency coils were used to cover thorax and
abdomen regions. A setup photo is shown in Fig.1. One
dynamic MRI image (trueFISP sequence) was obtained at
mid-coronal plane. The total acquisition time was about
14 seconds in a speed of 3 frames/s. The MR scan was
repeated under the conditions of FB, HAC, MAC and LAC.
Maximum diaphragm displacements were defined as the
differences between the most superior and the most
inferior diaphragm dome position in the dynamic MRI
images. Maximum diaphragm displacements were
compared among FB, HAC, MAC and LAC to investigate the
effectiveness of abdominal compression on diaphragm
motion control.
Results
One-way ANOVA was used to test the mean differences of
maximum diaphragm displacement among the groups and
the results are shown in table 1. The superior-inferior (SI)
motion of diaphragm was decreased with increasing
abdominal compression force. The mean of maximum right
diaphragm displacement had significant differences in
comparisons of HAC vs LAC, HAC vs FB, MAC vs FB (All
p
<0.05). Significant mean difference of maximum left
diaphragm displacement was found in HAC vs. FB (
p
<0.05).
The mean of maximum diaphragm displacement of right
and left diaphragm was significantly reduced from 14.23
mm to 10.59 mm and from 13.64 mm to 10.34 mm
respectively. 80% volunteers had less right diaphragm SI
motion under HAC than FB. 73.3% volunteers had less left
diaphragm SI motion under HAC than FB.
Conclusion
The performance of SBRT pressure bridge
system is positive in reducing the diaphragm motion.
However, because not all volunteers had reduced
diaphragm motion under abdominal compression,
screening is suggested for using the device to ensure
patient can be benefited from it.