Transcript INFLUENCE OF RADIOTHERAPY ON THE LATEST GENERATION OF PACEMAKERS Egon Scheepers

INFLUENCE OF RADIOTHERAPY ON
THE LATEST GENERATION OF PACEMAKERS
Egon
Catharina Hospital
1
Scheepers ,
Bob
2
Springorum ,
Hans
2
Uiterwaal ,
Coen
3
Hurkmans
1 Eindhoven
University of technology, Department of biomedical Engineering, Eindhoven, The Netherlands
2Onze Lieve Vrouwe Gasthuis, Department of Cardiology, Amsterdam, The Netherlands
3Catharina Hospital, Department of Radiotherapy, Eindhoven, The Netherlands, e-mail: [email protected],
INTRODUCTION
Radiotherapy can influence the
functioning of pacemakers. Guidelines for
radiotherapy treatment of patients with a
pacemaker have been published in 1994
by The American Association of
Physicists in Medicine (AAPM), and are
based on relatively old data of old
pacemaker types.
OBJECTIVE
to determine the influence of radiotherapy on modern pacemakers.
MATERIALS AND METHODS
19 new and modern pacemakers have
been irradiated in our department using a
6 MV beam. The given dose was
fractionated up to a cumulative dose of
120 Gy. Two to five days were kept
between consecutive irradiations.
Frequency, output, sensing, telemetry
and battery status were monitored.
Onze Lieve Vrouwe Gasthuis
RESULTS
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14 out of 19 pacemakers reached a point of failure.
One device permanently lost telemetry after 20 Gy.
All other points of failure revealed themselves after more than 80 Gy.
5 pacemakers showed an Elective Replacement Indication. This warning
is a result of a low battery voltage.
3 pacemakers lost telemetry.
7 pacemakers lost output, of which all but one recovered after one week.
2 pacemakers had problems with their sense channel at 120 Gy.
5 pacemakers did not show any error. All these devices
(numbers 10-13 and 15) where from the same manufacturer.
Device Manufacturer
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Medtronic
Medtronic
Medtronic
Vitatron
Vitatron
Vitatron
Vitatron
Vitatron
Vitatron
Guidant
Guidant
Guidant
Guidant
Guidant
Guidant
Guidant
St Jude Medical
St Jude Medical
St Jude Medical
Model
First
malfunction
EnPulse E2DR01
Kappa kd 701
Kappa kd 906
Model 860
Model 860
Model 640
Model C20A1
Model C50A1
Model C60A1
Meridian SSI 476
Meridian SSI 476
Discovery 11 SR 1186
Discovery 11 SR 1186
Contak TR CHFD 1241
Contak TR CHFD 1241
Contak TR CHFD 1241
Affinity 5230
Affinity 5230
Affinity 5230
Lead imp < 80%
Lead imp > 2000%
No comm.
Lead imp > 160%
Lead imp > 3600%
Lead imp > 200%
Lead imp 80%
Lead imp 70%
Lead imp 80%
Bad comm.
No comm.
Low amplitude
Low amplitude
Dose (Gy)
90
100
100
80
80
80
120
50
120
10
120
120
120
Point of failure
No output
No output
No output/no comm.
No output
No output
Bad output/bad sense
ERI/no sense
Short circuit/ERI
ERI
No output
No comm.
No output/no comm.
ERI
ERI
Dose (Gy)
90
100
100
120
80
120
Final
130/Final
Final
120
20
130
Final
Final
Table 1. Results for all 19 pacemakers. Eight out of 19 pacemakers exhibited inhibitions during irradiation (data not
shown). Type of malfunction is indicated together with the dose level(s) at which the malfunction manifested. In the
last column the definite point of failure is specified together with the dose level at which this occurred. Pacemakers 8
and 17 were erroneously irradiated to 130 Gy instead of 120 Gy. Final: measurement performed approximately 1-2
weeks after the last irradiation fraction.
CONCLUSIONS
The newest generation of pacemakers exhibit a variety of radiation induced defects. However, most malfunctions were
observed at dose levels exceeding 20 Gy. This is comparable to results observed for older pacemaker types.
Thus, the AAPM guidelines still seem to be valid.
Figure 1. Oscilloscope and Cenelec pulse
generator used at measurements
Figure 2. pacemaker within irradiation phantom attached
to a 510 Ohm resistance to simulate the heart load.