Increased dosage during intracoronary irradiation due to overlapped source stepping shows no long-term adverse changes in vessel morphology.
OBJECTIVE
The purpose of this analysis was to evaluate if overdosage during intracoronary irradiation due to overlapped source stepping may result in long-term morphologic changes in vessel anatomy.


METHODS
Baseline angiograms of patients with in-stent restenosis undergoing coronary reintervention followed by intracoronary irradiation with source stepping were analyzed. Overlapping was considered present for the segment with overlapped reference isodose length (RIL) (RIL = segment with > or = 90% of reference dose at 1 mm vessel wall depth). Baseline and 6-months follow-up volumetric intravascular ultrasound (IVUS) analysis were performed for the overlapped segment and for proximal and distal segments of equal length.


RESULTS
Overlapping was found in six patients (three patients: (32)P treatment; three patients: (90)Sr/Y treatment); final analysis was performed in four patients. Comparison of the baseline and follow-up IVUS volumetric parameters revealed no significant change in lumen or vessel volumes at segments of overlaps in comparison to proximal and distal reference segments.


CONCLUSIONS
Increased dosage due to overlapping during source stepping is not associated with morphologic changes in vessel anatomy at follow-up.
Syeda
Bonni
B
Department of Internal Medicine II, Division of Cardiology, University of Vienna, Vienna, Austria. bonni.syeda@akh-wien.ac.at
Yahya
Nabil
N
Schmid
Rainer
R
Kirisits
Christian
C
Denk
Stefan
S
Derntl
Michael
M
Schukro
Christoph
C
Pokrajac
Boris
B
Potter
Richard
R
Glogar
Dietmar
D
D000800:Angioplasty, Balloon; D023903:Coronary Restenosis / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D021621:Imaging, Three-Dimensional; D010761:Phosphorus Radioisotopes / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D013326:Strontium Radioisotopes / Q000008:administration & dosage* / Q000009:adverse effects; D018084:Ultrasonography, Interventional
D010761:Phosphorus Radioisotopes; D013326:Strontium Radioisotopes