Impact of geographic miss on adjacent coronary artery segments in diffuse in-stent restenosis with beta-radiation therapy: angiographic and intravascular ultrasound analysis.
BACKGROUND
The impacts of geographic miss on edge restenosis have not been sufficiently evaluated.


METHODS
Beta-radiation therapy with rhenium 188-filled balloon after rotational atherectomy for diffuse in-stent restenosis was performed in 50 patients. We evaluated the impacts of geographic miss on adjacent coronary artery segments beyond the stent by angiographic (QCA) and intravascular ultrasound (IVUS) analysis in 50 irradiated lesions and 100 edges. Serial IVUS and QCA comparisons between postradiation and 6 months' follow-up were available in 44 and 47 of 50 patients, respectively. QCA measurements of minimal lumen diameter (MLD) and IVUS analysis were performed in the reference and radiation segments. Edges that were touched by the angioplasty balloon but were not adequately covered by radiation constituted the geographic miss edges.


RESULTS
Geographic miss was observed in 55.6% and 52.6% in QCA and IVUS analysis, respectively. Edge restenosis after radiation therapy in 3 patients was associated with geographic miss. In contrast to uninjured edges (postradiation 2.9 +/- 0.6 mm to follow-up 2.8 +/- 0.6 mm, P =.292), MLD in the radiation segment by QCA analysis significantly decreased from 2.7 +/- 0.4 mm to 2.4 +/- 0.6 mm in geographic miss edges (P =.002). IVUS analysis showed that significant positive remodeling in the radiation segment occurred in uninjured edges (vessel area from 15.4 +/- 4.4 mm2 to 15.8 +/- 4.4 mm2, P =.001) but not in geographic miss edges (vessel area from 12.8 +/- 3.6 mm2 to 13.0 +/- 3.6 mm2, P =.119).


CONCLUSIONS
The geographic miss might be one of the predictors, which resulted in decreased MLD at follow-up in beta-radiation therapy. Sufficient lesion coverage with radiation might be associated with positive remodeling in the radiation segment.
Hong
Myeong-Ki
MK
Department of Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Park
Seong-Wook
SW
Moon
Dae-Hyuk
DH
Oh
Seung-Jun
SJ
Kim
Eun-Hee
EH
Lee
Cheol Whan
CW
Song
Jong-Min
JM
Kang
Duk-Hyun
DH
Song
Jae-Kwan
JK
Kim
Jae-Joong
JJ
Park
Seung-Jung
SJ
D015906:Angioplasty, Balloon, Coronary; D003324:Coronary Artery Disease / Q000628:therapy; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D011868:Radioisotopes / Q000627:therapeutic use*; D012211:Rhenium / Q000627:therapeutic use*; D015607:Stents; D014463:Ultrasonography
D011868:Radioisotopes; D012211:Rhenium