DOI: 10.1148/radiol.2392051233
(Radiology 2006;239:610-611.)
© RSNA, 2006
Endovascular Brachytherapy
Nicolas A. Diehm, MD,
Felix Mahler, MD,
Dai-Do Do, MD and
Iris Baumgartner, MD
Swiss Cardiovascular Center, Division of Angiology, Inselspital, University of Bern, Freiburgstrasse, Bern 3010, Switzerland
e-mail: iris.baumgartner{at}insel.ch
Editor:
We read with great interest the article by Dr Wolfram and colleagues (1) in the July 2005 issue of Radiology, in which they retrospectively analyzed subgroups of patients initially randomized within two different studies stratifying outcomes of patients treated for femoropopliteal obstructions by means of percutaneous transluminal angioplasty (PTA) alone or with adjunctive endovascular brachytherapy (EVBT).
Within both studies, ultrasonographic and angiographic morphologic outcomes in patients with de novo lesions of 5 cm or longer or recurrent lesions of any length were analyzed applying binary restenosis as a primary clinical end point by using Kaplan-Meier and log-rank statistics. The key message of this article is that EVBT has a beneficial effect in patients with recurrent femoropopliteal obstructions, significantly lowering recurrence rates after balloon angioplasty after 12 months of follow-up in this subgroup of patients.
Figures 1–4, which show Kaplan-Meier estimates of recurrence rates, are misleading and tend to show the direct opposite of the conclusions mentioned above. The y-axis shows the percentage of patients with recurrence starting at 100% at the onset, suggesting, for example, a recurrence rate higher than 95% after 1 month of follow-up in both groups. We suppose that the description of the y-axis should be "freedom from binary restenosis" rather than "recurrence rate." Even then, the treatment modality PTA with EVBT in figure 2 in recurrent stenoses would—contrary to the conclusions—show results worse than those with PTA alone. Figure 2 also contradicts figure 3, which shows, in accordance with the conclusions, that PTA alone is better than PTA with EVBT in de novo lesions. Interestingly, the lines in figures 2 and 3 are completely identical, although describing different things.
Moreover, the results of the multivariate Cox regression analysis are puzzling, since they would suggest a more than three times higher risk of recurrence with EVBT than without it in recurrent lesions.
Furthermore, the statement, "When we compared results in patients with restenotic lesions with those in patients with de novo lesions, patients with de novo lesions treated with PTA alone had a significantly better outcome than did those treated with PTA and brachytherapy (P = .005, log-rank test) (Fig 3)," given at the end of the second paragraph in the results section, does not match the data given in figure 3, which shows comparison of outcomes for patients with de novo versus those with recurrent stenoses treated by means of PTA alone.
In conclusion, reading this article to the end does more to confuse than to enlighten the statements given in the abstract.
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Reference
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- Wolfram RM, Budinsky AC, Pokrajac B, Potter R, Minar E. Endovascular brachytherapy: restenosis in de novo versus recurrent lesions of femoropopliteal artery—the Vienna experience. Radiology 2005;236(1):338–342.[Abstract/Free Full Text]
Response
Roswitha M. Wolfram, MD*,
Boris Pokrajac, MD
,
Erich Minar, MD*,
Richard Potter, MD and
Alexandra C. Budinsky, MD*
Departments of Angiology* and Radiation Therapy, Medical University of Vienna, Waehringer Guertel 18–20, Vienna 1090, Austria
e-mail: rmwolfram{at}hotmail.com
We appreciate the interest of Dr Diehm and colleagues concerning our article (1). As the authors of the letter correctly pointed out, a number of errors were found in our publication. We thank Dr Diehm and colleagues for pointing out the errors. The errors occurred due to an unfortunate combination of circumstances during the (our) internal submission and review process. The erratum follows and notes the correct captions of figures 1–4 and of the y-axis, which should read "Freedom from binary restenosis" instead of "recurrence rates."
We are deeply apologetic for the apparent confusion.
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Reference
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- Wolfram RM, Budinsky AC, Pokrajac B, Potter R, Minar E. Endovascular brachytherapy: restenosis in de novo versus recurrent lesions of femoropopliteal artery—the Vienna experience. Radiology 2005;236:338–342.[Abstract/Free Full Text]
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