DOI:10.2214/AJR.06.1445
AJR 2007; 188:W570
© American Roentgen Ray Society
Reply
Jin-hong Wang,
Pei-jun Wang and
Xiao-hu Zhao
Tong Ji Hospital Tong Ji University Shanghai, China
WEB—This is a Web exclusive article.
We read with great interest the comments from Dr. Masahiro Jinzaki and his
colleague regarding our article
[1], and we appreciate their
interest in our recent work. We are pleased that they share the same idea with
us that contrast-enhanced CT may reveal tumor microvascular heterogeneity
among individual tumors. However, there were some differences between the
Jinzaki et al. study [2] and
our study. In their study, the homogeneity of enhancement was defined when
more than 90% of the area was occupied by the same attenuation value
ascertained by visual inspection, and pathologic findings revealed any renal
cell carcinoma (RCC) with heterogeneity of enhancement that showed
intratumoral necrosis or hemorrhage on the histologic specimen.
Clearly, necrotic areas must not provide microvasculature. So the
heterogeneity of tumor in the Jinzaki et al. study
[2] referred to tumor with and
without microvascularity. In our study, we selected two regions of interest
(ROIs) on fairly heterogeneously enhanced parenchyma of tumor, avoiding
cystoid change and intratumoral necrosis because parenchyma of tumor can
reflect the characteristics of tumor. Therefore, we evaluated the
heterogeneity of only tumor with microvasculature. We fully agree with Dr.
Jinzaki and his colleague that multiphase scanning of the whole tumor will
result in a higher radiation dose. Single-phase CT might be a useful method in
evaluating the degree of angiogenesis. The key point is determining at what
exact time to start scanning tumors on single-phase CT.
It is necessary to define an optimized temporal window for scanning of RCC.
The time windows for renal scanning are linked to and affected by a number of
parameters, including biologic indicators such as weight, heart rate, blood
pressure, circulation time, functionality of the heart and kidneys, and so on
[3–6].
We do not think that single-phase scanning can make a definite evaluation of
tumor microvasculature, especially for small RCCs, because of these factors.
In another of our studies, the optimized temporal window of multiphase dynamic
CT for RCC was suggested [7].
We believe that further comparative studies of multiphase and single-phase
scanning are needed to determine whether single-phase scanning is sufficient
in evaluating the degree of angiogenesis.
In addition, according to the Jinzaki et al.
[2] study, the subtype of RCC
was one of the important factors affected by the degree of tumor enhancement
and the degree of angiogenesis of RCC. In our study, we observed 16 cases of
clear cell carcinoma, three cases of granular cell carcinoma, and five cases
of mixed-type RCC. Because the numbers of granular cell RCC and mixed-type RCC
were small, statistical analyses for each of these subtypes was of no
significance. Therefore, additional studies with larger numbers of each
subtype of RCC are needed to verify the correlation between the density
difference before and after contrast enhancement (
H) of RCC and its
subtype. We thank Dr. Jinzaki and his colleague for their interest in our
study and their valuable comments.
References
- Wang JH, Min PQ, Wang PJ, et al. Dynamic CT evaluation of tumor
vascularity in renal cell carcinoma. AJR2006; 186:1423
–1430[Abstract/Free Full Text]
- Jinzaki M, Tanimoto A, Mukai M, et al. Double-phase helical CT of
small renal parenchymal neoplasms: correlation with pathologic findings and
tumor angiogenesis. J Comput Assist Tomogr2000; 24:835
–842[CrossRef][Medline]
- Sheth S, Scatarige JC, Horton KM, et al. Current concepts in the
diagnosis and management of renal cell carcinoma: role of multidetector CT and
three-dimensional CT. RadioGraphics 2001;21
[spec no]:S237
–S254[Abstract/Free Full Text]
- Bosniak MA. The small (
3.0 cm) renal parenchymal tumor:
detection, diagnosis, and controversies. Radiology1991; 179:307
–317[Free Full Text] - Rubin GD, Napel SA, Leung AN. Volumetric analysis of volumetric
data: achieving a paradigm shift. Radiology1996; 200:312
–317[Free Full Text]
- Berland LL. Slip ring and conventional dynamic hepatic CT: contrast
material and timing considerations. Radiology1995; 195:1
–8[Abstract/Free Full Text]
- Wang JH, Min PQ, Wang PJ, et al. Optimized temporal window for
detection and characterization of renal cell carcinomas with dynamic CT
scanning. Chinese J Clin Oncol (English edition)2005; 2:546
–552
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