Purpose
Antiangiogenic therapy induces a decrease in tumor vasculature but is of limited efficacy in tumor shrinkage (more cytostatic than cytotoxic).
Clinical trials have demonstrated that RECIST may underestimate the benefit induced by these new therapies (1).
New radiological criteria based on changes in vascular supply rather than size and density have provided better results than RECIST in monitoring therapeutic response.
As the new therapeutic agents for the treatment of mRCC inhibit angiogenesis,
tumor perfusion imaging may therefore be more appropriate for the assessment of tumor...
Methods and Materials
From May 2011 to May 2012,
patients meeting the following inclusion criteria were enrolled in this prospective study:
Patients with metastatic RCC candidates for therapy with sunitinib.
Life expectancy ≥ 3 months.
Signed informed consent.
Sunitinib was administered according to standard schedule,
50mg orally once daily for four weeks,
followed by two weeks off treatment.
Treatment was continued until disease progression or unacceptable toxicity.
A thoraco-abdominal CT in arterial and venous phase and a volumetric study with perfusion-CT (Flash Definition,
Siemens,
Erlangen,
Germany) were performed...
Results
From March 2011 to May 2012,
16 patients were included.
Most of the patients had clear cell carcinoma (n=13,
81.25%) and good prognosis (n=14,
87.5%),
based on the Motzer and Heng criteria.
Descriptive baseline characteristics of the patients are summarized in Table 1.
CT scans at one and four months were performed in 14 and 12 patients,
respectively,
as described in Figure 1.
Two patients were lost before the 4 month CT follow-up.
Although initially six patterns were described,
at the final analysis we established...
Conclusion
The changes in density and perfusion parameters precede the changes in size.
This suggests that the early changes in tumor perfusion are indicative of effective response after the first cycle of antiangiogenic therapy with sunitinib.
Despite the small sample size and short follow-up of this study,
the data presented suggest that perfusion-CT may be a useful technique to predict the response to antiangiogenic therapy.
References
Motzer RJ,
Hutson TE,
Tomczak P,
Michaelson MD,
Bukowski RM,
Rixe O,
et al.
Sunitinib versus interferon alfa in metastatic renal-cell carcinoma.
N Engl J Med 2007;356(2):115-24.
Epub 2007/01/12.
Van der Veldt AA,
Meijerink MR,
van den Eertwegh AJ,
Boven E.
Targeted therapies in renal cell cancer: recent developments in imaging.
Targeted oncology.
2010;5(2):95-112.
Epub 2010/07/14.