Perfusion CT in patients with metastatic renal cell carcinoma treated with interferon.
ABSTRACT The objective of our study was to assess the potential value of tumor perfusion parameters measured by perfusion CT as possible biomarkers of prognosis and early indicator of treatment efficacy in patients with metastatic conventional renal cell carcinoma (RCC) treated with interferon.
This study comprised 37 patients with metastatic RCC who were enrolled in a larger (n=118) randomized clinical trial of intermediate- versus low-dose interferon. Tumor perfusion parameters-that is, tumor blood flow, blood volume, mean transit time (MTT), and permeability-surface area product-of index metastatic lesions were obtained at baseline and at 8-week follow-up. Baseline perfusion parameters and changes at follow-up were compared, and their associations with patient progression-free survival were estimated. Univariate and multivariate analyses were performed.
Twenty-eight patients were assessable. Median progression-free survival was 5.3 months (95% CI, 2.4-7.4 months), with one partial response. Tumor blood flow at baseline was inversely associated with patient progression-free survival in both univariate (hazard ratio [HR]=1.006, p=0.025) and multivariate (HR=1.007, p=0.012) analyses. There were significant increases in tumor blood flow and reductions in MTT on follow-up scans compared with baseline scans (both, p=0.04), but no association between changes in perfusion parameters and progression-free survival was detected.
Patients with highly vascularized metastatic RCC as shown by high baseline tumor blood flow appear to have a worse prognosis than those who do not. Tumor perfusion may be a useful biomarker of prognosis and additionally, in the future, may assist in treatment stratification. The potential utility of perfusion CT as an early response indicator was probably inadequately assessed in this study because of the limited antiangiogenic activity of interferon in metastatic RCC.
- Journal of Gastrointestinal Cancer 06/2012;
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ABSTRACT: The aim of our study was to correlate perfusion MDCT parameters and immunohistochemical markers of angiogenesis in prostate cancer. Twenty-two patients scheduled for radical surgical prostatectomy because of biopsy-proven prostate cancer underwent perfusion CT on a 64-MDCT scanner. Eight contiguous 5-mm sections were acquired at 1-second intervals for 45 seconds followed by three additional scans every 10 seconds after the administration of 80 mL of iodinated contrast medium (350 mg I/mL). Blood volume, blood flow, mean transit time, and permeability surface-area product were calculated, dividing each slice into nine square regions. Values obtained were correlated with the mean microvessel density (MVD) and mean vascular area of corresponding areas on histologic macrosections. The mean values of the perfusion parameters detected on all square fields of patients with prostate cancer, benign hyperplasia, chronic prostatitis, and healthy tissue were, respectively, 18.36 ± 6.30, 19.49 ± 8.46, 19.67 ± 11.44, and 20.32 ± 4.53 mL/min/100 g for blood flow; 8.45 ± 2.75, 6.21 ± 4.32, 4.94 ± 2.31, and 5.44 ± 2.67 mL/100 mg for blood volume; 19.19 ± 4.45, 18.74 ± 4.91, 16.24 ± 4.12, and 16.37 ± 4.83 seconds for mean transit time; and 26.34 ± 11.88, 18.67 ± 9.15, 18.08 ± 7.72, and 19.93 ± 7.22 mL/min/100 g for permeability surface-area product. Both blood volume and the permeability surface-area product of cancerous squares showed the highest correlation with mean MVD and mean vascular area (0.618 [p < 0.01] and 0.614 [p < 0.01], respectively) and the highest area under the curve (0.769 and 0.708). Our results show that blood volume and permeability surface-area product measurements obtained with perfusion CT have the highest correlation with immunohistochemical markers of angiogenesis in prostate cancer.American Journal of Roentgenology 11/2012; 199(5):1042-8. · 2.90 Impact Factor
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ABSTRACT: To compare two scanning protocols (free breathing versus breath-hold) for perfusion imaging using dynamic volume computed tomography (CT) and to evaluate their effects on image registration. Forty patients underwent dynamic volume CT for pancreatic perfusion analysis and were randomly assigned to either a shallow-breathing (I) or breath-hold (II) group. Both dynamic CT protocols consisted of 17 low-dose volumetric scans. Rigid image registration was performed by using the volume with highest aortic attenuation as reference. All other volumes were visually matched with the pancreatic lesion serving as the volumetric region of interest. The overall demand for post-processing per patient was calculated as the median of three-dimensional vector lengths of all volumes in relation to the relative patient origin. The number of volumes not requiring registration was recorded per group. Registration mismatch for groups I and II was 2.61 mm (SD, 1.57) and 4.95 mm (SD, 2.71), respectively (P < 0.005). Twenty-eight volumes in group I (8.2%) and 47 volumes in group II (14.1%) did not require manual registration (P = 0.014). Shallow breathing during dynamic volume CT scanning reduces the overall demand for motion correction and thus may be beneficial in perfusion imaging of the pancreas MAIN MESSAGES: • Shallow breathing during perfusion CT scanning reduces the overall demand for motion correction. • Shallow breathing may be beneficial in perfusion imaging of the pancreas. • Image registration is crucial for CT perfusion imaging.Insights into imaging. 05/2012; 3(4):323-8.