Perfusion-CT monitoring of cryo-ablated renal cells tumors

Journal of Experimental & Clinical Cancer Research, Oct 2009

Background No single and thoroughly validated imaging method in monitoring of cryoablated renal cell carcinoma (RCC) is available. The purpose of our study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (pCT) in evaluating the hemodynamic response of RCC. Methods 15 patients (14 male, 1 female; age range, 43-81 years; mean age, 62 years) with cryoablated RCC via a transperitoneal approach, underwent to pCT 6-8 months after cryo-therapy. pCT was performed for 65 seconds after intravenous injection of contrast medium (80 mL, 370 mg iodine per millilitre, 4 mL/sec). Perfusion parameters (Time/Density curve; Blood flow, BF; Blood Volume, BV; Mean Transit Time, MTT; Permeability-Surface Area Product, PS) were sampled in the cryoablated tumor area and in ipsilateral renal cortex using deconvolution-based method. A tumor was considered to be not responsive to treatment by CT evidence of pathological contrast enhancement in the cryoablated area or renal mass persistence compared with the preoperative CT control. Written informed consent was obtained from all participants before the study. Results After cryotherapy, successfully ablated tumor (n = 13) showed decrease in BV (5,39 +/- 1,28 mL/100 g), BF (69,92 +/- 20,12 mL/100 g/min) and PS (16,66 +/- 5,67 mL/100 g/min) value and increased value of MTT (25,35 +/- 4,3 sec) compared with those of normal renal cortex (BV: 117,86 +/- 31,87 mL/100 g/min; BF: 392,39 +/- 117,32 mL/100 g/min; MTT: 18,02 +/- 3,6 sec; PS: 81,68 +/- 22,75 mL/100 g/min). In one patient, assessment of perfusion parameters was not feasible for breathing artifacts. One tumor showed poor response to treatment by the evidence of nodular contrast enhancement in the region encompassing the original lesion. Two typical enhancement patterns were obtained comparing the Time-Density curves of responsive and not responsive ablated tumors. Conclusion Perfusion CT seems to be a feasible and promising technique in monitoring the effects of cryoablation therapy.

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Perfusion-CT monitoring of cryo-ablated renal cells tumors

Journal of Experimental & Clinical Cancer Research Perfusion-CT monitoring of cryo-ablated renal cells tumors Ettore Squillaci 1 Guglielmo Manenti 1 Carmelo Cicci 1 Francesca Nucera 1 Pierluigi Bove 0 Giuseppe Vespasiani 0 Laura Russolillo 1 Giovanni Simonetti 1 0 Department of Urology, University Tor Vergata , Rome , Italy 1 Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy - University Tor Vergata , Rome , Italy Background: No single and thoroughly validated imaging method in monitoring of cryoablated renal cell carcinoma (RCC) is available. The purpose of our study was to determine the feasibility of dynamic contrast-enhanced perfusion CT (pCT) in evaluating the hemodynamic response of RCC. Methods: 15 patients (14 male, 1 female; age range, 43-81 years; mean age, 62 years) with cryoablated RCC via a transperitoneal approach, underwent to pCT 6-8 months after cryotherapy. pCT was performed for 65 seconds after intravenous injection of contrast medium (80 mL, 370 mg iodine per millilitre, 4 mL/sec). Perfusion parameters (Time/Density curve; Blood flow, BF; Blood Volume, BV; Mean Transit Time, MTT; Permeability-Surface Area Product, PS) were sampled in the cryoablated tumor area and in ipsilateral renal cortex using deconvolution-based method. A tumor was considered to be not responsive to treatment by CT evidence of pathological contrast enhancement in the cryoablated area or renal mass persistence compared with the preoperative CT control. Written informed consent was obtained from all participants before the study. Results: After cryotherapy, successfully ablated tumor (n = 13) showed decrease in BV (5,39 +/1,28 mL/100 g), BF (69,92 +/- 20,12 mL/100 g/min) and PS (16,66 +/- 5,67 mL/100 g/min) value and increased value of MTT (25,35 +/- 4,3 sec) compared with those of normal renal cortex (BV: 117,86 +/- 31,87 mL/100 g/min; BF: 392,39 +/- 117,32 mL/100 g/min; MTT: 18,02 +/- 3,6 sec; PS: 81,68 +/ - 22,75 mL/100 g/min). In one patient, assessment of perfusion parameters was not feasible for breathing artifacts. One tumor showed poor response to treatment by the evidence of nodular contrast enhancement in the region encompassing the original lesion. Two typical enhancement patterns were obtained comparing the Time-Density curves of responsive and not responsive ablated tumors. Conclusion: Perfusion CT seems to be a feasible and promising technique in monitoring the effects of cryoablation therapy. - Background Renal cell carcinoma (RCC) is the most common type of kidney cancer (8.100 deaths and 33.130 expected new cases in United States for the 2007), encompassed among highly vascularised tumors [1,2]. Furthermore the common use of cross-sectional imaging method in clinical practise has increased the detection of incidental small RCC [3,4]. Minimally invasive treatments as cryoablation or radioablation have been proposed as a promising alternative to partial or total nephrectomy in selected cases, especially in patients who are poor candidates for conventional surgical resection. Cryoablation of renal tumors can be performed at open, laparoscopic, retroperitoneoscopic surgery and with imaging guided (Computed Tomography, CT; Magnetic Resonance Imaging, MRI) percutaneous approaches. By the evidence of effectiveness in renal tumor constraining of these new thermal therapies, attention is focused to identify a reliable marker of early residual tumor and a feasible imaging monitoring protocol. Vascularity degree of RCC is known as a prognostic factor correlated with clinical and pathologic stage, metastatic risk and histopathologic grade and it is a significant predictor of disease-specific outcome after therapy [5]. Although a standardized and thoroughly validated method to evaluate tumor vascularity is not available, some biomarkers have been currently proposed as indexes of tumor angiogenic activity. In particular, significant increase of micro vessel density (MVD) and high expression and secretion of vascular endothelial growth factor (VEGF), have been reported in tumor tissue [6]. However, the serial evaluation of these biomarkers as indexes of tumor activity, needs multiple biopsies and is limited because of its invasiveness especially during a long-term follow-up. An ideal test should be non-invasive, fast, easy to perform, repeatable and reproducible, and most importantly, it should provide in vivo early evidence of residual tumor after therapy and comprehensive data of the tumor structure with informations on tumor angiogenesis functional status. New imaging modalities (MRI, CT) may be used to obtain informations about microvascular circulation and neoangiogenesis. CT is the imaging technique of reference in surveillance after renal tumor ablation as its ability to distinguish residual tumor (nodular enhancement within the ablated lesion) from successfully cryo-ablated lesion (hypoattenuating areas without focal contrast enhancement with progressive (...truncated)


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Ettore Squillaci, Guglielmo Manenti, Carmelo Cicciò, Francesca Nucera, Pierluigi Bove, Giuseppe Vespasiani, Laura Russolillo, Giovanni Simonetti. Perfusion-CT monitoring of cryo-ablated renal cells tumors, Journal of Experimental & Clinical Cancer Research, 2009, pp. 138, 28, DOI: 10.1186/1756-9966-28-138