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MP92-20 DIFFERENTIATION BETWEEN NORMAL AND CANCEROUS RENAL TISSUES USING ELECTRICAL IMPEDANCE SPECTROSCOPY NEEDLE.
THE JOURNAL OF UROLOGYâ
Vol. 195, No. 4S, Supplement, Tuesday, May 10, 2016
MP92-19
MP92-20
EXPERIMENTAL IMAGING IN ORTHOTOPIC XENOGRAFT MODELS OF RENAL CELL CARCINOMA: COMPARATIVE EVALUATION OF HIGH-RESOLUTION ULTRASONOGRAPHY, IN-VIVO MICRO-CT AND 9.4T MRI
DIFFERENTIATION BETWEEN NORMAL AND CANCEROUS RENAL TISSUES USING ELECTRICAL IMPEDANCE SPECTROSCOPY NEEDLE.
€rbel, Andreas Mu € ller, Volker Jung, Johannes Linxweiler*, Christina Ko €ngel, Frankfurt/Main, Germany; Homburg/Saar, Germany; Eva Ju €ckle, Kerstin Junker, Michael D. Menger, Stefan Siemer, Michael Sto Matthias Saar, Homburg/Saar, Germany INTRODUCTION AND OBJECTIVES: Orthotopic xenografts are increasingly used preclinical in-vivo models for the study of renal cell carcinoma (RCC). However, monitoring of these tumors requires sophisticated imaging techniques. Herein we comparatively evaluated modern small animal imaging tools like high-resolution 3D-ultrasonography (3D-US), contrast-enhanced in-vivo micro-CT (CE-CT) and 9,4T MRI (MRI) to monitor tumor growth in an orthotopic RCC xenograft model. METHODS: 106 CAKI-1 cells were injected under the renal capsule of 18 Balb/c-nude mice. Every 14 days from week 4 imaging was performed by CE-CT and 3D-US. 10 weeks after cell inoculation, all animals additionally underwent MRI. At autopsy, tumor volumes were determined with a caliper and compared to in-vivo imaging results. CE-CT, MRI and 3D-US were evaluated regarding tumor detection, tumor volume analysis, radiographic imaging properties and examination time. Finally, RCC cell lines KTCTL30 (n¼2) and 786-0 (n¼1) were used to test their applicability for the orthotopic xenograft model. RESULTS: In 16/18 animals (take rate 89%) all methods enabled to adequately visualize orthotopic tumors and to display their growth over time. While the tumors had a homogenously radiolucent signal in CE-CT, 3D-US and MRI could better visualize intratumoral structures and surrounding soft tissue. CT had the best spatial resolution, followed by 3D-US and MRI. Median examination time was 4.8min per 3D-US, 12.5min per CT and 37.9min per MRI, respectively. Of interest, tumor volumes determined by CE-CT and 3D-US showed strong correlation with each other (n¼85, R¼0.985) as well as with caliper measurements at autopsy (CT: n¼16. R¼0.922; 3D-US: n¼16, R¼0.934). Similarly, tumor volumes measured with T2w MRI correlated well with those determined by CT, 3D-US and caliper. No side effects due to radiation exposure were seen. Mice inoculated with KTCTL30 cells developed partly cystic, partly solid tumors. 786-O cells yielded purely solid, fast growing tumors. CONCLUSIONS: All three imaging modalities are feasible tools for a non-invasive monitoring of orthotopic tumor growth and show excellent correlation with each other. While 3D-US allows for a fast analysis of tumor volume with excellent resolution, MRI provides the best soft tissue contrast and can give additional information about tumor biology (e.g. diffusion, perfusion). CT has the best spatial resolution and enables simultaneous screening for bone and lung metastases but relies on the use of contrast agent and ionizing radiation.
Hyeon Woo Kim*, Joho Yun, Yangkyu Park, Gwangju, Korea, Republic of; Dong Gil Shin, Jeong Zoo Lee, Busan, Korea, Republic of; Jong-Hyun Lee, Gwangju, Korea, Republic of; Wan Lee, Chang Yell Lee, Busan, Korea, Republic of INTRODUCTION AND OBJECTIVES: Electrical impedance spectroscopy (EIS) added on a hypodermic needle can analyze the impedance (consist of magnitude and phase angle) of tissues in the frequency domain. In this study, an EIS-on-a-Needle (EoN) was proposed for real-time discrimination between normal and cancerous renal tissues. METHODS: EoN was fabricated by adding an electrical sensor at the tip of a 22-guage hypodermic needle using photolithography technology in semiconductor process. To evaluate the efficacy of EoN in discriminating between normal and cancerous renal tissues, three nephrectomy kidney specimens with clear cell carcinoma was prepared. EoN was inserted 2 mm deep into the normal and tumor tissue of each specimen and the electrical impedance of the tissues were measured over the frequency range from 100 Hz to 1 MHz at an operating voltage of 200 mVrms. The mean of magnitude and phase angle from the three specimens at each frequency were compared between the normal and tumor tissues to evaluate the effectiveness of EoN. RESULTS: The normal and tumor tissues were apparently discriminated by mean magnitude and phase angle at the frequency range from 200 kHz to 1 MHz. The largest difference was observed at 630 kHz and 200 kHz for mean magnitude and phase angle, respectively. The mean impedance values of the normal tissues were tended to be larger than those of the tumor tissues at the frequency range from 200 kHz to 1 MHz. CONCLUSIONS: EoN could apparently discriminate between normal and cancerous renal tissues at the frequency range from 200 kHz to 1 MHz. Further studies using larger number of specimens are essential for a precise evaluation of EoN in tissue discrimination.
Source of Funding: Deutsche Forschungsgemeinschaft (DFG) Brigitta & Norbert Muth Stiftung HOMFOR
e1169
Source of Funding: None.
Vol. 195, No. 4S, Supplement, Tuesday, May 10, 2016
MP92-19
MP92-20
EXPERIMENTAL IMAGING IN ORTHOTOPIC XENOGRAFT MODELS OF RENAL CELL CARCINOMA: COMPARATIVE EVALUATION OF HIGH-RESOLUTION ULTRASONOGRAPHY, IN-VIVO MICRO-CT AND 9.4T MRI
DIFFERENTIATION BETWEEN NORMAL AND CANCEROUS RENAL TISSUES USING ELECTRICAL IMPEDANCE SPECTROSCOPY NEEDLE.
€rbel, Andreas Mu € ller, Volker Jung, Johannes Linxweiler*, Christina Ko €ngel, Frankfurt/Main, Germany; Homburg/Saar, Germany; Eva Ju €ckle, Kerstin Junker, Michael D. Menger, Stefan Siemer, Michael Sto Matthias Saar, Homburg/Saar, Germany INTRODUCTION AND OBJECTIVES: Orthotopic xenografts are increasingly used preclinical in-vivo models for the study of renal cell carcinoma (RCC). However, monitoring of these tumors requires sophisticated imaging techniques. Herein we comparatively evaluated modern small animal imaging tools like high-resolution 3D-ultrasonography (3D-US), contrast-enhanced in-vivo micro-CT (CE-CT) and 9,4T MRI (MRI) to monitor tumor growth in an orthotopic RCC xenograft model. METHODS: 106 CAKI-1 cells were injected under the renal capsule of 18 Balb/c-nude mice. Every 14 days from week 4 imaging was performed by CE-CT and 3D-US. 10 weeks after cell inoculation, all animals additionally underwent MRI. At autopsy, tumor volumes were determined with a caliper and compared to in-vivo imaging results. CE-CT, MRI and 3D-US were evaluated regarding tumor detection, tumor volume analysis, radiographic imaging properties and examination time. Finally, RCC cell lines KTCTL30 (n¼2) and 786-0 (n¼1) were used to test their applicability for the orthotopic xenograft model. RESULTS: In 16/18 animals (take rate 89%) all methods enabled to adequately visualize orthotopic tumors and to display their growth over time. While the tumors had a homogenously radiolucent signal in CE-CT, 3D-US and MRI could better visualize intratumoral structures and surrounding soft tissue. CT had the best spatial resolution, followed by 3D-US and MRI. Median examination time was 4.8min per 3D-US, 12.5min per CT and 37.9min per MRI, respectively. Of interest, tumor volumes determined by CE-CT and 3D-US showed strong correlation with each other (n¼85, R¼0.985) as well as with caliper measurements at autopsy (CT: n¼16. R¼0.922; 3D-US: n¼16, R¼0.934). Similarly, tumor volumes measured with T2w MRI correlated well with those determined by CT, 3D-US and caliper. No side effects due to radiation exposure were seen. Mice inoculated with KTCTL30 cells developed partly cystic, partly solid tumors. 786-O cells yielded purely solid, fast growing tumors. CONCLUSIONS: All three imaging modalities are feasible tools for a non-invasive monitoring of orthotopic tumor growth and show excellent correlation with each other. While 3D-US allows for a fast analysis of tumor volume with excellent resolution, MRI provides the best soft tissue contrast and can give additional information about tumor biology (e.g. diffusion, perfusion). CT has the best spatial resolution and enables simultaneous screening for bone and lung metastases but relies on the use of contrast agent and ionizing radiation.
Hyeon Woo Kim*, Joho Yun, Yangkyu Park, Gwangju, Korea, Republic of; Dong Gil Shin, Jeong Zoo Lee, Busan, Korea, Republic of; Jong-Hyun Lee, Gwangju, Korea, Republic of; Wan Lee, Chang Yell Lee, Busan, Korea, Republic of INTRODUCTION AND OBJECTIVES: Electrical impedance spectroscopy (EIS) added on a hypodermic needle can analyze the impedance (consist of magnitude and phase angle) of tissues in the frequency domain. In this study, an EIS-on-a-Needle (EoN) was proposed for real-time discrimination between normal and cancerous renal tissues. METHODS: EoN was fabricated by adding an electrical sensor at the tip of a 22-guage hypodermic needle using photolithography technology in semiconductor process. To evaluate the efficacy of EoN in discriminating between normal and cancerous renal tissues, three nephrectomy kidney specimens with clear cell carcinoma was prepared. EoN was inserted 2 mm deep into the normal and tumor tissue of each specimen and the electrical impedance of the tissues were measured over the frequency range from 100 Hz to 1 MHz at an operating voltage of 200 mVrms. The mean of magnitude and phase angle from the three specimens at each frequency were compared between the normal and tumor tissues to evaluate the effectiveness of EoN. RESULTS: The normal and tumor tissues were apparently discriminated by mean magnitude and phase angle at the frequency range from 200 kHz to 1 MHz. The largest difference was observed at 630 kHz and 200 kHz for mean magnitude and phase angle, respectively. The mean impedance values of the normal tissues were tended to be larger than those of the tumor tissues at the frequency range from 200 kHz to 1 MHz. CONCLUSIONS: EoN could apparently discriminate between normal and cancerous renal tissues at the frequency range from 200 kHz to 1 MHz. Further studies using larger number of specimens are essential for a precise evaluation of EoN in tissue discrimination.
Source of Funding: Deutsche Forschungsgemeinschaft (DFG) Brigitta & Norbert Muth Stiftung HOMFOR
e1169
Source of Funding: None.