FDG-MicroPET and Diffusion-Weighted MR Image Evaluation of Early Changes After Radiofrequency Ablation in Implanted VX2 Tumors in Rabbits

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Cardiovascular and Interventional Radiology

DOI:https://doi.org/10.1007/S00270-008-9394-5· OSTI ID:21426325

Ohira, Tomohiro; Okuma, Tomohisa; Matsuoka, Toshiyuki ^[1]; Wada, Yasuhiro ^[2]; Nakamura, Kenji ^[1]; Watanabe, Yasuyoshi ^[3]; Inoue, Yuichi ^[1]

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1. Osaka City University Graduate School of Medicine, Department of Radiology (Japan)
2. RIKEN, Molecular Imaging Research Program (Japan)
3. Osaka City University Graduate School of Medicine, Department of Physiology (Japan)

The objective of this study was to evaluate the early changes after radiofrequency ablation (RFA) in VX2 rabbit tumors implanted into the back muscles by diffusion-weighted magnetic resonance (MR) imaging and {sup 18}F-2-fluoro-2-deoxy-D-glucose positron emission tomography ({sup 18}F-FDG PET). Percutaneous CT-guided RFA was conducted in seven rabbits with implanted VX2 tumors. VX2 tumors on the other side were untreated and served as the control. MR imaging was performed with a clinical 1.5-T instrument 2 days after RFA, and FDG-PET, using a high-resolution PET scanner for small animals, was obtained 3 days after the procedure. The mean apparent diffusion coefficient (ADC) values and radioactivity count of untreated and ablated tumors were calculated. Untreated VX2 tumors showed hyperintensity on T1-, T2-, and diffusion-weighted MR images, ring-enhanced on contrast-enhanced T1-weighted imaging, and ring-shaped FDG accumulation on FDG-PET. Ablated VX2 tumors showed slight hyperintensity on T1-, T2-, and diffusion-weighed images, slight enhancement on contrast-enhanced T1-weighted images, and low accumulation on FDG-PET. The ADC value of ablated VX2 tumors (1.52 {+-} 0.24 x 10{sup -3} mm{sup 2}/s) was significantly higher than that of untreated tumors (1.09 {+-} 0.12 x 10{sup -3}; p < 0.05). The tumor/muscle ratio of ablated tumors (0.5 {+-} 0.3) was significantly lower than that of untreated tumors (11.6 {+-} 3.2; p < 0.05). Histopathological examination confirmed the lack of viable tumor cells in the ablated lesions. The results indicate that both ADC value and FDG-PET are potentially useful markers for monitoring the early effects of RFA.

• OSTI ID: 21426325
• Journal Information: Cardiovascular and Interventional Radiology, Journal Name: Cardiovascular and Interventional Radiology Journal Issue: 1 Vol. 32; ISSN 0174-1551; ISSN CAIRDG
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ABLATION
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
DISEASES
ELECTROMAGNETIC RADIATION
EMISSION COMPUTED TOMOGRAPHY
FLUORINE 18
FLUORINE ISOTOPES
HOURS LIVING RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAMMALS
MUSCLES
NANOSECONDS LIVING RADIOISOTOPES
NEOPLASMS
NMR IMAGING
NUCLEI
ODD-ODD NUCLEI
POSITRON COMPUTED TOMOGRAPHY
RABBITS
RADIATIONS
RADIOISOTOPES
RADIOWAVE RADIATION
TOMOGRAPHY
TUMOR CELLS
VERTEBRATES