Akira Toriihara1, Hiromitsu Daisaki2, Akihiro Yamaguchi3, Makoto Kobayashi4, Shogo Furukawa4, Katsuya Yoshida5, Jun Isogai3, Ukihide Tateishi6. 1. Department of Diagnostic Radiology and Nuclear Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: trihmrad@tmd.ac.jp. 2. Department of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1, Kamioki-machi, Maebashi, Gunma 371-0052, Japan. 3. Department of Radiology, Asahi General Hospital, 1326 I, Asahi, Chiba 289-2511, Japan. 4. Department of Neurology, Asahi General Hospital, 1326 I, Asahi, Chiba 289-2511, Japan. 5. PET Imaging Center, Asahi General Hospital, 1326 I, Asahi, Chiba 289-2511, Japan. 6. Department of Diagnostic Radiology and Nuclear Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
Abstract
PURPOSE: To evaluate potential of a semiquantitative method using standardized uptake value (SUV) in 123I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) single photon emission computed tomography/computed tomography (SPECT/CT) compared with specific binding ratio (SBR). MATERIALS AND METHODS: First, we performed a phantom study to validate the accuracy of measuring SUV. 52 patients (25 male, 27 female; mean age of 75.1-year-old; 40 and 12 patients with neurodegenerative diseases with or without presynaptic dopaminergic deficits, respectively) were enrolled in a retrospective study. We measured SBR, maximum SUV, peak SUV, mean SUV, and striatum-to-background ratio of SUV (SUVratio) for striatum with lower 123I-FP-CIT uptake using commercial software. We calculated Pearson's correlation coefficient between SBR and SUV. We also calculated the sensitivity, specificity, and accuracy of each parameter for differential diagnosis. RESULTS: The phantom study revealed errors of <10% between theoretical and actual SUVs. Although there were significant correlations between SBR and all SUV-based parameters, SUVratio showed the most strong correlation with SBR (r = 0.877, p < 0.001). However, diagnostic capability of SUVratio (cutoff = 2.35) yielded to that of SBR (cutoff = 3.90) for diagnosing neurodegenerative diseases with presynaptic dopaminergic deficits (sensitivity of 85.0% vs 92.5%, specificity of 100% vs 91.7%, and accuracy of 88.5% vs 92.3%, respectively). CONCLUSION: SBR is a promising parameter to aid differential diagnosis of neurodegenerative diseases with or without presynaptic dopaminergic deficit. Although technically acceptable, SUV may not be superior to SBR when clinically applied in 123I-FP-CIT SPECT/CT.
PURPOSE: To evaluate potential of a semiquantitative method using standardized uptake value (SUV) in 123I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) single photon emission computed tomography/computed tomography (SPECT/CT) compared with specific binding ratio (SBR). MATERIALS AND METHODS: First, we performed a phantom study to validate the accuracy of measuring SUV. 52 patients (25 male, 27 female; mean age of 75.1-year-old; 40 and 12 patients with neurodegenerative diseases with or without presynaptic dopaminergic deficits, respectively) were enrolled in a retrospective study. We measured SBR, maximum SUV, peak SUV, mean SUV, and striatum-to-background ratio of SUV (SUVratio) for striatum with lower 123I-FP-CIT uptake using commercial software. We calculated Pearson's correlation coefficient between SBR and SUV. We also calculated the sensitivity, specificity, and accuracy of each parameter for differential diagnosis. RESULTS: The phantom study revealed errors of <10% between theoretical and actual SUVs. Although there were significant correlations between SBR and all SUV-based parameters, SUVratio showed the most strong correlation with SBR (r = 0.877, p < 0.001). However, diagnostic capability of SUVratio (cutoff = 2.35) yielded to that of SBR (cutoff = 3.90) for diagnosing neurodegenerative diseases with presynaptic dopaminergic deficits (sensitivity of 85.0% vs 92.5%, specificity of 100% vs 91.7%, and accuracy of 88.5% vs 92.3%, respectively). CONCLUSION: SBR is a promising parameter to aid differential diagnosis of neurodegenerative diseases with or without presynaptic dopaminergic deficit. Although technically acceptable, SUV may not be superior to SBR when clinically applied in 123I-FP-CIT SPECT/CT.
Keywords:
(123)I-2β-Carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ((123)I-FP-CIT); Phantom; Single photon emission computed tomography/computed tomography (SPECT/CT); Specific binding ratio (SBR); Standardized uptake value (SUV)