• Tuberculosis and Respiratory Diseases
• /
• v.71 no.6
• /
• pp.425-430
• /
• 2011

Background: High 2-[$^{18}F$] fluoro-2-deoxy-D-glucose (FDG) uptake on positron emission tomography-computed tomography (PET-CT) is a prognostic factor for poor survival in non-small cell lung cancer (NSCLC), especially in Stage I. We determined whether the high FDG uptake value of a primary tumor was associated with recurrence and death in patients with resected Stage I and Stage II NSCLC. Methods: We identified consecutive patients who underwent complete surgical resection for Stage I and II NSCLC between 2006 and 2009, who had preoperative PET-CT, and reviewed clinical records retrospectively. FDG uptake was measured as the maximal standardized uptake value (SUVmax) for body weight. Patients were divided into two groups based on SUVmax: (i) above or (ii) below the cut-off value (SUVmax=5.9) determined by a receiver operating characteristic (ROC) curve. Results: Of 57 patients who were enrolled consecutively, 32 (56%) had Stage I NSCLC and 25 (44%) had Stage II. The 5-year recurrence-free survival (RFS) for patients with high (${\geq}5.9$) and low (<5.9) SUVmax were 31% and 57%, respectively (p=0.014). The 5-year overall survival (OS) rates were 39% and 60%, respectively (p=0.029). In univariate analyses, SUVmax (p=0.014), T staging (p=0.025), and differentiation of tumor tissue (p=0.034) were significantly associated with RFS. But, multivariate analyses did not show that SUVmax was an independently significant factor for RFS (p=0.180). Conclusion: High FDG uptake on PET-CT is not an independent prognostic factor for poor outcomes (disease recurrence in patients with resected Stage I and II NSCLC).

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.20
• /
• pp.8699-8703
• /
• 2014

18-fluoro-2-deoxyglucose positron emission tomography-computed tomography ($^{18}F$-FDG PET/CT) scans are commonly used for the staging and restaging of various malignancies, such as head and neck, breast, colorectal and gynecological cancers. However, the value of FDG PET/CT for detecting prostate cancer is unknown. The aim of this study was to evaluate the clinical value of incidental prostate $^{18}F$-FDG uptake on PET/CT scans. We reviewed $^{18}F$-FDG PET/CT scan reports from September 2009 to September 2013, and selected cases that reported focal/diffuse FDG uptake in the prostate. We analyzed the correlation between $^{18}F$-FDG PET/CT scan findings and data collected during evaluations such as serum prostate-specific antigen (PSA) levels, digital rectal examination (DRE), transrectal ultrasound (TRUS), and/or biopsy to confirm prostate cancer. Of a total of 18,393 cases, 106 (0.6%) exhibited abnormal hypermetabolism in the prostate. Additional evaluations were performed in 66 patients. Serum PSA levels were not significantly correlated with maximum standardized uptake values (SUVmax) in all patients (rho 0.483, p=0.132). Prostate biopsies were performed in 15 patients, and prostate cancer was confirmed in 11. The median serum PSA level was 4.8 (0.55-7.06) ng/mL and 127.4 (1.06-495) ng/mL in the benign and prostate cancer groups, respectively. The median SUVmax was higher in the prostate cancer group (mean 10.1, range 3.8-24.5) than in the benign group (mean 4.3, range 3.1-8.8), but the difference was not statistically significant (p=0.078). There was no significant correlation between SUVmax and serum PSA, prostatic volume, or Gleason score. $^{18}F$-FDG PET/CT scans did not reliably differentiate malignant or benign from abnormal uptake lesions in the prostate, and routine prostate biopsy was not usually recommended in patients with abnormal FDG uptake. Nevertheless, patients with incidental prostate uptake on $^{18}F$-FDG PET/CT scans should not be ignored and should be undergo further clinical evaluations, such as PSA and DRE.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.2
• /
• pp.35-43
• /
• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• Journal of radiological science and technology
• /
• v.30 no.4
• /
• pp.373-379
• /
• 2007

Purpose : There is difference between PET and PET/CT method on their transmission image for attenuation correction. The CT image is used for attenuation correction on PET/CT and the parameters of CT may be affected on PET image. We performed the phantom study to evaluate whether the change of CT parameters(kilovolts peak and milliampere) affect standardized uptake value(SUV) on PET image. Material and Method: The data spectrum lung phantom containing diluted [18F]fluorodeoxyglucose ([18F]FDG) solution(1.909 mCi for phantom 1, $913\;{\mu}Ci$ for phantom 2) was used. The CT images of phantom were acquired with varying parameters (80, 100, 120, 140 for kVp, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 for mA). The PET images were reconstructed with the each CT images and SUVs were compared. Result : The SUVs of phantom 1 reconstructed with each 80, 100, 120 and 140 kVp showed $12.26{\pm}0.009$, $12.27{\pm}0.005$, $12.27{\pm}0.006$ and $12.27{\pm}0.009$, respectively. The SUVs of phantom 2 revealed $4.52{\pm}0.043$, $4.53{\pm}0.004$, $4.52{\pm}0.007$ and $4.52{\pm}0.005$ with elevation of voltage. There was no statistically significant difference of SUVs between groups based on various kVp. Also SUVs of phantom 1 and 2 showed no significant change with elevation of milliampere in CT parameter. Conclusion : The parameters of CT did not significantly affect SUV on PET image in our study. Therefore we can apply various parameters of CT appropriated for clinical conditions without significant change of SUV on PET CT image.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.22 no.1
• /
• pp.35-42
• /
• 2018

Purpose Standardized uptake value(SUV) has been widely used as a quantitative metric of uptake in PET/CT for diagnosis of malignant tumors and evaluation of tumor therapy response. However, the SUV depends on various factor including PET/CT scanner specifications and reconstruction parameter. The purpose of this study is to validate a EQ PET to evaluate SUV across different PET/CT systems. Materials and Methods First, NEMA IEC body phantom data were used to calculate the EQ filter for OSEM3D with PSF and TOF reconstruction from three different PET/CT systems in order to obtain EARL compliant recovery coefficients of each spheres. The Biograph true point 40 PET/CT images were reconstructed with a OSEM3D+PSF reconstruction, images of the Biograph mCT 40 and Biograph mCT 64 PET/CT scanners were reconstructed with a OSEM3D+PSF, OSEM3D+TOF, OSEM3D+PSF+TOF. Post reconstructions, the proprietary EQ filter was applied to the reconstruction data. Recovery coefficient can be estimated by ratio of measured to true activity concentration for spheres of different volume and coefficient variability(CV) value of RC for each sphere was compared. For clinical study, we compared SUVmax applying different reconstruction algorithms in FDG PET images of 61 patients with lung cancer using Biograph mCT 40 PET/CT scanner. Results For the phantom studied, the mean values of CV for OSEM3D, OSEM3D+PSF, OSEM3D+TOF and OSEM3D+PSF+TOF reconstructions were 0.05, 0.04, 0.04 and 0.03 respectively for RC. Application of the proprietary EQ filter, the mean values of CV for OSEM3D, OSEM3D+PSF, OSEM3D+TOF and OSEM3D+PSF+TOF reconstructions were 0.04, 0.03, 0.03 and 0.02 respectively for RC. Clinical study, there were no statistical significance of the difference applying EQ PET on SUVmax of 61 patients FDG PET image. (p=1.000) Conclusion This study indicates that CV values of RC in phantom were decreased after applying EQ PET for different PET/CT system and The EQ PET reduced reconstruction dependent variation in SUVs for 61 lung cancer patients, Therefore, EQ PET will be expected to provide accurate quantification when the patient is scanned on different PET/CT system.

• Journal of Yeungnam Medical Science
• /
• v.23 no.2
• /
• pp.205-212
• /
• 2006

Background: Malignant pulmonary nodules account for about 30 to 40 percent of solitary pulmonary nodules (SPN). Therefore, tissue characterization of SPNs is very important. Recently, PET/CT has been widely used for tissue characterization, and has become of importance. The purpose of this study was to compare and to assess multiple factors in PET/CT comparing benign and malignant nodules. Materials and Method: Nineteen patients with SPN underwent PET/CT and biopsy. The difference of standardized uptake value 1 (SUV1), standardized uptake value 2 (SUV2) and retention index in PET/CT between malignancy and benignancy were compared by Levene's test. Result: There were twelve malignant and seven benign nodules. SUV1 and SUV2 were significantly different between malignant nodule and benign nodule (p=0.006 and 0.022), but retention index was not significantly different between malignant nodule and benign nodule (p=0.526). By receiver-operating-characteristic (ROC) analysis, the sensitivity was 66.7% and the specificity was 71.4% at a cut off value of 5.40 in SUV1. The sensitivity was 75% and the specificity was 71.4% at cut off value of 7.45 in SUV2. Conclusion: There was a statistically significant difference in SUV1 and SUV2 between benign and malignant nodules. However, the cut off value of SUV1 and SUV2 by receiver-operating-characteristic (ROC) analysis was 5.40 and 7.45 which is different from previous studies. Therefore, studies on a larger sample of patients are required for confirmation.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.17 no.2
• /
• pp.37-43
• /
• 2013

Purpose: PET/CT scan using the SUV (Standardized Uptake Value) of radiopharmaceutical uptake in organs and tissues as an objective indicator makes it possible to analyze physiological and chemical reactions of human organs. This study analyzes the change of the SUV uptake in accordance with the way how PET/CT patients take a rest after the injection of $^{18}F-FDG$ (Fluororo-deoxyglucose). And also subjective satisfaction is assessed listening to music while taking a rest. Materials and Methods: From April 2011 until February 2013, Among the Primary cancer patients who admitted to the Catholic Medical Center (Seoul & Bucheon St. Mary's Hospital) and scanned $^{18}F-FDG$ PET/CT and also received care through the tracking test (mean age $55.61{\pm}12.41$ years, 108 people, 48 men and 60 women) were selected. The patients were divided into two groups. The first group (A: basal study) is requested to take a rest in bed quietly after the injection. However the second one (B: follow up study) is requested to listen to the music while taking a rest. And then SUV analysis was performed respectively. At the end of the scan, ROI (Region Of Interest) were set from the center of the liver (right lobe) and 3 spots of the brain (frontal, temporal, and occipital lobes). And the SUV was calculated. To identify the correlation among those ROIs, paired t-test was performed using SPSS software (Version 12.0K for windows, P>0.05). Also, after the PET/CT scan the satisfaction study was conducted of all the patients. 1:1 questionnaire survey was performed, and that questionnaire was made using the Likert 5-point scale. By utilizing those questionnaires, the analysis about simple frequency, percentage, average, and standard deviation was performed. Results: The SUV change of the 4 designated ROIs in accordance with listening to music was not statistically significant. (Frontal lobe P-value=0.611, Occipital lobe P-value=0.499, Temporal lobe P-value=0.717, Liver P-value=0.334: P-value>0.05) And the satisfaction study indicated that group B was appear to be 0.42 points (5 basis points) higher than group A. It showed that patients are more satisfied in group B than group A. Conclusion: when performing PET/CT scan using $^{18}F-FDG$, listening to music after the injection of the radiopharmaceuticals does not affect the SUV but given the state of the psychological comfort that may increase the patient's satisfaction.

• Journal of the Korean Society of Radiology
• /
• v.12 no.5
• /
• pp.593-601
• /
• 2018

Recently in nuclear medicine, to improve diagnostic value, SUV, semi-quantitative indicator used in PET-CT, is adopted in SPECT-CT. Therefore, this research analyzed correlation of $SUV_{max}$ of two scanners through phantom test, and evaluated possibility of clinical application. Radiopharmaceuticals ($^{18}F$, $^{99m}Tc$) were injected with the ratios of 8:1 and 4:1, considering background radioactivity, into the phantom manufactured with 6 globes of different sizes, and, based on clinical protocol, positive phases were acquired with PET-CT and SPECT-CT scanners, and interesting areas were divided into ROI and VOI, and $SUV_{max}$ of them were measured, and analyzed. Tests found out no statistically significant difference in $SUV_{max}$ measured with two scanners (P>0.05). Thus, $SUV_{max}$ of PET-CT and SPECT-CT had a certain correlation within significant levels, and were evaluated as the same. Accordingly, it seems that $SUV_{max}$ quantitative analysis using SPECT-CT can provide significant diagnostic information as the case of PET-CT.

• Radiation Oncology Journal
• /
• v.32 no.4
• /
• pp.231-237
• /
• 2014

Purpose: To evaluate the predictive value of the early response of $^{18}F$-flurodeoxyglucose positron emission tomography (FDG PET) during concurrent chemoradiotherapy (CCRT) for locally advanced non-small cell lung cancer (NSCLC). Materials and Methods: FDG PET was performed before and during CCRT for 13 NSCLC patients. Maximum standardized uptake value ($SUV_{max}$), mean standardized uptake value ($SUV_{mean}$), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured and the changes were calculated. These early metabolic changes were compared with the standard tumor response by computed tomograms (CT) one month after CCRT. Results: One month after the completion of CCRT, 9 patients had partial response (PR) of tumor and 4 patients had stable disease. The percent changes of $SUV_{max}$ ($%{\Delta}SUV_{max}$) were larger in responder group than in non-responder group ($55.7%{\pm}15.6%$ vs. $23.1%{\pm}19.0%$, p = 0.01). The percent changes of $SUV_{mean}$ ($%{\Delta}SUV_{mean}$) were also larger in responder group than in non-responder group ($54.4%{\pm}15.9%$ vs. $22.3%{\pm}23.0%$, p = 0.01). The percent changes of MTV ($%{\Delta}MTV$) or TLG ($%{\Delta}TLG$) had no correlation with the tumor response after treatment. All the 7 patients (100%) with $%{\Delta}SUV_{max}{\geq}50%$ had PR, but only 2 out of 6 patients (33%) with $%{\Delta}SUV_{max}$ < 50% had PR after CCRT (p = 0.009). Likewise, all the 6 patients (100%) with $%{\Delta}SUV_{mean}{\geq}50%$ had PR, but only 3 out of 7 patients (43%) with $%{\Delta}SUV_{mean}$ < 50% had PR after CCRT (p = 0.026). Conclusion: The degree of metabolic changes measured by PET-CT during CCRT was predictive for NSCLC tumor response after CCRT.

• Journal of Gastric Cancer
• /
• v.20 no.1
• /
• pp.60-71
• /
• 2020

Purpose: The utility of 18-fluordesoxyglucose positron emission tomography ([¹⁸F]-FDG-PET) combined with computer tomography or magnetic resonance imaging (MRI) in gastric cancer remains controversial and a rationale for patient selection is desired. This study aims to establish a preclinical patient-derived xenograft (PDX) based [¹⁸F]-FDG-PET/MRI protocol for gastric cancer and compare different PDX models regarding tumor growth and FDG uptake. Materials and Methods: Female BALB/c nu/nu mice were implanted orthotopically and subcutaneously with gastric cancer PDX. [¹⁸F]-FDG-PET/MRI scanning protocol evaluation included different tumor sizes, FDG doses, scanning intervals, and organ-specific uptake. FDG avidity of similar PDX cases were compared between ortho- and heterotopic tumor implantation methods. Microscopic and immunohistochemical investigations were performed to confirm tumor growth and correlate the glycolysis markers glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) with FDG uptake. Results: Organ-specific uptake analysis showed specific FDG avidity of the tumor tissue. Standard scanning protocol was determined to include 150 μCi FDG injection dose and scanning after one hour. Comparison of heterotopic and orthotopic implanted mice revealed a long growth interval for orthotopic models with a high uptake in similar PDX tissues. The H-score of GLUT1 and HK2 expression in tumor cells correlated with the measured maximal standardized uptake value values (GLUT1: Pearson r=0.743, P=0.009; HK2: Pearson r=0.605, P=0.049). Conclusions: This preclinical gastric cancer PDX based [¹⁸F]-FDG-PET/MRI protocol reveals tumor specific FDG uptake and shows correlation to glucose metabolic proteins. Our findings provide a PET/MRI PDX model that can be applicable for translational gastric cancer research.