• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1246-1257
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• 2021

Purpose To assess the predictive factors and describe the imaging features of mediastinal lymph node (MLN) metastases in patients with head and neck cancer. Materials and Methods We compared the clinical features and disease characteristics (sex, age, site of primary tumor, histologic type, history of prior treatments, TNM stages, and metastasis in cervical LNs) of patients with head and neck cancers between the MLN metastasis and no MLN metastasis groups. We also evaluated the chest CT (distribution and maximum dimension of the largest LN) and PET/CT (maximum standardized uptake value) features of MLN metastases based on the MLN classification. Results Of the 470 patients with head and neck cancer, 55 (11.7%) had MLN metastasis, involving 150 mediastinal stations. Hypopharynx cancer, recurrent tumor, T4 stage, N2/N3 stages, and M1 stage were found to be significant predicting factors for MLN metastasis. The most common location of MLN metastasis was ipsilateral station 2 (upper paratracheal LNs, 36.4%), followed by ipsilateral station 11 (interlobar LNs, 27.3%) and ipsilateral station 10 (hilar LNs, 25.5%). Conclusion Metastasis to MLNs should be considered in patients with head and neck cancer, especially in cases that are associated with a hypopharyngeal cancer, recurrent tumor, and high TNM stages.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.29-38
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• 2008

Purpose: The aim of this study was to investigate the feasibility of 3 ' -[F-18]fluoro-3 ' -deoxythymidine positron emission tomography(FLT-PET) for the detection of locally advanced breast cancer and to compare the degree of FLT and 2' -deoxy-2 ' -[F-18]fluoro-d-glucose(FDG) uptake in primary tumor, lymph nodes and other normal organs. Material & Methods: The study subjects consisted of 22 female patients (mean age; $42{\pm}6$ years) with biopsy-confirmed infiltrating ductal carcinoma between Aug 2005 and Nov 2006. We performed conventional imaging workup, FDG-PET and FLT PET/CT. Average tumor size measured by MRI was $7.2{\pm}3.4$ cm. With visual analysis, Tumor and Lymph node uptakes of FLT and FDG were determined by calculation of standardized uptake value (SUV) and tumor to background (TB) ratio. We compared FLT tumor uptake with FDG tumor uptake. We also investigated the correlation between FLT tumor uptake and FDG tumor uptake and the concordant rate with lymph node uptakes of FLT and FDG. FLT and FDG uptakes of bone marrow and liver were measured to compare the biodistribution of each other. Results: All tumor lesions were visually detected in both FLT-PET and FDG-PET. There was no significant correlation between maximal tumor size by MRI and SUVmax of FLT-PET or FDG-PET (p>0.05). SUVmax and $$SUV_{75} (average SUV within volume of interest using 75% isocontour) of FLT-PET were significantly lower than those of FDG-PET in primary tumor (SUVmax; $6.3{\pm}5.2\;vs\;8.3{\pm}4.9$, p=0.02 /$SUV_{75};\;5.3{\pm}4.3\;vs\;6.9{\pm}4.2$, p=0.02). There is significant moderate correlation between uptake of FLT and FDG in primary tumor (SUVmax; rho=0.450, p=0.04 / SUV75; rho=0.472, p=0.03). But, TB ratio of FLT-PET was higher than that of FDG-PET($11.7{\pm}7.7\;vs\;6.3{\pm}3.8$, p=0.001). The concordant rate between FLT and FDG uptake of lymph node was reasonably good (33/34). The FLT SUVs of liver and bone marrow were $4.2{\pm}1.2\;and\;8.3{\pm}4.9$. The FDG SUVs of liver and bone marrow were $1.8{\pm}0.4\;and\;1.6{\pm}0.4$. Conclusion: The uptakes of FLT were lower than those of FDG, but all patients of this study revealed good FLT uptakes of tumor and lymph node. Because FLT-PET revealed high TB ratio and concordant rate with lymph node uptakes of FDG-PET, FLT-PET could be a useful diagnostic tool in locally advanced breast cancer. But, physiological uptake and individual variation of FLT in bone marrow and liver will limit the diagnosis of bone and liver metastases.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.19-25
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• 2009

Purpose: The aims of this study were to analyze correlation between the maximum standardized uptake value (SUVmax) of 2-[F-18]-fluoro-2-deoxy-d-glucose (FDG) on positron emission computed tomography (PET-CT) scan and the degree of contrast enhancement on computed tomography (CT) scan in lung cancers, and to recognize the difference in SUVmax and CT enhancement between groups of different histopathologic subtypes. Materials and Methods: Our study included 53 patients of pathologically confirmed primary lung cancer, who were performed PET-CT and post-contrast chest CT. We calculated initial and delayed SUVmax (SUV1, SUV2), difference between SUV1 and SUV2 (SUVd), retention index (RI), and the degrees of CT contrast enhancement of lung cancers. We analyzed these variables for subtypes of lung cancers. Results: The values (mean$\pm$ standard deviation) were $8.3{\pm}4.4$ for SUV1, $10.7{\pm}5.7$ for SUV2, $2.4{\pm}1.6$ for SUVd, $30{\pm}14$ for RI and $47.1{\pm}14.8$ HU (Hounsfield Unit) for degree of CT contrast enhancement. The difference of SUV1 and degree of CT enhancement between subtypes was not meaningful. SUV1 showed positive correlations with SUVd (r=0.74, p<0,01) and tumor size (r=0.58, p<0.01), but no significant correlation with degree of CT enhancement (r=0.06, p=0.69). In 10 cases, there was discrepancy in the same mass between the area of highest FDG-uptake and the area of highest contrast enhancement. Conclusion: We suggest that FDG uptake in lung cancer does not have a positive linear correlation with degree of CT enhancement. And there is no significant difference in FDG uptake and degree of CT enhancement between different subtypes of lung cancers.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.275-284
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• 2008

Purpose: We intended to evaluate myocardial oxygen consumption ($MVO_2)$ by applying recirculation correction and modified one-compartment model to have a reference range of $MVO_2$ in normal young population and to reveal the effect of recirculation on time-activity curve (TAC). Materials and Methods: In nine normal male volunteers with mean age of $26.3{\pm}4.0$, $MVO_2$ was estimated with 925 MBq (25mCi) of $^{11}C$-Acetate (Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea) and PET/CT (Biograph 6, Siemens Medical Solution, Germany). Analysis software such as $MATLAB^{(R)}$ v7.1 (Mathworks, Inc., United States), $Excel^{(R)}$ 2007 (Microsoft, United States), and $SPSS^{(R)}$ v12.0 (Apache Software Foundation, United States) were used. Twenty three frames were of $12{\times}10$, $5{\times}60$, $3{\times}120$, $2{\times}300's$ duration, respectively. The modified one-compartmental model and the recirculation correction method were applied. Statistical analysis was performed by using Test of Normality, ANOVA and Post-Hoc (Scheffe's) analysis, and p-value less than 0.05 was considered as significant. Results: The normal reference ranges of $MVO_2$ were presented as $3.18-4.64\;{\times}\;10^{-4}\;ml/g/sec$, $1.91-3.94\;{\times}\;10^{-4}\;ml/g/sec$, $4.31-6.40\;{\times}\;10^{-4}\;ml/g/sec$, $2.84-4.53\;{\times}\;10^{-4}\;ml/g/sec$ and $3.42-5.00\;{\times}\;10^{-4}\;ml/g/sec$ in the septum, the inferior wall, the lateral wall, the anterior wall and the entire wall, respectively. In addition, it was noted that the dual exponentiality of the clearance curve is due to the recirculation effect and that the characteristic of the curve is essentially mono-exponential. Conclusion: $^{11}C$-Acetate is a radiotracer worthwhile to assess $MVO_2$. Re-circulated $^{11}C$ can influence TAC of $^{11}C$ in myocadia and so the recirculation correction must be considered when measuring $MVO_2$.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.111-119
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• 2009

Purpose: This study aimed at assessing the value of fluorine-18 fluorodeoxyglucose positron emission tomography ($^{18}F$-FDG PET) for predicting the response of locally advanced rectal cancer to neoadjuvant CRT. Materials and Methods: Between August 2006 and January 2008, we prospectively enrolled 20 patients with locally advanced rectal cancer and who were treated with neoadjuvant CRT at the Korea Institute of Radiological and Medical Sciences. The treatment consisted of radiation therapy and chemotherapy, and this was followed by curative resection 6 weeks later. All the patients underwent $^{18}F$-FDG PET/CT both before CRT and 6 weeks after completing CRT. The measurements of the FDG uptake ($SUV_{max}$), the absolute difference (${\Delta}SUV_{max}$) and the percent $SUV_{max}$ difference (response index, $RI_{SUV}$) between the pre- and post-CRT $^{18}F$-FDG PET/CT scans were assessed. The measurements of the metabolic volume, the absolute difference (${\Delta}$metabolic volume) and the percent metabolic volume difference (response index, $RI_{metabolic\;volume}$) were also assessed. Results: Of the 20 patients who underwent surgery, 11 patients (55%) were classified as responders according to Dworak's classification. The post-CRT $SUV_{max}$ was significantly lower than the pre-CRT $SUV_{max}$. However, there were no significant differences in the $SUV_{max}$ and the metabolic volume reduction between the responders and non-responders. We used a minimum $SUV_{max}$ reduction of 67% as the cut-off value for defining a response, with a sensitivity of 45.5%, a specificity of 88.9%, a positive predictive value of 77% and a negative predictive value of 53.8%. Conclusion: Although there were no statistically significant results in this study, other studies have revealed that $^{18}F$-FDG PET/CT has the potential to assess the tumor response to neoadjuvant CRT in patients with locally advanced rectal cancer.

• The Korean Journal of Nuclear Medicine
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• v.33 no.5
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• pp.439-451
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• 1999

Purpose : It is important to differentiate malignant from benign lesions of intraocular masses in choosing therapeutic plan. Biopsy of intraocular tumor is not recommended due to the risk of visual damage. We evaluated the usefulness of F-18-FDG PET imaging in diagnosing intraocular neoplasms. Materials and Methods: F-18-FDG PET scan was performed in 13 patients (15 lesions) suspected to have malignant intraocular tumors. There were 3 benign lesions (retinal detachment, choroidal effusion and hemorrhage) and 10 patients with 12 malignant lesions (3 melanomas, 7 retinoblastomas and 2 metastatic cancers). Regional eye images ($256{\times}256$ and $128{\times}128$ matrices) were obtained with or without attenuation correction. Whole body scan was also performed in eight patients (3 benign and 6 malignant lesions). Results: All malignant lesions were visualized while all benign lesions were not visualized. The mean peak standardized uptake value (SUV) of malignant lesions was $2.64{\pm}0.57g/ml$. There was no correlations between peak SUV and tumor volume. Two large malignant lesions ($> 1000 mm^3$) showed hot uptake on whole body scan. But two medium-sized lesions ($100-1000mm^3$) looked faint and two small ($<100mm^3$) lesions were not visualized. The images reconstructed with $256{\times}256$ matrix showed lesions more clearly than those with $128{\times}128$ matrix Conclusion: F-18-FDG PET scan is highly sensitivity in detecting malignant intraocular tumor For the evaluation of small-sized intraocular lesions, whole body scan is not appropriate because of low sensitivity. A regional scan with sufficient acquisition time is recommended for that purpose. Image reconstruction in matrix size of $256{\times}256$ produced clearer images than the ones in $128{\times}128$, but it does not affect the diagnostic sensitivity.

• The Korean Journal of Nuclear Medicine
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• v.37 no.5
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• pp.288-300
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• 2003

Purpose: To obtain regional blood flow and tissue-blood partition coefficient with time-activity curves from ${H_2}^{15}O$ PET, fitting of some parameters in the Kety model is conventionally accomplished by nonlinear least squares (NLS) analysis. However, NLS requires considerable compuation time then is impractical for pixel-by-pixel analysis to generate parametric images of these parameters. In this study, we investigated several fast parameter estimation methods for the parametric image generation and compared their statistical reliability and computational efficiency. Materials and Methods: These methods included linear least squres (LLS), linear weighted least squares (LWLS), linear generalized least squares (GLS), linear generalized weighted least squares (GWLS), weighted Integration (WI), and model-based clustering method (CAKS). ${H_2}^{15}O$ dynamic brain PET with Poisson noise component was simulated using numerical Zubal brain phantom. Error and bias in the estimation of rCBF and partition coefficient, and computation time in various noise environments was estimated and compared. In audition, parametric images from ${H_2}^{15}O$ dynamic brain PET data peformed on 16 healthy volunteers under various physiological conditions was compared to examine the utility of these methods for real human data. Results: These fast algorithms produced parametric images with similar image qualify and statistical reliability. When CAKS and LLS methods were used combinedly, computation time was significantly reduced and less than 30 seconds for $128{\times}128{\times}46$ images on Pentium III processor. Conclusion: Parametric images of rCBF and partition coefficient with good statistical properties can be generated with short computation time which is acceptable in clinical situation.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.9-16
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• 2005

Purpose : To prospectively evaluate the use of positron emission tomography with the glucose analog fluoro-deoxyglucose (FDG-PET) to deoxyglucose (FDG-PET) to predict disease-free survival (DFS) after concurrent chemo-radiotherapy (CCRT) in patients with non-disseminated nasopharyngeal carcinoma (NPC). Materials and Methods : We studied 41 patients with non-disseminated NPC scheduled to undergo platinum-based CCRT were eligible for this study. Patients were studied by FDG-PET prior to the CCRT. FDG uptake of tumors were measured with the maximal standardized uptake value (SUV). Results : Complete response rate was $100\%$. In ten patients who presented with any component of treatment failure, the median $SUV_{max}$ was 8.55 (range: $2.49\~14.81$) in any component of failure and the median $SUV_{max}$ was 5.48 (range: $2.31\~26.07$) In the remaining patients without any such failure. Patients having tumors with high FDG uptake had a significantly lower 3-year DFS ($51\%\;{\nu}91\%$, p=0.0070) compared with patients having low uptake tumors. Conclusion : FDG uptake, as measured by the SUV, has potential value in predicting DFS in NPC treated by CCRT, High FDG uptake may be a useful parameter for Identifying patients requiring more aggressive treatment approaches.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.224-238
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• 2004

Multi-modality image registration is a widely used image processing technique to obtain composite information from two different kinds of image sources. This study proposes an image registration method based on moment information and surface distance, which improves the previous surface-based registration method. The proposed method ensures stable registration results with low registration error without being subject to the initial position and direction of the object. In the preprocessing step, the surface points of the object are extracted, and then moment information is computed based on the surface points. Moment information is matched prior to fine registration based on the surface distance, in order to ensure stable registration results even when the initial positions and directions of the objects are very different. Moreover, surface comer sampling algorithm has been used in extracting representative surface points of the image to overcome the limits of the existed random sampling or systematic sampling methods. The proposed method has been applied to brain MRI(Magnetic Resonance Imaging) and PET(Positron Emission Tomography), and its accuracy and stability were verified through registration error ratio and visual inspection of the 2D/3D registration result images.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1369-1373
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• 2014

Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.