• Korean Journal of Head & Neck Oncology
• /
• v.28 no.2
• /
• pp.118-121
• /
• 2012

Backgrounds : To evaluated the use of FDG PET/CT for the identification of extracapsular spread(ECS) with histologic correlation in laryngeal cancer. Methods : We reviewed 79 medical records of patients who underwent of FDG PET/CT for laryngeal cancer before surgery. Results : ECS was present in 41.9%(18/43) dissected necks and in 34.5%(20/58) dissected cervical levels. There was a significant difference in the SUVmax between cervical lymph nodes with ECS and without ECS($6.39{\pm}4.53$ vs. $1.19{\pm}1.64$, p<0.001). The cut-off value for the SUVmax for differentiating with ECS from without ECS was 2.8 with the sensitivity of 85.7% and the specificity of 85.6%. Conclusion : The median SUVmax cut-off values of FDG PET/CT higher than 2.8 was associated with greater risk cervical lymph node metastasis with ECS in patients with laryngeal cancer.

• Radiation Oncology Journal
• /
• v.36 no.2
• /
• pp.95-102
• /
• 2018

Purpose: To evaluate the prognostic value of $^{18}F$-fluorodeoxyglucose positron-emission tomography (FDG PET) with computed tomography (CT) before and during radiotherapy (RT) in patients with head and neck cancer. Methods: Twenty patients with primary head and neck squamous cell carcinoma were enrolled in this study, of whom 6 had oropharyngeal cancer, 10 had hypopharyngeal cancer, and 4 had laryngeal cancer. Fifteen patients received concurrent cisplatin and 2 received concurrent cetuximab chemotherapy. FDG PET/CT was performed before RT and in the 4th week of RT. The parameters of maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor were measured, and the prognostic significance of each was analyzed with the Cox proportional hazards model. Results: Higher TLG (>19.0) on FDG PET/CT during RT was a poor prognostic factor for overall survival (OS) (p = 0.001) and progression-free survival (PFS) (p = 0.007). In the multivariate analysis, TLG during RT as a continuous variable was significantly associated with OS and PFS rate (p = 0.023 and p = 0.016, respectively). Tumor response worse than partial remission at 1 month after RT was another independent prognostic factor for PFS (p = 0.024). Conclusions: Higher TLG of the primary tumor on FDG PET/CT during RT was a poor prognostic factor for OS and PFS in patients with head and neck cancer.

• The Journal of the Korean bone and joint tumor society
• /
• v.18 no.1
• /
• pp.45-49
• /
• 2012

Skip lesion is not uncommon feature in osteosarcoma and considered to be importantly associated with poor prognosis factor, and thus, should be excised with the main mass. The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, because it determines the level of bone resection. Among the reliable detection methods, bone scan has a drawback of high rate of false negative results and regional MRI has a difficulty to cover the whole involved lesions without clinical suspicion. The authors report a case of osteosarcoma of the distal femur with a proximal skip lesion that was not detected by either regional MR imaging or by bone scan, but which was visualized by FDG-PET/CT.

• Journal of radiological science and technology
• /
• v.38 no.1
• /
• pp.31-38
• /
• 2015

$^{18}F-FDG$ PET/CT has been known a useful modality to diagnose high-glucose-using cells such as cancer cells by glucose metabolism of FDG. Mainly, FDG takes on cancer and inflammatory cells; however, there have been FDG uptakes on normal tissues by individual physiological characteristics, occasionally. Especially, in fertile females, unusual FDG uptake of breast changes as the menstrual cycle, and disturb diagnosis. Therefore, the study aimed to evaluate the change of breast FDG uptake in menstrual cycle on $^{18}F-FDG$ PET/CT. 160 females ($34{\pm}3.5$ years old) who do not undergo a gynecologic anamnesis and have regular menstrual cycle over the previous 6 months were examined. They were divided 4 groups (each 40 patients) as flow phase, proliferative phase, ovulatory phase and secretory phase using Pregnancy Calculator 0.14. and history taking. Discovery Ste (GE Healthcare, Milwaukee, Mi, USA) was used a s PET/CT. We analyzed SUVs on accumulated region on breast, and 3 nuclear medicine specialists did the Blind test. SUVs on the Breast were flow phase ($1.64{\pm}0.25$), proliferative phase ($0.93{\pm}0.28$), ovulatory phase ($1.66{\pm}0.26$) and secretory phase ($1.77{\pm}0.28$). It showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). In gross analysis, the accumulation of breast was divided into 3 grades as comparing with lung and liver. The breast's uptake was equal to lung (Grade I); between lung and liver (Grade II); equal to or greater than liver (Grade III). The results showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). In fertile females, FDG uptake of breast changed as menstrual cycle, and it available to diagnose breast disease. Therefore, we consider reducing false-negative finding of breast disease, by doing examination on appropriate period through history taking about individual menstrual cycle.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.1
• /
• pp.39-44
• /
• 2011

Purpose: $^{18}F$-FDG PET/CT has been known a useful modality to diagnose high-glucose-using cells such as cancer cells by glucose metabolism of FDG. Mainly, FDG takes on cancer and inflammatory cells; However, There have been FDG uptakes on normal tissues by individual physiological characteristics, occasionally. Especially, in fertile females, unusual FDG uptake of breast changes as the menstrual cycle, and disturb diagnosis. Therefore, the study aimed to evaluate the change of breast FDG uptake in menstrual cycle on $^{18}F$-FDG PET/CT. Materials and Methods: 160 females ($34{\pm}3.5$ years old) who do not undergo a gynecologic anamnesis and have regular menstrual cycle over the previous 6 months were examined, from March 2009 to February 2010. They were divided 4 groups (each 40 patients) as flow phase, proliferative phase, ovulatory phase and secretory phase using Pregnancy Calculator 0.14. and history taking. Discovery Ste (GE Healthcare, Milwaukee, Mi, USA) was used as PET/CT. We analyzed SUVs on accumulated region on breast, and 3 nuclear medicine specialists did the Blind test. Results: SUVs on the Breast were flow phase ($1.64{\pm}0.25$), proliferative phase ($0.93{\pm}0.28$), ovulatory phase ($1.66{\pm}0.26$) and secretory phase ($1.77{\pm}0.28$). It showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). In gross analysis, the accumulation of breast was divided into 3 grades as comparing with lung and liver. The breast's uptake was equal to lung (Grade I); between lung and liver (Grade II); equal to or greater than liver (Grade III). The results showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). Conclusion: In fertile females, FDG uptake of breast changed as menstrual cycle, and it available to diagnose breast disease. Therefore, we consider reducing false-negative finding of breast disease, by doing examination on appropriate period through history taking about individual menstrual cycle.

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

• Journal of Chest Surgery
• /
• v.43 no.5
• /
• pp.506-512
• /
• 2010

Background: This study was designed to evaluate the FDG uptake ratio of mediastinal node and primary tumors using integrated PET/CT imaging combined with Glut-1 expression of the primary tumor in order to predict the N2 status more accurately in NSCLC patients. Material and Method: Patients who underwent integrated PET/CT scanning with a detectable mSUV for both primary tumors and mediastinal lymph nodes were eligible for this study. The FDG uptake ratio between the mediastinal node and the primary tumor was calculated. Result: The average mSUV of primary tumors and mediastinal nodes were, respectively, $7.4{\pm}2.2$ and $4.2{\pm}2.2$ in N2-positive patients and $7.6{\pm}3.7$ and $2.8{\pm}6.9$ in N2-negative patients. The mean FDG uptake ratio of mediastinal node to primary tumor were $0.58{\pm}0.23$ for malignant N2 lymph nodes and $0.45{\pm}0.20$ for benign lymph nodes (p<0.05). Models which combined Glut-1 expression with an FDG ratio have better diagnostic power than models that use the FDG uptake ratio alone. Conclusion: In some patients with a previous history of pulmonary tuberculosis or other inflammatory lung diseases, an FDG uptake ratio combined with Glut-1 expression may be useful in diagnosing mediastinal node metastasis more exactly.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.1 no.2
• /
• pp.130-136
• /
• 2015

We evaluate the influence of MR contrast agent on positron emission tomography (PET) image using phantom, animal and human studies. Phantom consisted of 15 solutions with the mixture of various concentrations of Gd-based MR contrast agent and fixed activity of [$^{18}F$]FDG. Animal study was performed using rabbit and two kinds of MR contrast agents. After injecting contrast agent, CT or MRI scanning was performed at 1, 2, 5, 10, and 20 minutes. PET image was obtained using clinical PET/CT scan, and attenuation correction was performed using the all CT images. The values of HU, PET activity and MRI intensity were obtained from ROIs in each phantom and organ regions. In clinical study, patients (n=20) with breast cancer underwent sequential acquisitions of early [$^{18}F$]FDG PET/CT, MRI and delayed PET/CT. In phantom study, as the concentration increased, the CT attenuation and PET activity also increased. However, there was no relationship between the PET activity and the concentration in the clinical dose range of contrast agent. In animal study, change of PET activity was not significant at all time point of CT scan both MR contrast agents. There was no significant change of HU between early and delayed CT, except for kidney. Early and delayed SUV in tumor and liver showed significant increase and decrease, respectively (P<0.05). Under the condition of most clinical study (< 0.2 mM), MR contrast agent did not influence on PET image quantitation.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.433-440
• /
• 2018

Recently, MTV(metabolic tumor volume) has been used as indices of the whole tumor FDG uptake on FDG PET image but it is influenced by image reconstruction. The purpose of this study was to evaluate the correlation between actual volume and metabolic tumor volume applying different SUVmax threshold for different reconstruction algorithm on phantom study. Measurement were performed on a Siemens Biograph mCT40 using a NEMA IEC body phantom containing different size six spheres filled with F18-FDG applying four SBRs (4:1, 8:1, 10:1, 20:1). Images reconstructed four algorithms (OSEM3D, OSEM3D+PSF, OSEM3D +TOF, OSEM3D+TOF+PSF) and MTV were measured with different SUVmax threshold. Overall, the use of increasing thresholds result in decreasing MTV. and increasing the signal to background ratio decreased MTV by applying same SUVmax threshold. The 40% SUVmax threshold gave the best concordance between measured and actual volume in PSF and PSF+TOF reconstruction image. and the 45% threshold had the best correlation between the volume measured and actual volume in OSEM3D and TOF reconstruction image. we believe that this study will be used when the measurement of MTV applying various reconstruction image.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.3
• /
• pp.169-176
• /
• 2006

Purpose: According to the development of CT scanner in PET/CT system, the role of CT unit as a diagnostic tool has been more important. To improve the diagnostic ability of CT scanner, it is a key aspect that CT scanning has to be performed with high dose energy and intravenous (IV) contrast. So we investigated the effect of IV contrast media on the maximum SUV (maxSUV) of normal tissues and pathologic lesions using PET/CT scanner with high dose CT scanning. Materials & Methods: The study enrolled 13 patients who required PET/CT evaluation. At first, the patients were performed whole body non-contrast CT (NCCT-120 kVp, 130 mAs) scan. Then contrast enhanced CT (CECT) scan was performed immediately. Finally PET scan was followed. The PET omission data were reconstructed twice, once with the NCCT and again with the CECT. We measured the maxSUV of 10 different body regions that were considered as normal in ail patients. Also pathologic lesions were investigated. Results: There were not seen focal artifacts in PET images based on CT with IV contrast agent. Firstly, 130 normal regions in 13 patients were evaluated. The maxSUV was significantly different between two PET images (p<0.00)). The maxSUV was $1.1{\pm}0.5$ in PET images with CECT-corrected attenuation and $1.0{\pm}0.5$ in PET images with NCCI-corrected attenuation. The limit of agreement was $0.1{\pm}0.3$ in Bland-Altman analysis. Especially there were significant differences in 6 of 10 regions, apex and base of the right lung, ascending aorta, segment 6 & segment 8 of the liver and spleen (p<0.05). Secondly, 39 pathologic lesions were evaluated. The maxSUV was significantly different between two PET images (p<0.001). The maxSUV was $4.7{\pm}2.0$ in PET images with CECT-corrected attenuation and $4.4{\pm}2.0$ in PET images with NCCT-corrected attenuation. The limit of agreement was $0.4{\pm}0.8$ in Bland-Altman analysis. Conclusion: Although there were increases of maxSUVs in the PET images based on CT with IV contrast agent, it was very narrow in the range of limit of agreement. So there was no significant effect to clinical interpretation for PET images that were corrected attenuation with high dose CT using IV contrast.