Clinical Role of F-18 FDG PET/CT in Squamous Cell Carcinoma of Head and Neck / 한양의대학술지

Diagnostic imaging plays an important role in accurate staging, restaging, and treatment monitoring, and is essential in both planning adequate treatment and minimizing treatment-related toxicity and functional impairment in head and neck squamous cell carcinoma (HNSCC). MRI and CT remains the primary imaging modalities for the assessment of HNSCC, but F-18 FDG PET/CT had emerged as a vital adjunct when used in the appropriate clinical setting, such as: delineation of extent of regional lymph node involvement, detection of distant metastasis, identification of an unknown primary tumor, detection of an occasional synchronous primary tumor, monitoring of the treatment response, and long-term surveillance for recurrence and metastases. In this manuscript, clinical application of F-18 FDG PET/CT on HNSCC in initial staging, radiotherapy planning, carcinoma of unknown primary of squamous cell origin, evaluation of response to radiation and/or chemoradiation therapy, and prediction of prognosis will be discussed and other promising PET radiotracers will be introduced.

Multiple Linear Analysis for Generating Parametric Images of Irreversible Radiotracer / 핵의학분자영상

PURPOSE: Biological parameters can be quantified using dynamic PET data with compartment modeling and Nonlinear Least Square (NLS) estimation. However, the generation of parametric images using the NLS is not appropriate because of the initial value problem and excessive computation time. In irreversible model, Patlak graphical analysis (PGA) has been commonly used as an alternative to the NLS method. In PGA, however, the start time (t*, time where linear phase starts) has to be determined. In this study, we suggest a new Multiple Linear Analysis for irreversible radiotracer (MLAIR) to estimate fluoride bone influx rate (Ki). METHODS: [18F]Fluoride dynamic PET scans was acquired for 60 min in three normal mini-pigs. The plasma input curve was derived using blood sampling from the femoral artery. Tissue time-activity curves were measured by drawing region of interests (ROIs) on the femur head, vertebra, and muscle. Parametric images of Ki were generated using MLAIR and PGA methods. RESULT: In ROI analysis, estimated Ki values using MLAIR and PGA method was slightly higher than those of NLS, but the results of MLAIR and PGA were equivalent. Patlak slopes (Ki) were changed with different t* in low uptake region. Compared with PGA, the quality of parametric image was considerably improved using new method. CONCLUSION: The results showed that the MLAIR was efficient and robust method for the generation of Ki parametric image from [18F]Fluoride PET. It will be also a good alternative to PGA for the radiotracers with irreversible three compartment model.

The Discriminating Nature of Dopamine Transporter Image in Parkinsonism: The Competency of Dopaminergic Transporter Imaging in Differential Diagnosis of Parkinsonism: 123I-FP-CIT SPECT Study / 핵의학분자영상

PURPOSE: The aim of this study was to evaluate the discriminating nature of 123I-FP-CIT SPECT in patients with parkinsonism. METHODS: 123I-FP-CIT SPECT images acquired from the 18 normal controls; NC (60.4+/-10.0 yr) and 237 patients with parkinsonism (65.9+/-9.2 yr) were analyzed. From spatially normalized images, regional counts of the caudate, putamen, and occipital lobe were obtained using region of interest method. Binding potential (BP) was calculated with the ratio of specific to nonspecific binding activity at equilibrium. Additionally, the BP ratio of putamen to caudate (PCR) and asymmetric index (ASI) were measured. RESULTS: BPs of NC (3.37+/-0.57, 3.10+/-0.41, 3.23+/-0.48 for caudate, putamen, whole striatum, respectively) had no significant difference with those of essential tremor; ET (3.31+/-0.64, 3.06+/-0.61, 3.14+/-0.63) and Alzheimer's disease; AD (3.33+/-0.60, 3.29+/-0.79, 3.31+/-0.70), but were higher than those of Parkinson's disease; PD (1.92+/-0.74,1.39+/-0.68, 1.64+/-0.68), multiple system atrophy; MSA (2.36+/-1.07, 2.16+/-0.91, 2.26+/-0.96), and dementia with Lewy body; DLB (1.95+/-0.72, 1.64+/-0.65, 1.79+/-0.66)(p<0.005). PD had statistically lower values of PCR and higher values of ASI than those of NC (p<0.005). And PD had significantly lower value of PCR, higher ASI and lower BP in the putamen and whole striatum than MSA (p<0.05). CONCLUSION: Dopamine transporter image of 123I-FP-CIT SPECT was a good value in differential diagnosis of parkinsonism.

The Discriminating Nature of Dopamine Transporter Image in Parkinsonism: The Competency of Dopaminergic Transporter Imaging in Differential Diagnosis of Parkinsonism: 123I-FP-CIT SPECT Study / 핵의학분자영상

PURPOSE: The aim of this study was to evaluate the discriminating nature of 123I-FP-CIT SPECT in patients with parkinsonism. METHODS: 123I-FP-CIT SPECT images acquired from the 18 normal controls; NC (60.4+/-10.0 yr) and 237 patients with parkinsonism (65.9+/-9.2 yr) were analyzed. From spatially normalized images, regional counts of the caudate, putamen, and occipital lobe were obtained using region of interest method. Binding potential (BP) was calculated with the ratio of specific to nonspecific binding activity at equilibrium. Additionally, the BP ratio of putamen to caudate (PCR) and asymmetric index (ASI) were measured. RESULTS: BPs of NC (3.37+/-0.57, 3.10+/-0.41, 3.23+/-0.48 for caudate, putamen, whole striatum, respectively) had no significant difference with those of essential tremor; ET (3.31+/-0.64, 3.06+/-0.61, 3.14+/-0.63) and Alzheimer's disease; AD (3.33+/-0.60, 3.29+/-0.79, 3.31+/-0.70), but were higher than those of Parkinson's disease; PD (1.92+/-0.74,1.39+/-0.68, 1.64+/-0.68), multiple system atrophy; MSA (2.36+/-1.07, 2.16+/-0.91, 2.26+/-0.96), and dementia with Lewy body; DLB (1.95+/-0.72, 1.64+/-0.65, 1.79+/-0.66)(p<0.005). PD had statistically lower values of PCR and higher values of ASI than those of NC (p<0.005). And PD had significantly lower value of PCR, higher ASI and lower BP in the putamen and whole striatum than MSA (p<0.05). CONCLUSION: Dopamine transporter image of 123I-FP-CIT SPECT was a good value in differential diagnosis of parkinsonism.

Comparison of the Results for Sentinel Lymph Node Mapping in the Breast Cancer Patients using 99mTc-Antimony Trisulfide Colloid, 99mTc-Tin Colloid, and 99mTc-Human Serum Albumin / 핵의학분자영상

PURPOSE: In the breast cancer patient, lymphatic mapping and sentinel lymph node biopsy are the most important procedure for axillary lymph node staging. We aimed to compare the three radiocolloids [99mTc-antimony trisulfide colloid (ASC), 99mTc-tin colloid (TC), and 99mTc-human serum albumin (HSA)] for sentinel lymph node mapping. SUBJECTS AND METHODS: Totally, 397 patients with clinically N0 stage were enrolled. 99mTc-ASC was injected in 202 out of 397 patients, 99mTc-TC was injected in 120 patients, and 99mTc-HSA was injected in the remaining 75 patients. The sentinel lymph nodes were localized by lymphoscintigraphy and selected using intraoperative gamma probe. All sentinel lymph nodes were investigated by intraoperative pathologic consultation. The axillary lymph nodes which were harvested by the lymph node dissection were also investigated. RESULTS: The patients of each group showed similar clinical characteristics. There were no significant differences (p>0.05) in the identification rate of sentinel lymph nodes (IR), false negative rate (FNR), and negative predictive value (NPV). The axillary lymphadenectomy revealed axillary lymph node metastases in those three groups (ASC-33.2%, TC-31.7%, HSA-22.7%). The IR, FNR, and NPV were not significantly different among those groups. CONCLUSION: Those three 99mTc-labeled radiocolloids showed equivalent results in sentinel lymph node mapping of breast cancer.