Longitudinal Decline of Striatal Subregional ¹⁸FFP-CIT Uptake in Parkinson's Disease / 대한핵의학회잡지

PURPOSE: Dopamine transporter imaging is suggested to be a useful imaging biomarker for Parkinson's disease (PD) progression and monitoring drug effects.We investigated the longitudinal decline characteristics of striatal [¹⁸F]FP-CIT uptake in PD.METHODS: We retrospectively reviewed 35 PD patients and 9 non-PD patients. All patients underwent [¹⁸F]FP-CIT PET at the initial diagnosis and follow-up. PET images were spatially normalized and analyzed with eight striatal and one occipital VOI templates. We measured the specific to non-specific binding ratio (SNBR) of the striatal subregions and calculated the absolute annual reduction (AAR) and relative annual reduction (%RAR) of the SNBRs.RESULTS: Total striatal SNBRs in PD patients were significantly lower than those in non-PD patients, with the most significant difference in the posterior putamen. Both AAR (0.26 ± 0.14 vs. 0.09 ± 0.19, p < 0.05) and %RAR (6.9 ± 3.5 vs. 1.2 ± 2.7, p < 0.001) of total striatal SNBRs were significantly greater in PD than non-PD patients. There were no significant differences in the AAR and %RAR of total striatal SNBRs between elderly and young onset PD. The AARs of the posterior putamen were higher in early PD than in advanced PD. Conversely, the %RARs were not significantly different between early and more advanced PD. The disease duration was significantly negatively correlated with the AAR but not with the %RAR of the posterior putamen.CONCLUSIONS: The longitudinal decline of striatal [¹⁸F]FP-CIT uptake in PD was nonlinear and significantly faster than that in non-PD, with a different rate of decline among the striatal subregions.

Relationship Between Dual Time Point FDG PET/CTand Clinical Prognostic Indexes in Patients with High Grade Lymphoma: a Pilot Study / 대한핵의학회잡지

PURPOSE: This study investigated the correlative relationship between metabolic parameters estimated from dual time point 2-deoxy-2-[¹⁸F] fluoro-D-glucose (¹⁸F-FDG) positron emission tomography/computerized tomography (PET/CT) and the clinical tools predicting the outcome of a lymphoma. We also measured metabolic and volumetric alterations between early and delayed ¹⁸F-FDG PET/CT in patients with high grade lymphoma (HGL).METHODS: The samples were 122 lymph nodes and extralymphatic lesions from 26 patients diagnosed with HGL. All patients were applied to the International Prognostic Index (IPI), Ann Arbor stage, and revised IPI as clinical prognostic parameters. ¹⁸F-FDG dual time point PET/ CT (DTPFP) consisted of an early scan 1 h after ¹⁸F-FDG injection and a delayed scan 2 h after the early scan. Based on an analysis of DTPFP, we estimated the standardized uptake value (SUV) of tumors from the early and delayed scans, retention index (RI) representing the percentage change between early and delayed SUV, and metabolic volume different index (MVDI) calculated using metabolic tumor volumes (MTV).RESULTS: RI(max) showed a multiple positive correlative relationship with stage and IPI in lesion-by-lesion analysis (p < 0.01). In the case of IPI, the high risk group exhibited higher RI(max) than the low risk group (p = 0.004). In the case of revised IPI, the RI(max) of the low risk group were significantly lower than the intermediate and high risk groups, respectively (p < 0.01). The MVDIs of the best outcome group were decreased in comparison to the moderate outcome group (p = 0.029). There was a significant negative correlative relationship between RI(max) and MVDI, and the inclinations for decreased MVDIs were slightly associated with increased RIs.CONCLUSIONS: RI(max) extracted from DTPFP had a significant relationship to extranodal involvement, staging, IPI, and revised IPI. MVDI showed significant negative correlation with RI(max). Further large scale studies are warranted to support and extend these preliminary results.

Mucoepidermoid Carcinoma with Distant Metastases to the Kidney, Adrenal Gland, Skull and Gluteus Maximus Muscle: a Case Report

INTRODUCTION: Distant metastases of mucoepidermoid carcinoma (MEC) are reported with the most common sites being the soft tissue of skin, lung, liver, and bone. We report here a very rare case of MEC with multiple metastases to the kidney, adrenal gland, skull and gluteus maximus muscle. CASE REPORT: A 63-year-old male patient presented with left-sided headache. Radiologic evaluations including CT and MRI showed ill-defined soft tissue lesion involving the left infratemporal fossa and left sphenoid sinus, and multiple enlarged lymph nodes in neck and mediastinum. PET-CT demonstrated multiple hypermetabolic lesions in and around the left kidney, left adrenal gland, right ischium, right gluteus maximus and skull base. These lesions were confirmed as MEC with multiple metastases through biopsy. DISCUSSION: Only one case of metastasis to the skull has been previously reported, and moreover, there has not been a case of metastatic MEC to the kidney, adrenal gland and gluteus maximus muscle so far in the medical literature. It is important to acknowledge the possibility of every unusual MEC metastases, since the presence of metastasis has statistically significant influence on the survival of MEC.

An Unusual Case of Superior Vena Cava Syndrome Caused by the Intravascular Invasion of an Invasive Thymoma / 결핵및호흡기질환

Superior vena cava syndrome (SVCS) is usually caused by extrinsic compression or invasion of the superior vena cava (SVC) by malignant tumors involving mediastinal structures. Although thymomas are well-known causes of SVCS, cases of SVCS caused by malignant thymomas protruding into adjacent vessels draining the SVC with thrombosis have been very rarely reported worldwide. We experienced a 39-year-old female patient with SVCS that developed after the direct invasion of the left brachiocephalic vein (LBCV) and SVC by an anterior mediastinal mass with a high maximum standardized uptake value on the chest computed tomography (CT) and positron emission tomography-CT. Based on these results, she underwent en bloc resection of the tumor, including removal of the involved vessels, and was eventually diagnosed as having a type B2 thymoma permeating into the LBCV and SVC. We present this case as a very rare form of SVCS caused by an invasive thymoma.

A Case of Rectal Cancer in a Patient with Neurofibromatosis Type 1

A rectal cancer was found in a 67-year-old man with a history of neurofibromatosis type 1. A low anterior resection was performed, and he received concurrent chemoradiation for 6 months. Twelve months after the surgery, a tumor was found at the anastomotic site by positron emission tomography-computed tomography and colonoscopy and was mistaken as anastomotic site recurrence. The tumor was confirmed as an inflammatory myofibroblastic tumor through transanal excision.

The Serial Change of Cerebral Hemodynamics by Vascular Territory after Extracranial-Intracranial Bypass Surgery in Patients with Atherosclerosis of Cerebral Arteries / 핵의학분자영상

PURPOSE: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using (99m)Tc-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). MATERIAL AND METHODS: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. RESULTS: Seventeen patients (M:F=12:5, mean age: 53+/-2yr) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p=0.003) and decreased to the preoperative level at 3-6 months (p=0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. CONCLUSION: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

A Pilot Study for the Feasibility of F-18 FLT-PET in Locally Advanced Breast Cancer: Comparison with F-18 FDG-PET / 핵의학분자영상

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 AND METHODS: The study subjects consisted of 22 female patients (mean age; 42+/-6 years) with biopsy-confirmed infiltrating ductal carcinoma between Aug 2005 and Nov 2006. We perfomed conventional imaging workup, FDG-PET and FLT PET/CT. Average tumor size measured by MRI was 7.2+/-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 SUV75 (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+/-5.2 vs 8.3+/-4.9, p=0.02 / SUV75; 5.3+/-4.3 vs 6.9+/-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+/-7.7 vs 6.3+/-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+/-1.2 and 8.3+/-4.9. The FDG SUVs of liver and bone marrow were 1.8+/-0.4 and 1.6+/-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.

A Case of Esophageal Leiomyoma Showing High FDG Uptake on F-18 FDG PET / 핵의학분자영상

An esophageal leiomyoma is the most common benign tumor of the esophagus mainly occurred in intramural portion. Occasionaly, it is difficult to discriminate esophageal malignancy from large leiomyoma. Although F-18 FDG PET has been used for differentiating malignant from benign disease, false-positive cases have been reported. Recently, uterine leiomyoma has been reported to have relatively high F-18 FDG uptake in some patients but little is known about how an esophageal leiomyoma might be showed on F-18 FDG PET. We report a case of esophageal leiomyoma that showed high FDG uptake on PET images.

A Case of Incidentally Detected Nasopharyngeal Tuberculosis on F-18 FDG PET/CT / 핵의학분자영상

It is well known that F-18 FDG PET/CT is a highly sensitive diagnostic modality for cancer patients. However, false positive cases resulting from benign disease such as tuberculosis in the endemic area often compromise the diagnostic accuracy of F-18 FDG PET/CT. Nasopharyngeal tuberculosis is a rare disease although extrapulmonary tuberculosis can involve any region in the body. We report one case of nasopharyngeal tuberculosis incidentally detected on F-18 FDG PET/CT.

A Case of Hepatic Angiomyolipoma Showing Different Uptake on F-18 FDG and C-11 Acetate PET / 핵의학분자영상

A hepatic angiomyolipoma is a rare benign tumor mainly composed of blood vessels, smooth muscle cells and fat cells in varying proportion. Hepatic angiomyolipoma is often misdiagnosed as a hepatocellular carcinoma in preoperative imaging work-up. To date, there has been little published data describing PET findings of hepatic angiomyolipoma. We report one case of hepatic angiomyolipoma that showed a high acetate and relatively low FDG uptake on PET images.

Clinical Application of PET in Head and Neck Cancer / 한양의대학술지

Head and neck cancers are the sixth most common type of human cancer worldwide. Squamous cell carcinomas are the most common cancer of the head and neck. Due to the higher glycolytic rates of squamous cell carcinomas relative to normal tissue, the glucose analog 18F-FDG can be used to detect umors, and 18F-FDG PET has been used inpatients with head and neck cancers for initial staging, management of recurrent cancers, and therapeutic onitoring. We reviewed the clinical application and diagnostic usefulness of 18F-FDG PET in the management of head and neck cancer.