F-18 Fluorodeoxyglucose PET/CT and Post Hoc PET/MRI in a Case of Primary Meningeal Melanomatosis

Primary meningeal melanomatosis is a rare, aggressive variant of primary malignant melanoma of the central nervous system, which arises from melanocytes within the leptomeninges and carries a poor prognosis. We report a case of primary meningeal melanomatosis in a 17-year-old man, which was diagnosed with 18F-fluorodeoxyglucose (F-18 FDG) PET/CT, and post hoc F-18 FDG PET/MRI fusion images. Whole-body F-18 FDG PET/CT was helpful in ruling out the extracranial origin of melanoma lesions, and in assessing the therapeutic response. Post hoc PET/MRI fusion images facilitated the correlation between PET and MRI images and demonstrated the hypermetabolic lesions more accurately than the unenhanced PET/CT images. Whole body F-18 FDG PET/CT and post hoc PET/MRI images might help clinicians determine the best therapeutic strategy for patients with primary meningeal melanomatosis.

(18)F-FDG PET/CT in Patients with Initially Diagnosed Adenoid Cystic Carcinoma of the Head and Neck: Clinicoplathologic Correlation / 핵의학분자영상

PURPOSE: We evaluated (18)F-FDG PET/CT findings in initially diagnosed adenoid cystic carcinoma (ACC) of the head and neck in association with pathological subtype, staging, uptake comparison with squamous cell carcinoma (SqCC) and prognosis. MATERIALS AND METHODS: The subjects were 16 patients with initially diagnosed ACC of head and neck who underwent pretreatment (18)F-FDG PET/CT. Histological subtype (solid pattern vs. tubular/cribriform pattern), SUV(max) of size-matched SqCC of the head and neck as control group, disease-free survival (DFS) were compared with the SUV(max) of ACC of the head and neck. RESULTS: Of total 16 patients, 6 had solid pattern and the remaining 10 had tubular/cribriform pattern. The SUV(max) were significantly higher in solid pattern group than in tubular/cribriform pattern group (6.7+/-3.2 vs. 4.2+/-0.9, p=0.03). PET/CT found unexpected distant metastasis in 18.7% of patients (3/16) and changed the therapeutic plan in those patients. The SUV(max) of ACC was significantly lower than that of size-matched SqCC (5.1+/-2.4 vs. 13.6+/-6.0, p or =6.0) had significantly shorter DFS than those with low (18)F-FDG uptake (SUV(max) <6.0). CONCLUSION: (18)F-FDG uptake of ACC of the head and neck is significantly associated with histological subtype and DFS. (18)F-FDG PET/CT may be useful for detecting unexpected metastasis. Since (18)F-FDG uptake of tubular/cribriform ACC compared with SqCC is relatively low, it is necessary to interpret PET images carefully in patients without alleged ACC.

Current Status and Problems of PET/CT Data on CD for Inter-hospital Transfer / 핵의학분자영상

PURPOSE: This study was performed to find the current problems of positron emission tomography / computed tomography (PET/CT) data on CD for inter-hospital transfer. MATERIALS AND METHODS: The subjects were 746 consecutive 18F-fluorodeoxyglucose PET/CT data CDs from 56 hospitals referred to our department for image interpretation. The formats and contents of PET/CT data CDs were reviewed and the email questionnaire survey about this was performed. RESULTS: PET/CT data CDs from 21 of 56 hospitals (37.5%) included all transaxial CT and PET images with DICOM standard format which were required for authentic interpretation. PET/CT data from the others included only secondary capture images or fusion PET/CT images. According to this survey, the main reason of limited PET/CT data on CD for inter-hospital transfer was that the data volume of PET/CT was too large to upload to the Picture Archiving and Communication System. CONCLUSION: The majority of hospitals provided limited PET/CT data on CD for inter-hospital transfer, which could be inadequate for accurate interpretation and clinical decision making. It is necessary to standardize the format of PET/CT data on CD for inter-hospital transfer including all transaxial CT and PET images with DICOM standard format.