Lymphoblastic Involvement of the Bone Marrow as a Cause of Superscan Appearance in 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

The 18F-fluorodeoxylucose (FDG) positron emission tomography (PET) is the gold standard imaging modality in the staging of lymphoma. The superscan appearance in the FDG PET/computerized tomography (CT) imaging might be because of benign diseases or malignant infiltrations. This case report presents lymphomatous blastic infiltration as a cause of superscan appearance in 18F-FDG PET/CT.

Minimal Invasive Radioguided Ectopic Parathyroidectomy in Upper Mediastinum

In this study we wanted to present a case with the history of multiple previous neck explorations and persisting upper mediastinal ectopic parathyroid adenoma who underwent a successful operation with radioguided minimal invasive approach.

In-transit sentinel lymph nodes predicted by F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Although the in-transit lymph node is a well-known issue in malignant melanoma, it is not documented sufficiently in breast cancer. In this case report an in-transit lymph node demonstrated by both PET/CT and sentinel lymph node mapping and diagnosed by pathology is reported.

The F-18 FDG PET/CT and CT evaluation of pleural plaques.

INTRODUCTION: Pleural plaques have the possibility of bearing malignancy thus investigation of this entity is important and the most important indicator of malignancy in general is fluorodeoxyglucose (FDG) accumulation in radiological appearance. However there is discrepancy between results of previous studies in the literature about this subject. The aim of this study is to analyze the standardized uptake value of pleural plaques and the cut off levels for malignancy in comparison with computed tomography (CT). MATERIALS AND METHODS: Seventy one patients were included in the study (27F, 44M; mean: 59.9 ± 13.1 years). Oncologic F-18 FDG positron emission tomography/computed tomography (PET/CT) was performed to all the subjects for a different primary tumor. Pleural plaques were identified in all patients in CT component of PET/CT examination. Contrast enhanced and nonenhanced CT images were evaluated by a Radiology Physician independently according to the gold standard pathology. RESULT: The diagnostic sensitivity, specificity of CT was; 39%, 79% respectively and if the cut-off SUVmax level was accepted "4.8" the diagnostic sensitivity and specificity of PET was 71%, and 63% respectively. CONCLUSIONS: According to the results and ROC curves determined in the study the cut-off level for evaluation of pleural plaques in PET examination was "4.8". The sensitivity and accuracy of PET was higher compared to CT with this cut-off value.

The Role of 18F-FDG PET/CT in Detecting Ovarian Cancer Recurrence in Patients with Elevated CA-125 Levels

Objectives: To investigate the role of 18F-FDG positron emission tomography/computed tomography (PET/CT) in detection of recurrence in ovarian cancer patients with increased CA-125 levels. Methods: Fifty-two patients (30-80 years old, mean: 58.5±10.6 years) who had been histopathologically diagnosed with ovarian cancer, underwent 18F-FDG PET/CT imaging for re-staging due to elevation of CA-125 levels were included in this retrospective study. 18F-FDG PET/CT findings were compared with histopathological, radiological and clinical follow-up results. Results: CA-125 levels ranged between 35.2-2740 U/mL (N: 0-35 U/mL). Recurrent disease was detected in 45 of 52 patients on PET/CT imaging. There were three false negative and one false positive result. In addition to abdominal and pelvic lesions, 14 distant metastatic lesions (brain, lung, liver and bone metastasis) were identified correctly on PET/CT imaging. Sensitivity, specificity, positive and negative predictive value and accuracy of 18F-FDG PET/CT were calculated as 94%, 75%, 98%, 50% and 96%, respectively. Conclusion: 18F-FDG PET/CT is a useful imaging method that can be used in detection of ovarian cancer recurrence in patients with elevated CA-125 levels. Since this modality offers whole body imaging, distant metastases could be detected in addition to abdominal and pelvic lesions thus contributing to patient management.

Splenosis Mimicking Lymphoma Relapse Confirmed by 18F-FDG PET/CT and Tc-99m Nano-colloid Scintigraphy Thirty Years After Splenectomy for Trauma

Splenosis is implantation of the splenic tissue in the abdominal region or elsewhere in the body as a consequence of trauma or splenectomy, which might mimic intra-abdominal involvement of several malignancies. This case report presents a patient with abdominal implants without 18F-FDG accumulation confirmed to be splenosis by Tc-99m nano-coloid scintigraphy.

Radioiodine Contamination Artifacts and Unusual Patterns of Accumulation in Whole-body I-131 Imaging: A Case Series.

INTRODUCTION: Radioactive iodine has been used for more than 50 years for the treatment of thyroid diseases. Differentiated thyroid cancers have the ability to trap iodine. Therefore, radioiodine can be used both diagnostically and therapeutically. In the follow-up of patients, it is critical to interpret radioiodine scans correctly. CASE PRESENTATION: Non-physiological Iodine-131 (I-131) extra-thyroidal uptake detected on post-therapy or diagnostic I-131 scanning are not always interpreted as functioning metastatic thyroid cancer. CONCLUSIONS: This study provides detailed information and case samples of radiodine contamination artifacts and non-physiological, non-metastatic extra-thyroidal I-131 accumulation in whole-body I-131 imaging.

Prone imaging allows efficient radiopharmaceutical usage by obviating the necessity of a rest study in Tc-99m-methoxyisobutylisonitrile myocardial perfusion scintigraphy.

OBJECTIVE: In myocardial perfusion single-photon emission computed tomography studies, diaphragmatic attenuation of the inferior wall is a common artifact, which can be minimized by prone imaging. The aim of this retrospective study was to validate the impact of stress-prone imaging on the necessity of a rest perfusion study with a final goal of effective radiopharmaceutical usage. METHODS: The findings of 98 patients who had been examined by a combined supine and prone imaging were retrospectively evaluated. Prone acquisition was performed only when reduced perfusion was observed in the inferior wall on the stress supine images. The reconstructed images were evaluated both visually and quantitatively. Rest myocardial single-photon emission computed tomography study was omitted in patients with complete normalization of uptake in the prone images. Results obtained were also compared with the clinical data and follow-up. RESULTS: Prone imaging obviated the necessity of a rest perfusion study in 76 of 98 patients (77.5%). Among normally reported patients (n=89), 76 (85.4%) were saved from a rest study due to the prone study results. Prone study provided improved results in quantitative analysis as well. The difference between the mean summed stress scores of supine and prone studies was statistically significant in normally reported patients (P=0.013). However, no significant difference was observed in scores of ischemic patients (P=0.341). CONCLUSION: Adding prone imaging to a post-stress Tc-99m-methoxyisobutylisonitrile myocardial perfusion study not only minimizes the inferior wall attenuation, but also reduces the need for a rest test, particularly in low-risk or intermediate-risk patients. Thus, prone imaging seems to be both safe and effective.

Rare Thyroid Cartilage and Diaphragm Metastases from Lung Cancer Visualized on F-18 FDG-PET/CT Imaging.

UNLABELLED: Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) has evolved as a useful imaging modality in the assessment of a variety of cancers, especially for tumor staging and post treatment monitoring. It provides metabolic information. Although, when used alone, relative lack of anatomic landmarks, is a major limitation of PET imaging, this limitation of PET imaging is overcome by the availability of integrated PET/CT imaging. PET and CT images are acquired in one procedure, yielding fused anatomical and functional data sets. Studies with integrated PET/CT imaging have shown promising results. In this case, we present an interesting integrated PET/CT imaging in a lung cancer patient with rare, diaphragm and thyroid cartilage metastases. CONFLICT OF INTEREST: None declared.

Detection of bone metastases in initial staging of orbital embryonal rhabdomyosarcoma by fluorodeoxyglucose positron emission tomography/computed tomography.

UNLABELLED: Rhabdomyosarcoma is the most common form of soft tissue sarcoma in young children. In soft tissue sarcomas, isolated metastases are seen in the lung, soft tissue, and bone. The optimal management of these tumors depends on the site, size, and grade of the local growth, and accurate staging of the disease when first seen. Although detection of the primary site of disease is usually accomplished well with conventional techniques, the performance of fluorodexyglucose (FDG) positron emission tomography/computed tomography (PET/CT) may be useful to determine metastases that are not clinically evident. We describe a case of early detection of distant metastases by FDG PET/CT in a young patient diagnosed with orbital embryonal rhabdomyosarcoma. CONFLICT OF INTEREST: None declared.

Findings on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in a patient with malignant pheochromocytoma.

UNLABELLED: Pheochromocytomas are rare tumors arising from chromaffin cells of the sympathoadrenal system and 85% of them are located in the adrenal medulla. Malignant pheochromocytomas account for 10% of all pheochromocytomas. Since clinical, biochemical and histopathological features can not reliably distinguish malignant from benign tumors, malignancy is established in the presence of distant metastases. Although in some cases, metastases may develop during follow-up, most of these tumors have metastatic disease at initial presentation. In this case report, detection of distant metastases and recurrence developed during follow-up with 18-flouro-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in a patient with malignant pheochromocytoma was presented. CONFLICT OF INTEREST: None declared.

The role of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiating between benign and malignant adrenal lesions.

OBJECTIVES: This retrospective study was designed to investigate the clinical role of whole-body positron emission tomography/computed tomography (PET/CT) by using 2-[18F]fluoro-2-deoxy-D-glucose (FDG), for the evaluation of adrenal lesions and to find the best index to distinguish benign from malignant lesions in various cancer patients. MATERIALS AND METHODS: A total of 81 patients (55 male and 26 female, age range: 31-81 years, mean: 61.5) who had confirmed primary malignancies (lung cancer in 47 patients, gastrointestinal malignancies in 13 patients, malignant melanoma in one patient, renal cell cancer in three patients, mesothelioma in two patients, breast carcinoma in nine patients, cervical cancer in one patient, ovarian cancer in two patients, pheochromocytoma in one patient, unknown primary in two patients) underwent PET/CT examinations for cancer screening, staging, restaging, and detection of suspected recurrence. Of the 81 patients, 104 adrenal lesions (34 benign and 70 malignant adrenal lesions) were shown by CT. On visual analysis of PET/CT imaging, adrenal uptake was based on a three-scale grading system. For final assessment standards of references for adrenal malignant lesions was based on biopsy (n=2), interval growth, or reduction after chemotherapy. An adrenal lesion, which remained unchanged on clinical and imaging follow-up of at least 7 months (mean follow-up time 19.31 months±6.46, range 7-30 months), was decided as a benign lesion. RESULTS: In adrenal malignant lesions maximum standardized uptake value (SUVmax) (8.82±4.47) was higher than that of adrenal benign lesions (3.02±1.15, P<0.0001). In the differentiation of adrenal benign and malignant lesions, a CT threshold of 10 Hounsfield units corresponded to a sensitivity of 64.7%, specificity of 98.6%, and accuracy of 87.5%. An SUVmax cut-off value of 2.5 corresponded to a sensitivity of 100%, specificity of 38.2%, and accuracy of 80%. An SUVmax cut-off value of 4.2 corresponded to a sensitivity of 88.6%, specificity of 88.2%, and accuracy of 88.5%. The ratio of tumor SUVmax to liver SUVmean was 3.61±1.77 for adrenal malignant lesions whereas it was 1.20±0.38 for adrenal benign lesions (P<0.0001). T/L SUV ratio cut-off value of 1.8 corresponded to a sensitivity of 87%, specificity of 91%, and accuracy of 88.5%. T/L SUV ratio cut-off value of 1.68 corresponded to a sensitivity of 90%, specificity of 91.1%, and accuracy of 90.4%. CONCLUSION: 2-[18F]fluoro-2-deoxy-D-glucose-PET/CT improves the diagnostic accuracy in the differentiation of benign from malignant adrenal lesions in various cancer patients. Combined information obtained from PET/CT (SUVmax, T/L SUV ratio, visual analysis) and unenhanced CT (size, Hounsfield units measurement) is recommended for better differentiation.

Askin's Tumor in an Adult: Case Report and Findings on 18F-FDG PET/CT.

Primitive neuroectodermal tumor (PNET) of the chest wall or Askin's tumor is a rare neoplasm of chest wall. It most often affects children and adolescents and is a very rare tumor in adults. In this case report, we present an Askin's tumor occurred in a 73-year-old male. The patient was admitted with a history of 3-month lower back pain and cough. In computed tomography, there was a lesion with dimensions of 70 x 40 x 65 mm in the superior segment of the lower lobe of the left lung. Positron emission tomography/computed tomography with 18F-flourodeoxyglucose revealed a pleural-based tumor in the left lung with a maximum standardized uptake value of 4.36. No distant or lymph node metastases were present. The patient had gone through surgery, and wedge resection of the superior segment of left lobe and partial resection of the ipsilateral ribs were performed. Pathology report with immunocytochemistry was consistent with PNET and the patient received chemotherapy after that.

McCune-Albright syndrome associated with acromegaly and bipolar affective disorder.

McCune-Albright syndrome is a rare disorder caused by an activating mutation in the gene (GNAS1) encoding the subunit of the G protein. This syndrome is characterized by polyostotic fibrous dysplasia, café-au-lait pigmentation, and multiple endocrine hyperfunction. A 29-year-old male with polyostotic fibrous dysplasia, café-au-lait pigmentations, and pituitary adenoma is presented in this report. The patient had accompanying bipolar affective disorder, which might have been caused by the underlying genetic abnormality.