Tuberous Sclerosis Complex Demonstrated on 18F-FDG PET/CT.

Tuberous sclerosis complex is a rare neurocutaneous genetic disorder that can affect multiple organ systems including the skin, eyes, brain, kidneys, heart, and lungs. Herein, we report 18F-FDG PET/CT findings of brain and skin lesions, bilateral renal angiomyolipomas, and pulmonary lymphangioleiomyomatosis in a patient with tuberous sclerosis complex.

Paraganglioma With Intracranial Invasion Demonstrated on 68 Ga-DOTATATE PET/CT.

68 Ga-DOTATATE PET/CT demonstrates superior sensitivity compared with other cross-sectional and functional imaging techniques in detecting head and neck paragangliomas. It is the primary recommended imaging modality for the evaluation of head and neck paragangliomas, especially in patients suspected of having locally aggressive, multifocal, or metastatic disease, as well as those being considered for targeted peptide-receptor therapy. Herein, we demonstrate the 68 Ga-DOTATATE PET/CT findings of a skull base paraganglioma with extensive local invasion and intracranial extension.

Extranodal Mantle Cell Lymphoma Presented as Bilateral Adrenal Masses on 18 F-FDG PET/CT and 68 Ga-DOTATATE PET/CT.

Mantle cell lymphoma (MCL) is a rare type of B-cell non-Hodgkin lymphoma that commonly presents with constitutional symptoms, lymphadenopathy, and laboratory abnormalities. Although less common, extranodal involvement of MCL may be seen at initial presentation and most commonly occurs in the spleen, liver, bone marrow, and gastrointestinal tract. Adrenal involvement in MCL is extremely rare, and only a few cases have been reported in the literature.

Value of 68 Ga-DOTATATE PET/CT in Follow-up of Renal Cell Carcinoma With Multiple Atypical Metastatic Sites.

The development of late metastatic recurrence after nephrectomy is a well-known characteristic of renal cell carcinoma (RCC). Correct diagnosis is often challenging due to the long time between primary tumor excision and the development of metastases. 68 Ga-DOTATATE PET/CT has the potential to be employed in the follow-up of RCC, because RCC expresses somatostatin receptors.

Renal Cell Carcinoma With Tumor Thrombus Extending Into the Inferior Vena Cava and the Right Atrium Demonstrated by 68 Ga-DOTATATE PET/CT.

Approximately 10% of all renal cell carcinoma (RCC) patients develop a venous tumor thrombus, a major negative prognostic factor. Surgical excision is commonly required for RCC patients with tumor thrombus. Accurate preoperative diagnosis and assessment of tumor thrombus level is vital because the level of thrombus may influence treatment decisions.

Defining the optimal segmentation method for measuring somatostatin receptor expressing tumor volume on 68 Ga-DOTATATE positron emission tomography/computed tomography to predict prognosis in patients with gastroenteropancreatic neuroendocrine tumors.

Objective: We aimed to compare different segmentation methods used to calculate prognostically valuable volumetric parameters, somatostatin receptor expressing tumor volume (SRETV), and total lesion somatostatin receptor expression (TLSRE), measured by 68 Ga-DOTATATE PET/CT and to find the optimal segmentation method to predict prognosis.

Patients And Methods: Images of 34 patients diagnosed with gastroenteropancreatic neuroendocrine tumor (GEPNET) who underwent 68 Ga-DOTATATE PET/CT imaging were reanalyzed. Four different threshold-based methods (fixed relative threshold method, normal liver background threshold method, fixed absolute standardized uptake value (SUV) threshold method, and adaptive threshold method) were used to calculate SRETV and TLSRE values.

18F-FDG PET/CT and 99mTc-MDP Bone Scintigraphy Findings of Multifocal Desmoid Fibromatosis.

Desmoid fibromatosis, also called desmoid tumors, is a group of locally aggressive fibromatous proliferative disorders. They represent less than 3% of all soft tissue sarcoma and are multifocal in approximately 10% of cases. However, there are only a few cases in the literature describing 18F-FDG PET/CT and 99mTc-MDP bone scan features of extra-abdominal desmoid fibromas, and all were solitary bone lesions.

Evaluating therapeutic efficacy of extended shelf-life 90 Y glass microspheres in transarterial radioembolization for colorectal cancer: a quantitative FDG PET/CT analysis.

Objectives: There is a lack of sufficient evidence regarding the use of extended shelf-life (ExSL) Yttrium-90 ( 90 Y) glass radiomicrospheres in metastatic colorectal cancer (mCRC) patients. We aimed to investigate the efficacy of ExSL 90 Y glass radiomicrospheres with a personalized treatment approach by analyzing 18 F-FDG PET/CT quantitative parameters [metabolic tumor volume (MTV) and total lesion glycolysis (TLG)] separately before and after the treatment.

Methods: A total of 93 radioembolization sessions involving 77 patients were included.

Skin and Subcutaneous Tissue Metastases of the Pulmonary Carcinoid Tumor on 68 Ga-DOTATATE PET/CT.

Pulmonary carcinoid tumors are a very rare type of neuroendocrine tumor, accounting for only 1% to 2% of all primary lung cancers. Pulmonary carcinoids most commonly metastasize to the mediastinal lymph nodes, liver, and bones. Metastasis of pulmonary carcinoids to the skin and subcutaneous tissue is extremely rare and has been reported in only a small number of cases.

Metastatic Esophageal Adenocarcinoma Showing 68 Ga-DOTATATE Uptake.

The role of 68 Ga-DOTATATE PET/CT in the evaluation of neuroendocrine tumors is well defined. Nevertheless, 68 Ga-DOTATATE uptake may be seen in some tumors other than neuroendocrine tumors as a reflection of tumor blood supply and somatostatin receptor expression. Although 68 Ga-DOTATATE uptake has been described in a number of nonneuroendocrine tumors, no case of 68 Ga-DOTATATE uptake in esophagus adenocarcinoma has been reported.

Ga-Tetraazacyclododecane Tetraacetic Acid-DPhe1-Tyr3-Octreotate Positron Emission Tomography/Computed Tomographic Findings of Large-Cell Neuroendocrine Carcinoma of the Lung in a Child.

Primary lung cancers in children are rare, and most children are diagnosed incidentally while being investigated for another medical problem. The diagnosis of primary lung tumors in children is very difficult because many children are asymptomatic until the advanced stages of the disease and nonspecific imaging findings. Although the usage of Ga-tetraazacyclododecane tetraacetic acid-DPhe1-Tyr3-octreotate (Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT) in adult patients is well known, it is a relatively new imaging modality for the pediatric patient group.

Brown Tumors Secondary to Tertiary Hyperparathyroidism Masquerading as Lytic or Sclerotic Skeletal Metastases on Preoperative/Postoperative 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Case Report.

Tertiary hyperparathyroidism (TH) is a rare condition that develops from secondary hyperparathyroidism in cases when the secretion becomes autonomous. Brown tumors (BTs) are rare skeletal lesions of hyperparathyroidism that may mimic cancer metastasis. We report a case of a patient who was diagnosed with TH with multiple BTs which mimics osteolytic/osteoblastic metastases that were evaluated with two fluorodeoxyglucose positron emission tomography scans with an interval of 23 months in the preoperative and postoperative period.

Prognostic significance of 18F-FDG PET/CT indices in metastatic renal cell cancer and evaluation of revised IMDC risk model by including 18F-FDG PET-CT parameters.

Background: Prognostic markers in metastatic renal cell cancer (mRCC) are still insufficient. Any prognostic model objectively determines disease burden.

Purpose: To investigate the relationship between 18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters and outcomes in mRCC, and to define a revised International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) model for the intermediate-risk group.

Isolated Scapular Lesion of Langerhans Cell Histiocytosis Detected by F-FDG PET/CT.

Langerhans cell histiocytosis (LCH) is a rare disease that occurs mainly in pediatric patients and most adult LCH is considered a part of multisystem or multifocal disease. Only 7.3% of cases present as unifocal bone lesion.

Nasolacrimal Duct Obstruction on I SPECT/CT: Atypical False-positive Paranasal Radioiodine Uptake as a Complication of Single-dose RAI Treatment.

Nasolacrimal duct obstruction (NLDO) is a rare complication after radioiodine therapy and may cause false positive I uptake at the point of obstruction in I whole body scan. Here, we report a 59-year-old female patient with papillary thyroid cancer treated with total thyroidectomy followed by I therapy. I whole body scan revealed focal uptake in the head.

Role of baseline Ga-PSMA PET/CT-derived whole-body volumetric parameters in predicting survival outcomes of metastatic castration-resistant prostate cancer patients receiving first-line treatment.

Objective: We aimed to evaluate whether baseline Ga-PSMA PET/CT-derived whole-body volumetric parameters could be used as predictive biomarkers for survival in metastatic castration-resistant prostate cancer (mCRPC) patients receiving first-line treatment.

Materials And Methods: This retrospective study included 54 mCRPC patients, who underwent baseline Ga-PSMA PET/CT imaging within 1 month before starting first-line treatment. Pre-treatment prostate-specific antigen (PSA) levels and treatments were recorded.

Neurofibromatosis Type 2: Multiple Meningiomatosis and Vestibular Schwannomas on 68 Ga-DOTATATE PET/CT.

Neurofibromatosis type 2 (NF2) is an autosomal-dominant tumor predisposing syndrome that results from mutations in the NF2 tumor suppressor gene on chromosome 22. The development of bilateral vestibular schwannomas is the characteristic feature of the disease. However, other nervous system tumors, including meningiomas, ependymomas, and schwannomas, can be seen frequently.

18F-FDG PET/CT Metabolic Response With Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Treated With Cyclin-Dependent 4/6 Kinase Inhibitors.

Dysregulation of the cyclin D-CDK4/6-INK4-RB pathway, which leads to uncontrolled cell proliferation, is frequently observed in breast cancer. Recently, 3 CDK4/6 inhibitors have been FDA approved as first-line treatment for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. Despite promising clinical results, the metabolic response to treatment with these new drugs has not been elaborately demonstrated yet.

Bone Metastasis of Glomus Caroticum Demonstrated on 68 Ga-DOTATATE PET/CT.

A 71-year-old man who was diagnosed with carotid body paraganglioma was referred to 68 Ga-DOTATATE PET/CT for primary evaluation, which revealed unknown bony metastasis with intense 68 Ga-DOTATATE uptake. Head and neck paragangliomas are rare neuroendocrine tumors, with a 10% of malignancy rate, and identification of metastatic sites is important in staging and prognosis of the disease. We aimed to highlight the impact of 68 Ga-DOTATATE PET/CT on patient management, especially for equivocal lesions, as in our case.

Azygos Vein Enlargement Secondary to Superior Vena Cava Syndrome on 18 F-FDG PET/CT.

Obstruction of the blood flow from the superior vena cava (SVC) to the right atrium causes the SVC syndrome. The azygos system is the most important way to overcome SVC obstruction. Azygos vein enlargement can be seen secondary to the SVC syndrome.