Paget's disease of pelvis mimicking metastasis in a patient with lung cancer evaluated using staging and follow-up imaging with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

Paget's disease of bone is a benign disease, of uncertain etiology, characterized by an accelerated turnover, that is, bone resorption and formation. Paget's disease may be present in up to 5% of the population, and the majority of cases are asymptomatic. We report the imaging findings of Paget's disease of pelvis discovered incidentally in patient with lung cancer evaluated by fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging. FDG PET-CT scan showed intense uptake in the right lung lower lobe primary and mediastinal lymph nodes. Furthermore, increased uptake noted in left hemipelvis suggestive of Paget's disease. He underwent follow-up FDG PET-CT after chemotherapy showed decrease in lung mass and mediastinal nodes. However, the uptake in left hemipelvis remains same confirming Paget's disease.

Gliomatosis cerebri mimicking encephalitis evaluated using fluorine-18 fluorodeoxyglucose: Positron emission tomography/computed tomography.

Gliomatosis cerebri (GC) is a rare condition in which an infiltrative glial neoplasm spreads through the brain with preservation of the underlying structure. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has an important role in demonstrating the appropriate metabolism and differentiating pathologies mimicking GC on CT and magnetic resonance imaging. We describe imaging findings of FDG PET/CT in GC in a 9-year-old male child mimicking encephalitis.

Image findings of monomorphic non-hogdkin lymphoproliferative disorder in a post renal transplant patient diagnosed with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferations caused by immunosuppression after solid organ or bone marrow transplantation. PTLD is categorized by early lesion, polymorphic PTLD and monomorphic PTLD. Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) scans have clinical significance in the evaluation of PTLD following renal transplantation. We report imaging findings of a monomorphic non-Hodgkin lymphoma, post renal transplant seen on FDG PET/CT in a 32-year-old lactating woman. Whole body FDG- ET/CT demonstrated uptake in right external iliac and inguinal lymph nodes.

Primary central nervous system lymphoma in an human immunodeficiency virus-infected patient mimicking bilateral eye sign in brain seen in fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has proven useful in the diagnosis, staging, and detection of metastasis and posttreatment monitoring of several malignancies in human immunodeficiency virus (HIV)-infected patients. It also has the ability to make the important distinction between malignancy and infection in the evaluation of central nervous system (CNS) lesions, leading to the initiation of the appropriate treatment and precluding the need for invasive biopsy. We report an interesting case of HIV positive 35-year-old woman presented with headache, disorientation, and decreased level of consciousness. She underwent whole body PET/CT which showed multiple lesions in the cerebrum which mimics bilateral eye in brain. A diagnosis of a primary CNS lymphoma was made and patient was started on chemotherapy.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging of an isolated subcutaneous loin metastasis from primary papillary carcinoma of the thyroid.

Differentiated thyroid cancer frequently metastasizes but generally spreads to regional cervical lymph nodes and, in advanced cases, to the lungs and/or skeleton. Metastases to the skin/subcutaneous tissue are rare. We report 45-year-old male patient presented with a loin swelling which on biopsy showed a papillary carcinoma and referred for fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) to find out the primary disease. PET/CT showed abnormal FDG uptake within a loin metastasis and right lobe thyroid nodule. Fine-needle aspiration from nodule showed papillary carcinoma. Because thyroid cancer can rarely metastasize to the skin, attention should be given to that region during interpretation of the images. He was advised total thyroidectomy and metastasis excision.

Rare case of trilateral retinoblastoma with spinal canal drop metastasis detected with fluorine-18 fluorodeoxyglucose positronemission tomography/computed tomography imaging.

Trilateral retinoblastoma (TRb) is a rare syndrome associating hereditary bilateral or unilateral retinoblastoma (Rb) with an intracranial neuroblastic tumor. The latter arises in the midline, most often in the pineal gland, less frequently in the suprasellar or parasellar region. The outcome is usually fatal because of secondary spinal dissemination. We report 10-year-old boy presented with a right eye proptosis and leukocoria, and the magnetic resonance imaging (MRI) showed right orbital mass lesion infiltrating optic nerve and diagnosis of retinoblastoma was made. He was referred for fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) to find out the extent of the disease. PET/CT showed abnormal FDG-uptake within right orbital mass lesion, suprasellar enhancing lesion and drop metastasis in the cervical spinal canal level. He was diagnosed as a case of TRb with spinal canal drop metastasis. He underwent chemotherapy and craniospinal irradiation.

Primary neuroendocrine carcinoma of breast with liver and bone metastasis detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

Cases of primary neuroendocrine carcinoma (NEC) of the breast have been reported, though rare. We report the case of a 45-year-old woman presented with jaundice and evaluated to have liver metastasis from neuroendocrine origin. She underwent whole body positron emission tomography/computed tomography, which showed left breast lesion and bone metastasis. Fine-needle aspiration (FNA) of breast revealed a NEC. A diagnosis of a primary NEC of the breast was rendered with hepatic and bone metastasis. She was treated with peptide receptor radionuclide therapy and is on follow-up.

¹77Lu-EDTMP for treatment of bone pain in patients with disseminated skeletal metastases.

UNLABELLED: (177)Lu-labeled ethylenediaminetetramethylene phosphonic acid ((177)Lu-EDTMP) is an agent that concentrates in areas of enhanced osteoblastic activity. The potential of (177)Lu-EDTMP for palliation of metastatic bone pain has been documented in the recent literature. The objective of the present work was to study the efficacy and safety of the agent after administration to a limited number of patients. METHODS: Ten patients (median age, 68.5 y) with disseminated skeletal metastases received a single bolus infusion of (177)Lu-EDTMP (3.7 GBq). All patients had painful bone metastases in more than one anatomic region that were not relieved by narcotic analgesics. The efficacy of the agent was studied by following pain scores assessed at baseline and at 4, 8, and 12 wk after therapy, by using Karnofsky indices and mobility scores, and by determining the requirement for analgesics at baseline and 4 wk after therapy. The toxicity of the agent was assessed by analyzing complete blood counts. RESULTS: A significant reduction in the mean pain score was noted in all patients. The initial mean pain score of 8.44 dropped to 5.73 within 1 mo of treatment. Six patients who required analgesics for pain management had either reduced or completely withdrawn from their use by 4 wk. Compared with initial scans, scans obtained 1 mo after therapy also showed a decreased uptake of the radiotracer. The mobility scores of all patients were higher at 4 wk. The mean Karnofsky performance score of all patients was initially 45 and increased markedly to 69 at 4 wk. None of the patients experienced blood-related toxicity. CONCLUSION: (177)Lu-EDTMP, with only low bone marrow toxicity, provided significant pain relief to patients and considerably increased their mobility, resulting in an overall improvement in the quality of life. The results of the preliminary clinical studies indicate that (177)Lu-EDTMP can be considered an effective and safe therapeutic radiopharmaceutical for pain palliation of patients with disseminated skeletal disease.

Rare case of isolated splenic metastases from gastric cancer detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

We report a rare case of isolated splenic metastasis from gastric cancer detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT). A 55-year-old man with gastric cancer 1 year post surgery, evaluated with PET/CT showed focal, intense uptake in the spleen, with no other abnormal findings. On splenectomy, the lesion was confirmed as metastasis from gastric cancer pathologically.

Empiric Therapy with Low-Dose I-131 in Differentiated Cancer Thyroid: What is the Magic Number?

Low dose radioactive iodine-131 (RAI) has been widely reported in the treatment of patients with differentiated thyroid cancer (DTC) since 1970's. However, the clinical outcomes, dosage of I-131 and criteria for successful ablation are different in various studies. The aim of this study was to assess clinical outcome 18-month after RAI therapy in selected DTC patients and identify factors associated with a good response. In this experimental study, among patients with DTC referred to the Nuclear Medicine Department and had an indication for RAI therapy in the period between December 2008 and January 2011, 108 subjects were selected randomly. The patients were randomly divided into three groups and empiric low dose therapy with 30, 50 or 75 mCi of I-131 was administered. Patients were monitored closely clinically and with serum thyroglobulin assays and I-131 whole-body scans at 6 monthly intervals for 18-month after treatment. Among 105 patients who completed follow-up, 86% were successfully ablated with a single low dose of I-131. There was no statistically significant difference in ablation rates in the subgroups receiving 30.50 or 75 mCi of I-131. Cumulative ablation rate was 99% in patients after the second dose of low dose therapy. If appropriate selection criteria are used in DTC, successful remnant ablation can be achieved with low doses of I-131 in the range of 30-75 mCi. No significant differences were found in results achieved with 30.50 or 75 mCi of I-131. As the majority of the DTC patients fall within the inclusion criteria of this study, they can be treated on an ambulatory basis with associated low cost, convenience, and low whole-body radiation-absorbed dose to the patients.