Positron Emission Tomography/Computed Tomography in Thyroid Cancer.

Fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) plays an important role in the management of thyroid malignancies. Incidentally found FDG avid nodule needs further workup to rule out its malignant potential. 18F-FDG PET/CT has a proven role in detecting recurrent disease or the metastatic workup of the thyroglobulin elevated negative radioiodine scan (TENIS) scenario. In managing histologically aggressive carcinoma of the thyroid, 18F-FDG PET/CT has a proven role. The theranostic potential has been explored with PET/CT using 68Ga-SSA, 68Ga-PSMA,68Ga-FAPI, and 68Ga-DOTA-RGD. The 124I PET/CT role is just being investigated for better spatial resolution and helps in dosimetry.

BRAF V600E and TERT promoter mutations in paediatric and young adult papillary thyroid cancer and clinicopathological correlation.

Objectives The primary objective of this study was to determine the prevalence of BRAF V600E and TERTpromoter mutations in paediatric and young adult patients with papillary thyroid carcinoma (PTC) and the secondary objective, to assess their association with clinicopathological features. Methods Patients ≤20 years who underwent surgery for differentiated thyroid cancer (DTC) from 2005 to 2018 were consecutively enrolled for BRAF V600E and TERTpromoter mutations analysis and records analysed for the association of aggressive features. Univariate analysis and multivariate logistic regression were used to identify the independent predictors of BRAF V600E mutations. Results Among 100 patients with DTC, 68 patients were ≤18 years and the remaining 30 patients were >18 years of age with a median age of 17 years (IQR 14-19 years) 98 patients had PTC and 2 had FTC. BRAF V600E mutation was present in 14/98 (14.3%) PTC and TERTpromoter mutation noted in none. Multivariate analysis identified RAI refractoriness (OR:10.57, 95% CI: 2.6 to 41.6, P-0.0008) as an independent factor associated with BRAF V600E mutation. 17 patients with distant metastases were negative for both BRAF V600E or TERTpromoter mutation. No significant association was observed between age, gender, PTC variants, extra-thyroidal extension, lymphovascular invasion, multifocality, RAI administration and event rate with BRAF V600E mutation. Irrespective of BRAF V600E mutation, radioiodine refractory status (p-0.0001) had a reduced EFS probability. Conclusion In paediatric & young adult PTC, TERTpromoter mutation is absent and BRAFV600E mutation is not associated with distant metastasis. The prevalence rate of the BRAF V600E mutation is much lower compared to adult PTC patients.

Spectrum of 18F-FDG Uptake in Bilateral Lung Parenchymal Diseases on PET/CT.

Bilateral lung parenchymal involvement is seen in infective as well as noninfective conditions, appearing as focal or diffuse lung disease. PET/CT with FDG helps in characterization (increased glucose utilization is seen by both inflammatory and neoplastic cells). In this article, we describe the spectrum of patterns of FDG uptake and associated CT changes involving bilateral lung parenchyma. Benign conditions described are aspiration pneumonia; pulmonary toxicity by bleomycin; infections, namely, sarcoidosis, miliary pulmonary tuberculosis, and pulmonary nocardiosis; and inflammatory conditions such as pulmonary Langerhans cell histiocytosis and pulmonary alveolar proteinosis. Neoplastic conditions described are bilateral pulmonary metastases and lymphangitic carcinomatosis.

Diagnostic Role of Fluorodeoxyglucose PET in Breast Cancer: A History to Current Application.

Histologic subtype, receptor status, and other biologic factors greatly affect the avidity of breast malignancy on fluorodeoxyglucose (FDG) PET. FDG PET/computed tomography (CT) has demonstrated excellent value in the evaluation of extra-axillary nodal and distant metastases. Patients with early-stage breast cancers do not benefit from FDG PET/CT; however, unsuspected distant metastases may be revealed by systemic staging of locally advanced breast cancers by FDG PET/CT, and this has substantial impact on patient management. FDG PET/CT has demonstrated value in the evaluation of treatment response and in detection of disease recurrence.

Unilateral Brown Fat Suppression on FDG PET/CT-detecting Sympathetic Denervation.

We present here a case of primitive neuroectodermal tumor (PNET) who initially presented with involvement of the right 3rd rib and underwent neoadjuvant chemotherapy, rib excision, and adjuvant chemoradiotherapy and later underwent posterolateral thoracotomy, pleural nodule excision, and the right 11th rib metastatic lesion excision. Follow-up 18F-FDG PET/CT/computed tomography revealed unilateral brown fat suppression in the form of decreased metabolic uptake in the ipsilateral cervical, axillary, and paravertebral brown fat as compared to metabolically active contralateral brown fat, likely due to paravertebral sympathetic chain damage.

68Ga-DOTANOC PET/CT in Medulloblastoma.

Medulloblastoma, also known as cerebellar primitive neuroectodermal tumor, is the most common brain tumor in children and arises in the posterior cranial fossa. We present the case of a patient with desmoplastic type of medulloblastoma, which showed recurrence more than once. When Ga-DOTANOC PET-CT was done, the lesions showed somatostatin receptor expression, opening another potential therapeutic option for this patient.

Impedimetric genosensor for detection of hepatitis C virus (HCV1) DNA using viral probe on methylene blue doped silica nanoparticles.

An impedimetric genosensor was fabricated for detection of hepatitis C virus (HCV) genotype 1 in serum, based on hybridization of the probe with complementary target cDNA from sample. To achieve it, probe DNA complementary to HCVgene was immobilized on the surface of methylene blue (MB) doped silica nanoparticles MB@SiNPs) modified fluorine doped tin oxide (FTO) electrode. The synthesized MB@SiNPs was characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) pattern. This modified electrode (ssDNA/MB@SiNPs/FTO) served both as a signal amplification platform (due to silica nanoparticles (SiNPs) as well as an electrochemical indicator (due to methylene blue (MB)) for the detection of the HCV DNA in patient serum sample. The genosensor was optimized and evaluated. The sensor showed a dynamic linear range 100-106 copies/mL, with a detection limit of 90 copies/mL. The sensor was applied for detection of HCV in sera of hepatitis patient and could be renewed. The half life of the sensor was 4 weeks. The MB@SiNPs/FTO electrode could be used for preparation of other gensensors also.

Point of care with micro fluidic paper based device integrated with nano zeolite-graphene oxide nanoflakes for electrochemical sensing of ketamine.

The present study was aimed to develop an ultrasensitive technique for electroanalysis of ketamine; a date rape drug. It involved the fabrication of nano-hybrid based electrochemical micro fluidic paper-based analytical device (EµPADs) for electrochemical sensing of ketamine. A paper chip was developed using zeolites nanoflakes and graphene-oxide nanocrystals (Zeo-GO). EµPAD offers many advantages such as facile approach, economical and potential for commercialization. Nanocrystal modified EµPAD showed wide linear range 0.001-5nM/mL and a very low detection limit of 0.001nM/mL. The developed sensor was tested in real time samples like alcoholic and non-alcoholic drinks and found good correlation (99%). The hyphenation of EµPAD integrated with nanocrystalline Zeo-GO for detection of ketamine has immense prospective for field-testing platforms. An extensive development could be made for industrial translation of this fabricated device.

Patterns of brown fat uptake of 18F-fluorodeoxyglucose in positron emission tomography/computed tomography scan.

Fluorodeoxyglucose (FDG) positron emission tomography (PET) has become the common imaging modality in oncological practice. FDG uptake is seen in brown adipose tissue in a significant number of patients. Recognizing the uptake patterns is important for optimal FDG PET interpretation. The introduction of PET/computed tomography (PET/CT) revolutionized PET imaging, bringing much-needed anatomical information. Careful review and correlation of FDG PET images with anatomical imaging should be performed to characterize accurately any lesion having high FDG uptake.

Role of fluorodeoxyglucose positron emission tomography/computed tomography in diagnostic evaluation of carcinoma urinary bladder: comparison with computed tomography.

Bladder carcinoma is the most frequent tumor of the urinary tract and accounts 7% of all malignancies in men and 2% of all malignancies in women. This retrospective study was carried out to assess the diagnostic utility of F18-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the imaging evaluation of bladder carcinoma. Seventy-seven consecutive patients diagnosed to have carcinoma urinary bladder referred for F18-FDG PET/CT were included in this study. Thirty-four patients were for initial staging after transurethral biopsy and remaining 43 patients were for restaging. All patients also underwent CT scan of the abdomen and pelvis. PET/CT findings were correlated with diagnostic CT scan and histopathological findings. In 30 of the 34 patients for initial staging, both PET/CT and CT confirmed the primary lesion in the bladder. Histopathology report was available in 23 patients. Lymph nodes FDG uptake reported to be metastatic in 10/23 patients while CT detected lymph node metastasis in 12 patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy have been calculated to be 87.5%, 80%, 70%, 92%, 82% for PET/CT and 66%, 57%, 50%, 72%, 60% for CT respectively. PET/CT detected metastatic disease in 8 patients whereas CT detected in 4 patients. Of the 43 patients for restaging, local recurrence was detected in 24 patients on both PET/CT and CT. Histopathology report was available in 17 patients. Sensitivity, specificity, PPV, NPV and accuracy were 85%, 60%, 60%, 85%, 70% for PET/CT and 80%, 50%, 40%, 85%, 58% for CT respectively. Nineteen patients were detected to have metastatic disease by PET/CT, whereas CT detected metastases in 11 patients. F-18 FDG PET/CT is a very useful modality in pre-operative staging and monitoring after surgery, chemotherapy or radiotherapy of patients with carcinoma urinary bladder.

Skull base osteomyelitis in otitis externa: The utility of triphasic and single photon emission computed tomography/computed tomography bone scintigraphy.

BACKGROUND: Skull base osteomyelitis (SBO) refers to infection that has spread beyond the external auditory canal to the base of the skull in advanced stages of otitis externa. Clinically, it may be difficult to differentiate SBO from severe otitis externa without bony involvement. This study was performed to determine the role of three phase bone scintigraphy (TPBS) and single photon emission tomography/computed tomography (SPECT/CT) in detecting SBO. MATERIALS AND METHODS: We retrospectively analyzed records of 20 patients (14 M, 6 F) with otitis externa and suspected SBO. TPBS and SPECT/CT of the skull were performed. Findings were correlated with clinical, laboratory and diagnostic CT scan findings. RESULTS: All patients were diabetic with elevated erythrocyte sedimentation rate. A total of 18 patients had bilateral and two unilateral symptoms. Cranial nerves were involved in eight patients and microbiological culture of ear discharge fluid positive in seven. Early images showed increased temporal vascularity in nine patients and increased soft-tissue uptake in 10, while delayed images showed increased bone uptake in 19/20 patients. Localized abnormal tracer uptake was shown by SPECT/CT in the mastoid temporal (15), petrous (11), sphenoid (3) and zygomatic (1) and showed destructive changes in five. Thus, TPBS was found positive for SBO in 10/20 patients and changed the management in four. CONCLUSION: Our study suggests that TPBS with SPECT/CT is a useful non-invasive investigation for detection of SBO in otitis externa.

Comparison of 18F fluoride PET/CT and 99mTc-MDP bone scan in the detection of skeletal metastases in urinary bladder carcinoma.

AIM: The aim of this study was to compare (18)F-fluoride PET/CT and (99m)Tc-MDP bone scintigraphy in the detection of skeletal metastases in urinary bladder carcinoma. PATIENTS AND METHODS: In this prospective study, 48 patients with urinary bladder carcinoma (44 male and 4 female patients, aged 35-80 years) underwent (99m)Tc-MDP planar and SPECT/CT bone scan (BS) followed by (18)F-fluoride PET/CT within 48 hours. Skeletal metastasis diagnosed on each of these techniques was compared against a final diagnosis based on contrast-enhanced CT, MRI, skeletal survey, clinical follow-up, and histological correlation. RESULTS: (18)F-fluoride PET/CT identified bony metastases and changed the management in 17 of 48 patients (35%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of (99m)Tc-MDP planar BS were 82.35%, 64.51%, 56%, 86.95%, and 70.83%; of (99m)Tc-MDP SPECT/CT were 88.23%, 74.19%, 65.21%, 92%, and 79.16%; and of (18)F-fluoride PET/CT were 100%, 87.09%, 80.95%, 100%, and 91.66%, respectively. Fair agreement between (99m)Tc-MDP planar BS and F-fluoride PET/CT (κ = 0.42) and excellent agreement between SPECT/CT and (18)F-fluoride PET/CT (κ = 0.74) were found. CONCLUSIONS: ( 18)F-fluoride PET/CT has higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in detecting bone metastases in urinary bladder carcinoma than conventional (99m)Tc-MDP planar BS. SPECT/CT improves all these parameters compared with planar BS and may serve as a cost-effective screening procedure for the detection of skeletal metastases in high-risk patients.

Radioiodine treatment in McCune-Albright syndrome with hyperthyroidism.

McCune-Albright syndrome (MAS) is a sporadic disease characterized by polyostotic fibrous dysplasia, "café-au-lait" spots and hyperfunctional endocrinopathies. Pathophysiological basis is activating mutation of the gene that encodes the alpha subunit of Gs membrane protein that stimulates the intracellular production of cAMP, conferring autonomous secretion of the gland in particular. One of the uncommon endocrine manifestations is hyperthyroidism. We present a patient who had café-au-lait spots, polyostotic fibrous dysplasia and hyperthyroidism. She was treated with radioactive iodine for the symptoms of hyperthyroidism and subsequently relieved from hyperthyroid features.

Single photon emission computed tomography/computed tomography of the skull in malignant otitis externa.

Malignant otitis externa is a severe, rare infective condition of the external auditory canal and skull base. The diagnosis is generally made from a range of clinical, laboratory, and imaging findings. Technetium 99m methylene diphosphonate bone scintigraphy is known to detect osteomyelitis earlier than computed tomography. The authors present a patient with bilateral malignant otitis externa where the extent of skull base involvement was determined on 3-phase bone scintigraphy with single photon emission computed tomography/computed tomography.

Urinary bladder carcinoma associated with Paget's disease of skull: Imaging findings on Tc99m-MDP bone scintigraphy, F18-Fluoride PET/CT and F18-FDG PET/CT.

We report the imaging findings of a patient with Paget's disease in metastatic carcinoma bladder evaluated by Tc99m-Methylene diphosphonate (MDP) bone scintigraphy, F18-Fluoride positron emission tomography/computed tomography (PET/CT) and F18-fluorodeoxy glucose (FDG) PET/CT. Tc99m-MDP bone scan showed intense uptake in the skull bones without any other abnormal tracer distribution. F18-Fluoride PET/CT revealed intense uptake in the pelvic bones along with skull bones, but F18-FDG PET/CT showed intense multifocal FDG uptake in the bladder and bilateral inguinal lymph nodes, with no abnormal uptake in the skull bones. CT images showed thickening of skull bones.

Spectrum of single photon emission computed tomography/computed tomography findings in patients with parathyroid adenomas.

Primary hyperparathyroidism results from excessive parathyroid hormone secretion. Approximately 85% of all cases of primary hyperparathyroidism are caused by a single parathyroid adenoma; 10-15% of the cases are caused by parathyroid hyperplasia. Parathyroid carcinoma accounts for approximately 3-4% of cases of primary disease. Technetium-99m-sestamibi (MIBI), the current scintigraphic procedure of choice for preoperative parathyroid localization, can be performed in various ways. The "single-isotope, double-phase technique" is based on the fact that MIBI washes out more rapidly from the thyroid than from abnormal parathyroid tissue. However, not all parathyroid lesions retain MIBI and not all thyroid tissue washes out quickly, and subtraction imaging is helpful. Single photon emission computed tomography (SPECT) provides information for localizing parathyroid lesions, differentiating thyroid from parathyroid lesions, and detecting and localizing ectopic parathyroid lesions. Addition of CT with SPECT improves the sensitivity. This pictorial assay demonstrates various SPECT/CT patterns observed in parathyroid scintigraphy.

Tc99m-MDP uptake in ascitic fluid in a patient with prostate carcinoma: A clue to detect metastases.

Bone scintigraphy with Tc-99m methylene diphosphonate (MDP) is used to detect metastases in patients with cancer. Uptake in non-osseous, non-urologic tissues is occasionally found in the routine bone scintigraphy, which may mimic as metastatic lesions. The authors describe the case of a 70-year-old man with prostate cancer, showing diffuse tracer uptake in the left hemithorax and entire abdomen on bone scan that required additional imaging modality for localization. Careful interpretation is needed of the unusual uptake of radiotracer in regions other than the skeleton for metastatic work up.