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The current National Comprehensive Cancer Network (NCCN) Guidelines consider the role of 2-deoxy-2- ¹⁸ F-fluoro-d-glucose positron emission tomography/computer tomography (FDG PET/CT) in the evaluation of cholangiocarcinoma (CCA) as "uncertain," and have recommended contrast enhanced computed tomography (CECT) but not FDG PET/CT as a routine imaging test for CCA workup. We set out to compare the diagnostic performance of FDG PET/CT and CECT in patients with CCA. The retrospective study included patients with CCA who underwent FDG PET/CT and CECT within 2-month interval between 2011 and 2013 in our hospital. Lesion-based comparison was conducted. Final diagnoses were made based on the composite clinical and imaging data with minimal 6-month follow-up. A total of 18 patients with 28-paired tests were included. There is a total of 142 true malignant lesions as revealed by the 6-paired pre-treatment and 22-paired post-treatment tests. On a lesion-based analysis, the sensitivities, specificities, positive predictive values (PPVs), negative predictive values (NPVs), and accuracies of PET/CT and CECT for detection of CCA were 96.5%, 55.5%, 97.2%, 50.0%, 94.1% and 62.2%, 66.7%, 96.7%, 10.0%, 62.5%, respectively. FDG PET/CT detected more intrahepatic malignant and extrahepatic metastases; and had significant higher sensitivity, NPV, and accuracy than CECT, while similar in specificity and PPV. No true positive lesion detected on CECT that was missed on PET/CT, and none of the false negative lesions on PET/CT were detected on CECT. Six patients had paired pretreatment tests, and FDG PET/CT results changed planned management in three patients. Our data suggest that FDG PET/CT detect more primary and metastatic lesions and lead to considerable changes in treatment plan in comparison with CECT.

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Findings of a solitary "hot spot" at the superior lateral orbital margin on bone scan scintigraphy is not uncommonly seen, and is often dismissed as a benign lesion. However, the exact etiology is indeterminate. We present two cases in which hybrid single photon emission computed tomography/computed tomography imaging was able to characterize and localize this uptake, demonstrating correlation to the right fronto-zygomatic suture.

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Hydrocephalus-related symptoms that worsen after shunt placement may indicate a malfunctioning or obstructed shunt. The assessment of shunt patency and site of obstruction is important for planning of treatment. The radionuclide cerebrospinal fluid (CSF) shunt study provides a simple, effective, and low-radiation-dose method of assessing CSF shunt patency. The radionuclide CSF shuntography is a useful tool in the management of patients presenting with shunt-related problems not elucidated by conventional radiological examination. This article described the imaging technique of ventriculoperitoneal (VP) shunt and lumbar puncture (LP) shunt. The normal finding, abnormal finding of completed obstruction and partial obstruction is present by our cases experience. The radiopharmaceutical (Tc-99m diethylenetriaminepentaacetic acid) was injected via the reservoir for VP shunt and via lumbar puncture needle in subarachnoid space for LP shunt, then serial image in the head and abdominal area. The normal function of VP and LP shunt usually rapid spillage of the radioactivity in the abdominal cavity diffusely. The patent proximal tube VP shunt demonstrates ventricular reflux. The early image of patent LP shunt reveals no activity in the ventricular system contrast to distal LP shunt reveals early reflux of activity in the ventricular system. The completed distal VP and LP shunt obstruction show absence of tracer in the peritoneal area or markedly delayed appearance of abdominal activity. The partial distal VP and LP shunt obstruction recognized by slow transit or accumulation of tracer at the distal end or focal tracer in the peritoneal cavity near the tip of distal shunt. The images of the normal and abnormal CSF shunt as describe before are present in the full paper. Radionuclide CSF shuntography is a reliable and simple procedure for assessment shunt patency.

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A 52-year-old male was subjected to an F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) study for the evaluation of newly diagnosed non-Hodgkin's lymphoma. An incidental non-FDG avid urinary bladder mass was detected, as well as an absent kidney. Ureterocele was suspected, but subsequently a seminal vesicle cyst was confirmed on a CT urogram.

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Natural history of prostate cancer (PCa) is extremely variable, as it ranges from indolent and slow growing tumors to highly aggressive histotypes. Genetic background and environmental factors co-operate to the genesis and clinical manifestation of the tumor and include among the others race, family, specific gene variants (i.e., BRCA1 and BRCA2 mutations), acute and chronic inflammation, infections, diet and drugs. In this scenario, remaining actual the clinical interest of bone scan (BS) in detecting skeletal metastases, an important role in diagnostic imaging may be also carried out by, positron emission tomography/computed tomography (PET/CT) and PET/magnetic resonance imaging (PET/MRI), which combine morphological information provided by CT and MRI with functional and metabolic data provided by PET acquisitions. With respect to PET radiotracers, being ancillary the usefulness of F-18 fluoro-deoxyglucose and not yet demonstrated the cost-effectiveness of F-18 Fluoride respect to BS, the main role is now played by choline derivatives, in particular by 11C-choline and 18F-fluorocholine. More recently, a greater interest for both diagnostic and therapeutic purposes has been associated with radiotracers directed to prostate-specific membrane antigen (PSMA), a transmembrane protein expressed on the cell surface, which showed high selective expression in PCa, metastatic lymph nodes and bone metastases. Several PSMA-targeted PET tracers have been developed many of which showing promising results for accurate diagnosis and staging of primary PCa and re-staging after biochemical recurrence, even in case of low prostate specific antigen values. In particular, the most widely used PSMA ligand for PET imaging is a ⁶⁸Ga-labelled PSMA inhibitor, ⁶⁸Ga-PSMA-HBED-CC (⁶⁸Ga-PSMA-11). ^99mTc-HYNIC-Glu-Urea-A for single photon emission computed tomography, and ¹⁷⁷Lu-PSMA-617 for radioligand therapy has also been applied in humans, with interesting preliminary results related to a possible theranostic approach. A potential role of PSMA radioligands in radio-guided surgery has also been proposed.

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The increasing number of patients with coronary artery disease (CAD) undergoing major noncardiac surgery justifies guidelines concerning preoperative cardiac evaluation. This is compounded by increasing chances for a volatile perioperative period if the underlying cardiac problems are left uncorrected prior to major noncardiac surgeries. Preoperative cardiac evaluation requires the clinician to assess the patient's probability to have CAD, severity and stability of CAD, placing these in perspective regarding the likelihood of a perioperative cardiac complication based on the planned surgical procedure. Coronary events like new onset ischemia, infarction, or revascularization, induce a high-risk period of 6 weeks, and an intermediate-risk period of 3 months before performing noncardiac surgery. This delay is unwarranted in cases where surgery is the mainstay of treatment. The objective of this review is to offer a comprehensive algorithm in the preoperative assessment of patients undergoing noncardiac surgery and highlight the importance of myocardial perfusion imaging in risk stratifying these patients.

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Metabolic bone disease due to hyperparathyroidism is characterized by increased bone resorption and new bone formation. ^99m Tc- hexakis-2-methoxyisobutylisonitrile ( ^99m Tc MIBI) accumulation is controlled by metabolic function and cell viability. To investigate, for the first time, the potential of whole body ^99m Tc MIBI scan for detecting, visually and with the aid of quantitative analysis, bony changes associated with hyperparathyroidism. Eighty-six patients with hyperparathyroidism, referred routinely for parathyroid localization, were included in this case-control prospective study. Each patient was injected with 20-25 mCi of ^99m Tc MIBI. Routine anterior cervico-thoracic images were obtained for parathyroid localization. Two extra whole body images were acquired and assessed visually and by drawing regions of interest over the mandible, sternum, femur, humeri, spine, and the soft tissue adjacent to the bone. The ratios of bone to soft tissue were calculated and compared to ratios drawn in a control group routinely referred for cardiac imaging and injected with ^99m Tc MIBI, after confirming the absence of any bone disease. The visual interpretation of the scans showed 48 patients to have increased bone uptake. Quantitative assessment showed significant difference between the mean ratios of the case and control groups. The Kruskal-Wallis test showed significant agreement between visual and quantitative ratios drawn from delayed right and left femora and left humerus images (P < 0.05). ^99m Tc MIBI whole body imaging is a potentially useful technique for assessing metabolic bone disease associated with hyperparathyroidism. Quantitative analysis helped in confirming the visual findings.

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Radiosynovectomy is a well-established therapy in arthritis and involves an intra-articular injection of small radioactive particles to treat a synovitis. In Europe, frequent indications are rheumatoid and poly-arthritis. Especially in Germany radiosynovectomy is the second common therapy in Nuclear Medicine with about 40,000-60,000 treated joints per year. In Spain, USA, Turkey, Argentines and Philippines the therapy is more use in hemophilic arthritis with excellent results. Especially in developing countries with low availability of clotting factors, the radiosynovectomy represent a cost effective therapeutic option for repeated bleedings in hemophilic arthropathy. The special focus in these countries is maintaining of mobility and work ability. Often only the knee and medium joints (ankle, elbow and shoulder) are treated using yttrium-90, rhenium-186 or phosphorus-32. However, in rheumatoid arthritis most common affected joints are the fingers. For the treatment in these small joints, erbium-169 is necessary. Unfortunately, erbium-169 is only available in Europe. Further indications for radiosynovectomy are osteoarthritis and the articular effusion after joint replacement. The reported response rates in rheumatoid and poly-arthritis range from 60% to 80% depends from the stage of previous arthrosis. The best effectiveness of therapy was observed in hemophilic arthritis with response rate of 90% and significant reducing of bleeding frequency. The therapy is well-tolerated with low rate of side effects. In respect of the specific uptake of particles in the synovia and short range of beta radiation, the radiation exposure outside the joint is very low. The radiosynovectomy has efforts in comparison to surgical synovectomy: it's a minor intervention with low costs; and simultaneous treatments of multiple joints or treatment in short intervals are possible. The presented paper summarized the published papers and reports our own experiences in >15,000 treated joints.

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Radiopharmaceutical therapy, once touted as the "magic bullet" in radiation oncology, is increasingly being used in the treatment of a variety of malignancies; albeit in later disease stages. With ever-increasing public and medical awareness of radiation effects, radiation dosimetry is becoming more important. Dosimetry allows administration of the maximum tolerated radiation dose to the tumor/organ to be treated but limiting radiation to critical organs. Traditional tumor dosimetry involved acquiring pretherapy planar scans and plasma estimates with a diagnostic dose of intended radiopharmaceuticals. New advancements in single photon emission computed tomography and positron emission tomography systems allow semi-quantitative measurements of radiation dosimetry thus allowing treatments tailored to each individual patient.

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We present a case of carcinoma cervix found to have a soft tissue lesion in retroperitoneal region with intense FDG uptake. However, this FDG uptake was false positive as the final diagnosis was retroperitoneal fibrosis.

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In clinical practice, physicians often encounter patients with persistent elevated serum parathyroid hormone levels and normal serum calcium levels, a state known as normocalcemic hyperparathyroidism (NHPT). The investigation of NHPT cases can lead to unnecessary use of parathyroid scintigraphy (PS) and consequently unnecessary health-care costs. In this clinical review, the most common causes of NHPT and the possible indications for PS performance in such cases are mainly presented and discussed.

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This prospective clinical study aimed at assessing three pulmonary scintigraphic algorithms to detect acute pulmonary embolism (PE): Lung ventilation/perfusion (V/Q) scintigraphy along with modified prospective investigation of pulmonary embolism diagnosis (PIOPED) criteria; lung perfusion scintigraphy along with prospective investigative study of acute pulmonary embolism diagnosis (PISAPED) criteria; and lung perfusion scan in combination with ventilation scan, along with modified PISAPED criteria, which were newly developed. Patients with suspicion of PE were eligible for this study if they had no abnormal chest x-ray. Their diagnostic workup included a clinical assessment, a pulmonary V/Q scintigraphy, and CT pulmonary angiography (CTPA), as well as a clinical outcome assessment over a period of 24 weeks. Referred to the final clinical diagnosis of patients, the sensitivity and specificity of each algorithm were evaluated. The diagnostic performance of each algorithm by the area under the maximum likelihood fitted receiver operating characteristic (ROC) curve was determined. With respect to the PISAPED criteria, the sensitivity was 60.8% and specificity was 87.3%. No patient was classified into nondiagnostic category. The PIOPED criteria showed that the sensitivity was 95.0% and specificity was 88.2%, while 57.4% of the patients were in nondiagnostic category. The areas under the ROC curve constructed from the PISAPED criteria results and the modified PIOPED criteria results were 0.734 and 0.859 (P < 0.01), respectively. The modified PISAPED criteria demonstrated that the sensitivity was 83.8% and specificity was 89.1%. No patient was classified into nondiagnostic category. The area under the ROC curve constructed from modified PISAPED criteria was 0.864 (P < 0.01). Perfusion scans used with ventilation scans and modified PISAPED criteria may increase the diagnostic accuracy of pulmonary scintigraphy for acute PE, compared with the two major algorithms.

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Impending spinal cord compression and vertebral fractures are considered contraindications for radionuclide bone pain palliation therapy. However, most of the patients with widespread bone metastases already have weakened vertebral segments that may be broken. Therefore, local field external-beam radiotherapy or percutaneous vertebroplasty (VP) should be considered to improve the patient's quality of life and to institute subsequent appropriate treatment, including radionuclide therapy for bone pain palliation. The objective of this study was to develop a strategy for an effective treatment of bone metastases in patients with widespread bone metastases and intolerable pain, associated with impending cord compression or vertebral fractures. Eleven patients (5 females and 6 males, aged 32-62 years; mean age 53.8 ± 2.7 years) with multiple skeletal metastases from carcinomas of prostate (n = 3), breast (n = 3) and lung (n = 5) were studied. Their mean pain score measured on a visual analogue scale of 10 was found to be 8.64 ± 0.15 (range 8-9) and the mean number of levels with impending cord compression or vertebral fracture was 2.64 ± 0.34 (range 1-4). All patients underwent vertebroplasty and after 3-7 days received Sm-153 ethylene diamine tetra methylene phosphonic acid (EDTMP) therapy. Sm-153 EDTMP was administered according to the recommended standard bone palliation dose of 37 MBq/kg body weight. Whole body (WB) bone scan, computed tomography and magnetic resonance imaging (MRI) were performed before and after treatment in all patients. Pain relief due to stabilization of vertebrae after VP occurred within the first 12 hours (mean 4.8 ± 1.2 hours; range 0.5-12 hours), and the mean pain score was reduced to 4.36 ± 0.39 (range 2-6). Subsequent to Sm-153 EDTMP treatment, further pain relief occurred after 3.91 ± 0.39 days (range 2-6 days) and the pain score decreased to 0.55 ± 0.21 (range 0-2). The responses to treatment were found to be statistically significant (P < 0.0001). Based on the results on this limited patient population, we conclude that spinal stabilization using VP in patients with widespread bone metastases and impending cord compression is an effective way to decrease disability with pain and to facilitate subsequent systemic palliation of painful skeletal metastases by Sm-153 EDTMP therapy.

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