Safety and tolerability of regadenoson compared with dipyridamole in myocardial perfusion imaging in patients scheduled to undergo medium to high-risk noncardiac surgery: a randomized controlled study.

OBJECTIVE: Regadenoson is the first Food and Drug Administration-approved selective A2A adenosine receptor agonist used in myocardial perfusion imaging. Its main benefits are its simplified and brief protocol, along with the ability to be administered safely in patients with asthma or chronic obstructive pulmonary disease of moderate severity. This study aims to identify any potential benefits of regadenoson, regarding the frequency of adverse reactions and its tolerability, over dipyridamole. METHODS: This is a randomized controlled study of 200 patients scheduled for medium to high-risk noncardiac surgery, of whom 100 were stressed with regadenoson (study group) and the rest with dipyridamole (control group). RESULTS: A greater proportion of adverse reactions was recorded in the regadenoson group as compared to the dipyridamole group (53 vs. 36%; P = 0.023), though the duration of most adverse reactions was shorter in the regadenoson group. Dyspnea (P < 0.001) and gastrointestinal disturbances (P = 0.001) were significantly more frequent in the regadenoson group. The use of aminophylline in patients who developed any adverse events was similar in the two groups (P > 0.05). When multiple regression analyses were performed, differences in adverse reactions between the two groups were no longer significant (odds ratio = 1.96; 95% confidence interval, 0.88-3.25; P = 0.11). CONCLUSION: In our group of patients scheduled for myocardial perfusion imaging for preoperative assessment, the two agents, regadenoson and dipyridamole, have no significant differences in the frequency of mild adverse reactions and in aminophylline use, with regadenoson also having the advantage of faster symptom resolution. Nevertheless, dipyridamole can be considered as a well-tolerated and low-cost alternative.

A case of fever of unknown origin: (18)F-FDG-PET/CT findings in Takayasu's arteritis.

This is a case of a 54 years old woman with fever of unknown origin. Physical examination showed nothing remarkable. Chest radiographs, abdominal ultrasound examination (US) and chest-abdominal-pelvic CT, showed segmental thickening of the wall of the aorta. On admission, the C-reactive protein level and the erythrocyte sedimentation rate were elevated. (18)Fluoro-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET/CT) showed increased uptake of the aorta wall and its main branches that could be indicative of arteritis. The temporal artery biopsy was negative for giant-cell arteritis. The patient responded well to prednisolone treatment. A second (18)F-FDG-PET/CT scan showed great improvement. (18)F-FDG-PET/CT scan early indicates arteritis of the great vessels that in this case was considered to be TA and contributes in monitoring disease activity.

A case of non-malignant multifocal lesions on the methyl diphosphonate technetium-99m bone scan with enteropathy. SAPHO syndrome.

This is a case of a 24-year-old man with non-malignant multifocal bone lesions on the methyl diphosphonate technetium-99m bone scan, that may represent a variant of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome. The patient complained for diffuse osseous pain, focused mainly in the hip joints. X-rays of the hips were normal but X-rays of the shoulders showed hyperostosis of the right clavicle with no erosions. SAPHO is a rare syndrome of unknown aetiology with no more than a hundred cases reported during the last 10 years. Its typical form consists of characteristic painful osteoarticular manifestations and dermatological findings. In a variant of this syndrome, such as in our case, dermatological manifestations may be absent, but hyperostosis with osseous hypertrophy and enteropathy are present. No other malignant or benign disease was diagnosed. All routine laboratory tests for an inflammatory rheumatoid disease were negative. Treatment with non steroid anti-inflammatory agents was successful and after six months, there were no clinical symptoms and lesions on the bone scan faded. Four years later the patient remained free from symptoms. We discuss the scintigraphic, radiological laboratory clinical findings, the therapeutic criterion and the exclusion of any malignant or other benign bone disease that suggest the diagnosis of SAPHO syndrome. In conclusion, although we were unable to perform a bone biopsy, we suggest that no other diagnosis but an enteropathic variant of SAPHO syndrome may better describe the above clinical and laboratory findings. Bone scan findings have a principal diagnostic role in SAPHO syndrome.

[Positron emission tomography in evaluating the response to treatment of brain tumors, lymphomas and breast cancer].

Positron emission tomography (PET) with the glucose analogue (18)F-FDG is increasingly used to monitor tumour response in patients undergoing chemotherapy, radiotherapy or new therapeutic schemes including antiangiogenesis and molecular targeted cancer treatment. PET as a functional imaging technology provides timely, quantitative, cross-sectional, non invasive assessment of several biologic processes targeted by the above-mentioned therapies. Tests by the camera PET can be useful in distinguishing between radiation necrosis or scarring and tumour recurrence, thus evaluating response to therapy. The information provided by this technique is more sensitive and specific than that provided by conventional anatomic imaging modalities such as computerised tomography, magnetic resonance imaging or ultrasound and superior in evaluating the effectiveness of various treatment regimens early during therapy or after the completion of therapy. With this information in hand, physicians can modify ineffective therapy and consequently improve patient's outcome and reduce the cost of treatment. In the present review article we discuss the contribution of tests performed by the PET camera, mainly using (18)F-FDG as a radiotracer, in the evaluation of treatment response in patients with brain tumours, lymphomas and breast cancer.

[Brown tumors in the technetium-99m methyldiphosphonate bone scan mimicking metastases of parathyroid carcinoma].

This is a case of a 78 year old male with parathyroid carcinoma and multiple bone lesions in the technetium-99m methyldiphosphonate ((99m)Tc-MDP) bone scan, initially interpreted as metastatic bone disease, but finally proved to be brown tumors. The interest of this case lies on the rarity of the disease, as well as the co-existence of osteitis fibrosa cystica, which often resembles metastatic bone disease and leads to diagnostic pitfalls.

Clinical importance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography in the management of patients with bronchoalveolar carcinoma: Role in the detection of recurrence.

[18F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been reported to have a low sensitivity in the initial diagnosis of bronchoalveolar carcinoma (BAC) due to BAC's low metabolic activity. The aim of this study was to assess the value of [18F]FDG-PET/CT in the detection of BAC recurrence. Between February 2007 and September 2011, the [18F]FDG-PET/CT scans that were performed on patients with known, histologically proven BAC were studied. A total of 24 [18F]FDG-PET/CT scans were performed in 22 patients, including 16 males and 6 females, with a mean age of 65±9 years. Among the scans, 15 were performed to assess for possible recurrence with equivocal findings in conventional imaging methods and 9 for restaging post-therapy. In all cases conventional imaging studies (CT and MRI) were performed 5-30 days prior to PET/CT. Among the 24 [18F]FDG-PET/CT scans, 18 were positive and 6 negative. Among the 15 [18F]FDG-PET/CT scans performed for suspected recurrence, 34 lesions were detected and the mean maximum standardized uptake value (SUVmax) was 6.8±3.26. In nine scans, upstaging was observed, while two were in agreement with the findings of the conventional modalities. A greater number of lesions were detected in two scans and fewer lesions were detected in one, with no change in staging. Only one scan was negative. By contrast, in patients examined for restaging, there were only five lesions with a mean SUVmax of 4.86±3.18. Agreement between the findings of [18F]FDG-PET/CT and the conventional modalities was observed in 8 out of 9 cases. Although [18F]FDG-PET/CT has been reported to have a low sensitivity in the initial diagnosis of BAC, the present results indicate that when there is recurrence, the lesions become [18F]FDG avid. [18F]FDG-PET/CT may provide further information in patients evaluated for recurrence and thus improve patient management.

The role of SPET and PET in monitoring tumour response to therapy.

Positron emission tomography (PET) and single-photon emission tomography (SPET) are cross-sectional, quantitative functional imaging modalities in routine use in oncology for the initial staging of cancer, the assessment of patients with recurrent or residual disease and, more recently, for monitoring tumour response to therapy. Both PET and SPET can track tumour biological and metabolic changes caused by therapy or by disease progression, which usually precede the anatomical alterations conventionally detected by anatomical imaging methods. These highly sensitive functional imaging modalities have been used for the early assessment of subclinical tumour response, the evaluation of therapy after its completion and the detection of viable recurrent or relapsing tumour. Timely assessment of response to treatment using PET and SPET may result in modifications in treatment planning and individualisation of therapy and may have prognostic value for the long-term outcome. This review attempts to summarise the current data available on the expanding role of SPET and PET, using a variety of tracers, in monitoring tumour response to therapy in a wide range of malignancies, with emphasis on their clinical impact.