Prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients.

Hypersensitivity reaction to abacavir (ABC hypersensitivity syndrome, AHS) is strongly associated with the presence of the HLA-B*57:01 allele. This study was designed to estimate the prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients. We analyzed the presence of HLA-B*57:01 allele in 1646 HIV-1 infected patients from different regions of Argentina. This allele was detected in 81 patients; most of them corresponded to patients living in the central region of the country. The prevalence of HLA-B*57:01 was 4.9%, similar to other Caucasian populations and higher than other data reported for South American populations. This strongly supports screening for the presence of HLA-B*57:01 in abacavir treatment of HIV-1 in our country.

11C-Choline PET/CT in the primary diagnosis of prostate cancer: impact on treatment planning.

AIM: Aim of the present study was to evaluate the usefulness of 11C-choline PET/CT for detecting lymphatic or haematogenous spread and for planning radiotherapy in patients with medium-to-high risk prostate cancer. METHODS: We have included 61 consecutive patients recently diagnosed with cancer prostate by biopsy. All patients were classified as medium-to-high risk: Gleason: 7-9; PSA: 6.3-30.4 ng/mL; stage T2c (N.=20) or stage T3 (N.=41). Image acquisition began 5 min after intravenous injection of 11C-choline (656+119 MBq), starting at the pelvis and continuing craniocaudally. Images were interpreted visually to evaluate uptake by the prostate gland. Lymph nodes with 11C-choline uptake were considered invaded, regardless of their size. Bone lesions were considered positive when they showed greater focal uptake than the surrounding bone. In patients with evidence of lymph-node invasion or bone metastases (15 patients), disease was classified as locoregional, oligometastatic, or multimetastatic. RESULTS: All patients had prostate gland uptake (20 focal, 8 bifocal, and 33 multifocal). Extraprostatic disease was present in 15 patients (24.6%), as follows: 9 (60%) in a single location: in an infradiaphragmatic lymph node (N.=6), in a supradiaphragmatic lymph node (N.=1), and in bone (M1) (N.=2). Six (40%) as multifocal invasion: with both infra- and supradiaphragmatic lymph node involvement (N.=2); with infradiaphragmatic lymph node involvement and M1 bone metastases (N.=3); and infra- and supradiaphragmatic lymph node involvement plus M1 bone metastases (N.=1). Disease was classified as locoregional (N.=6), oligometastatic (N.=5), and multimetastatic (N.=4). The 11 (73.3%) patients with locoregional and oligometastatic disease were selected to undergo intensity-modulated radiation therapy with dose escalation based on the PET findings. CONCLUSION: Our results suggest that 11C-choline PET/CT is a useful one-stop diagnostic procedure for evaluating patients with medium/high risk prostate cancer scheduled for radical treatment. 11C-choline PET/CT can reliably rule out lymph node involvement and remote metastases, allowing to select candidates for radiotherapy and to plan their treatment.

[Study of patients with prolonged fever with (18)F-FDG PET/CT]. / Estudio de pacientes con síndrome febril prolongado con 18F-FDG PET-TC.

OBJECTIVE: To review the findings on (18)F-FDG PET-CT in patients with fever of unknown origin lasting more than 7 days. MATERIAL AND METHODS: This retrospective descriptive observational study included 93 (18)F-FDG PET-CT studies to detect a fever-causing focus done at three nuclear medicine centers from October 2006 through February 2014. A nuclear medicine specialist and a radiologist reviewed the images for foci of pathological uptake; another specialist's opinion resolved discrepancies. The findings on (18)F-FDG PET-CT studies were checked against clinical and/or histological findings. RESULTS: Abnormal (18)F-FDG uptake on PET-CT that could explain the cause of the fever was found in 52 (56%) of the 93 studies, and the cause of the fever was confirmed in 50 of these 52 studies. In the 50 cases in which the cause of the fever was confirmed, infection was the most common cause (54%), followed by noninfectious inflammatory disease (28%) and tumors (18%). CONCLUSION: (18)F-FDG PET-CT is useful in diagnosing the cause of prolonged febrile illness, so it might be practical to use it earlier in the diagnostic process.

Listeria monocytogenes meningoencephalitis in adults: analysis of factors related to unfavourable outcome.

PURPOSE: To analyse the short-term outcome in patients with Listeria monocytogenes meningoencephalitis (LMME) to improve management and outcome. METHODS: Observational study with adult patients with LMME between 1977 and 2009 at a tertiary hospital in Barcelona, Spain. Parameters that predicted outcome were assessed with univariate and logistic regression analysis. RESULTS: Of 59 cases of LMME, 28 occurred in the last decade. Since 1987, a new protocol has been used and 29/45 patients (64%) treated since then received adjuvant dexamethasone. In patients who received this treatment there was a trend towards fewer neurological sequelae (5 vs 33%; p = 0.052). Antiseizure prophylaxis with phenytoin was administered in 13/45 (28%) patients. Seizures occurred in 7/45 (16%) patients, all in the group who did not receive phenytoin. Hydrocephalus presented in 8/59 (14%). It was never present at admission and five patients needed neurosurgical procedures. Sequelae after 3 months were present in 8/45 (18%), mostly cranial nerve palsy. Rhombencephalitis (RE) was related to the presence of neurologic sequelae (OR: 20.4, 95% CI: 1.76-236). Overall mortality was 14/59 (24%), 9/59 (15%) due to neurological causes related to hydrocephalus or seizures. Mortality was defined as early in 36% and late in 64%. In the multivariate analysis, independent risk factors for mortality were presence of hydrocephalus (OR: 17.8, 95% CI: 2.753-114) and inappropriate empirical antibiotic therapy (OR: 6.5, 95% CI: 1.201-35). CONCLUSIONS: Outcome of LMME may be improved by appropriate empirical antibiotic therapy, suspicion and careful management of hydrocephalus. Use of adjuvant dexamethasone or phenytoin in a subgroup of these patients might have a benefit.

Bulky cervical liposarcoma associated with sleep apnea syndrome.

Sarcomas of the head and neck are relatively infrequent tumors. Liposarcomas represent 10-16% of all soft tissue sarcomas and <5% of them arise from the head and neck. The retropharyngeal area is rarely involved. We present the case of a middle-aged male with clinical symptoms of sleep apnea. A fiber-optic examination revealed a soft submucosal lesion compressing the posterior pharyngeal wall, with partial obstruction of the airway tract. CT showed a large heterogeneous prevertebral mass (6 x 20 cm(2)) occupying the posterior mediastinum. A transoral submucosal biopsy was performed. Histological findings were compatible with a low-grade liposarcoma. The mass was removed in monoblock using a classical laterocervical neck incision. The surgical specimen weighed 500 g. After 24 months of follow-up no signs of tumor recurrence or sleep apnea syndrome were noted.

[Extension study and evaluation of the therapeutic response in a patient with metastatic lung adenocarcinoma using sequential study with ¹8F-FDG PET-CT and ¹8F-fluoride PET-CT]. / Estudio de extensión y valoración de la respuesta terapéutica en un paciente con adenocarcinoma pulmonar metastásico mediante estudio secuencial con (18)F-FDG PET-TC y (18)F-fluoruro PET-TC.

We report a case of a patient with lung adenocarcinoma and bone and extraosseus metastases studied with (18)F-FDG PET-CT, (99m)Tc-HMDP and (18)F-fluoride PET-CT. It assesses the usefulness of (18)F-FDG PET-CT for initial staging of the disease and monitoring response to therapy. For the study of the sclerotic bone metastases it shows the superiority of 99mTc-HMDP bone scintigraphy and (18)F-fluoride PET-CT over (18)F-FDG PET-CT, and (18)F-fluoride PET-CT over bone scintigraphy. It also shows the usefulness of (18)F-fluoride PET-CT for monitoring the bone metastases.

(11)C-choline PET/CT and multiparametric MRI in patients with biochemical relapse of prostate cancer.

CLINIC PROBLEM AND CASE SERIES: To assess the diagnostic usefulness of (11)C-choline PET/CT vs. multi-parametric MRI in the prostate cancer relapse. A retrospective study of 21 patients with prostate cancer treated initially with surgery (n=12), radiotherapy (n=9). PSA levels were increased (post-surgery: .3-3.6 ng/ml; post-radiotherapy: 2.4-8.8 ng/ml). In an interval of time of 15 days all patients were underwent to: whole-body-dual-modality PET-CT carried out early after (11)C-choline (296 ± 29 MBq) injection, and multiparametric prostate MRI with paramagnetic intravenous contrast (using anatomical imaging sequences, diffusion-weighted imaging and dynamic contrast-enhanced imaging). On the basis of our results, all patients were underwent to directed diagnosis and/or clinical, analytic and imaging follow-up. In 15 patients (71.4%) both procedures showed concordant results: 4 negative and 11 positive cases [7 local recurrences, 3 isolated pelvic lymph nodes (2 infracentimetric), 1 local relapse and only one M1 bone metastases]. The results were discordant in 6 patients (28.6%): 3 local relapses in MRI with no PET significance, 1 local relapse in PET with no MRI significance. 2 bone metastases were identified with PET (out of the field-of-view of MRI). COMMENT: (11)C-choline PET/CT and multi-parametric MRI play a complementary role in the detection of local relapse in prostate cancer patients, with similar sensitivity for the detection of lymph involvement. Whole-body 11C-choline PET/CT technique is also useful for bone staging.

[Diagnostic performance of bone scintigraphy and (11)C-Choline PET/CT in the detection of bone metastases in patients with biochemical recurrence of prostate cancer]. / Rendimiento diagnóstico de la gammagrafía ósea y la PET/TAC con (11)C-colina en la detección de metástasis óseas en pacientes con recidiva bioquímica de cáncer de próstata.

AIM: To compare bone scan (BS) with (11)C-Choline PET/CT for the detection of bone metastases in patients with biochemical recurrence of prostate cancer (PC). MATERIAL AND METHODS: A total of 169 patients with biochemical recurrence of PC(PSA:2.4-58 ng/ml) who were referred for both exams (0-15 days-in-between) were included. Lesion-detection-rate per patients and lesions were analyzed for both BS and (11)C-Choline PET/CT. Metastasis diagnosis was reached by: biopsy, CT/(18)F-Fluoride PET/MRI confirmation, or evidence of progression in subsequent imaging procedures. RESULTS: A total of 91 lesions were found to be active in BS and/or (11)C-choline PET/CT (40 patients), with 78 of which were metastatic. BS detected 38 blastic, 2 lytic and 10 non-CT-evident lesions. (11)C-Choline PET/CT detected 41 blastic, 4 lytic and 29 non-CT-evident lesions. BS and (11)C-Choline PET/CT sensitivities were 65.4% and 96.1%; specificities ere 38.5 and 92.3% (χ(2) 8.27, p<0.04). Both imaging techniques were negative in 118 patients. Tracer avid lesions were found in 51 patients: with 30/51 being BS and (11)C-Choline PET/CT concordant; in 21/51 patients had discordant lesions (kappa 0.712, p=0.00). Lesions were absolutely discordant in 10/19 patients,: 5 FN BS, 2 FP BS (degenerative changes; dysplasia), 1 FN (11)C-Choline PET/CT (blastic), 1 FP (11)C-Choline PET/CT (degenerative), 1 out of field-of-view lesion with (11)C-Choline PET/CT (tibia alone). (11)C-Choline PET/CT showed extraosseous involvement in 26/51 patients with bone metastases: 9 local recurrences, 5 infra-diaphragmatic-lymph-nodes, 2 supra-diaphragmatic, 5 local and infra-diaphragmatic, 4 infra- and supra-diaphragmatic, 1 supra-diaphragmatic and lung metastases. CONCLUSION: (11)C-Choline PET/CT yielded better sensitivity and specificity than BS for the detection of bone involvement in patients with biochemical recurrence of PC and allowed extraosseous restaging, with an impact in the clinical management of these patients.

Indium-111-labeled platelets in monitoring human pancreatic transplants.

We have performed 59 111In-labeled platelet scintigraphies in 12 patients with pancreas transplant, and we have compared retrospectively the 111In platelet uptake with the graft immunological situation. A diffuse uptake in the graft was seen in five of six patients with pancreatic rejection. The scans became positive before changes in biochemical tests were detected. No 111In platelet uptake was seen in five of seven normally functioning grafts. Two cases of venous thrombosis and two perigraft hematomas appeared like a focal 111In platelet accumulation. Indium-111-labeled platelet scintigraphy can be a useful method for monitoring pancreas transplants. It may be helpful in the early detection of pancreatic allograft rejection and in the differential diagnosis between this and other complications such as thrombosis or hematomas.

Procedure for red blood cell labelling with 99mTc-HMPAO. Methodology and quality control.

We present here results on the labelling of red blood cells with 99mTc-HMPAO as an alternative method to the usual in vitro technique. Anticoagulant agents, the labelling medium with plasma, and the lapse of time between 99mTc-HMPAO preparation and labelling are the main factors which affect the efficiency of the procedure. A 93.9 +/- 2.3% labelling yield was obtained with freshly prepared 99mTc-HMPAO. In vitro (tracer elution of 4.3 +/- 1.2% at 60 mins) and in vivo (percentage of plasma activity at 60 mins, 7.8 +/- 2.8%) stability of the label, as well as image quality, qualify 99mTc-HMPAO labelled red blood cells as a suitable agent for clinical use.

Prognostic value of TPS in patients with head and neck malignancies: comparison with SCC.

TPS and SCC serum levels were evaluated in 113 patients with primary tumors, 19 with relapse and 59 with no evidence of disease after radical treatment. Abnormal serum levels were found in 37% and 33% of patients with primary untreated tumors and in 53% and 59% of patients with relapse, respectively, using 100 U/L and 2.5 ng/ml as the upper limit of normality for TPS and SCC, respectively. Either tumor marker was abnormal in 57.5% of primary tumors and in 74% of patients with relapse. TPS and SCC serum levels were related to nodal involvement, with significantly higher levels in patients with nodal invasion (p < 0.02 and p 0.001, respectively). No relationship was found between tumor size, age or histological grade and SCC or TPS values. Pretreatment TPS and SCC serum levels had prognostic interest in patients with locoregional tumors, with a significantly shorter disease-free interval (DFI) in patients with abnormal values (p < 0.01 and p < 0.02, respectively). When tumor marker levels and nodes were simultaneously evaluated, a trend toward shorter DFI in patients with abnormal serum concentrations was found, with no statistical significance. By contrast, TPS and SCC were useful in prognosis in node-negative patients (p < 0.02 and p < 0.001, respectively). Likewise, using both TAAs simultaneously, it is possible to increase prognostic information. Patients with TPS and/or SCC abnormal levels had a significantly lower DFI than those patients with normal values, in both node positive and negative patients (P < 0.01). In summary, TPS and SCC are useful TAAs in patients with head and neck malignancies. Likewise, with the simultaneous use of SCC and TPS, the TAA utility in this malignancy increases in the prognosis as well as disease follow-up.

99Tcm-HMPAO leucocyte scintigraphy in the diagnosis of bone infection.

The utility of 99Tcm-HMPAO leucocytes has been studied in combination with 99Tcm-MDP bone scanning in the diagnosis of bone infection in a series of 50 patients with a clinical suspicion of bone infection. Thirty-three patients were referred to our Service from the Department of Orthopaedic Surgery (Group A) and seventeen from the Infectious Disease Unit (Group B). A total of 52 lesion sites were studied. The leucocyte and bone studies were performed within four days. The leucocyte scan was obtained at 30-60 min and 4-6 h after i.v. injection of 370 +/- 74 MBq of 99Tcm-HMPAO leucocytes. After confirming the scintigraphic findings, the results obtained were: Group A, 12 true positive, 21 true negative and 2 false positive; and in Group B, 5 true positive, 9 true negative and 4 false negative. The overall sensitivity was 80.9% with a specificity of 93.7%. Although the high bone marrow activity seen with 99Tcm-HMPAO leucocytes may reduce sensitivity, very good results were obtained in bone infection. The use of 99Tcm means great progress in the radiolabelling of white blood cells in terms of availability and better image quality. The combination of 99Tcm-HMPAO leucocytes and 99Tcm-MDP can be recommended as one of the most suitable methods for use in the diagnosis of bone infection, especially in patients with previous bone disease.

Radioimmunoscintigraphy of colorectal carcinoma with a 99Tcm-labelled anti-CEA monoclonal antibody (BW 431/26).

Radioimmunoscintigraphy (RIS) with BW 431/26 monoclonal antibody (MoAb) labelled with 99Tcm (962 MBq) has been performed in 64 patients with colorectal carcinoma, one of them with two independent tumours. The group consisted of 46 primary lesions, 15 pelvic recurrences and four suspected recurrences which were shown to be liver metastases. Imaging of liver was obtained in all patients, but surgical liver examination was performed in only 56 of them. Planar scans were obtained at 4 and 24 h postinjection. Tomographic images were also performed in five patients. The final diagnosis was confirmed in all patients by their clinical course and by findings at surgery and pathology. A comparative study between the RIS results and the final diagnosis gave a global sensitivity in primary tumours and pelvic recurrences of 59.7% with an accuracy of 59.0%. When rectal tumours were excluded, the results were 81.1 and 84.9%, respectively. In liver metastases the sensitivity was 50%, with an accuracy of 85.7% and a specificity of 100%. No correlation has been found between CEA serum levels and lesion detection. In conclusion, RIS is a useful technique for the study and localization of colorectal tumours, being also indicated in patients with normal carcinoembryonic antigen (CEA) serum levels and clinical suspicion of illness.

Diagnostic value of technetium-99m-MIBI as a myocardial perfusion imaging agent: comparison of long and short intervals between rest and stress injections.

To assess the diagnostic value of technetium-99m-MIBI (99mTc-MIBI) as a myocardial perfusion imaging agent, and if rest and exercise scans could be performed on the same day, 21 patients with coronary artery disease were studied. Qualitative planar 201-thallium (201Tl) scans, coronary angiography, or both were also performed (median between studies 11 days). In 10 patients an injection of 740 mBq of 99mTc-MIBI at stress was followed by a second injection of 740 mBq at rest 24 h later (long interal) (LI). In 11 patients injection of 370 mBq at rest was followed 3 h later by an injection of 740 mBq at stress (short interval) (SI). Exercise scans were performed to similar maximal work load (LI = 6.6 +/- 1.8 METs; SI = 6.3 +/- 1.7 METs; 201Tl = 6.8 +/- 1.2 METs; p = NS) and double product (LI = 19551 +/- 7370; SI = 19900 +/- 6797; 201Tl = 19965 +/- 5282; p = NS). Overall, 99mTc-MIBI and 201Tl agreed in 92% of the patients tested and in 165 of 180 (92%) left ventricular segments in both 99mTc-MIBI protocols using short and long intervals between injections. In 15 patients with significant stenosis, 99mTc-MIBI correctly identified 13 patients (sensitivity of 87%). Thus, 99mTc-MIBI is a useful imaging agent with similar diagnostic value as 201Tl. In spite of its lack of myocardial redistribution, 99mTc-MIBI rest and exercise scans performed on the same day seem to have a similar concordance rate with 201Tl as when performed on separate days.

Tc-99m galactosyl-neoglycoalbumin hepatic scintigraphy in fulminant hepatic failure.

Tc-99m galactosyl-neoglycoalbumin (NGA) is a new liver imaging agent that specifically binds to a hepatocyte specific membrane receptor, the hepatic binding protein. Scintigraphy with Tc-99m NGA is a noninvasive method that provides functional images of the liver. This report deals with one case of fulminant hepatic failure in which hepatic scintigraphy with Tc-99m NGA predicted hepatic recovery before clinical and biochemical parameters, being a prognostic index in this patient.

[Immunoscintigraphy with monoclonal antibody Tc99m BW 431/26 in the diagnosis of colorectal carcinoma]. / Inmunogammagrafía con el anticuerpo monoclonal 99mTc BW 431/26 en el diagnóstico del carcinoma colorrectal.

BACKGROUND: The use of monoclonal antibodies against tumoral antigens marked with radioactive isotopes is the basis of immunoscintigraphy. The specificity of the technique is high owing to its intrinsic characteristics. METHODS: 40 patients with colorectal cancer who were awaiting surgery were evaluated by immunoscintigraphy. The group consisted of 34 primary diseases and 7 recurrences. Two days before surgery the specific monoclonal antibody BW 431/26 (Behringwerke, FRG) labeled with 99mTc was injected and scintigraphic images were obtained 4 and 24 hours after its administration. RESULTS: The following results were found after a comparison of the data with those from other diagnostic procedures and surgical findings: in primary disease, sensitivity (S) was 59% and accuracy (A) was 56% (these rates increased to 82% and 75%, respectively, when rectal tumors were excluded). For hepatic metastases, S was 44% and A was 85%. In the recurrence group the results were: 4 true positives, 2 false negatives (in the rectum), and one false positive. CONCLUSIONS: These results confirm the validity of immunoscintigraphy in patients with colorectal carcinoma. This test may supplement the information of other diagnostic tests, particularly when these have more limitations as it is the case for recurrences.

[The laryngeal involvement in Kaposi's sarcoma in the acquired immunodeficiency syndrome]. / Afectación laríngea por sarcoma de Kaposi en el síndrome de inmunodeficiencia adquirida.

Kaposi's sarcoma (KS) is a malignant vascular neoplasm characterized, in its classical form, by a slow evolutive course, beginning in the lower extremities. Lately have been reported more and more cases of this entity associated with the acquired immunodeficiency syndrome (AIDS), running much more aggressively. In ENT-pathology are not uncommon this kind of neoplasm in the oral cavity and oropharynx. However at larynx's level such descriptions till now had been sporadic. The AA. present a KS case sitting in the epiglottis of an AIDS patient. They emphasize the importance of a throughout ENT-examination of these patients and also remark the necessity of performing various and deep biopsies in order to gain a diagnosis that can be relied on. Finally, they review the updated management alternatives for this sort of pathology.

[Detection of second tumors in 11C-choline PET/CT studies performed due to biochemical recurrence of prostate cancer]. / Detección de segundos tumores en estudios de la PET/TC con (11)C-colina realizados por recurrencia bioquímica de cáncer de próstata.

Early localization of biochemical recurrence in patients after radical treatment of prostate cancer is a widely accepted clinical indication of (11)C-choline PET/CT. Its widespread clinical use has prompted the depiction of incidentalomas, unusual sites of metastatic lesions, as well as false positive and negative cases. Over the last 6 years, a total of 454 (11)C-choline PET/CT studies have been performed in our institution to locate biochemical recurrence of patients with prostate cancer. With these studies, a second neoplasm has been found in 7 patients (1.54%): 3 lung, 2 colorectal, 1 esophagus and 1 esophageal junction, respectively. Although the clinical usefulness of this technique for detecting cancer lesions other than prostate origin is known for those patients who undergo this technique in the accepted indication, the diagnosis of a second tumor has a significant impact on their therapeutic management.