Optimization of the protocols for the use of contrast agents in PET/CT studies. / Optimización de los protocolos y del uso de contrastes en tomografía computarizada de los equipos de tomografía por emisión de positrones.

The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients.

[Magnetic resonance imaging of the prostate: usefulness of diffusion sequences in detecting postembolization ischemia in patients with benign prostatic hyperplasia]. / Resonancia magnética de próstata: utilidad de la secuencia de difusión en la detección de isquemia postembolización en pacientes con hiperplasia prostática benigna.

OBJECTIVE: To analyze the usefulness of diffusion magnetic resonance (MR) sequences before and after prostatic artery embolization (PAE) in patients with benign prostatic hyperplasia (BPH). MATERIAL AND METHODS: We analyzed MR studies done before (7-10 days) and after (30 days) PAE in 19 patients with BPH treated with PAE between June 2012 and December 2013. We used 1.5 Tesla scanners with body surface coils. In pre-PAE MR studies, we recorded mean b40 values and minimum (min) and maximum (max) apparent diffusion coefficient (ADC) values. In post-PAE MR studies, we recorded b40, b400, and b1000 values and min, mean, and max ADC values. We compared diffusion behavior/ADC before and after PAE and areas without ischemia. We correlated these with decreased prostatic volume (PV). RESULTS: We identified ischemia with contrast in 8 (42.1%) patients. No significant difference was found in mean b40 (p= 0.1650) or in the b40 ratio (p= 0.8868) between patients with ischemia and those without before PAE. Min b40, b40 ratio, and min ADC values differed significantly between ischemic areas and nonischemic areas within patients [p= 0.048 (b40min and ratio) and p= 0.002 (min ADC)]. No significant correlation was found between the percentage decrease in PV and mean b40 (p= 0.8490) or b40 ratio (p=0.8573). CONCLUSION: Post-PAE ischemia generates objective changes in diffusion and ADC values that enable ischemic sectors to be differentiated from nonischemic sectors. Future studies should analyze whether it is possible to subjectively differentiate between these areas through the visualization of nonischemic sectors and the feasibility of replacing them with contrast to detect ischemia.

Contrast Enhanced CT Radiogenomics in a Retrospective NSCLC Cohort: Models, Attempted Validation of a Published Model and the Relevance of the Clinical Context.

RATIONALE AND OBJECTIVE: To develop a radiogenomic predictive model for non-small cell lung cancer (NSCLC) patients studied through contrast enhanced chest computed tomography (CE-CT) targeting the most frequent gene alterations. M&M: A retrospective study of patients with NSCLC imaged with CE-CT before treatment and had their tumor genomics sequenced at our institution was performed. Data was gathered from their imaging studies, their electronic medical records and a web-based database search (cBioPortal.ca). All of the patient data was tabulated for analysis. Two predictive models (M1 & M2) were created using different approaches and a third model was extracted from the literature to also be tested in our population. RESULTS: Out of 157 patients, eighty were male (51%) and 124 (79%) had a history of smoking. The three most prevalent genes were KRAS, TP53 and EGFR. The M1 radiomics-only model median AUC were 0.61 (TP53), 0.53 (KRAS) and 0.64 (EGFR) and for M1 radiomics + clinical were 0.61 (TP53), 0.61 (KRAS) and 0.80 (EGFR). The M2 radiomics-only model median AUC were 0.63 (TP53), 0.60 (KRAS) and 0.65 (EGFR) and for M2 radiomics + clinical were 0.64 (TP53), 0.62 (KRAS) and 0.81 (EGFR). The external EGFR radiomic model showed an AUC of 0.69 and 0.86 for the radiomics-only and combined radiomics + clinical respectively. CONCLUSION: Our study was able to provide robust predictive radiomics model evaluation for the detection of TP53, KRAS and EGFR. We also compared our performance with an already published model and observed how impactful clinical variables can be on models' performance. CLINICAL RELEVANCE STATEMENT: Identifying tumor mutations in patients that can't undergo biopsy is critical for their outcomes. KEYPOINTS: • Tumor genomic profiling is critical for treatment selection • CE-CT radiomics produce robust predictive models comparable to those already published • Clinical variables should be considered/included in predictive models.

N staging of lung cancer patients with PET/MRI using a three-segment model attenuation correction algorithm: initial experience.

OBJECTIVES: Evaluate the performance of PET/MRI at tissue interfaces with different attenuation values for detecting lymph node (LN) metastases and for accurately measuring maximum standardised uptake values (SUVmax) in lung cancer patients. MATERIALS AND METHOD: Eleven patients underwent PET/CT and PET/MRI for staging, restaging or follow-up of suspected or known lung cancer. Four experienced readers determined the N stage of the patients for each imaging method in a randomised blinded way. Concerning metastases, SUVmax of FDG-avid LNs were measured in PET/CT and PET/MRI in all patients. A standard of reference was created with a fifth experienced independent reader in combination with a chart review. Results were analysed to determine interobserver agreement, SUVmax correlation between CT and MRI (three-segment model) attenuation correction and diagnostic performance of the two techniques. RESULTS: Overall interobserver agreement was high (κ = 0.86) for PET/CT and substantial (κ = 0.70) for PET/MRI. SUVmax showed strong positive correlation (Spearman's correlation coefficient = 0.93, P < 0.001) between the two techniques. Diagnostic performance of PET/MRI was slightly inferior to that of PET/CT, without statistical significance (P > 0.05). CONCLUSIONS: PET/MRI using three-segment model attenuation correction for LN staging in lung cancer shows a strong parallel to PET/CT in terms of SUVmax, interobserver agreement and diagnostic performance. KEY POINTS: •F18-FDG PET/MRI shows similar performance to F18-FDG PET/CT in lung cancer N staging. •PET/MRI has substantial interobserver agreement in N staging. •A three-segment model attenuation correction is reliable for assessing the mediastinum.

Intravenous metronidazole or clindamycin with tobramycin for therapy of pelvic infections.

Anaerobic bacteria are important pathogens in obstetric and gynecologic infections. As metronidazole has excellent in vitro activity against almost all clinically significant anaerobes, the newly available parenteral form of the drug was evaluated in a comparative study with clindamycin. Forty-seven patients with postpartum endomyometritis with or without wound infection, acute or chronic salpingo-oophoritis, tuboovarian abscess, postoperative pelvic cellulitis or wound infection, or other soft-tissue infection were included in the study. Initially 6 patients were treated with metronidazole, usually combined with tobramycin, in an open study. Subsequently, 41 patients were treated on a randomized schedule of either metronidazole or clindamycin, each combined with tobramycin. Anaerobic bacteria were isolated from 86% (37 of 43) of the patients who had positive cultures from sites cultured for aerobes and anaerobes. Anaerobic gram-negative rods and gram-positive cocci were the predominant isolates from infected tissues. Of the patients who received metronidazole, 96% (25 of 26) were considered clinically cured; the remaining patient initially responded but continued to have slight temperature elevations. There were no adverse reactions to this drug. Of the patients who received clindamycin, 100% were considered clinically cured. The excellent therapeutic response to intravenous metronidazole and the predominance of pathogenic anaerobes observed in these infections support its use in the treatment of infections of the female genital tract.

[Renal vascular lesion and microangiopathic hemolytic anemia in systemic lupus erythematosus]. / Lesión vascular renal y anemia hemolítica microangiopática en lupus eritematoso sistémico.

A 22 year-old woman with a seven year history of (SLE) was readmitted because of oliguria, edema, dyspnea and arterial hypertension. She had a previous biopsy diagnosis of focal glomerulonephritis, (WHO III b), and had been treated with immunosuppressors and steroids. Laboratory data showed lupus activity, AHM with thrombocytopenia, nephrotic-range proteinuria and renal failure. A second renal biopsy was performed showing diffuse proliferative nephritis, (WHO IV), in association with noninflammatory necrotizing vasculopathy with luminal obliteration. She started with hemodialysis and was subsequently treated with methylprednisolone pulses, plasmapheresis, cyclophosphamide and oral steroids. During the inpatient period, she had generalized seizures, acute lung injury and pulmonary hemorrhage. These complications, the AHM and the thrombocytopenia receded totally. Renal function was never resumed. We emphasize that this association of diffuse proliferative nephritis with noninflammatory necrotizing vasculopathy is not infrequent and has a poor renal prognosis. The AHM with thrombocytopenia was interpreted as secondary to endothelial cell damage due to vasculopathy.

[Heteroimmune hemolytic anemia associated with antilymphocyte globulin treatment in a patient with aplastic anemia]. / Anemia hemolítica heteroinmune asociada a tratamiento con globulina antilinfocítica en un paciente con anemia aplástica.

A 24-year-old male patient with a severe aplastic anemia (SAA) was treated with equine-antilymphocyte globulin (ALG). As complication of this treatment he developed a severe heteroimmune hemolytic anemia mediated by anti-species pan-agglutinin antibodies present in ALG. In spite of the fact that ALG is absorbed with red-cell stroma and platelets to remove anti-erythrocyte and anti-platelet contaminating antibodies, often only partial absorption is achieved, and the remaining antibodies are passively acquired by the recipient. Neutropenia and especially thrombocytopenia are usual complications of this treatment, but it is also possible to detect anti-erythrocyte antibodies in the serum and on the red cells of those patients. However, the unusual severity of the hemolysis suffered by our patient, with a striking decrease of the hemoglobin levels (Fig. 1) can be ascribed to the administration of ALG at a time at which the hematocrit was close to normal as a result of the previous administration of anabolics. It is likely that in severely anemic patients, with a high transfusional demand, such a hemolytic episode may remain undetected. The patient acquired reactivity to the direct antiglobulin test, as well as the positive results of investigation of unexpected antibodies and compatibility testing can be accounted for by the fact that commercial antihuman globulin serum (AGS) contains antibodies reacting with a globulin component shared by human and horse sera. Neutralization of AGS with ALG administered to the patient removed those cross-reacting antibodies, making it possible to perform reliable transfusion compatibility testing and to rule out the eventual presence of hidden alloantibodies or warm autoantibodies. Neutralized Coombs serum maintained its human antiglobulin properties unaltered (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

[Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]. / Trasplante hematopoyético alogénico con células progenitoras extraidas de la sangre periférica.

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkin's disease, major thalasemia and Hunter's syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15%. Acute graft versus host disease (GVHD) was observed in 43.4% of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4% by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.

Qualitative and quantitative performance of ¹8F-FDG-PET/MRI versus ¹8F-FDG-PET/CT in patients with head and neck cancer.

BACKGROUND AND PURPOSE: MR imaging and PET/CT are integrated in the work-up of head and neck cancer patients. The hybrid imaging technology (18)F-FDG-PET/MR imaging combining morphological and functional information might be attractive in this patient population. The aim of the study was to compare whole-body (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT in patients with head and neck cancer, both qualitatively in terms of lymph node and distant metastases detection and quantitatively in terms of standardized uptake values measured in (18)F-FDG-avid lesions. MATERIALS AND METHODS: Fourteen patients with head and neck cancer underwent both whole-body PET/CT and PET/MR imaging after a single injection of (18)F-FDG. Two groups of readers counted the number of lesions on PET/CT and PET/MR imaging scans. A consensus reading was performed in those cases in which the groups disagreed. Quantitative standardized uptake value measurements were performed by placing spheric ROIs over the lesions in 3 different planes. Weighted and unweighted κ statistics, correlation analysis, and the Wilcoxon signed rank test were used for statistical analysis. RESULTS: κ statistics for the number of head and neck lesion lesions counted (pooled across regions) revealed interreader agreement between groups 1 and 2 of 0.47 and 0.56, respectively. Intrareader agreement was 0.67 and 0.63. The consensus reading provided an intrareader agreement of 0.63. For the presence or absence of metastasis, interreader agreement was 0.85 and 0.70. The consensus reading provided an intrareader agreement of 0.72. The correlations between the maximum standardized uptake value in (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT for primary tumors and lymph node and metastatic lesions were very high (Spearman r = 1.00, 0.93, and 0.92, respectively). CONCLUSIONS: In patients with head and neck cancer, (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT provide comparable results in the detection of lymph node and distant metastases. Standardized uptake values derived from (18)F-FDG-PET/MR imaging can be used reliably in this patient population.

Pulmonary intravascular lymphoma detected by FDG PET-CT: a case report.

Intravascular lymphoma is a rare subtype of extranodal Non-Hodgkin's lymphoma. Its prognosis is poor in a high percentage of cases due to its insidious appearance and low clinical suspicion. Its diagnosis is usually only reached after an autopsy. It may affect different organs as a whole or only one organ. It is extremely rare that the lung is the only damaged organ. Its diagnosis depends of the clinician's suspicion and proper evaluation with imaging studies as well as correct selection of the organ to be biopsied. When detected on time, the treatment of choice is a combination of a series of chemotherapy associated to a monoclonal antibody (anti-CD20). We present the case of a male patient who underwent a positron emission tomography-computed tomography with 2-[F-18]-fluoro-2 deoxy-D-glucose (FDG) due to symptoms suggestive of a lymphoproliferative disease with no clear structural abnormalities. The images led to a diagnosis of pulmonary intravascular large B cell lymphoma.

[Positron emission tomography/magnetic resonance: Present and future]. / Tomografía por emisión de positrones/resonancia magnética: presente y futuro.

PET/MRI has recently been introduced onto the market after several years of research and development. The simple notion of combining the molecular capabilities of the PET and its difference available radiotracers with the excellent tissue resolution of the MRI and wide range of multiparametric imaging techniques has generated great expectations upon the possible uses of this technology. Many challenges must be worked out. However, the most urgent one is the derivation of the MRI-based attenuation correction map. This is especially true because the PET/CT has already demonstrated a huge clinical impact within oncology, neurology and cardiology during its short existence. Despite these difficulties, research is being carried out at a rapid pace in the clinical setting in order to find areas in which the PET/MRI is superior to other existing imaging modalities. In the few initial publications found up to date that have analyzed its clinical role, areas have been identified where PET/CT can migrate to PET/MRI, even if only to suppress the CT scan's ionizing radiation. Nonetheless, there are many theoretical applications in which the PET/MRI can further improve the field of diagnostic imaging. In this article, we will review those applications, the evidence existing regarding the MRI and PET that support those premises as well as that which we have learned in the short period of one year with our experience using the PET/MRI.

Recurrent and metastatic breast cancer PET, PET/CT, PET/MRI: FDG and new biomarkers.

Primary breast cancer often displays only moderately increased glucose metabolism resulting in a low sensitivity of positron emission tomography (PET) using [F-18]fluorodeoxyglucose (FDG) in detecting small breast carcinomas, locoregional micrometastases and non-enlarged tumor infiltrated lymphnodes. In contrast, distant breast cancer metastases are generally characterized by significantly increased metabolic activity compared to normal tissue. Therefore, FDG-PET provides accurate diagnostic information as a whole body imaging modality in staging of breast cancer patients. The metabolic information from FDG-PET/CT is often more sensitive than conventional imaging for the detection of distant metastases, particularly in the recurrent setting. FDG-PET is superior in detecting tumor-involved distant lymphnodes, particularly those which are normal in size, as well as in characterizing enlarged lymphnodes as positive or negative for malignancy. Of note, CT is superior in detecting small lung metastases. Although the overall sensitivity for bone scintigraphy and FDG-PET are comparable, bone scintigraphy seems to be superior in the detection of osteoblastic disease whereas FDG-PET is superior for osteolytic metastases, suggesting a complementary role for both imaging procedures. FDG-PET/MR has an evolving role in breast cancer management, for example in the detection of liver metastases and in the research setting for treatment monitoring. The utilization of PET for prediction of treatment response to primary chemotherapy is an area of active research, using FDG as well as other PET biomarkers including [F-18]Fluoroestradiol, [F-18]Fluorothymidine and integrin targeting tracer for monitoring anti-angiogenic therapy.

Thrombin injection failure with subsequent successful stent-graft placement for the treatment of an extracranial internal carotid pseudoaneurysm in a 5-year-old child.

Internal carotid artery pseudoaneurysm is a rare life-threatening condition that may develop in different clinical situations. We report the case of an extracranial internal carotid artery pseudoaneurysm secondary to a throat infection in a pediatric patient that was initially treated with percutaneous thrombin injection under ultrasound guidance. However, recanalization occurred at 48 h, and definitive treatment was then performed by endovascular stent-graft placement. We briefly review the clinical characteristics of this uncommon clinical condition as well as the treatment options.

Rendimiento diagnóstico de la histerosalpingografía por resonancia magnética: resultados iniciales / Diagnostic performance of magnetic resonance hysterosalpingography: initial results Abstract

Objetivo: Determinar el rendimiento diagnóstico de la histerosalpingografía por resonancia magnética (HSG-RM), utilizando la laparoscopia como método de referencia. Materiales y métodos: Se incluyeron 22 pacientes. A todas se les realizó una HSG-RM con un resonador 1.5 Tesla y luego una laparoscopia con cromotubación. Dos radiólogos examinaron las RM, determinando la permeabilidad tubaria por consenso. Se realizaron análisis descriptivos y de rendimiento diagnóstico. Resultados: La HSG-RM tuvo una tasa de éxito del 91%. La duración del estudio fue 49ą15 minutos, el volumen inyectado 26 ą 16 cm³ y la escala de dolor 30ą 19 de 100. La sensibilidad y especificidad de la HSG-RM fueron del 100% para la prueba de Cotte global y a la izquierda, y del 25% y 93,3% para la prueba de Cotte a la derecha, respectivamente. Hubo 2 complicaciones menores y ninguna importante. Discusión: Nuestros resultados iniciales demostraron una alta sensibilidad y especificidad. Si bien otros estudios analizaron la capacidad de la HSG-RM para evaluar la permeabilidad tubaria con buenos resultados, el uso de un patrón de referencia defectuoso dejaba margen para una duda razonable, impidiendo una recomendación basada en pruebas sólidas. Sin embargo, al cotejar nuestros resultados con los publicados, observamos un alto grado de concordancia en tanto el derrame positivo se diagnostica correctamente con una especificidad de 100% o con un porcentaje cercano a esta cifra. Conclusión: La HSG-MR es una alternativa factible y segura de la HSG convencional o virtual, la histerosonografía y la cromotubación.

Objective: To determine the diagnostic performance of magnetic resonance hysterosalpingography (MRHSG) using laparoscopic chromotubation as a method of reference. Materials and methods: Twenty-two patients were included. The MRHSG was performed in a 1.5 Tesla MR scanner. Afterwards, patients underwent laparoscopic chromotubation. MR images were examined by two trained radiologists, and tubal patency was determined by consensus. A descriptive analysis was carried out, as well as an analysis of the diagnostic performance. Results: MRHSG had a 91% success rate. Exam duration of the examination was 49ą15min, with an injected volume 26ą 16cc, and pain scale 30ą 19 out of 100. Sensitivity and specificity of MRHSG was 100% for global and left Cotte, and 25% and 93.3% for right Cotte, respectively. Only 2 minor and no major complications were observed. Discussion: The initial results of MRHSG have shown high sensitivity and specificity. Even though other studies have analysed the potential of MRHSG with good results, the use of a flawed reference standard left a margin for a reasonable doubt as regards its true potential, thus preventing a solid evidence based recommendation. Nevertheless, if our results are compared to those published, a high level of agreement is observed in that positive spillage is correctly diagnosed with specificities near or at 100%. Conclusion: MRHSG is a feasible and safe alternative to conventional or virtual HSG, ultrasound-hysterography and chromotubation.

Termólisis facetaria por radiofrecuencia en el dolor dorso lumbar crónico / Facet radiofrequency thermolysis in chronic thoracolumbar pain

Objetivo: Evaluar la seguridad de la termólisis facetaria por radiofrecuencia en el tratamiento del dolor dorsolumbar crónico. Materiales y métodos: Entre julio de 2013 y julio de 2014, se analizaron retrospectivamente 12 pacientes con dolor dorsolumbar crónico de tipo facetario, a los que se les había realizado previamente un bloqueo bajo tomografía computada (TC). Se evaluaron las complicaciones inmediatas y tardías, registrándose también la mejoría de síntomas de forma directa (escala visual analógica) e indirecta (consumo de medicación). Resultados: Hubo menos de un 20% de complicaciones tempranas leves, todas autolimitadas. No se constataron complicaciones tempranas graves ni tardías. A los tres meses del procedimiento se confirmó un descenso del dolor en el 83% de los casos (n = 10), con una supresión total de la ingesta de medicamentos en un 25% (n = 3) y una reducción de la misma en un 58% (n = 7) de los pacientes. Discusión: A pesar del número reducido de pacientes de nuestro estudio, los resultados en cuanto a la seguridad y el éxito del procedimiento fueron muy similares a los reportados en otros trabajos con mayor casuística. La mejora se vio reflejada no solo en la reducción del dolor, sino también en la menor ingesta de analgésicos. Conclusión: La termólisis facetaria por radiofrecuencia es un método seguro y útil, con un bajo porcentaje de complicaciones que pueden manejarse ambulatoriamente

Objective: To evaluate the safety of facet-dependent radiofrequency thermolysis for the treat-ment of chronic thoracolumbar pain. Materials and methods: A retrospective analysis was performed on 12 patients with chronic thoracolumbar pain of facet type, who had previously undergone a radicular blockage using computed tomography (CT), in the period between July 2013 and July 2014. Inmediateand delayed complications where assessed. Improvement of symptoms was also assessed, both directly (visual analogue scale), and indirectly (reduction in pain relief medication). Results: Self-limited early complications were noted in 20% of the patients. No late nor serious complications were reported. Three months after the procedure was performed, pain relief was observed in 83% of the cases (n= 10), with absolute reduction in pain relief medication in 25% (n = 3) of the patients, and a partial reduction in 58% (n = 7). Discussion: In spite of the reduced number of patients in our study, the results were similar to other publications with larger populations in regard to safety and procedure success. Improvement was not only reflected by the reporting of reduced pain, but it was also observed in a reduced intake of pain relief medications. Conclusión: Our study shows that facet-dependent radiofrequency thermolysis is a safe and useful method, with low complication rates, that can be managed on an outpatient basis

Characteristics and sites of infection of Eubacterium nodatum, Eubacterium timidum, Eubacterium brachy, and other asaccharolytic eubacteria.

Three new species, Eubacterium nodatum, Eubacterium timidum, and Eubacterium brachy, were described, primarily from subgingival samples taken from patients with moderate and severe adult periodontitis. Except for the isolation of E. brachy from a pleuropulmonary infection, these species have not been reported from other infected body sites. We report on the isolation of these species and an undescribed group (D-6) of asaccharolytic eubacteria also found in periodontal disease from numerous different sites of infection, mostly the head and neck. A similarity in cellular morphological properties of E. nodatum and Actinomyces sp. was noted previously. Additional similarities, particularly to Actinomyces israelii, that we found are the formation of molar tooth colonies and the isolation from cases of lumpy jaw and from the genital tract of women in association with the use of an intrauterine contraceptive device. E. timidum and E. brachy did not occur more often from any particular site outside of the head, neck, and respiratory tract. The group D-6 strains came from a variety of sites in the trunk and pelvis. These species are all obligately anaerobic, asaccharolytic, and generally nonreactive, and they grow poorly and slowly on media commonly used to isolate anaerobic bacteria. L-Lysine (0.5%) markedly stimulated the growth of E. nodatum and, to a lesser extent, another acetate- and butyrate-producing group, Eubacterium sp. group D-6, but we did not find comparable stimulants for the other species. We found the production of phenyl acetate to be a helpful marker in the identification of E. timidum and Eubacterium sp. group D-6. Although the isolation and identification of most of these species remain somewhat difficult, the evidence from dental infections and the present report suggests that these species are potential pathogens that are likely to be overlooked in infected clinical material without special attention to more prolonged incubation and use of enriched isolation media.

The perioperative charge equivalence of interstitial brachytherapy and radical prostatectomy with 1-year followup.

PURPOSE: We compare the comprehensive 1-year charges in a consecutive group of patients undergoing radical prostatectomy and transperineal interstitial brachytherapy for clinically localized prostate cancer at a single urban institution. MATERIALS AND METHODS: A total of 60 consecutive men with clinically localized prostate cancer (T1-T2, N0, M0) were treated during a 15-month period with radical prostatectomy or interstitial brachytherapy. Hospital and outpatient records were analyzed for each patient in regard to preoperative, operative and postoperative charges. Parameters included number of encounters, diagnostic and therapeutic interventions, hospitalization and operative charges, and followup visits, diagnostic tests and interventions for 1 year. All charge calculations were based arbitrarily on the 1996 Medicare fee schedule, factoring in the mandated global charge reimbursement period of 90 days for both procedures. RESULTS: Of the patients 38 underwent radical prostatectomy (prostatectomy group) and 22 underwent interstitial brachytherapy (brachytherapy group). The brachytherapy group was older with higher pretreatment serum prostate specific antigen and clinical stage disease, and more frequently received neoadjuvant hormonal therapy compared to the prostatectomy group. The 2 groups were similar in Gleason score and, when applicable, duration of neoadjuvant hormonal therapy. Preoperative charges were 15.3% lower for prostatectomy than for brachytherapy (not statistically significant). Conversely, operative charges for prostatectomy were 13.5% higher (p = 0.04). The major difference among preoperative, operative and postoperative charges was for those incurred postoperatively by the brachytherapy group, which were 56.0% higher than those for the prostatectomy group ($2,285.20 versus $1,007.20, p = 0.0004). CONCLUSIONS: Transperineal interstitial seed implantation is perceived by many as more cost-effective than radical prostatectomy for patients with clinically localized prostate cancer. We demonstrated that when such patients were followed for 1 year, the comprehensive charges for radical prostatectomy and interstitial brachytherapy were equivalent.

Indinavir urolithiasis: an emerging cause of renal colic in patients with human immunodeficiency virus.

PURPOSE: We evaluate the clinical, diagnostic and radiographic findings in patients on indinavir therapy who presented with renal colic, and propose appropriate treatment options for indinavir urolithiasis. MATERIALS AND METHODS: A total of 16 patients positive for human immunodeficiency virus on indinavir were evaluated for 18 episodes of severe renal colic requiring hospitalization. Laboratory evaluation was performed in all patients followed by an imaging study. Conservative treatment included intravenous hydration, narcotic analgesics and temporary cessation of indinavir. Intervention was elected only in patients with persistent fever or intractable pain. A month after hospital discharge an excretory urogram and metabolic stone evaluation were performed. Mean followup was 9.3 months and 2 patients had recurrent symptoms. RESULTS: All patients presented with nausea or vomiting and hematuria. Imaging studies confirmed obstruction in all patients with 13 radiolucent (indinavir) and 3 radiopaque (calcium oxalate) stones. Patients with radiolucent and radiopaque stones demonstrated significant differences in urinary pH (p = 0.002) and serum creatinine (p = 0.03). Conservative therapy was successful in 11 patients (68.8%) within 48 hours and 4 patients (25%) with radiolucent calculi required endoscopic stenting for persistent fever. Metabolic stone evaluation demonstrated significant hypocitruria (less than 50 mg./24 hours) in all patients with radiolucent calculi. CONCLUSIONS: The urologist should be familiar with this growing cause of renal colic in patients on indinavir therapy. Pure indinavir stones are radiolucent and have a soft, gelatinous endoscopic appearance. Conservative treatment is successful in most patients and if intervention is deemed medically necessary, endoscopic stent placement should be the procedure of choice.