Echocardiography and FDG-PET/CT scan in Gram-negative bacteremia and cardiovascular infections.

PURPOSE OF REVIEW: Current evidence on cardiovascular infections in Gram-negative blood stream infections (GNBSI) with focus on the use of transesophageal echocardiography (TEE) and 18F-Fluorodeoxyglucose - positron emission tomography/Computed tomography (FDG-PET/CT) in the diagnostic workup. RECENT FINDINGS: Most evidence focuses on characteristics of diagnosed cardiovascular infections and the proportion caused by GNBSI. These proportions are low (1-5%) when it comes to native and prosthetic valve endocarditis as well as cardiac implantable electronic device (CIED) infections whereas the proportion of vascular graft infections caused by GNBSI seems substantially higher (30-40%). Information on the prevalence of cardiovascular infection in patients with GNBSI is limited to a few studies finding around 3% endocarditis in patients with GNBSI and a prosthetic heart valve and 4-16% device-related infection in patients with CIED and GNBSI. SUMMARY: Patients with GNBSI and native or prosthetic valves should only undergo work-up for endocarditis (TEE and FDG-PET/CT) if they present GNBSI relapse or signs suggestive of endocarditis. CIED patients with GNBSI with Pseudomonas or Serratia spp. should undergo TEE and PET/CT because of the high prevalence of device-related infection. In other GNBs without IE suggestive signs, normal BSI treatment is reasonable and only cases with relapse need work-up. GNBSI in patients with vascular grafts should lead to consideration of PET/CT.

Clinical applicability of diagnostic biomarkers in early-onset cognitive impairment.

BACKGROUND AND PURPOSE: Several diagnostic biomarkers are currently available for clinical use in early-onset cognitive impairment. The decision on which biomarker is used in each patient depends on several factors such as its predictive value or tolerability. METHODS: There were a total of 40 subjects with early-onset cognitive complaints (<65 years of age): 26 with Alzheimer's disease (AD), five with frontotemporal dementia and nine with diagnostic suspicion of non-neurodegenerative disorder. Clinical and neuropsychological evaluation, lumbar puncture for cerebrospinal fluid (CSF) AD core biochemical marker determination, medial temporal atrophy evaluation on magnetic resonance imaging, amyloid-positron emission tomography (PET) and 18 F-fluorodeoxyglucose-PET were performed. Neurologists provided pre- and post-biomarker diagnosis, together with diagnostic confidence and clinical/therapeutic management. Patients scored the tolerability of each procedure. RESULTS: Cerebrospinal fluid biomarkers and amyloid-PET increased diagnostic confidence in AD (77.4%-86.2% after CSF, 92.4% after amyloid-PET, P < 0.01) and non-neurodegenerative conditions (53.6%-75% after CSF, 95% after amyloid-PET, P < 0.05). Biomarker results led to diagnostic (32.5%) and treatment (32.5%) changes. All tests were well tolerated. CONCLUSIONS: Biomarker procedures are well tolerated and have an important diagnostic/therapeutic impact on early-onset cognitive impairment.

Risk factors for cefepime nonsusceptible Gram-negative infections in allogeneic hematopoietic cell transplant recipients.

PURPOSE: Allogeneic hematopoietic cell transplant recipients undergo myelosuppressive chemotherapy to allow engraftment of stem cells and are at particularly high risk for bacterial infections and adverse outcomes. Patients undergoing hematopoietic cell transplant are at increased risk for healthcare-associated infections, including infections with multidrug-resistant pathogens. Cefepime is a commonly prescribed antibiotic for empiric therapy in hematopoietic cell transplant patients, but there is minimal data describing cefepime resistance rates, risk factors for resistance, and clinical outcomes associated with cefepime-resistant infections. METHODS: Adult (≥18 years old) allogeneic hematopoietic cell transplant recipients with a culture positive for a gram-negative rod between January 2010 and January 2016 were spilt into two groups: cefepime susceptible and cefepime nonsusceptible . The primary objective of this study was to identify risk factors for cefepime nonsusceptible through multivariable logistic regression. RESULTS: A total of 107 patients were included (27 cefepime nonsusceptible, 80 cefepime-susceptible), yielding a 25.2% nonsusceptibility rate. Multivariable analysis yielded age >60 years old, Klebsiella spp. infection, Acinetobacter spp. infection, healthcare exposures within 90 days, acute gastrointestinal graft-vs-host-disease, and chronic graft-vs-host-disease at multiple locations as significant risk factors for cefepime nonsusceptible. The receiver operating characteristic area under the curve of the model was 0.851. Thirty-day all-cause mortality (29.6% versus 16.3%, p = 0.13) and length of hospitalization (19 versus 12.5 days, p = 0.0650) were numerically higher in the cefepime nonsusceptible group. CONCLUSIONS: Hematopoietic cell transplant patients with acute gastrointestinal graft versus host disease, extensive chronic graft-vs-host-disease, advanced age, previous healthcare exposures, or infections with Klebsiella and Acinetobacter are at increased risk for cefepime nonsusceptible. Patients infected with cefepime nonsusceptible pathogens may have higher rates of mortality and length of hospitalization.

Multidisciplinary radio-guided surgery team: Alternative to change the current paradigm.

INTRODUCTION: Given the constant increase in the healthcare demand for examinations related to radio-guided surgery (RGS), our hospital adopted new professional profiles in the RGS team, in order to partially reduce the time spent by nuclear medicine physicians on this task. AIM: To analyze the process of incorporating the profiles of Diagnostic Imaging Technician (DIT) and Sentinel Node Referent Nurse (SNRN), evaluating their deployment in the procedures linked to the technique. MATERIAL AND METHODS: Analysis of RGS activity during the period 2018-2022, focusing on pre-surgical and surgical procedures related to breast cancer (BC) and malignant melanoma (MM), as they are those pathologies on which the transfer of care competencies was concentrated. Chronological evolution of the competencies assumed by the different profiles during their integration into the RGS team. RESULTS: RGS's healthcare activity during the analyzed period experienced an increase of 109%. BC and MM were the pathologies that accounted for by far the greatest demand for care. The transfer of competencies in these two pathologies occurred in a progressive and staggered manner, with 74% (460/622) of the administration phase being carried out by the SNRN and 64% (333/519) of the surgeries by the DIT in 2022. CONCLUSIONS: The creation of a multidisciplinary RGS team that includes different professional profiles (nuclear medicine physician [MN], ERGC and TSID) is an effective strategy to respond to the increase in the complexity and number of all procedures related to RGS.

Use of SPECT/CT for improved sentinel lymph node localization in endometrial cancer.

OBJECTIVE: To assess the usefulness of adding SPECT/CT to planar images for pre-surgical sentinel lymph node (SLN) identification in endometrial cancer (EC), a technique that could have an important clinical impact on the staging, treatment, and prognosis of EC patients. METHODS: We compared the planar and SPECT/CT lymphoscintigraphic images of 44 patients with high-risk EC who underwent sentinel lymph node procedure (SLN) using an injection technique recently developed at our center known as TUMIR (Transvaginal Ultrasound Myometrial Injection of Radiotracer). 148 MBq (4 mCi) of 99mTc-nanocolloid were injected, guided by transvaginal ultrasound imaging. Planar and SPECT/CT images were performed in all 44 patients. RESULTS: SLNs were seen on planar images in 32 cases (73%) and in 34 cases (77%) using SPECT/CT. A total of 88 SLNs were depicted by planar lymphoscintigraphy while SPECT/CT visualized a total of 110 SLNs. SPECT/CT changed the assessment of the SLNs visualized in planar lymphoscintigraphy in 26 cases, either by modifying the number and/or the location of the SLNs detected. External iliac chain was the most frequent location of SLN detection (71%) in the 34 cases. Fifteen of these patients (44%) showed para-aortic SLNs. One case had exclusive para-aortic drainage (3%) that was only visualized by SPECT/CT. In another case, SPECT/CT was able to localize the only pelvic metastatic lymph node not visualized by planar images. CONCLUSIONS: SPECT/CT combined with planar imaging improves preoperative SLN detection and provides valuable anatomic information that enhances the presurgical stage of the SLN technique in endometrial cancer.

Sentinel node referent nurse: Description, validation and application in clinical practice.

INTRODUCTION: In 2019 the opportunity to add a nurse within the radioguided surgery (RGS) team was generated. The referent nurse model was adapted to, the sentinel node (SN) preoperative approaches. OBJECTIVES: To describe the process performed to define the sentinel node referent nurse (SNRN) profile, to validate its practical application and to establish its clinical implementation. MATERIAL AND METHODS: Methodology of analysis and continuous improvement in the management of processes (cycle PDCA): definition and planning of the SNRN functions in the breast cancer protocol, performance of a pilot test with 20 patients and analysis of the data in order to validate the circuit and establish its final clinical implementation. RESULTS: New procedure flows-charts were elaborated, adding the figure of the SNRN, its function and nursing interventions during the process. In the pilot test a 58.3% reduction in subjective anxiety, a 75% decrease of the overall anxiety level, a 100% knowledge of the test and an acceptable patient perception of pain's level during the radiotracer administration were obtained. Regarding technical quality, 8/10 items assessed reached the level previously established by the RGS team. CONCLUSIONS: The increasing complexity of the SN biopsy technique has created the opportunity to implement nursing care in the presurgical SN localization process. The profile of the SNRN is ideal for carrying it out and has led to improvements in the nursing diagnoses and assessed items.

Radioactive and non-radioactive seeds as surgical localization method of non-palpable breast lesions.

The increasingly early diagnosis of breast disease and the more widespread use of primary systemic therapy leads to an increasing number of surgeries for non-palpable breast lesions (NPL) in clinical practice. Breast-conserving surgery often requires the use of an image-guided preoperative localization procedure, in which a device is placed within the lesion to be removed to guide the surgeon during surgery. These are patients with small, non-palpable tumors detected in the population screening mammogram, cases with significant reduction of the lesion after neoadjuvant chemotherapy and sometimes it is even necessary to mark axillary lymphadenopathies prior to systemic treatment. For decades, wire localization has been the standard for preoperative marking in breast cancer. Due to the external component of this device, extreme care must be taken not to alter its position before surgery, which is why it is placed hours before surgery and entails complex and limited flexibility in surgical programming. Intraoperative ultrasound improves this drawback but has the limitation that it can only be performed in those NPLs that have ultrasound translation. The Radioguided Occult Lesion Localization (ROLL) technique, although it is another alternative adopted by many institutions, is not without complications, among which the possibility of diffusion of the radiotracer into healthy tissue stands out. To overcome these problems, more recently, 125I radioactive seeds began to be used. Subsequently, thanks to technological advances, non-radioactive seed alternatives such as radar reflectors, magnetic seeds and radio frequency markers have emerged. These locating devices can be placed days before surgery, avoiding wire-related problems and complications. They are introduced percutaneously and identified intraoperatively using a detector device. There is no perfect intraoperative localization method for NPL excision, but fortunately, we have multiple techniques with different advantages and disadvantages that must be assessed and adapted to the center's own resources, the type of surgery, and always to the benefit of the patient.

Detection of epileptogenic focus with two new methods of processing of SPECT and PET cerebral images: PET-Analysis and PISCOM. / Detección del foco epileptógeno mediante dos nuevos métodos de procesamiento de imágenes SPECT y PET cerebral: PET-Analysis y PISCOM.

Functional neuroimaging with positron emission tomography with 18F-fluorodeoxyglucose (PET-18F-FDG) and perfusion single photon emission computerized tomography (SPECT) are increasingly more essential for presurgically locating the epileptogenic focus. We present the case of an 18-year-old male with epileptic seizures refractory to antiepileptic treatment. Magnetic resonance (MR) showed dysplasia in the posterior right insular cortex. Subtraction of ictal SPECT co-registered to MR (SICOM) detected a focal increase of uptake in the left fronto-parietal cingulate and PET-FDG showed normal distribution of the radiotracer. The posterior right insula was resected with histopathological results of grade I ganglioglioma according to the World Health Organization classification. The patient made favourable post-surgical progress, and remains seizure-free after 5 years (Engel I). Retrospective analysis of this case with two new image processing methods (PET analysis and PET interictal subtracted ictal SPECT coregistered with MR [PISCOM]) correctly localized the epileptogenic focus in the posterior right insular cortex.

[Utility of positron emission tomography with 18F-FDG in a case of juvenile recurrent respiratory papillomatosis]. / Utilidad de la tomografía por emisión de positrones con 18F-FDG en un caso de papilomatosis pulmonar recurrente juvenil.

Juvenile recurrent respiratory papillomatosis (JRRP) is an infectious disease caused by the growth of papillomas in the airway. Up to 4% of these cases degenerate into squamous cell carcinoma. We present the case of a 17-year-old female patient with JRRP in which the utility of (18)F-FDG-PET/CT in the characterization of suspicious papillomatous lesions of malignancy is evaluated. Morphometabolic techniques, CT scan and PET/CT scans were suggestive of malignancy. However, this was not confirmed in the histopathological analysis after its resection. The (18)F-FDG-PET/CT does not seem to be a useful tool for early detection of malignancy in JRRP. However, it does increase the diagnostic accuracy of the biopsy as it identifies the most active lesions and, therefore, those most likely to be malignant.

[Dual-time point images of the liver with (18)F-FDG PET/CT in suspected recurrence from colorectal cancer]. / (18)F-FDG PET/TC con imagen hepática en dos tiempos en la sospecha de recidiva del cáncer colorrectal

AIM: To analyze the potential improvement of (18)F-fluorodeoxyglucose (FDG) PET/CT using additional delayed images of the liver in operated colorectal cancer. MATERIAL AND METHODS: The study prospectively included 71 patients (22 women, 49 men) with mean age of 65 ± 11 years with clinical, analytic or radiological suspicion of current disease. A whole body PET/CT scan was performed at 60 min. (standard images) and after 2 hr (delayed images) post-injection of 4.07 MBq/Kg of (18)F-FDG. Visual and quantitative SUV analysis of PET/CT findings was done. All findings were confirmed by histopathology and/or at least 6 months follow-up. RESULTS: Thirty-seven out of 71 patients were diagnosed of liver metastases (79 metastases). In 38/71 cases there was extra-hepatic disease in the form of local recurrence (10), abdominopelvic (3) or mediastinal (3) lymph nodes, bone (1) or lung metastases (16) and carcinomatosis (10). Sensitivity and specificity in the diagnosis of liver metastases in a patient-by-patient basis in standard (81% and 91%) and in delayed images (95% y 97%) was calculated. The number of lesions detected in delayed images was significantly higher (66/79) than in standard images (57/79). Sensitivity and specificity for PET/CT in the diagnosis of extra-hepatic disease was 84% and 70%, contributing to the detection of synchronous tumors in 5 patients. CONCLUSIONS: PET/CT may be useful in the diagnosis of extra-hepatic disease in suspected recurrence of colorectal cancer. Delayed images on PET/CT may increase the sensitivity to identify liver metastases.