Prevalencia de anticuerpos neutralizantes frente al SARS-CoV-2 inducidos tras 2 dosis de vacuna BNT162b2 (Pfizer–BioNTech) en trabajadores sanitarios / Prevalence of neutralizing antibodies against SARS-CoV-2 using a rapid serological test in health workers of a Spanish Department of Health in Alicante (Spain) before the booster dose of the vaccine

Fundamento: Estudiar la prevalencia de anticuerpos neutralizantes en el personal sanitario y de apoyo tras la administración de la segunda dosis de vacuna BNT162b2 (Pfizer–BioNTech). Material y métodos: En diciembre 2021 llevamos a cabo un estudio en el Departamento de Salud de Orihuela, Alicante (España), formado por 1.500 trabajadores. En los participantes del estudio, recogimos variables demográficas y realizamos un test «point-of-care» (POC) de inmunocromatografía para medir la presencia de anticuerpos neutralizantes (OJABIO® SARS-CoV-2 Neutralizing Antibody Detection Kit, fabricado por Wenzhou OJA Biotechnology Co., Ltd.- Wenzhou, Zhejiang, China) antes de la administración de la tercera dosis de vacuna. Resultados: Obtuvimos información completa de 964 (64%) trabajadores, siendo 290 varones y 674 mujeres. La edad media fue de 45,8 años (mín: 18, máx: 68) y el tiempo desde la última dosis (TUD) de vacuna fue 40,5 semanas (mín: 1,71; máx: 47,71). Un total de 131 (13,5%) habían padecido infección por SARS-CoV-2 confirmada mediante RT-PCR. La proporción de sujetos con presencia de anticuerpos neutralizantes fue de 38,5%. En el análisis multivariable el TUD de vacuna (razón de probabilidades ajustada [ORa] semana: 1,07; IC 95%: 1,04; 1,09) y la infección previa por SARS-CoV-2 (ORa: 3,7; IC 95%: 2,39; 5,63) mostraron asociación estadísticamente significativa con la presencia de anticuerpos neutralizantes. Conclusiones: El TUD de vacuna y la infección previa por SARS-CoV-2 determinaron la presencia de anticuerpos neutralizantes en 38,5% del personal sanitario y personal de apoyo.(AU)

Aim: To study the prevalence of neutralizing antibodies in healthcare workers and healthcare support personnel after the administration of the second dose of the BNT162b2 vaccine (Pfizer-BioNTech). Materials and methods: In December 2021, we undertook a study in the Health Department in Orihuela, Alicante (Spain), which consists of 1500 workers. We collected demographic variables about the study participants, and we performed a «point-of-care» immunochromatography test to measure the presence of neutralizing antibodies (OJABIO® SARS-CoV-2 Neutralizing Antibody Detection Kit, manufactured by Wenzhou OJA Biotechnology Co., Ltd. Wenzhou, Zhejiang, China) before the administration of the third dose of the vaccine. Results: We obtained complete information about 964 (64%) workers, which consisted of 290 men and 674 women. The average age was 45,8 years (min. 18, max. 68) and the average time since the last dose of the vaccine was 40,5 weeks (min. 1,71, max. 47,71). A total of 131 participants (13,5%) had suffered infection by SARS-CoV-2 confirmed using RT-PCR. The proportion of participants who showed presence of neutralizing antibodies was 38,5%. In the multivariable analysis, the time since the last dose of the vaccine (aOR week: 1,07; 95%CI: 1,04; 1,09) and previous infection by SARS-CoV-2 (aOR: 3,7; 95CI: 2,39; 5,63) showed a statistically significant association with the presence of neutralizing antibodies. Conclusions: The time since the administration of the last dose of the vaccine and the previous infection by SARS-CoV-2 determined the presence of neutralizing antibodies in 38,5% of the healthcare workers and support workers.(AU)

Prevalence of neutralizing antibodies against SARS-CoV-2 using a rapid serological test in health workers of a Spanish Department of Health in Alicante (Spain) before the booster dose of the vaccine.

AIM: To study the prevalence of neutralizing antibodies in healthcare workers and healthcare support personnel after the administration of the second dose of the BNT162b2 vaccine (Pfizer-BioNTech). MATERIALS AND METHODS: In December 2021, we undertook a study in the Health Department in Orihuela, Alicante (Spain), which consists of 1500 workers. We collected demographic variables about the study participants, and we performed a "point-of-care" immunochromatography test to measure the presence of neutralizing antibodies (OJABIO® SARS-CoV-2 Neutralizing Antibody Detection Kit, manufactured by Wenzhou OJA Biotechnology Co., Ltd. Wenzhou, Zhejiang, China) before the administration of the third dose of the vaccine. RESULTS: We obtained complete information about 964 (64%) workers, which consisted of 290 men and 674 women. The average age was 45,8 years (min. 18, max. 68) and the average time since the last dose of the vaccine was 40,5 weeks (min. 1,71, max. 47,71). A total of 131 participants (13,5%) had suffered infection by SARS-CoV-2 confirmed using RT-PCR. The proportion of participants who showed presence of neutralizing antibodies was 38,5%. In the multivariable analysis, the time since the last dose of the vaccine (aOR week: 1,07; 95%CI: 1,04; 1,09) and previous infection by SARS-CoV-2 (aOR: 3,7; 95CI: 2,39; 5,63) showed a statistically significant association with the presence of neutralizing antibodies. CONCLUSIONS: The time since the administration of the last dose of the vaccine and the previous infection by SARS-CoV-2 determined the presence of neutralizing antibodies in 38,5% of the healthcare workers and support workers.

Development of a leakage monitoring system in isolated limb perfusion with portable gamma camera. / Desarrollo de un protocolo de monitorización de fuga en perfusión de miembro aislado con gammacámara portátil.

Isolated limb perfusion (ILP) is a method for treating unresectable lesions of limbs in patients with melanoma or sarcoma by using high doses of tumor necrosis factor alpha and melphalan. These high doses can result in high systemic toxicity if there is a drug leak from the isolated circulation of the limb to the systemic. This makes it imperative to monitor the leakage rate (F[%]) during the infusion, currently performed with radiotracers. The objective of this work was to develop a leakage monitoring protocol as accurate as possible to ensure safe ILP. MATERIAL AND METHOD: We built a phantom with 3compartments (body, limb and precordial area) and a high sensitivity collimator fitted to a portable gammacamera. We simulate ILP with scheduled leaks every 10minutes from 1% to 9% (theorical F[%]). We mesured F(%) using 2equation: one is the proposed in the literature and another corrected by decay of the radioisotope. We test the optimal radiopharmaceutical doses to minimize the detector dead time error and compare F(%) mesured by both equations regarding the theoretical F(%). The leakage monitoring protocol was used in 17 ILP of 16 patients and an analysis of the recorded data was performed. RESULTS: We found significant differences between F(%) mesured using the first equation and theoretical F(%), obtaining results very adjusted to the theorical after applying the decay correction. CONCLUSIONS: The decay correction of the radioisotope is a simple manner to carry out the procedure more safely, reducing the error in the calculation of F(%).

Hybrid imaging in foot and ankle disorders. / Imagen híbrida en la patología del pie y tobillo.

Disorders of the foot and ankle are some of the most frequent ones affecting the musculoskeletal system and have a great impact on patients' quality of life. Accurate diagnosis is an important clinical challenge because of the complex anatomy and function of the foot, that make it difficult to locate the source of the pain by routine clinical examination. In the study of foot pathology, anatomical imaging (radiography, magnetic resonance imaging [MRI], ultrasound and computed tomography [CT]) and functional imaging (bone scan, positron emission tomography [PET] and MRI) techniques have been used. Hybrid imaging combines the advantages of morphological and functional studies in a synergistic way, helping the clinician manage complex problems. In this article we delve into the anatomy and biomechanics of the foot and ankle and describe the potential indications for the current hybrid techniques available for the study of foot and ankle disease.

Dose painting by means of Monte Carlo treatment planning at the voxel level.

PURPOSE: To develop a new optimization algorithm to carry out true dose painting by numbers (DPBN) planning based on full Monte Carlo (MC) calculation. METHODS: Four configurations with different clustering of the voxel values from PET data were proposed. An optimization method at the voxel level under Lineal Programming (LP) formulation was used for an inverse planning and implemented in CARMEN, an in-house Monte Carlo treatment planning system. RESULTS: Beamlet solutions fulfilled the objectives and did not show significant differences between the different configurations. More differences were observed between the segment solutions. The plan for the dose prescription map without clustering was the better solution. CONCLUSIONS: LP optimization at voxel level without dose-volume restrictions can carry out true DPBN planning with the MC accuracy.

Bone scintigraphy as cornerstone in the diagnosis of Erdheim-Chester disease.

The Erdheim-Chester disease (ECD) is an extremely rare form of non-Langerhans cell histiocytosis. The main difficulty for its diagnosis lies in the wide variety of non-specific symptoms and signs that can occur in the disease process, leading, therefore, to there being no clear-cut algorithm as a guide for an optimal biopsy to confirm the diagnosis. An 81-year-old male with history of diabetes insipidus was admitted due to non-specific respiratory signs. Imaging techniques revealed osteoblastic lesions in the lumbar spine. Whole-body bone-scintigraphy (BS) was performed, in which lesions involving the axial and appendicular skeleton, with different rates of osteoblastic activity, were observed. This highlighted a symmetrical severely intense uptake in the knees, leading to an accurate biopsy specimen that enabled making the definitive diagnosis. BS is a widely available, safe, and inexpensive technique that shows a characteristic pattern of uptake for ECD, thus its use is highly recommended for screening and guiding biopsy if clinical suspicion exists. Furthermore, when the scintigraphy pattern is incidentally observed, biopsy of increased uptake areas (tibia preferably) is mandatory in order to rule out the disease.

Role of SPECT-CT in sentinel lymph node biopsy in patients diagnosed with head and neck melanoma.

OBJECTIVE: Assess the role of SPECT-CT in sentinel lymph node (SLN) biopsy in the accurate anatomical location of the SNL in patients with cutaneous head and neck melanoma. MATERIAL AND METHODS: A retrospective study was conducted from February 2010 to June 2013 on 22 consecutive patients with a diagnosis of cutaneous head and neck melanoma (9 female, 13 male), with a mean age of 55 years old and who met the inclusion criteria for SLN biopsy. Patients underwent preoperative scanning after peri-scar injection of (99m)Tc-labeled-nanocolloid. Planar images of the injection-site, whole-body, and SPECT-CT scanning were acquired. RESULTS: Detection rate of SLN reached up to 91% (20/22 patients) by planar lymphoscintigraphy and 95.4% (21/22 patients) by SPECT-CT. SPECT-CT provided an accurate location of SLN in 14/22 patients, enabling to improve the surgical approach (clinical impact: 63.6%). SLN was positive for metastatic cells in 9.1% patients. CONCLUSION: SPECT-CT provides detailed anatomical SLN location and allows detecting a higher number of SLN than planar lymphoscintigraphy. Routine use of SPECT-CT is recommended in order to optimise the SLN detection and location in patients with head and neck melanoma.

The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes that stain positively for CD68 marker but not express CD1a and S100 proteins. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. Multisystemic involvement leads to a wide variety of clinical manifestations that results in a poor prognosis although recent advances in treatment. We present the clinical, nuclear medicine findings and therapeutic aspects of a serie of 6 patients with histopathological diagnosis of ECD, who have undergone both bone scintigraphy (BS) and 18F-fluorodeoxyglucose (18FDG)-PET/CT scans in our institution. A complementary 18F-fluorodopa (18FDOPA)-PET/CT was performed in one case. Three different presentations of the disease were observed in our casuistic: most indolent form was a cutaneous confined disease, presented in only one patient. Multifocal involvement with central nervous system (CNS) preservation was observed in two patients. Most aggressive form consisted in a systemic involvement with CNS infiltration, presented in three patients. In our experience neurological involvement, among one case with isolate pituitary infiltration, was associated with mortality in all cases. 18FDG-PET/CT and BS were particularly useful in despite systemic involvement; locate the site for biopsy and the treatment response evaluation. By our knowledge, 18FDOPA-PET/CT not seems useful in the initial staging of ECD. A baseline 18FDG-PET/CT and BS may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically 18FDG-PET/CT must be performed in the follow up to evaluate treatment response.