A machine-learning regional clustering approach to understand ventilator-induced lung injury: a proof-of-concept experimental study.

BACKGROUND: The spatiotemporal progression and patterns of tissue deformation in ventilator-induced lung injury (VILI) remain understudied. Our aim was to identify lung clusters based on their regional mechanical behavior over space and time in lungs subjected to VILI using machine-learning techniques. RESULTS: Ten anesthetized pigs (27 ± 2 kg) were studied. Eight subjects were analyzed. End-inspiratory and end-expiratory lung computed tomography scans were performed at the beginning and after 12 h of one-hit VILI model. Regional image-based biomechanical analysis was used to determine end-expiratory aeration, tidal recruitment, and volumetric strain for both early and late stages. Clustering analysis was performed using principal component analysis and K-Means algorithms. We identified three different clusters of lung tissue: Stable, Recruitable Unstable, and Non-Recruitable Unstable. End-expiratory aeration, tidal recruitment, and volumetric strain were significantly different between clusters at early stage. At late stage, we found a step loss of end-expiratory aeration among clusters, lowest in Stable, followed by Unstable Recruitable, and highest in the Unstable Non-Recruitable cluster. Volumetric strain remaining unchanged in the Stable cluster, with slight increases in the Recruitable cluster, and strong reduction in the Unstable Non-Recruitable cluster. CONCLUSIONS: VILI is a regional and dynamic phenomenon. Using unbiased machine-learning techniques we can identify the coexistence of three functional lung tissue compartments with different spatiotemporal regional biomechanical behavior.

Early Detection of Bone Metastasis in Small Cell Neuroendocrine Carcinoma of the Cervix by 68Ga-DOTATATE PET/CT Imaging.

The neuroendocrine small cell carcinoma of the cervix is a rare malignancy that has a poor prognosis due to early lymphatic and hematogenous spread. We herein report a case of a 27- year-old woman who was referred for initial staging of a neuroendocrine small cell carcinoma with previous unremarkable structural imaging. Ga-DOTATATE PET/CT revealed focal uptake at the primary tumor and in a solitary pelvic bone lesion suggestive of metastases that was further confirmed by CT-guided biopsy. Somatostatin receptor PET/CT may be a useful image modality for early detection of metastases to guide treatment in these patients.

Implementing sentinel lymph node biopsy programs in developing countries: challenges and opportunities.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is the accepted standard of care in early-stage breast cancer and cutaneous melanoma. This technology is accurate for nodal staging and determining the prognosis of these patients. There are several randomized controlled trials confirming the accuracy of this technique and confirming its role in reducing morbidity and improving quality of life. It is also gaining increased acceptance in the management of other solid tumors. Despite the established benefits of SLNB as a minimally invasive approach for nodal staging, the procedure is still underutilized in many developing countries. METHODS: The Human Health Division of the International Atomic Energy Agency (IAEA) convened advisory meetings with panels of multidisciplinary experts from different backgrounds with the remit to analyze the difficulties encountered by developing countries in establishing a successful SLNB program. The other remit of the panel was to recommend an effective program based on existing evidence that can be adapted and implemented in developing countries. The experience of some members of the panel in the training for this technique in Asia, Latin America, and Africa provided the insight required for the development of a comprehensive and structured program. The panel included recommendations on the technical aspects of the procedure, as well as a comprehensive training program, including theoretical teaching, practical training in surgical skills, laboratories, and hands-on proctored learning. Particular emphasis was placed on in-built quality assurance requirements to ensure that this powerful staging investigation is implemented with the highest possible standard in the management of cancer patients, with the lowest false negative rate. CONCLUSIONS: It is hoped that this article will be a useful resource for our colleagues planning to establish a SLNB program.

[99mTc-OCTREOTIDE in patients with neuroendocrine tumors from the GI tract]. / 99mTc-OCTREOTIDE en pacientes con tumores neuroendócrinos gastroenteropancreáticos.

INTRODUCTION: It has been demonstrated that scintigraphy with somatostatin analogues is useful for the diagnosis, staging and follow up of patients with neuroendocrine tumors from the gastrointestinal tract (NET-GIT). Some studies suggest that the use of 99mTc-Hydrazinonicotinyl-Tyr3-octreotide (99mTc-HYNIC-TOC) yields similar diagnostic results than the use of 111In-DTPA-octreotide. OBJECTIVE: To determine the clinical value of scintigraphy using 99mTc-HYNIC-TOC for the detection of primary and secondary lesions in patients with NET-GIT. METHODS: From September 2004 to May 2009, 32 patients (17 women, age range 18 to 82 years old) with histologically proven or clinically suspected NET-GIT underwent scintigraphy using 99mTc-HYNIC-TOC Patients underwent a whole body scan, with additional static images of abdomen and pelvis, followed by SPECT at 4-hrs post injection of 925 MBq of the tracer. Patients underwent clinical, imaging and histopathology follow-up during 3 to 18 months. RESULTS: Histopathology demonstrated carcinoid tumor in 20 patients, insulinoma in 2, gastrinoma in 2 and non-specific NET-GIT in 6. Total sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87%, 100%, 100%, 89% and 94%, respectively. To detect the primary lesion, the values were 94%, 100% 100%, 94% and 97%, respectively and to detect secondary lesions, 79%, 100%, 100%, 86% and 91%, respectively. CONCLUSIONS: 99mTc-HYNIC-TOC is a specific somatostatin analog, with high affinity to receptor subtype SST-2, widely available and affordable by Latin American countries. It has a good performance to be used for diagnosis, staging and follow-up of patients with NET-GIT.

El SPECT cerebral en los trastornos psiquiátricos de la dermatitis atópica severa / Brain SPECT evaluation of psychiatric dysfunctions in severe atopic dermatitis

Introducción: La dermatitis atópica (DA) severa suele tener un componente psiquiátrico que puede influir en el desencadenamiento y exacerbación de los síntomas cutáneos. La neuroimagen funcional podría objetivar disfunciones neuronales existentes en estos pacientes.Objetivo: Investigar la presencia de trastornos de la perfusión cerebral en pacientes con DA severa y describir sus características mediante SPECT. Materiales y métodos: 11 pacientes adultos con DA severa fueron estudiados por evaluación psiquiátrica clínica y SPECT cerebral con 99mTc-ECD. Resultados: 90.3 por ciento de los pacientes presentaron un trastorno de ansiedad generalizada, 63.6 por ciento un trastorno obsesivo compulsivo y 63.6 por ciento depresión. Todos los pacientes presentaron trastornos de perfusión, que predominaron en la corteza prefrontal. Se evidenciaron alteraciones concordantes con los patrones descritos en pacientes que asocian síntomas depresivos y ansiosos. Conclusiones: Demostramos la presencia frecuente de alteraciones de la perfusión cerebral en la DA severa con componente psiquiátrico y describimos sus características mediante un método de neuroimagen.

Comparison of 99mTc-MIBI scintigraphy and sentinel node biopsy in the detection of occult lymph node metastases from cutaneous melanoma.

99mTc-MIBI scintigraphy has been proposed as a technique that can diagnose clinically undetectable melanoma metastases. The aim of the study was to compare the sensitivity of 99mTc-MIBI with that of sentinel node biopsy (SNB) in the detection of nodal disease. Twenty-eight patients with melanoma >1.0 mm thick were enrolled. Patients underwent 99mTc-MIBI scintigraphy and a preoperative lymphoscintigraphy followed by SNB. Sentinel nodes were identified in 27/28 patients. Twelve patients had an involved sentinel node (SN), being 99mTc-MIBI positive in 10. No patient with negative SNB developed regional recurrence during the study. 99mTc-MIBI had a sensitivity of 83% and a specificity of 93%. We conclude that SNB remains the procedure of choice for detecting subclinical lymph node involvement from melanoma. 99mTc-MIBI could have an alternative role in lymph node staging of patients who are not good candidates of SNB, that needs to be tested in appropriate trials.

Staging of regional lymph nodes in melanoma patients by means of 99mTc-MIBI scintigraphy.

UNLABELLED: Most first relapses in patients with melanoma occur in regional lymph node basins. Such lesions are frequently diagnosed clinically during the first 2 y of follow-up. In the last few years, our group has been studying the usefulness of (99m)Tc-methoxyisobutylisonitrile (MIBI) scintigraphy in the evaluation of recurrent melanoma lesions. The aim of the present study was to prospectively evaluate the clinical value of (99m)Tc-MIBI scintigraphy in the diagnosis of subclinical nodal metastases. METHODS: We included 66 patients within 3 mo of melanoma diagnosis, with Breslow thickness > 1.0 mm, all treated with wide local excision of the primary lesion. When (99m)Tc-MIBI scanning was performed, 49 of them did not have evidence of nodal disease, and 17 had clinically questionable regional lymph node lesions. Planar images of lymph node regions were acquired 10 min after injection, using a dose of 740-1,110 MBq and a large-field-of-view gamma camera equipped with a low-energy high-resolution collimator. Scan findings were confirmed by pathology or by clinical follow-up (median, 35 mo). RESULTS: Thirty of 33 patients with regional lymph node metastases received a correct diagnosis, 14 with palpable lesions and 16 with nonpalpable lesions. In 3 cases that were initially (99m)Tc-MIBI negative, nodal metastases were found during follow-up. The following diagnostic values were calculated: sensitivity, 0.91 (95% confidence interval [CI], 0.75-0.98); specificity, 0.85 (95% CI, 0.67-0.94); likelihood ratio of a positive test, 6.0 (95% CI, 2.7-13.5); and likelihood ratio of a negative test, 0.11 (95% CI, 0.036-0.32). CONCLUSION: (99m)Tc-MIBI scanning may have a secondary role in the staging of regional lymph nodes in patients with clinically localized melanoma who are not good candidates for sentinel node biopsy.

Mapeo linfático e identificación de ganglios centinelas en pacientes con cáncer de cuello uterino sometidas a histerectomía radical / Lymphatic mapping and identification of sentinel ganglia in patients with uterine cervix cancer submitted to radical histerectomy

Objetivo. El compromiso tumoral de los ganglios regionales es uno de los factores pronósticos más importantes del cáncer precoz del cuello uterino. Si bien no ha sido extensamente estudiada en esta patología, la estrategia del ganglio centinela (GC) tiene el potencial de evitar linfadenectomías innecesarias en estas pacientes. El objetivo del presente trabajo fue el de determinar la factibilidad de la identificación del GC por medio de linfocentellografía preoperatoria y detección intraoperatoria guiada por sonda gama (SG) en pacientes sometidas a histerectomía radical con linfadenectomía pélvica y periaórtica para el tratamiento de cáncer de cuello uterino en estadios precoces