Rheumatology experience with FDG PET / CT in inflammation of unknown origin: a single - centre report for determining factors associated with diagnostic precision.

BACKGROUND / AIM: The use of PET / CT is becoming more common in the elucidation of inflammatory processes in which the underlying cause cannot be determined by conventional examinations. Although PET / CT is an effective method for detecting inflammatory foci, the precise diagnosis may not be obtained in all cases. In addition, considering factors such as radiation exposure and cost, it becomes important to identify patients who can get results with PET / CT. In this study, it was aimed to examine the factors that can predict the differential diagnostic value of PET / CT by retrospectively scanning patients who underwent PET / CT for inflammation of unknown origin (IUO) in rheumatology practice. METHODS: Demographic, clinical and laboratory information of the patients followed up in our clinic and who underwent PET / CT for differential diagnosis were enrolled. Whether they were diagnosed after PET / CT and during the follow - up period, and their diagnoses were examined. RESULTS: A total of 132 patients were included in the study. A previous diagnosis of rheumatic disease was present in 28.8 % of the patients, and a history of malignancy was present in 2.3 % . The patients were divided into three groups: group 1 patients with increased FDG uptake in PET / CT and diagnosis confirmed by PET / CT, group 2 patients with increased FDG uptake in PET / CT but diagnosis was not confirmed, and group 3 patients without increased FDG uptake in PET / CT. Increased FDG uptake in PET / CT was detected in 73 % of the patients. While PET / CT helped the diagnosis in 47 (35.6 %) patients (group 1), it did not help the diagnosis in 85 (64.4 %) (groups 2 and 3). Thirty - one (65.9 %) of the diagnosed patients were diagnosed with a rheumatologic disease. When the 3 groups were compared, male gender, advanced age, CRP levels, presence of constitutional symptoms, SUVmax values and number of different organs with increased FDG uptake were higher in Group 1. Sixty - six percent and 74 % of the patients in groups 2 and 3 were not diagnosed during the follow - up period. No patient in group 3 was diagnosed with malignancy during follow - up. CONCLUSION: PET / CT has high diagnostic value when combined with clinical and laboratory data in the diagnosis of IUO. Our study revealed that various factors can affect the diagnostic value of PET / CT. Similar to the literature, the statistically significant difference in CRP levels shows that patients with high CRP levels are more likely to be diagnosed with an aetiology in PET / CT. Although detection of involvement in PET / CT is not always diagnostic, there was an important finding that no malignancy was detected in the follow - up in any patient without PET / CT involvement. Key points • PET / CT is an effective method for detecting inflammatory foci. • PET / CT has proven to be effective in the diagnosis of rheumatological diseases, the extent of disease and the evaluation of response to treatment. • Indications for the use of PET / CT in the field of rheumatology and the associated factors and clinical features supporting the diagnosis with PET / CT are still to be fully clarified. • In routine practice, with PET / CT, both delays in diagnosis and examinations performed during diagnosis and the cost can be reduced.

A new combined index of SUVmax of lymph node in PET / CT by a weighting coefficient plus its maximum minor axis in CECT to evaluate occult lymph node metastasis in clinical N0 patients with tongue cancer.

To predict occult nodal metastasis in clinical N0 patients with tongue cancer, we developed combined index (CI) : SUVmax of the largest lymph node in PET / CT by weighting coefficient plus its maximum minor axis (< 10 mm) in contrast-enhanced CT (CECT). In this retrospective study, 57 clinical N0 patients with tongue cancer, who underwent elective supraomohyoid neck dissection at cervical levels of I-III were enrolled. The cutoff value of SUVmax of 2.0 obtained using receiver operating characteristic (ROC) analysis predicted the postoperative positive cervical levels containing metastatic lymph nodes from clinical N0 cervical levels in tongue cancer patients with a sensitivity of 54.5% and a specificity of 78.2%. The cutoff value of CI with weighting coefficient of 1.5 obtained using ROC analysis was 9.8 at the maximum area under the curve of 0.750. The cutoff value of 9.8 predicted the postoperative positive cervical levels containing metastatic lymph nodes from clinical N0 cervical levels in tongue cancer patients with a sensitivity of 68.2% and a specificity of 81.5%. These findings suggest that CI of functional PET / CT and morphological CECT components might improve the diagnostic performance of occult nodal metastasis to select clinical N0 patients with tongue cancer preferable for elective neck dissection. J. Med. Invest. 68 : 154-158, February, 2021.

[Computed tomography and positron emission tomography with 18F-FDG can help in the differential diagnosis of kidney hypoplasia and scarring].

AIM: PET/CT evaluation of the energy metabolism of 18F-FDG in the normal kidney parenchyma, as well as in patients with a newly diagnosed renal hypoplasia or scarring was performed. MATERIALS AND METHODS: Among 30 patients who volunteered to undergo a whole-body PET/CT, in 2 (6.7%) cases an asymptomatic decrease in the kidney size was found. RESULTS: In the framework of this work, an attempt was made to determine a standard approach to visual and mathematical PET/CT assessment of the energy metabolism of 18F-FDG in the normal renal parenchyma and patients with a newly diagnosed renal hypoplasia or scarring. CONCLUSION: The obtained visual and digital data can be used to decide on the feasibility and mapping of a renal biopsy.

Análisis y selección de técnicas para la fusión de imágenes PET/CT basado en software / Analysis and selection of techniques for the fusion of PET/CT imaging based on software

Técnicas como la Tomografía por Emisión de Positrones y la Tomografía Computarizada permiten determinar la naturaleza maligna o benigna de un tumor y estudiar las estructuras anatómicas del cuerpo con imágenes de alta resolución, respectivamente. Investigadores a nivel internacional han utilizado diferentes técnicas para la fusión de la Tomografía por Emisión de Positrones y la Tomografía Computarizada porque permite observar las funciones metabólicas en correlación con las estructuras anatómicas. La presente investigación se propone realizar un análisis y selección de algoritmos que propicien la fusión de neuroimágenes, basado en la precisión de los mismos. De esta forma contribuir al desarrollo de software para la fusión sin necesidad de adquirir los costosos equipos de adquisición de imágenes de alto rendimiento, los cuales son costosos. Para el estudio se aplicaron los métodos Análisis documental, Histórico lógico e Inductivo deductivo. Se analizaron e identificaron las mejores variantes de algoritmos y técnicas para la fusión según la literatura reportada. A partir del análisis de estas técnicas se identifica como mejor variante el esquema de fusión basado en Wavelet para la fusión de las imágenes. Para el corregistro se propone la interpolación Bicúbica. Como transformada discreta de Wavelet se evidencia el uso de la de Haar. Además, la investigación propició desarrollar el esquema de fusión basado en las técnicas anteriores. A partir del análisis realizado se constataron las aplicaciones y utilidad de las técnicas de fusión como sustitución a los altos costos de adquisición de escáneres multifunción PET/CT para Cuba(AU)

Techniques such as Positron Emission Tomography and Computed Tomography allow to determine the malignant or benign nature of a tumor and to study the anatomical structures of the body with high resolution images, respectively. International researchers have used different techniques for the fusion of Positron Emission Tomography and Computed Tomography because it allows observing metabolic functions in correlation with anatomical structures. The present investigation proposes to carry out an analysis and selection of algorithms that favor the fusion of neuroimaging, based on their precision. In this way, contribute to the development of fusion software without the need to purchase expensive high-performance imaging equipment, which is expensive. For the study the documentary analysis, logical historical and deductive inductive methods were applied. The best algorithm variants and techniques for fusion were analyzed and identified according to the reported literature. From the analysis of these techniques, the Wavelet-based fusion scheme for image fusion is identified as the best variant. Bicubic interpolation is proposed for co-registration. As a discrete Wavelet transform, the use of Haar's is evidenced. In addition, the research led to the development of the fusion scheme based on the previous techniques. From the analysis carried out, the applications and usefulness of fusion techniques were verified as a substitute for the high costs of acquiring PET / CT multifunction scanners for Cuba(AU)

Clinical value of colonoscopy and positron emission tomography with computed tomography for colorectal cancer diagnosis.

INTRODUCTION: Colonoscopy and PET / CT are among the major diagnostic tests for colorectal cancer. The sensitivity, specificity, and accuracy of these studies are still being assessed differently. OBJECTIVE: The aim of the study was to compare the sensitivity, specificity and accuracy of colonoscopy and PET / CT in the diagnosis of colorectal cancer. MATERIAL AND METHODS: The medical records of 125 patients with colonoscopy and PET / CT in the years 2014-2015 were analyzed retrospectively. The research was done at the Professor Franciszek Lukaszczyk Oncology Center in Bydgoszcz. Based on the macroscopic description of colonoscopy, the results were divided into two groups: with and without probability of cancer. The average SUV value in PET / CT for colorectal cancer was calculated and without this diagnosis. The average value of SUV 14 and higher was considered probable, while 11 or less had no probability of cancer. Standardized mathematical formulas were used to evaluate the sensitivity, specificity and accuracy. RESULTS: More than half of the patients - 78 (62.4%) were males. The majority of patients -42 (36.6%) were aged 65-74. The majority (106) (68.8%) were diagnosed as polyps and 24 (15.6%) as tumor-like lesions. Polyps were placed in the rectum -32 (30.2%), in the sigmoid colon - 26 (24.5%) and 15 (13.2%) in the ascending colon. Tumors were located in the rectum - 11 (45.8%) and 4 (16.7%) in the recto-sigmoid junction. 38 (24.6%) adenocarcinomas and 67 (43.5%) adenomas were diagnosed. The detection rate of RJG was 32% in colonoscopy and PET / CT. The sensitivity of the colonoscopy was 80%, the specificity - 68.4% and the accuracy - 71.4%. The sensitivity, specificity and accuracy of PET / CT were 65%, 75%, 4% and 72.7%, respectively. CONCLUSIONS: Colonoscopy has a higher sensitivity in colorectal cancer diagnosis, but specificity and accuracy are higher in PET / CT.

Comparison of Bone Uptake in Bone Scan and Ga-68 PSMA PET/CT Images in Patients with Prostate Cancer.

OBJECTIVE: The aim of this study was to compare images from Tc-99m MDP bone scan (BS) and Ga-68 PSMA PET/CT of patients with prostate cancer in terms of bone metastases. METHODS: Overall, 34 patients exhibited a mean age of 66 ± 9.5 (50-88) years, mean PSA of 51 ± 159ng/ml (0-912), and mean Gleason score of 8 (6-9). BS and Ga-68 PSMA PET/CT were applied to 34 patients within 30 days, and the results were evaluated, retrospectively. In both tests, radiopharmaceutical uptake in bones were compared. RESULTS: In 7 patients (20.5%), uptake was not significant on BS and Ga-68 PSMA PET / CT images, which is related to metastasis. In 14 (41%) patients, bone metastases were observed in both examinations. However, more metastatic lesions were observed in the Ga-68 PSMA PET/CT of 3 patients and in the bone scintigraphy of 2 patients. PSMA expression was not observed on Ga-68 PSMA PET / CT in 13 (38%) patients with increased activity in bone scintigraphy. Two (6%) of these patients were thought to be metastatic, 2 (6%) were suspicious for metastasis, and 9 (26%) had no metastasis. When a lesion-based evaluation was performed, a total of 480 activities were evaluated: increased activity uptake was found in 305 BS, and 427 PSMA expression activity was detected. Furthermore, 435 of these activities were evaluated as metastatic. CONCLUSION: Ga-68 PSMA PET/CT provides an additional contribution to the BS evaluation of activity areas because of the presence of PSMA expression and anatomical lesions. In 6% of the patients, activity on BS and metastatic appearance in CT images were observed and the presence of lesions in the absence of PSMA was determined. This suggests that bone metastases without PSMA expression may also be present.

PET/CT en melanoma cutáneo. Etapificación, control de tratamiento y factores pronósticos asociados / PET / CT in cutaneous melanoma. Staging, treatment control and associated prognostic factors

Introducción: el melanoma representa el 4% de los tumores malignos de la piel, siendo responsable del 80% de las muertes por cáncer de piel. Su incidencia ha ido en ascenso en las últimas décadas, convirtién dose en un problema de salud pública. El PET/CT (Positron Emission Tomography/ComputedTomography) ha demostrado ser útil en la detección de metástasis, con una sensibilidad de 87% y un VPP (valor predictivo positivo) de 90%. El PET/CT puede mostrar resultados inesperados hasta en un 15% de los casos, incluyendo la detección de metástasis,hallazgo que puede modificar el tratamiento. Objetivos: El objetivo deeste estudio es la descripción del compromiso secundario y eventuales asociaciones con la localización del tumor y su profundidad. Metodología: Estudio descriptivo retrospectivo de los PET/CT realizados entremarzo del 2011 y mayo del 2013. Se seleccionaron los casos de melanoma cutáneo, considerando variables demográficas, características del melanoma y metástasis. Resultados: De un total de 1510 PET/CT realizados, 105 exámenes (67 pacientes), correspondieron a casos demelanoma (6,9%). De ellos, el 63% correspondían a hombres. El promedio de edad del grupo fue de 54,8 años (DS 9,9 años)...

Introduction: melanoma represent 4 percent of malignant skin tumors, accounting for 80 percent of deaths from skin cancer. Its incidence has been increasing in recent decades, posing a public health problem. The PET / CT (Positron Emission Tomography/ Computed Tomography) has proven useful in detecting metastases, with a sensitivity of 87percent and a PPV ( positive predictive value) of 90 percent, and may show unexpected results in up to 15 percent of cases that may modify treatment. Objectives: Describe metastases distribution and association with tumour location and depth. Methodology: Retrospective descriptive study of PET / CT performed between March 2011 and May 2013. Cases of cutaneous melanoma were identified, demographic variables, and characteristics of melanoma metastases were extracted from electronic health reports. Results: From a total of 1510 PET / CT performed, 105 exams (67patients) were related to melanoma cases (6.9 percent) . 63 percent of these were male subjects. The average age was 54.8 years (SD =9.9 years)...

Colorectal cancer - patterns of locoregional recurrence and distant metastases as demonstrated by FDG PET / CT.

Colorectal cancer (CRC) can recur locoregionally or at distant sites. Timely diagnosis of recurrence is of paramount importance, as radical treatment of the localized disease can prolong survival. Fluorodeoxyglucose positron emission tomography / computed tomography (PET / CT) is routinely used in restaging and surveillance of colorectal cancer, as it can demonstrate recurrent disease with good accuracy. This article illustrates the spectrum of standard as well as unusual patterns of local recurrence and distant metastases of colorectal cancer.