Tumor Microenvironment Features as Predictive Biomarkers in Metastatic Differentiated Thyroid Cancer and Their Relationship With 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) Metabolic Parameters.

OBJECTIVE: The role of the tumor microenvironment in tumor progression and treatment response is being investigated for different types of cancer. This study aimed to determine the relationships between tumor microenvironment, histopathology, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)-based metabolic parameters, treatment response, and overall survival (OS) in metastatic differentiated thyroid cancer (DTC).  Methods: Metastatic DTC patients who underwent 18F-FDG PET/CT between 2015-2019 were evaluated. Clinicopathological, histopathological features and PET/CT parameters of patients were recorded. Microenvironmental characteristics of the primary tumor, such as mitosis, intratumoral and peritumoral lymphocytosis, intratumoral and peritumoral fibrosis, were evaluated from the tissue samples. The relationships between these factors were statistically analyzed. RESULTS:  Sixty-five patients (38 females, 27 males, age: 49±15 years) were included. Mitosis, intra/peritumoral lymphocytosis, and intra/peritumoral fibrosis were frequent; however, none of them had a statistically significant association with PET-positive metastases, treatment response, or OS. Univariate analysis showed that gender, size, thyroglobulin values, residual thyroid tissue, PET-positive metastases, and maximum standardized uptake value (SUVmax) were significant predictors of OS. At multivariate analysis, PET-positive metastases (HR=-2.65, 95%CI 0.007-0.707, p=0.024) and SUVmax (HR=-2.74, 95%CI 0.006-0.687, p=0.023) were the only independent predictors for OS.  Conclusion: Our study revealed that microenvironmental characteristics of the primary tumor did not show prognostic significance in metastatic DTC. PET-positive metastases and SUVmax levels were the only significant factors that predicted overall survival in DTC. Supporting the results of our study with further studies with a larger sample size may be necessary to determine the relationship between the tumor microenvironment and prognosis in DTC.

Assessment of three different radioiodine doses for ablation therapy of thyroid remnants: Efficiency, complications and patient comfort.

I-131 radioiodine (RAI) ablation removes postoperative residual tissue and facilitates follow-up in low- and intermediate-risk differentiated thyroid cancer (DTC). Although low doses have been reported to be as effective as higher doses for ablation, the doses administered still vary depending on the patient and the practitioner. We aimed to evaluate the ablation efficiency, complications, and length of stay (LOS) of patients with DTC treated with 3 different doses for ablation. Patients with DTC who received RAI therapy were retrospectively reviewed. One hundred thirty patients with low-intermediate-risk, according to American Thyroid Association classification, without known lymph nodes or distant metastases were included. Patients were divided into 3 groups as 30 to 50 mCi, 75 mCi, and 100 mCi. Residue thyroid and salivary glands were evaluated from 9 to 12 months post-RAI I-131 scans. No significant difference was found between groups regarding ablation success (P = .795). In multivariable analyses, pretreatment thyroglobulin (hazard ratio = 0.8, 95% confidence interval 0.601-0.952, P = .017) and anti- thyroglobulin antibody (hazard ratio = 1.0, 95% confidence interval 0.967-0.998, P = .024) were 2 independent predictors of ablation success. The mean LOS was 2.1 ±â€…0.3, 2.6 ±â€…0.6, and 2.9 ±â€…0.4 days, respectively, (P = .001). LOS rates of ≥ 3 days were 13.2%, 54.3%, and 84.8%, respectively. Mild decreases in hemoglobin, white blood cell (WBC), and platelet counts were observed in all groups after 6 weeks without any clinically significant findings. A lower rate of change in WBC counts was observed in the 30 to 50 mCi group compared to others. There was no dose-dependent difference regarding the early complaints questioned. Ablation with 30 to 50 mCi provides benefits such as shorter LOS, better patient comfort, less salivary gland dysfunction, and less WBC suppression, thus reducing costs without decreasing efficacy.

Radionuclide Therapy Videos on YouTube as An Educational Material: Has the COVID-19 Pandemic Changed the Quality, Usefulness, and Interaction Features.

Introduction: Current treatment approach aims to achieve greater efficacy with fewer side effects, by targeted cancer therapy as much as possible. Radionuclide therapy is a modality that uses cancer theranostics and is increasingly applied for various cancers as a targeted therapy. YouTube is a preferred tool for obtaining medical information from the internet. This study aims to determine the content quality, level of interaction and usefulness as education material of radionuclide therapy YouTube videos and to reveal the impact of the COVID-19 process on these parameters. Materials and Methods: The keywords were searched on YouTube on August 25, 2018, and May 10, 2021. After removing duplicate and excluded videos, all remaining videos were scored and coded. Results: Majority of the videos were useful educational material. Most of them were high quality. Popularity markers were unrelated to quality level. After COVID, the power index of videos with high JAMA scores increased. The COVID-19 pandemic did not have a negative effect on video features; the quality of the content increased even more after the pandemic. Conclusion: Radionuclide therapy YouTube videos have high-quality content and provide useful education material. The popularity is independent of the content quality. During the pandemic, video quality and usefulness characteristics did not change, while the visibility is increased. We consider YouTube to be an appropriate educational material for patients and healthcare professionals to gain basic knowledge of radionuclide therapy. The Covid-19 pandemic highlighted the power of radionuclide therapy YouTube videos as an educational material.

68Ga-PSMA-I&T-PET/CT interobserver and intraobserver agreement for prostate cancer: a lesion based and subregional comparison study among observers with different levels of experience.

OBJECTIVE: 68Ga-PSMA-PET/CT is a relatively new technique, that is rapidly becoming widespread. We aimed to contribute interobserver-intraobserver agreement of 68Ga-PSMA-PET/CT, among low/high-experienced interpreters. METHODS: 68Ga-PSMA-PET/CT of 56 patients with prostate cancer were evaluated blindly by four observers. Visual interpretation of malignant disease and SUVmax for lymph node (LN) regions, local tumor, bones and visceral organs were recorded. Cohen's Kappa and Fleiss' Kappa analyses were used to measure agreement between low/high/all-experienced observers. Variations were compared for regions, and the effect of prostate-specific antigen or Gleason score on the results was investigated. RESULTS: Interobserver agreement was almost perfect for all LN regions (LN1 low-experienced κ: 0.84/0.84, high-experienced 0.89/0.96; LN2 low-experienced κ: 0.88/0.79, high-experienced 0.95/0.95; LN3 low-experienced κ: 0.84/0.89, high-experienced 0.87/0.94, first/second readings, respectively) and bone lesions (low-experienced κ: 0.88/0.88, high-experienced 0.92/0.92, first/second readings, respectively). For local tumor, interobserver agreement was substantially-almost perfect among a high-experienced group (κ: 0.74/0.89, first/second readings, respectively), and was moderate-substantial among a low-experienced group (κ: 0.62/0.56, first/second readings, respectively). Intraobserver agreement was almost perfect for three observers for all regions and substantial for the observer with the lowest experience in LN3, local and visceral lesions (κ: 0.74/0.79/0.62, respectively). CONCLUSION: Interpretation of prostate-specific membrane antigen (PSMA) for prostate cancer is acceptably consistent among observers, but some details are noteworthy. The evaluation should be done more algorithmically for local tumors, since all observers showed relatively lower agreement. The agreement increased as prostate-specific antigen and Gleason score increased. The observer with PSMA experience <30 readings showed lower reliability, distinct from the others. This indicates that although a reader may be familiar with other PET agents, a more consistent interpretation of 68Ga-PSMA-PET/CT requires training with a small number of identified cases.

The Diagnostic Contribution of SPECT/CT Imaging in the Assessment of Gastrointestinal Bleeding: Especially for Previously Operated Patients.

OBJECTIVES: Gastrointestinal bleeding (GIB) is a life-threatening problem that requires a multidisciplinary approach for successful treatment. This study aims to emphasize the clinical contribution of single photon emission computed tomography/computed tomography (SPECT/CT) for the diagnosis of acute bleeding. METHODS: All 14 patients referred to the nuclear medicine department in 3 years with suspicion of acute GIB were evaluated retrospectively. Clinical records were analyzed to assess the scintigraphic findings, emphasizing the correlative contribution of the CT portion on SPECT/CT studies. RESULTS: Five patients were negative on dynamic and static planar images. SPECT/CT was performed in 9 patients who had positive findings on planar imaging. SPECT/CT could identify the same bleeding site originating from the anastomosis in four patients with a history of abdominal surgery. SPECT/CT confirmed bleeding from the cecum in a patient with cervical cancer. SPECT/CT showed the bleeding focus in the bladder neck of a patient with bladder cancer and the bleeding from peritoneal metastases of a patient with gastric cancer. In 1 patient, the right upper quadrant activity accumulation, which may cause false positives, was found to be the gallbladder on SPECT/CT. Delayed images showed the true bleeding focus in the cecum. In 1 patient, suspicious activity accumulation in the midline of the abdomen was found to be due to a previously unknown aortic aneurysm on SPECT/CT. CONCLUSION: SPECT/CT imaging is a feasible technique to facilitate image interpretation in patients with GIB. SPECT/CT imaging can guide the surgeon through more accurate localization. Therefore, for proper patient management, SPECT/CT should be applied to detect the bleeding focus, if present, especially in patients who had undergone a previous operation.

Infection of cardiac prosthetic valves and implantable electronic devices: early diagnosis and treatment.

There has been a recent rise in the use of implantable cardiac devices, mostly valves but also electronic ones, such as pacemakers, and implantable defibrillators. The increasing use of these devices had as a consequence the raised incidence of endocarditis, an infrequent but morbid complication of these procedures. Thus, early diagnosis of the implantable cardiac devices related infection and endocarditis became pivotal for appropriate management. For diagnostic purposes, the modified Duke criteria are widely used, which are based on clinical and imaging findings, in addition to serological analyses and blood cultures. 18F-fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a recently employed method in order to improve the early diagnosis of endocarditis as well as infection of the implantable device. It is likely, that combining the modified Duke criteria with the FDG PET/CT, will increase the sensitivity and specificity of diagnosis and will guide the treating physician to an early and appropriate management.

Sarcopenia in Hodgkin's lymphoma evaluated with 18-FDG PET/CT, focus on age, performance, and treatment.

Sarcopenia is defined as a progressive and generalized muscle disorder associated with certain physiological and pathological conditions. We aimed to evaluate the prevalence of sarcopenia in patients with HL using 18-fluoro deoxyglucose (FDG) PET/CT, which would provide a data of muscle mass with the CT compartment and also data of muscle metabolism with the 18-FDG compartment of the imaging modality. Fifty-nine patients diagnosed with HL were included in the study. PET/CT images before and after treatment were evaluated with regard to lumbar muscle mass and metabolism. Mean lumbar muscle evaluation with CT before treatment was 92, 40 HU, and after treatment was 89, 41 HU. Mean metabolic tumor volume (MTV) evaluated with FDG PET before treatment was 4, 13 mm3 while after treatment was 4, 10 mm3. The lumbar muscle mass in terms of HU which was evaluated with CT was observed to be decreased after treatment. Likewise, the metabolic evaluation was observed to be also decreased after treatment. Despite the decline in muscle mass after treatment in the whole group, this decline was particularly observed in the better initial performance group. In patients with BMI > 32, there was a significant decline in muscle mass. Abdominal nodal involvement was related with poorer muscle mass and quality. In HL care, particular attention should be given to patients who are younger and with better physical condition in terms of preserving the muscle reserves and preventing sarcopenia.

Experimental Breast Cancer Models: Preclinical Imaging Perspective.

BACKGROUND: Breast cancer is the leading cause of cancer in women. 13% of breast cancer patients are at a distant stage and mortality is due to metastases rather than primary disease. The unique genetic structure and natural process of breast cancer make it a very suitable area for targeted therapies. Experimental tumor models are validated methods to examine the pathogenesis of cancer, the onset of the neoplastic process and progression. OBJECTIVE: This study aims to review the current literature on experimental breast cancer models and to bring a new perspective to the use of these models in teranostic preclinical studies in terms of the imaging. METHODS: Search for relevant literature from academic databases using keywords (Breast cancer, theranostic, preclinical imaging, tumor models, animal study, and tailored therapy) was conducted. The full text of the articles was reached and reviewed. Current scientific data has been reevaluated and compiled according to subtitles. RESULTS AND CONCLUSION: The development of animal models for breast cancer research has been done in the last century. Imaging methods used in breast cancer are used for tumor localization, quantification of tumor mass, imaging of genes and proteins, evaluation of tumor microenvironment, evaluation of tumor cell proliferation and metabolism and treatment response evaluation. Since human breast cancer is a heterogeneous group of diseases in terms of genetics and phenotype; it is not possible for a single model to adequately address all aspects of breast cancer biology. Considering that each model has advantages and disadvantages, the most suitable model should be chosen to verify the thesis of the study.

GM-CSF and IL-33 Orchestrate Polynucleation and Polyploidy of Resident Murine Alveolar Macrophages in a Murine Model of Allergic Asthma.

Allergic asthma is a chronical pulmonary disease with high prevalence. It manifests as a maladaptive immune response to common airborne allergens and is characterized by airway hyperresponsiveness, eosinophilia, type 2 cytokine-associated inflammation, and mucus overproduction. Alveolar macrophages (AMs), although contributing to lung homeostasis and tolerance to allergens at steady state, have attracted less attention compared to professional antigen-presenting and adaptive immune cells in their contributions. Using an acute model of house dust mite-driven allergic asthma in mice, we showed that a fraction of resident tissue-associated AMs, while polarizing to the alternatively activated M2 phenotype, exhibited signs of polynucleation and polyploidy. Mechanistically, in vitro assays showed that only Granulocyte-Macrophage Colony Stimulating Factor and interleukins IL-13 and IL-33, but not IL-4 or IL-5, participate in the establishment of this phenotype, which resulted from division defects and not cell-cell fusion as shown by microscopy. Intriguingly, mRNA analysis of AMs isolated from allergic asthmatic lungs failed to show changes in the expression of genes involved in DNA damage control except for MafB. Altogether, our data support the idea that upon allergic inflammation, AMs undergo DNA damage-induced stresses, which may provide new unconventional therapeutical approaches to treat allergic asthma.

Evaluation of Sarcopenia with F-18 FDG PET/CT and relation with disease outcomes in patients with multiple myeloma.

INTRODUCTION: Multiple myeloma (MM) is a potentially incurable haematological malignancy with devastating manifestations including lytic bone lesions leading to fractures and renal insufficiency. As a disease of patients with a mean age of 66 years, both the disease and the continuous efforts of treatments lead to frailty and devastation. From this stand point, we aimed to evaluate the development of muscle loss in MM patients and also with a new method of sarcopenia evaluation, F-18 FDG PET/CT. While used for bone disease routinely, this method brings a fresh perspective of metabolic quantitation of alteration of muscles which may be regarded as muscle quality. MATERIALS AND METHODS: Data and images of 105 patients with MM both before and after treatment were evaluated in a retrospective manner. RESULTS: Both female and male patients were observed to be effected after MM treatment in terms of lumbar and femoral muscle evaluations with CT. Metabolic evaluations confirmed a loss of quality in muscles in terms of metabolic volume and total lesion glycolysis. CONCLUSION: Sarcopenia should be evaluated in every patient and regarded as a treatment target. FDG PET/CT is an easy and handy tool to assess muscle mass and quality as well as MM disease status.

The relationship between FDG PET/CT-defined metabolic parameters and the histopathological subtype of oesophageal carcinomas.

PURPOSE: 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) combined with computed tomography (CT) scan is accepted as a standard tool in the staging of oesophageal cancer (OC). Histological subtype of tumour is known to be a major determinant of prognosis and metabolic behaviour. In this study, we aimed to evaluate the effect of histological subtypes of OC on standard uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) obtained by PET/CT, and also to compare this effect with prognosis. MATERIAL AND METHODS: Images and clinical course data of 57 patients who were diagnosed with EC and treated in our hospital between 2009 and 2016 were evaluated in a retrospective manner. PET/CT images were re-analysed in terms of metabolic parameters, and observations were compared with histological subtypes. RESULTS: No significant difference was observed between histological subtypes with SUVmax, overall survival (OS), or progression-free survival (PFS). Thus, MTV was observed to be related with histological subtype; MTV values of adenocancer patients were significantly higher than those of squamous cell cancer patients. CONCLUSIONS: Metabolic tumour volume was related with histological subtype of OC, but clinical staging, TLG, and SUVmax values were not related with histological subtype, which may suggest the use of MTV as a routine parameter for OC and inclusion of MTV observations in prognostic scoring.

18F-NaF PET/CT and Extraordinary Involvement: Non-calcific Brain Involvement in a Prostate Cancer Case

With the increase in the diagnosis of the cancer, the frequency of using imaging methods for diagnosis and for staging is also increased. Because of the complex structure of cancer and tumor behavior, the assessment methods have been updated and metabolic imaging has gained weight. The most popular of these techniques is hybrid positron emission tomography/computed tomography (PET/CT) systems. Prostate cancer is the second most common cancer in the world, is the fifth common type in cancer-related male deaths. Estimation of prognosis and treatment planning of the patients are based on the TNM classification. Bone metastasis is a prognostic factor of morbidity and mortality in prostate cancer. Sodium fluoride (NaF) PET/CT is a promising imaging modality in evaluation of skeletal system. This article will review the involvement of 18F-NaF in extra-osseous tissues in the prostate cancer and reveal the fundamental differences between 18F-NaF imaging and 18F-FDG imaging in these areas.

Intrathoracic toxic thyroid nodule causing hyperthyroidism with a multinodular normal functional cervical thyroid gland.

Radionuclide scintigraphy with I-131 and Tc-99m pertechnetate ((99)mTc04) has been widely used in detecting toxic nodules. Intrathoracic goiter usually presents as an anterior mediastinal mass. Mostly the connection between intrathoracic mass and the cervical thyroid gland is clearly and easily identified occurring as a result of inferior extension of thyroid tissue in the neck, which is called as secondary intrathoracic goiter. Completely separated, aberrant or in other words primary intrathoracic goiters arise as a result of abnormal embryologic migration of ectopic thyroid closely associated with aortic sac and descend into the mediastinum. Intrathoracic goiters are generally nontoxic nodules existing with mass effect without causing hyperthyroidism. However, mostly reported cases had enlarged thyroid glands in the neck. This report demonstrates the usefulness of I-131 and (99)mTc04 scintigraphy for detecting intrathoracic goiter causing hyperthyroidism with a normal functioned cervical thyroid gland.