Multiple Nervous System Involvement of Erdheim-Chester Disease With Responsive Perinephritic Hypermetabolism.

ABSTRACT: A 36-year-old man who was at follow-up for histiocytosis had sudden-onset symptoms of unilateral ophthalmic increased pressure. The patient was referred to the FDG PET/CT for determination of involvement with suspicion of Erdheim-Chester disease. The reduction of the FDG uptake in all of the lesions (medial temporal lobes, nasal septum, medulla spinalis in sacral region, as well as perinephritic infiltrations), which were determined by the first PET/CT, was achieved at second imaging.

Axillary Lymph Nodes in Breast Cancer Patients After COVID-19 Vaccine.

One of the side effects of vaccines used to end the COVID-19 epidemic is non-specifically enlarged axillary lymph nodes. Such lymphadenopathy detected during clinical examination of breast cancer patients may require additional imaging or interventional procedures that should not normally be performed. This study has been designed to estimate the incidence of palpable enlarged axillary lymph node in breast cancer patients who had received COVID-19 vaccination in the past 3 months in the same arm as compared to those without vaccination. Breast cancer patients admitted to M.U. Medical Faculty Breast polyclinic between January 2021 and March 2022 were screened, and clinical staging was performed after thorough clinical examination. Among these patients with suspected enlarged axillary lymph node and those undergoing sentinel lymph node biopsy (SLNB), they were divided into two groups as vaccinated and unvaccinated. Age, menopausal status, tumor size, tumor location, surgery, pathology results, hormonal receptor status, and SLNB results were statistically compared with groups. There was no significant difference between groups in terms of age, menopause, tumor size, tumor location, surgery, pathological results, and hormone receptor status. The SLNB being reported as reactive only was 89.1% in the vaccinated group and 73.2% in the non-vaccinated group which was statistically significant different. Reactive lymph nodes were commonly found with an excess of 16% in patients who had received COVID-19 vaccination in the past 3 months. This required caution and additional examination of the axillary lymph nodes in this period.

The Relationship between Pathological Features and 18 F-FDG PET/CT that Changed the Surgeon's Decision as Neoadjuvant Therapy in Breast Cancer.

Objective Patients diagnosed with breast cancer and decided to undergo surgical treatment can undergo neoadjuvant therapy following their 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) findings. The present study aims to determine the statistical significance of these patients whose treatment plan was changed and the reasons for the change in the plan. Materials and Methods The demographic features and treatment plans of 151 cases who were diagnosed with any stage of breast cancer were evaluated. These patients consist of those who admitted to Mersin University Hospital Breast Outpatient Clinic between January 2016 and December 2019. All of these patients aged between 41 and 85 years were examined with 18 F-FDG PET/CT after the decision for surgical treatment is made. The analysis included tumor pathology, side, type, subtype, size, and centricity in this study. Results About 18.5% ( n = 28) of patients' treatment plan was changed after 18 F-FDG PET/CT. They received neoadjuvant therapy. About 81.5% ( n = 123) of patients did not receive neoadjuvant therapy. Significant differences were observed between patients changed treatment plan and not changed concerning age, lymph node involvement, tumor size, centricity, and subtypes parameters. Conclusion Conventional imaging examinations are used in patients with breast cancer. These examinations may not be sufficient to determine advanced disease requiring neoadjuvant treatment. With 18 F-FDG PET/CT examination, these advanced stage patients are not overlooked. In our study, approximately one in five patients, treatment plan changed after 18 F-FDG PET/CT examination.

Cancers and Benign Processes on 68 Ga PSMA PET-CT Imaging Other than Prostate Cancer.

Background Imaging plays an important role in the evaluation of prostate cancer patients. In recent years, much attention has been focused on gallium 68 prostate-specific membrane antigen positron emission tomography-computed tomography ( 68 Ga PSMA PET-CT) in prostate cancer patients and has been widely used for staging, restaging, and therapy response for these patients. The aim of this study was to report 68 Ga PSMA PET-CT in other cancers and benign processes incidentally detected on 68 Ga PSMA PET-CT in patients with prostate cancer. Materials and Methods A total of 600 68 Ga PSMA PET-CT scans were performed for initial staging, restaging, detection of suspected recurrence, and therapy response in prostate cancer patients between December 2018 and June 2020. A total of 38 patients with histopathologically proven prostate cancer were included in the current study with other malignancies and benign processes. Mainly histopathology in most of cases and clinical and radiological follow-up in few cases after PET/CT scanning served as the standard of reference. Results A total of 38 patients (age range: 52-85 years; mean age: 68.6) with prostate cancer final histopathology results were included in the study. A total of 51 lesion sites were evaluated in 38 patients. Forty-one lesion regions of these 51 regions were based on histopathological diagnosis, whereas 10 of them were based on clinical follow-up and conventional radiological follow-up as differential criteria. Thirty of 51 lesion regions were evaluated as malignant and 21 were benign lesions. The most common 68 Ga PSMA ligand avid malignancy was lung adenocarcinoma (6/38). Conclusions Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein and mainly expressed in prostate epithelium. 68 Ga PSMA PET-CT imaging is very sensitive and specific imaging modality in prostate cancer patients. However, other malignancies and some benign processes may also have 68 Ga PSMA ligand avidity and some prostate cancer metastases may imitate other malignancies.

Diagnostic Performance of 99mTc-Methoxy-Isobuty-Isonitrile (MIBI) for Risk Stratification of Hypofunctioning Thyroid Nodules: A European Multicenter Study.

99mTc-MIBI (MIBI) imaging is able to exclude malignancy of hypofunctioning thyroid nodules (TNs) with high probability but false positive results are frequent due to low specificity. Therefore, pre-test selection of appropriate TNs is crucial. For image evaluation visual and semiquantitative methods (Washout index, WOInd) are used. Aim of this study was to evaluate the diagnostic performance of MIBI imaging in hypofunctioning TNs with indeterminate fine-needle aspiration cytology results in a multicentric European setting. Patients with hypofunctioning TNs, EU-TIRADS 4 or 5, Bethesda III/IV and MIBI imaging were included. For visual evaluation the intensity of MIBI uptake in the TN was compared to normal thyroid tissue. 358 patients with 365 TNs (n = 68 malignant) were included. Planar imaging (SPECT) showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 96% (94%), 21% (22%), 22% (15%), 96% (96%), and 35% (32%). The WOInd (38.9% of all cases, optimal cutoff: -19%) showed a sens 100% (spec 89%, PPV 82%, NPV 100%, ACC 93%). For hypofunctioning TNs at intermediate or high risk with indeterminate cytology, a MIBI negative result on visual evaluation is an effective tool to rule-out thyroid malignancy. The semi-quantitative method could considerably improve overall diagnostic performance of MIBI imaging.

Superscan Appearance of 68Ga PSMA PET/CT in a Patient with Refractory Prostate Cancer.

A 64-year-old male patient with metastatic prostate carcinoma diagnosis received lutetium-177 prostate-specific membrane antigen (PSMA) treatment; however, his disease progressed. Herein, presented the final images of the patient that demonstrated a superscan appearance in the Gallium-68 PSMA positron emission tomography/computed tomography, which is a rare phenomenon.

Perineum and penile invasion of recurrent prostate carcinoma shown by Ga-68 PSMA PET/CT.

Imaging of prostate cancer has recently had new modalities. Ga-68 Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) has gained important diagnostic role in the management of the patients with prostate cancer. Patients with progressively elevated serum prostate specific antigen (PSA) level may be evaluated by Ga-68 PSMA PET/CT imaging. This case report presents a seventy five year old man with diagnosis of prostate cancer and progressive serum PSA increase. Local recurrence of the tumor as well as spread to the penis, perineum and skeleton was determined by Ga-68 PSMA imaging. This case illustrates that Ga-68 PSMA imaging may show unexpected sites of disease spread.

Metabolic Characterization of Anterior Mediastinal Masses by 18F-FDG PET/CT

Objectives: To evaluate the role of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the diagnosis of anterior mediastinal masses. Methods: The oncological 18F-FDG PET/CT images of 41 patients (17 women, 24 men; age: 16-83 years, mean age: 50.5±19.5 years) who attended the nuclear medicine department between November 2016 and September 2017 were retrospectively evaluated for the metabolic characterization of their anterior mediastinal masses. Results: Based on our results, the lesions of 4 patients were benign [maximum standard uptake value (SUVmax) <3] and that of 2 patients were non-tumoral (i.e., tuberculosis and sarcoidosis). The mean dimensions and the SUVmax levels of the malignant lesions were 6.4±3.7 cm and 11.9±9.6, respectively. The pathological results for the malign tumors were thymus tumors (n=8), lymphoma (n=8), lung cancer (n=11), carcinoid metastasis (n=2), thyroid carcinoma (n=2), germ cell carcinoma (n=1), schwannoma (n=1), and sarcoma (n=1). The degree of 18F-FDG accumulation could precisely identify the malign and benign tumors. Conclusion: Thus, contrary to the known causes, it is possible that anterior mediastinal masses originate from structures other than the anterior mediastinal structures. In this study, the lymphoma and lung carcinoma pathology were more frequent than thymic lesions.

Bone marrow involvement in pediatric malignancies: a comparison study of Positron emission tomographycomputed tomography and bone marrow biopsy.

BACKGROUND AND OBJECTIVES: The comparison of Positron emission tomography- computed tomography (PETCT) and bone marrow biopsy (BMB) modalities in detecting bone marrow disease is an up to date research topic. In this study, we aimed to compare the results of PET-CT and BMB procedures in detecting bone marrow involvement in pediatric malignancies. METHOD: At the time of diagnosis, PET-CT imaging and BMB performed patients` data were evaluated, retrospectively. Malign diagnoses were Hodgkin's lymphoma in 23 (30.7%), non-Hodgkin's lymphoma in 20 (26.7%), neuroblastoma in 11 (14.7%), Ewing sarcoma in 10 (13.7%), Langerhans cell histiocytosis in 6 (8%), and rhabdomyosarcoma in 5 (6.6%) patients. RESULTS: Bone marrow involvement was detected in 39 (52%) of 75 patients. Bone marrow involvement was identified by both PET-CT and BMB in 18 (46.1%) patients, by only PET-CT in 12 (30.7%) patients, by only BMB in 9 (23%) patients. The sensitivity of PET-CT was 66%, specificity was 75%, positive predictive value was 60%, and negative predictive value was 80%. Sensitivity, spesificity, positive and negative predictive values of PETCT were different in before mentioned malignancy groups. CONCLUSION: PET-CT may not have high sensitivity and specificity to identify bone marrow involvement for each type of cancer. The approach of using bone marrow biopsy and PET-CT as complementary modalities seems reliable.

Amyloidosis Associated Kidney Failure with Gross Hypermetabolic Intra-abdominal Mass

A 23-year-old male patient who presented with impaired kidney function tests attended to hospital for hemodialysis and underwent 18F-FDG positron emission tomography/computed tomography (PET/CT) examination for the metabolic characterization of the intra-abdominal mass which was found in the ultrasonography. 18F-FDG PET/CT revealed a mass lesion adjacent to the liver which was hypermetabolic and the pathology of the lesion was determined as amyloidosis. To the best of our knowledge, the case with 18F-FDG PET/CT images of a huge amyloid mass is the first in the literature.