FAPI Uptake in Gallbladder Is It Normal Biodistribution?

ABSTRACT: Radiolabeled fibroblast activation protein inhibitors (FAPIs) have been extensively used in different types of cancers, although not yet FDA approved. Normal patterns of FAPI biodistribution have been investigated, and it is known that FAPI is expressed in nonmalignant pathophysiological lesions, characterized by tissue remodeling such as atherosclerosis, arthritis, and scar/fibrotic tissues. In this interesting image, we are presenting the accumulation of 68 Ga-FAPI in the gallbladder. This finding could be related to a normal distribution of the radiotracer as a physiologic finding. This is a potentially important finding as FAPI may be used as theragnostic agent in the future.

Interesting Manifestation of Autoimmune Encephalitis on FDG PET Scan.

ABSTRACT: We are presenting a 22-year-old man with intractable seizures. Autoimmune epilepsy, vasculitis, and paraneoplastic disorder were among initial differential diagnoses. His initial laboratory tests and toxicology screen were unremarkable. His initial brain MRI demonstrated generalized cortical atrophy. Features such as progressive encephalopathy, neuropsychiatric symptoms, personality change, and autonomic dysfunction were in favor of autoimmune encephalitis. Autoantibody evaluations including anti-NMDA receptor (NR1) IgG were negative in both serum and CSF samples. FDG PET scan demonstrated intense FDG uptake in the basal ganglia, more prominent in the caudate nuclei and putamina, which is one of the known autoimmune encephalitis imaging features.

Clinical Significance of Quantitative FDG PET/CT Parameters in Non-Small Cell Lung Cancer Patients.

BACKGROUND: An initial evaluation of non-small cell lung cancer (NSCLC) patients with 18F- fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan can modify treatment planning. We investigated the clinical significance of FDG PET/CT quantitative parameters (QPs) in NSCLC patients. MATERIALS AND METHODS: We included 125 NSCLC patients for initial staging FDG PET/CT scan. The primary tumor (T), regional lymph node metastases (N), and distant metastases (M) were evaluated on FDG PET/CT images. QPs, including standard uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated separately for each T, N, and M lesion and also for the whole body. Statistical analysis through SPSS version 22 was used to evaluate the clinical significance of PET/CT QPs concerning primary tumor pathology characteristics, initial tumor stage, and patient's prognosis. RESULTS: We followed the patients for 19.28 (±11.42) months. Considering primary tumor pathology, there was a significant difference in FDG PET/CT QPs, including primary tumor SUVmax (p=0.00), metastases SUVmax (p=0.014), whole-body MTV (p=0.045), and whole-body TLG (p=0.002). There was also a significant difference in QPs, including primary tumor SUVmax (p=0.00) and regional lymph node metastases SUVmax (p=0.048) when accounting for tumor initial stage. There was a significant prognostic value for the whole-body TLG (p=0.01) and a cut-off point of 568 was reached to differentiate better versus worse survival outcome. CONCLUSION: We demonstrated a statistically significant difference in FDG PET/CT QPs when accounting for primary NSCLC pathology characteristics and initial stage, as well as patient's prognosis, and recommend incorporating QP values into clinical PET/CT reports.

Spirometry, cardiopulmonary exercise testing and the six-minute walk test results in sarcoidosis patients.

Background: The 6-minute walking test, cardiopulmonary exercise testing, and spirometry are useful tools for evaluation of respiratory impairment and functional capacity in patients with lung disease. Sarcoidosis is a multisystem granulomatous disease of unknown etiology. Objectives: Since the pulmonary involvement can affect the quality of life in sarcoidosis patients, this study is aimed to evaluate the tests mentioned above in order to examine the functional capacity of sarcoidosis patients in different stages as well as the cause of exercise intolerance. Methods: This cross-sectional study was carried out on 50 Iranian patients with sarcoidosis. Patients were classified into three groups based on the findings of the chest radiography as well as the pulmonary CT scan, reported by an expert radiologist. Pulmonary, cardiac, and activity function have been evaluated in the patients, using cardiopulmonary exercise testing, the 6-minutes walking test, and spirometry. Results: In cardiopulmonary exercise testing, percent-predicted peak VO2 (57.75±15.49, p=0.015) and percent-predicted O2 pulse (70.54±17.37, p=0.013) were significantly lower in the third group, in comparison with the others. Also, VE/CO2 (AT) (34.99±5.67, p=0.000) was significantly higher in the third group, in comparison with the other ones. Percent-predicted VO2 showed a strong positive correlation with age (r=0.377, p=0.009), TSH (r= 0.404, p=0.007), and percent-predicted FVC (r=0.443, p=0.002). In addition, O2 pulse had a positive correlation with BMI (r=0.324, p=0.026), percent-predicted FVC (r=0.557, p= 0.000), and percent-predicted FEV1 (r=0.316, p=0.032). Conclusions: According to this study, ventilatory limitation, pulmonary involvement, and deconditioning are the main causes of activity limitations in sarcoidosis patients.

Mantle cell lymphoma presenting as bilateral adrenal huge masses.

We present a middle-aged woman complaining of weakness, lethargy and weight loss for 6 months. Positron emission tomography (PET)/CT scan revealed huge bilateral adrenal masses with intense 18F-fluorodeoxyglucose avidity. Biopsy and immunohistochemical staining were compatible with mantle cell lymphoma (MCL). The patient received six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) followed by four cycles of intrathechal methotrexate chemotherapy. Bone marrow aspiration biopsy was performed for initial staging and also before bone marrow transplantation. Follow-up PET/CT scan after completion of chemotherapy and before bone marrow transplantation demonstrated complete metabolic response with no evidence of abnormal metabolic activity in either adrenal gland or bone marrow. MCL has an aggressive nature and is usually considered incurable; however, there have been a few reports indicating favourable treatment response when MCL is rarely arising from the adrenal glands. Dramatic response of a primary adrenal MCL to R-CHOP is documented in this case.

Hypermetabolic Thyroid Incidentaloma on Positron Emission Tomography: Review of Laboratory, Radiologic, and Pathologic Characteristics.

INTRODUCTION: Incidental hypermetabolic thyroid lesions on Positron Emission Tomography have significant clinical value and may harbor malignancy. In this study we evaluated laboratory, radiologic, and pathologic characteristics of incidental hypermetabolic thyroid lesions. MATERIALS AND METHODS: We evaluated 18 patients prospectively with various malignancies and hypermetabolic thyroid incidentaloma. The thyroid function tests, ultrasound assessment, and guided FNA biopsy were performed on all cases. RESULTS: We included 9 male and 9 female patients with mean age of 51 years. Most common malignancy was colon cancer. Metabolic activity quantification using maximum standard uptake value demonstrated range between 1.4 and 65.4 with mean value of 9.4. We found highest metabolic activity in patients with lung adenocarcinoma, B-cell lymphoma, and colon adenocarcinoma. On ultrasound exam most thyroid lesions were of solid, hypoechoic, noncalcified nature with either normal or peripheral increased vascularity. FNA biopsy report was benign in 15 cases and malignant or highly suggestive for malignancy in 3 other cases. Two of the three malignant cases demonstrated metabolic activity higher than average SUV max. CONCLUSION: Most thyroid hypermetabolic incidentalomas are benign lesions, while higher values of SUV max are in favor of malignancy. This mandates further evaluation of incidentally found thyroid hypermetabolic lesions on routine PET/CT scans.

Role of FDG PET/CT Scan in Head and Neck Cancer Patients.

INTRODUCTION: PET/CT scan has an emerging role in head and neck oncology with a few well-established indications, including: detection of unknown primary tumor site, tumor staging, radiotherapy planning, treatment response assessment and detection of recurrent disease. The purpose of this study is reporting PET/CT findings in head and neck cancer patients to emphasize its role in head and neck oncology. MATERIALS AND METHODS: In a retrospective study, we reviewed our PET/CT database and found 94 patients with primary head and neck cancer. This is a descriptive report of PET/CT scan findings in head and neck cancer patients referred to Masih Daneshvari hospital, Tehran, Iran between 2013 and 2016. RESULTS: The most common primary tumor sites were oral cavity (27%) and nasopharynx (22%). The most common indication for referral was tumor restaging (76%) including treatment response evaluation and differentiation between recurrence and post-treatment fibrosis. In 60% of patients with negative primary tumor site, PET/CT was able to detect evidence of regional or distant metastasis. PET/CT was able to localize the primary tumor site in 66% of patients with unknown primary tumor site. We also had 19 patients with primary head and neck cancer referred for initial staging, demonstrating evidence of metastasis in 66% of all cases. CONCLUSION: Most patients are referred for restaging and demonstrate evidence of regional or distant metastasis with significant value for further treatment planning. Providing insurance coverage and familiarizing referring physicians about correct indications of this relatively new diagnostic modality will be to the best interest of head and neck cancer patients in the long run.

Synovial Sarcoma of the Esophagus: A Case Report and Review of Literature.

Synovial sarcoma is an uncommon soft tissue tumor occurring mainly in the periarticular region of the extremities in young adults. It happens less frequently in the head and neck, mediastinum, lungs, heart, and digestive tract. A 28-year-old man two months after total esophagectomy with final diagnosis of esophageal synovial sarcoma was referred to our Positron Emission Tomography (PET-CT) department for the evaluation of treatment response and further treatment planning. To our knowledge this case is the 11th case of esophageal synovial sarcoma, being reported in the literature. We presented the 11th case of esophageal synovial sarcoma. Synovial sarcomas are very rare tumor entities, particularly in the gastrointestinal tract and are likely to be mistaken with other more common tumors such as gastrointestinal stromal tumors.

Malignant Mesothelioma Versus Metastatic Carcinoma of the Pleura: A CT Challenge.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare malignant neoplasm of the pleura that typically affects individuals occupationally exposed to asbestos through a variety of industries. MPM presents with several CT features similar to more common pleural diseases such as metastatic pleural malignancy. OBJECTIVES: The aim of this study is to differentiate malignant pleural mesothelioma from metastatic carcinoma of the pleura by pathological and radiological assessment in order to investigate accuracy of CT scan in this regard and to compare CT features of these two malignancies. PATIENTS AND METHODS: Chest CT scans of 55 pleural malignancy patients including MPM and metastatic pleural malignancy were evaluated in this retrospective study. The pathologist made the definite diagnosis based on immunohistochemistry. A chest radiologist unaware of the pathology diagnosis observed all CT scans. Several parameters including pleural thickening, pleural effusion, thickening of inter lobar fissure, contralateral extension, contraction of involved hemithorax, parenchymal involvement (infiltration, nodules, fibrosis), pleural mediastinal involvement, lymphadenopathy, extrapleural invasion (hepatic, chest wall, diaphragm, intraperitoneal), and pericardial involvement were checked. Data analysis was carried out using SPSS version 16, and the ability of CT scan to differentiate malignant pleural mesothelioma and metastatic pleural diseases was investigated. RESULTS: Totally 29 males and 26 females were assessed in this study. Based on pathology, 17 MPM and 38 metastatic pleural malignancies were diagnosed. According to CT study, about 82% of the patients with MPM and about 79% of the patients with metastatic pleural diseases were correctly diagnosed by a radiologist. The most common findings suggestive of MPM were pleural thickening (88.2%), loculated effusion (58.8%), and thickening of the interlobar fissure (47.1%). Whereas free pleural effusion (71.7%), parenchymal infiltration (65.8%) and pleural thickening (63.2%) were most prevalent parameters among metastatic cases. CONCLUSION: CT scan is highly accurate in differentiating malignant pleural mesothelioma and metastatic pleural diseases. Pleural thickening and thickening of interlobar fissure lead us to the diagnosis of MPM and massive free pleural effusion is more commonly seen in metastatic pleural malignancy.

Radiographic manifestations of Tuberculosis in HIV positive patients: Correlation with CD4+ T-cell count.

BACKGROUND: Observations on Tuberculosis/HIV co-infection in addition to epidemiologic molecular studies have recently provided strong evidence for the state of immune system as the major determinant of the TB imaging spectrum. However, the presence of any correlation between radiographic findings and the degree of immunosuppression in HIV+ patients still remains controversial. The present study aimed to investigate the TB radiographic manifestation in HIV+ patients and its relationship to the CD4 cell count. METHOD AND MATERIAL: Chest radiography of 15 HIV+ patients with a definite diagnosis of pulmonary Tuberculosis in Masih Daneshvari Hospital, between 2013 and 2014, were retrospectively reviewed. Radiographic findings and severity were categorized as typical (upper lobe infiltration/cavity) and atypical (middle/lower lobe opacity, adenopathy, pleural effusion and normal X-ray). Demographics and CD4+ cell count were also recorded. Data analysis was performed using SPSS version 23 (frequency and mean for descriptive quantitative variables and Logistic regression analysis for correlation, p<0.05). RESULTS: Of a total 15 patients (86.7% men and 13.3% women), 78.6% had CD4+ counts <350 (mean±SD; 229.15±199.45). The most common radiographic findings in descending order of frequency were adenopathy (53.3%), pleural effusion (26.7%) and cavitation (6.7%) with an overall atypical presentation of 93.3%. This study failed to reveal any statistically significant correlation between CD4+ cell count and radiographic manifestation as well as severity. CONCLUSION: In CD4+ cell count <500, the dominant radiographic pattern of Tuberculosis is atypical presentation. At this level of immunity, CD4+ T cell dysfunction may play a deterministic role in TB radiographic manifestation.

Comparison of clinicoradiologic manifestation of nonspecific interstitial pneumonia and usual interstitial pneumonia/idiopathic pulmonary fibrosis: a report from NRITLD.

BACKGROUND: Ever since Katzenstein and Fiorelli introduced the term nonspecific interstitial pneumonia (NSIP) to denote those cases of interstitial pneumonia that cannot be categorized as any of the other types of idiopathic interstitial pneumonias (IIP), there has been continuing debate on whether it is a real clinical entity or not. The American Thoracic Society/European Respiratory Symposium task group tried to identify idiopathic NSIP as a separate disease and exclude it from the category of IIP. However, it appears that the clinical presentation of NSIP and usual interstitial pneumonia (UIP) are the same. OBJECTIVE: To show that the radiologic features of NSIP and UIP should be relied upon, instead of clinical presentation and pathologic findings, to differentiate between the two. MATERIALS AND METHODS: Consecutive patients who had received a diagnosis of either NSIP or UIP on the basis of open lung biopsy between January 2001 and December 2007 were identified for inclusion in this retrospective review. The study included 61 subjects: 32 men and 29 women with a mean age of 59.39 +/- 14.5 years. Chest computed tomography images of all the cases were collected for a review. High resolution computed tomography (HRCT) and all pathologic specimens were also evaluated. A weighted kappa coefficient was used to evaluate whether radiology can be used instead of biopsy for the diagnosis of NSIP and UIP. Comparison of the mean ages and the time intervals (i.e., interval between symptom onset and the time of diagnosis) in the UIP and NSIP groups was done using the Mann-Whitney U test. Association between gender and biopsy result was evaluated by the Fisher exact test. Data were evaluated using SPSS, v.13. RESULTS: Sixty-one patients were included in this study, 32 were male and 29 were female. On the basis of biopsy findings, 50 (82%) patients had UIP and 11 (18%) had NSIP. Thirty (60%) of the 50 patients who had UIP were male and 20 (40%) were female; 2 (18.2%) of the 11 patients who suffered from NSIP were male and 9 (81.8%) were female. Based on HRCT findings, 36 (60%) patients were diagnosed to have UIP and 24 (40%) were diagnosed with NSIP. When diagnosis was based on biopsy findings, the time interval in the UIP group was 13.59 +/- 8.29 months and in the NSIP group it was 7.90 +/- 4.18 months. When diagnosed on the basis of HRCT findings, the time interval in the UIP group was 14.22 +/- 8.94 months and in the NSIP group it was 10.54 +/- 5.78 months. When diagnosis was on the basis of biopsy, the mean age in the UIP group was 61.30 +/- 14.18 years and in the NSIP group it was 50.73 +/- 13.14 years. CONCLUSION: HRCT can be used instead of invasive methods like lung biopsy to differentiate between UIP and NSIP.