Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome: A Case Report.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare and delayed complication of brain irradiation involving impaired cerebrovascular autoregulation, and diagnosis is based on distinct clinic-radiographic findings and exclusion of differentials. We report a 38-year-old man, who received cranial irradiation 28 years before and developed episodes of headache and visual aura, followed by left hemianopia, aphasia, behavioral disturbances, and focal seizures. An MRI of the brain revealed gyral swelling with restricted diffusion and mild contrast enhancement over the right temporoparietal and occipital region, and fludeoxyglucose-FDG PET scan showed hyperperfusion in the corresponding brain region. He improved completely with pulse steroids and antiseizure medications. The recognition of this syndrome is important as we can reassure patients and their families and help avoid unnecessary and invasive diagnostic tests.

International Benchmark for Total Metabolic Tumor Volume Measurement in Baseline 18F-FDG PET/CT of Lymphoma Patients: A Milestone Toward Clinical Implementation.

Total metabolic tumor volume (TMTV) is prognostic in lymphoma. However, cutoff values for risk stratification vary markedly, according to the tumor delineation method used. We aimed to create a standardized TMTV benchmark dataset allowing TMTV to be tested and applied as a reproducible biomarker. Methods: Sixty baseline 18F-FDG PET/CT scans were identified with a range of disease distributions (20 follicular, 20 Hodgkin, and 20 diffuse large B-cell lymphoma). TMTV was measured by 12 nuclear medicine experts, each analyzing 20 cases split across subtypes, with each case processed by 3-4 readers. LIFEx or ACCURATE software was chosen according to reader preference. Analysis was performed stepwise: TMTV1 with automated preselection of lesions using an SUV of at least 4 and a volume of at least 3 cm3 with single-click removal of physiologic uptake; TMTV2 with additional removal of reactive bone marrow and spleen with single clicks; TMTV3 with manual editing to remove other physiologic uptake, if required; and TMTV4 with optional addition of lesions using mouse clicks with an SUV of at least 4 (no volume threshold). Results: The final TMTV (TMTV4) ranged from 8 to 2,288 cm3, showing excellent agreement among all readers in 87% of cases (52/60) with a difference of less than 10% or less than 10 cm3 In 70% of the cases, TMTV4 equaled TMTV1, requiring no additional reader interaction. Differences in the TMTV4 were exclusively related to reader interpretation of lesion inclusion or physiologic high-uptake region removal, not to the choice of software. For 5 cases, large TMTV differences (>25%) were due to disagreement about inclusion of diffuse splenic uptake. Conclusion: The proposed segmentation method enabled highly reproducible TMTV measurements, with minimal reader interaction in 70% of the patients. The inclusion or exclusion of diffuse splenic uptake requires definition of specific criteria according to lymphoma subtype. The publicly available proposed benchmark allows comparison of study results and could serve as a reference to test improvements using other segmentation approaches.

sICAM-1 concentrations are associated with inflammation in contralateral carotid plaque in patients with ischemic stroke.

BACKGROUND: Atherosclerotic plaques in the internal carotid artery are responsible for more than 15% of ischemic strokes. Carotid 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) detects plaque inflammation. Plasma ICAM-1 and LRP1 concentrations have been associated with inflammation in ipsilateral carotid plaque. The aim of the present study was to test the association between the soluble (s) form of these biomarkers and contralateral carotid plaques. METHODS: Prospective study conducted in 53 patients with a recent ischemic stroke and at least one atherosclerotic plaque in both carotid arteries. All of the patients underwent an early carotid 18F-FDG PET, and a blood sample was obtained at 7±1 days. Several plasma inflammatory markers were evaluated by Multiplex and sLRP1 levels were measured by commercial ELISA. Bivariate and multivariable linear regression was used to assess the association between inflammatory markers and the clinical variables, including contralateral maximum standardized uptake value (SUVmax) and mean SUVmax (mean of contralateral and ipsilateral SUVmax) of 18F-FDG uptake. Hazard ratio (HR) was estimated with Cox models adjusted for potential confounding factors to evaluate recurrence. RESULTS: Multivariable linear regression analysis showed an independent association between sICAM-1 and sVCAM-1 and mean SUVmax (CI=-0.064-0.325, p=0.004; CI=0.079-0.554, p=0.010). In addition, in bivariate regression analysis, sICAM-1 was associated with contralateral SUVmax (CI=0.049-0.382, p=0.012). Cox regression showed that mean SUVmax was associated with stroke recurrence (HR=5.604, p=0.044). CONCLUSIONS: sICAM-1 was independently associated with mean carotid plaque inflammation and with inflammation in contralateral plaque. sICAM-1 could be an indicator of plaque inflammation even in asymptomatic plaques.

A 18F-FDG PET/CT based radiomics nomogram for predicting disease-free survival in stage II/III colorectal adenocarcinoma.

OBJECTIVES: This study aimed to establish a clinical nomogram model based on a radiomics signatures derived from 18F-fluorodeoxyglucose positron-emission tomography (18F-FDG PET/CT) and clinical parameters to predict disease-free survival (DFS) in patients with stage II/III colorectal adenocarcinoma. Understanding and predicting DFS in these patients is key to optimizing treatment strategies. METHODS: A retrospective analysis included 332 cases from July 2011 to July 2021 at The Sixth Affiliated Hospital, Sun Yat-sen University, with PET/CT assessing radiomics features and clinicopathological features. Univariate Cox regression, the least absolute shrinkage and selection operator (LASSO) Cox, and multivariable Cox regression identified recurrence-related radiomics features. We used a weighted radiomics score (Rad-score) and independent risk factors to construct a nomogram. Evaluation involved time-dependent receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). RESULTS: The nomogram, incorporating Rad-score, pN, and pT demonstrated robust predictive ability for DFS in stage II/III colorectal adenocarcinoma. Training cohort areas under the curve (AUCs) were 0.78, 0.80, and 0.86 at 1, 2, and 3 years, respectively, and validation cohort AUCs were 0.79, 0.75, and 0.73. DCA and calibration curves affirmed the nomogram's clinical relevance. CONCLUSION: The 18F-FDG PET/CT based radiomics nomogram, including Rad-score, pN, and pT, effectively predicted tumor recurrence in stage II/III colorectal adenocarcinoma, significantly enhancing prognostic stratification. Our findings highlight the potential of this nomogram as a guide for clinical decision making to improve patient outcomes.

68Ga-PSMA PET/CT and 18F-FDG PET/CT in the diagnosis of prostatic ductal cancer.

PURPOSES: To explore the characteristics of PSMA PET/CT and FDG PET/CT images in prostatic ductal adenocarcinoma (DA) patients. METHODS: We retrospectively enrolled prostatic DA patients with PET/CT scans at Tongji Hospital from 2018 to 2022. Patients with prostatic acinar adenocarcinoma (AA) and benign pathology (BP) were enrolled by 1:1 matching. Differences in the uptake of primary and metastatic foci on PET among the groups were analyzed. RESULTS: A total of 42 patients were enrolled: 14 in each group. In primary foci, the mean PSMA uptake in the DA group was lower than that in the AA group (14.2 ± 9.6 vs. 27.1 ± 14.3, P = 0.009) and greater than that in the BP group (14.2 ± 9.6 vs. 4.7 ± 1.3, P = 0.003). The AUCs of the DA-AA ROC curve and DA-BP ROC curve were 0.781 and 0.872, respectively. The median PSMA uptake of metastatic lymph nodes in the DA group was lower than that in the AA group (5.6 vs. 14.2, P = 0.033), with no significant difference in metastatic bone lesions (9.5 vs 19.1, P = 0.485). No significant difference was found in the FDG uptake of primary and metastatic foci between the DA and AA groups (P > 0.05). CONCLUSION: Prostatic DA has greater PSMA uptake than BP diseases, but lower uptake in both primary foci and metastatic lymph nodes than AA on PSMA PET/CT, aiding in the differential diagnosis of DA, AA and BP diseases. Clinicians should combine traditional imaging with PSMA PET/CT to avoid underestimating the clinical stage of DA patients.

Application Effect of 18F-FDG PET/CT Technique in Diagnosis and Prognosis Evaluation of Lymphoma.

The objective of the study was to research diagnostic and prognostic values of 18F fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with diffuse large B-cell lymphoma (DLBCL). The diagnostic sensitivity (Sen) of PET/CT (94.75%) was remarkably higher than 83.56% of B-US. Age ≥ 65 years old, maximum focal diameter ≥5 cm, clinical stages III-IV, systemic symptoms, increased lactate dehydrogenase level, high modified international prognostic index score, Ecog score ≥1, B-cell lymphoma 2 (Bcl-2) gene, MYC protein expression rate, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were all factors that influenced the recurrence or progression of DLBCL. With higher MTV and TLG, patients would have a greater probability of recurrence or progression. 18F-FDG PET/CT showed a high diagnostic Sen in lymphoma lesions, and could accurately guide clinical staging. Combined with clinical parameters, laboratory indicators, and metabolic parameters, prognostic indicators of patients could be evaluated more accurately.

Warthin's Tumour as a Parotid Gland Incidentaloma Identified by PET-CT Scan in a Large Series of Cases.

Occasionally in imaging scans there are findings unrelated to the pathology for which the scan was indicated, findings that are called incidentalomas. Warthin tumors have a high glucose avidity, being one of the common incidentalomas in PET-CT scans. The aim of the present study is to analyze the frequency of occurrence of Warthin's tumor as an incidental finding in a large series of patients undergoing 18F-FDG PET-CT. Retrospective analysis of 18F-FDG PET-CT scans performed in our center during the period 2010-2021. Parotid hypermetabolic lesions were identified, as well as their SUVmax, size, smoking habit, BMI (body mass index), and otorhinolaryngology follow-up. 31,423 PET-CT-18FDG studies corresponding to 12,806 patients were analyzed. The frequency of incidentalomas at the parotid level with a diagnosis compatible with Warthin's tumor was 0.87% (n = 111). Eighty percent of the patients with incidentalomas accordant to Warthin's tumor had a history of tobacco use. The highest percentage of incidentalomas compatible with a Warthin tumor was found in patients in whom the indication for PET-CT was the study of a lung carcinoma (1.44%). Only 37% of patients with a PET-CT lesion compatible with a Warthin's tumor were referred for evaluation by the Otorhinolaryngology service. The incidence of Warthin's tumor in 18-FDG PET-CT scans in our center was 0.87%.

Radiomics based on 18F-FDG PET/CT for prediction of pathological complete response to neoadjuvant therapy in non-small cell lung cancer.

Purpose: This study aimed to establish and evaluate the value of integrated models involving 18F-FDG PET/CT-based radiomics and clinicopathological information in the prediction of pathological complete response (pCR) to neoadjuvant therapy (NAT) for non-small cell lung cancer (NSCLC). Methods: A total of 106 eligible NSCLC patients were included in the study. After volume of interest (VOI) segmentation, 2,016 PET-based and 2,016 CT-based radiomic features were extracted. To select an optimal machine learning model, a total of 25 models were constructed based on five sets of machine learning classifiers combined with five sets of predictive feature resources, including PET-based alone radiomics, CT-based alone radiomics, PET/CT-based radiomics, clinicopathological features, and PET/CT-based radiomics integrated with clinicopathological features. Area under the curves (AUCs) of receiver operator characteristic (ROC) curves were used as the main outcome to assess the model performance. Results: The hybrid PET/CT-derived radiomic model outperformed PET-alone and CT-alone radiomic models in the prediction of pCR to NAT. Moreover, addition of clinicopathological information further enhanced the predictive performance of PET/CT-derived radiomic model. Ultimately, the support vector machine (SVM)-based PET/CT radiomics combined clinicopathological information presented an optimal predictive efficacy with an AUC of 0.925 (95% CI 0.869-0.981) in the training cohort and an AUC of 0.863 (95% CI 0.740-0.985) in the test cohort. The developed nomogram involving radiomics and pathological type was suggested as a convenient tool to enable clinical application. Conclusions: The 18F-FDG PET/CT-based SVM radiomics integrated with clinicopathological information was an optimal model to non-invasively predict pCR to NAC for NSCLC.

18F-Fluorodeoxyglucose (18F-FDG) PET/CT Appearance of Baastrup's Disease and Its Multimodality Correlation.

Baastrup's disease (BD), commonly known as "kissing spine syndrome," presents a significant cause of lower back pain, predominantly affecting the lumbar region. Diagnosis is often challenging due to its symptomatology and radiographic presentation. Herein, we present a case series demonstrating the utility of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosing BD accurately, particularly in oncologic settings where it may mimic metastatic lesions. Through a series of cases, we demonstrate the distinctive imaging features of BD on 18F-FDG PET/CT and its differentiation from malignancies. In addition, we emphasize the importance of clinical awareness and proper correlation with CT or MRI to avoid misinterpretation. Furthermore, we discuss the pathophysiology, clinical presentation, and diagnostic modalities of BD, highlighting its underdiagnosis and potential to mimic metastasis on imaging. By enhancing recognition of BD's appearance on 18F-FDG PET/CT, this study aims to prevent misdiagnoses, reduce unnecessary investigations, and ultimately improve patient care in oncologic practice.

18FDG PET/CT imaging of adenovirus-associated acute interstitial nephritis after allogeneic bone marrow transplantation.

Adenovirus-associated acute interstitial nephritis (AAIN) should always be considered in the differential diagnosis of acute kidney failure following allogeneic bone marrow transplant. Although not intended for the definitive diagnosis of AAIN, 18FDG PET/CT can be a helpful noninvasive diagnostic tool, especially when a biopsy is not feasible.

Adrenal Oncocytoma: A Rare Tumor with Conflicting Imaging Features.

Oncocytic adenomas are rare benign tumors that typically originate in organs such as the kidneys, thyroid, parathyroid, salivary glands, or pituitary gland. Oncocytic adenoma of the adrenal gland is extremely rare. It often shows heterogeneous, nonspecific features on anatomic imaging, as well as high 18F-FDG avidity despite its benign nature. The definitive diagnosis relies on histopathologic examination, including immunohistochemistry. We present an incidentally detected benign adrenal oncocytic adenoma with intense 18F-FDG uptake mimicking sinister pathologies.

Developing Communication Support Material for Sharing Information with Patients Undergoing an 18F-FDG PET/CT Examination.

Our aim was to develop communication support material for information sharing related to an 18F-FDG PET/CT examination. Methods: The study had a qualitative design adapting a multiphase structure. A prototype of communication support material consisting of illustrations and text related to an 18F-FDG PET/CT examination was developed. Interviews were conducted with patients scheduled for an 18F-FDG PET/CT examination for the first time, and questionnaires were collected from health care professionals with experience in 18F-FDG PET/CT. The communication support material was revised until consensus was reached about it. Results: The results are based on interviews with patients (n = 10) and questionnaires collected from health care professionals (n = 9). The overall theme revealed that patient information about an 18F-FDG PET/CT examination is a balancing act between text and illustrations. The analysis showed 2 categories: "illustrations as a complement" and "easy-to-understand layout." Conclusion: The participants strengthened the development of the communication support material by bringing in valuable viewpoints from various perspectives. The results support a person-centered approach in which information about an 18F-FDG PET/CT examination can be adapted to each patient's needs as a balancing act between text and illustrations.

FDG-PET/MRI in the presurgical evaluation of pediatric epilepsy.

In patients with drug-resistant epilepsy, difficulties in identifying the epileptogenic zone are well known to correlate with poorer clinical outcomes post-surgery. The integration of PET and MRI in the presurgical assessment of pediatric patients likely improves diagnostic precision by confirming or widening treatment targets. PET and MRI together offer superior insights compared to either modality alone. For instance, PET highlights abnormal glucose metabolism, while MRI precisely localizes structural anomalies, providing a comprehensive understanding of the epileptogenic zone. Furthermore, both methodologies, whether utilized through simultaneous PET/MRI scanning or the co-registration of separately acquired PET and MRI data, present unique advantages, having complementary roles in lesional and non-lesional cases. Simultaneous FDG-PET/MRI provides precise co-registration of functional (PET) and structural (MR) imaging in a convenient one-stop-shop approach, which minimizes sedation time and reduces radiation exposure in children. Commercially available fusion software that allows retrospective co-registration of separately acquired PET and MRI images is a commonly used alternative. This review provides an overview and illustrative cases that highlight the role of combining 18F-FDG-PET and MRI imaging and shares the authors' decade-long experience utilizing simultaneous PET/MRI in the presurgical evaluation of pediatric epilepsy.

Predictive Value of PERCIST for Locally Advanced Non-Small Cell Lung Cancer Treated with Preoperative Induction Therapy - A Multicenter Study in Japan.

Background: Induction therapy followed by surgery is recommended as an alternative treatment strategy for locally advanced non-small cell lung cancer (NSCLC). Patients who achieve pathologic response after induction therapy have better outcomes than non-responders; therefore, therapeutic response must be evaluated. Recently, new approaches for monitoring therapeutic responses, which are based on 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET), have been developed. In this study, we evaluated the predictive value of Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST), which uses standardized uptake values corrected for lean body mass (SUL) and total lesion glycolysis (TLG). Methods: A total of 130 patients in the Setouchi Lung Cancer Group who underwent FDG-PET imaging before and after induction therapy prior to a planned surgical resection for NSCLC between 2007 and 2016 were studied retrospectively. The pathologic responses of the primary lung tumors and metastatic lymph nodes were compared with their responses based on evaluation using PERCIST. Results: Postoperative pathologic studies revealed pathologic complete response (pCR) in 42 (32.3%) patients. PERCIST was significantly correlated with pathologic response (p < 0.001). The sensitivity, specificity, and accuracy of PERCIST for predicting pCR were 16.7% (7/42), 88.6% (78/88), and 65.4% (85/130), respectively. Patients with pCR had significantly higher reduction rates in SULpeak for both primary lung tumors and metastatic lymph nodes and TLG for primary tumors than non-responders. In a multivariate Cox regression analysis, tumor site in upper lobes, reduction rate of TLG in primary tumor, and pathologic N0 were independent predictors of favorable recurrence-free survival (RFS). Conclusion: Our study suggested that PERCIST, especially the rate of TLG reduction rate, are useful to predict the pathological response and prognosis after induction therapy. Although improvement is necessary, PERCIST can be a promising method of the post-induction status in lung cancer. Further research is needed to confirm our findings.

Augmenting CT-Guided Bone Biopsies Using 18F-FDG PET/CT Guidance.

Computer tomography (CT)-guided percutaneous core biopsies are currently the gold standard in diagnostic procedures for patients with bone lesions of unknown kind. CT-guided biopsies can lead to misdiagnosis or repetition of biopsies in case of small or heterogeneous lesions. We hypothesize that molecular image guidance could be used to optimize the biopsy strategy, by supporting the detection of heterogeneous lesions or lesions without radiographic substrate. To evaluate this hypothesis, we investigated if and how the addition of 2-deoxy-2-18F-fluoro-D-glucose-positron emission tomography (18F-FDG-PET)/CT could augment routine CT-guided bone biopsies. To this end, 106 patients who underwent a CT-guided bone biopsy between April 2019 and April 2020, obtained from either a vertebral or peripheral bone, were included. Patients were divided into 2 groups: 36 patients received an 18F-FDG-PET/CT scan prior to their CT-guided bone biopsy (PET group), while 70 patients only had a morphological CT scan (CT group). Histopathology was used to categorize biopsies into five subgroups (inconclusive, benign, malignant or infectious disease, or normal tissue). In the PET group, the number of conclusive biopsies was significantly higher compared to the CT group (N = 33/36 (92%) versus N = 53/70 (76%); p < 0.05). Furthermore, the number of first-try biopsies was lower in the PET group compared to the CT group (1.9 vs. 2.54, p = 0.051). In conclusion, 18F-FDG-PET/CT imaging significantly increased the success rate of first-try CT-guided bone biopsies by showing less inconclusive biopsies and misdiagnosis.

The Prognostic Significance of Pontine-White Matter Score in Primary Central Nervous System Lymphoma Patients.

BACKGROUND: Limited data exist on the significance of PET imaging and quantitative PET parameters in primary central nervous system (CNS) lymphoma due to its relative rarity. This study was conducted to investigate the prognostic value of a novel internal standardization indicator, the pontine-white matter (PW) score, in primary CNS lymphoma patients undergoing post-treatment 18F-FDG PET/CT and PET/MR imaging. METHODS: From January 2014 to December 2022, eligible patients with primary CNS lymphoma who underwent post-treatment PET imaging were enrolled. Using the FDG uptake of the pons and white matter as an internal reference, the PW score was graded based on the metabolism of the post-therapeutic lesion for each patient, and its associations with patients' prognosis were investigated. RESULTS: In total, 41 patients with post-treatment PET/CT and 49 patients with post-treatment PET/MR imaging were enrolled. ROC curve analysis indicated that the PW score possessed robust discriminative ability in distinguishing patients with worse outcomes. Furthermore, a higher PW score was significantly correlated with and identified as an independent prognostic indicator for, worse prognosis in both the PET/CT and PET/MR cohorts. CONCLUSION: The study demonstrated that the PW score was an effective prognostic indicator for identifying post-treatment primary CNS lymphoma patients with worse outcomes.

Enhanced Pancreatitis Detection: FAPI PET/CT Emerging Utility in Patient with Pancreatic Mass.

Fibroblast Activation Protein Inhibitor (FAPI) positron emission tomography (PET) imaging has emerged as a useful method for identifying pancreatic disorders, notably pancreatitis. Unlike Fluorine-18 fluorodeoxyglucose (FDG), FAPI uptake is directly proportional to the degree of fibrosis, making it very useful in separating pancreatic tumors from inflammation. Recent investigations have shown that FAPI positron emission tomography/computer tomography (PET/CT) can identify pancreatic inflammation with great sensitivity, providing vital diagnostic information. In this case study, a 52-year-old male with a history of Ewing sarcoma presented with epigastric pain. Pancreatitis was confirmed on a computer tomography (CT) scan showing mild fat stranding in the pancreatic body and tail, in addition to a significant increase in pancreatic head mass, necessitating further evaluation with FDG PET/CT and FAPI PET/CT, as the patient was known to have metastatic sarcoma. While FDG PET/CT revealed an avid infiltrative lesion in the duodenal/pancreatic head area, FAPI PET/CT showed diffuse uptake in the pancreatic body and tail, indicating fibroblast-mediated inflammation consistent with pancreatitis. This case demonstrates the usefulness of FAPI imaging in discriminating between pancreatic metastasis and pancreatitis, with FAPI PET/CT providing crucial diagnostic information when FDG uptake is ambiguous.

Outcome prediction based on [18F]FDG PET/CT in patients with pleural mesothelioma treated with ipilimumab and nivolumab +/- UV1 telomerase vaccine.

PURPOSE: The introduction of immunotherapy in pleural mesothelioma (PM) has highlighted the need for effective outcome predictors. This study explores the role of [18F]FDG PET/CT in predicting outcomes in PM treated with immunotherapy. METHODS: Patients from the NIPU trial, receiving ipilimumab and nivolumab +/- telomerase vaccine in second-line, were included. [18F]FDG PET/CT was obtained at baseline (n = 100) and at week-5 (n = 76). Metabolic tumour volume (MTV) and peak standardised uptake value (SUVpeak) were evaluated in relation to survival outcomes. Wilcoxon rank-sum test was used to assess differences in MTV, total lesion glycolysis (TLG), maximum standardised uptake value (SUVmax) and SUVpeak between patients exhibiting an objective response, defined as either partial response or complete response according to the modified Response Criteria in Solid Tumours (mRECIST) and immune RECIST (iRECIST), and non-responders, defined as either stable disease or progressive disease as their best overall response. RESULTS: Univariate Cox regression revealed significant associations of MTV with OS (HR 1.36, CI: 1.14, 1.62, p < 0.001) and PFS (HR 1.18, CI: 1.03, 1.34, p = 0.02), while multivariate analysis showed a significant association with OS only (HR 1.35, CI: 1.09, 1.68, p = 0.007). While SUVpeak was not significantly associated with OS or PFS in univariate analyses, it was significantly associated with OS in multivariate analysis (HR 0.43, CI: 0.23, 0.80, p = 0.008). Objective responders had significant reductions in TLG, SUVmax and SUVpeak at week-5. CONCLUSION: MTV provides prognostic value in PM treated with immunotherapy. High SUVpeak was not associated with inferior outcomes, which could be attributed to the distinct mechanisms of immunotherapy. Early reductions in PET metrics correlated with treatment response. STUDY REGISTRATION: The NIPU trial (NCT04300244) is registered at clinicaltrials.gov. https://classic. CLINICALTRIALS: gov/ct2/show/NCT04300244?cond=Pleural+Mesothelioma&cntry=NO&draw=2&rank=4.

High Physiological 18 F-FDG Uptake in Normal Pituitary Gland on Digital PET Scanner.

Purpose Recently developed digital positron emission tomography/computed tomography (PET/CT) scanners (digital PET [dPET]) have given new dimensions to molecular imaging. dPET scanner has very high sensitivity, spatial resolution, and image contrast that leads to increased uptake of signal in small-volume structures like pituitary gland (PG) making them visible on PET/CT scan even in absence of any pathology. Adequate knowledge of physiological fluoro-2 deoxy D glucose uptake in PG is required in interpretation of dPET for correct diagnosis and reducing unnecessary additional imaging. The aim of this study is to evaluate the frequency of physiological PG uptake on dPET. Material and Methods Eighty-eight subjects (mean age, 54.44 ± 14.18 years; range, 26-84 years; 63 females and 25 males) with normal PG on magnetic resonance imaging brain and imaged within 6 months on dPET were included in this research study. Out of 88 patients, 20 control subjects (mean age, 58.15 ± 11.08 years: 15 females and 5 males) underwent PET/CT on conventional PET. All images were acquired with similar and standard acquisition protocol and reconstruction done with Time of flight with Point spread function. PG uptake was compared visually and quantitatively. Results PG uptake was seen in 43 patients (48.8%). Out of 43 patients, 31 (72%) showed low uptake, 11 (26%) showed intermediate grade of uptake, and 1 patient (2%) showed intermediate-to-high uptake and was categorized as high-grade uptake. In the control group of 20 patients, 3 (15%) showed low uptake, while none of them showed intermediate or high uptake. Conclusion Physiological PG uptake is commonly seen on dPET. Low-to-intermediate grade of PG uptake on dPET in an asymptomatic patient is physiological and does not require further evaluation and should be reported with caution.

Complimentary Role of [18F]FDG and [18F]NaF-PET/CT in Evaluating Synchronous Thyroid Carcinoma and Parathyroid Adenoma with Brown Tumors.

We herein present a patient initially suspected of multiple lytic skeletal metastasis of unknown primary on anatomical imaging. Metabolic imaging by [18F]-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) detected focal [18F]FDG uptake in the right thyroid nodule, mild [18F]FDG uptake in soft tissue lesion in the left inferior parathyroid region, and multiple nonavid osteolytic skeletal lesions. Fine-needle aspiration cytology of the right thyroid nodule showed papillary thyroid carcinoma (PTC). The patient had raised serum parathyroid hormone and serum calcium levels, suggesting parathyroid disease. [18F]-sodium fluoride (NaF)-PET/CT showed a metabolic superscan pattern of hyperparathyroidism with brown tumors rather than metastatic lytic skeletal lesions. Patient underwent total thyroidectomy and bilateral central compartment clearance, along with soft tissue lesion resection in the left inferior parathyroid region. Finally, histopathology confirmed PTC classical variant with no aggressive histology features (pT1N0) for thyroid nodule and parathyroid adenoma for soft tissue lesion in the left inferior parathyroid region. The findings of the [18F]FDG and [18F]NaF-PET/CT imaging were helpful for making a final diagnosis of synchronous thyroid cancer and parathyroid adenoma, which in turn guided the appropriate treatment strategy.