Mean Maximum Standardized Uptake Value Research Articles

A report on five cases of cholesterol granulomas in the thymus

BackgroundCholesterol granuloma (CG) is a benign entity characterized by the presence of cholesterol crystals and foreign body giant cells. This condition can be attributed to cholesterol crystals that are deposited in the tissues and react with foreign body giant cells, resulting in granuloma formation. Lesions commonly develop in the otolaryngeal region, such as the middle ear. However, crystals rarely form in the thymus, accounting for 1% of all mediastinal tumors. Herein, we present five cases of mediastinal CG.Case presentationThe patients were aged 49–61 (mean, 55.4) years. Among them, three were men and two women. One patient had fever, and four patients were asymptomatic. The patients’ lesions were detected during follow-up of other diseases or medical examinations showing the presence of abnormal chest shadows. The patients did not have a history of trauma or surgery. All lesions were located within the thymus gland. Three patients presented with multifocal lesions and two with a single lesion. Four patients had contrast effect on computed tomography scan. Four patients had abnormal fluorodeoxyglucose accumulation (mean maximum standardized uptake value, 4.67) on positron emission tomography-computed tomography. Four patients underwent complete surgical resection. The size of the resected lesions ranged from 1.8 to 5.1 (mean, 3.24) cm. Histologically, all patients presented with small nodules with cholesterol clefts and foreign body giant cells and histiocyte infiltration within the thymic tissue. The postoperative course was excellent. None of the patients who underwent complete resection presented with recurrence. Moreover, the patient who underwent partial resection did not have lesion enlargement.ConclusionsCG in the thymus is clinically challenging to differentiate from malignant lesions, and histologic diagnosis via surgical resection is required.

The diagnostic value of [18F]FAPI-42 PET/CT for pulmonary artery masses: comparison with [18F]FDG PET/CT.

To investigate the potential utility of [18F]fibroblast activation protein inhibitor (FAPI) positron emission tomography/computed tomography (PET/CT) for evaluating pulmonary artery (PA) masses, and compare it with [18F]fluorodeoxyglucose (FDG) PET/CT. Participants with clinically suspected PA malignancy were prospectively enrolled and underwent dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging. Visual analysis and semi-quantitative parameters were compared between the two types of radiotracers. The tissue specimen underwent immunohistochemical staining to verify FAP expression in the tissue. Thirty-three patients (18 males/15 females; mean age 53.1 ± 15.4 years) were enrolled. All 21 patients with malignant PA masses were FDG-positive (100%), whereas 20 out of 21 patients were FAPI-positive (95.2%). All 12 patients with benign PA masses were both negative in FDG and FAPI PET. The mean maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR) of FAPI and FDG in malignant PA masses were significantly higher than those of benign masses. Although there was no significant difference in SUVmax between FDG and FAPI in malignant PA masses (11.36 vs. 9.18, p = 0.175), the TBR (liver) and TBR (left ventricle) were more favorable for FAPI than for FDG (13.04 vs. 5.17, p < 0.001); (median: 7.75 vs. 2.75, p = 0.007). Immunohistochemical analysis (n = 16) validated that the level of FAP expression corresponded strongly to the uptake of FAPI in PET/CT scans (rs = 0.712, p = 0.002). For clinical management, FAPI PET found more metastatic lesions than FDG PET in 4 patients, with 2 patients upgrading and 1 patient changing treatment decisions. FAPI PET/CT is feasible in the diagnosis of PA masses. Although not superior to FDG PET/CT, FAPI PET/CT showed better target-to-background contrast. This study found that FAPI PET/CT is not superior to FDG PET/CT in diagnosing PA masses, but FAPI PET/CT displays better target-to-background contrast and more positive lesions, which may help improve disease management. Pulmonary malignancies lack specificity in clinical manifestations, laboratory tests, and routine imaging examinations. FAPI PET/CT is not diagnostically better than FDG PET/CT but displays better target-to-background contrast and more positive lesions. Dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging improves clinical management of pulmonary artery masses.

Complete Primary Pathological Response Following Neoadjuvant Treatment and Radical Resection for Pancreatic Ductal Adenocarcinoma.

Neoadjuvant treatment (NAT) for borderline (BD) or locally advanced (LA) primary pancreatic cancer (PDAC) is now a widely adopted approach. We present a case series of patients who have achieved a complete pathological response of the primary tumour on final histology following neoadjuvant chemotherapy +/- chemoradiation and radical surgery. Patients who underwent radical pancreatic resection following neoadjuvant treatment between March 2006 and March 2023 at a single institution were identified by retrospective case note review of a prospectively maintained database. Ten patients were identified to have a complete primary pathological response (ypT0) on postoperative histology. Before treatment, five patients were considered BD and five were LA according to National Comprehensive Cancer Network guidelines. All patients underwent staging Computed Tomography (CT) and nine underwent 18Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET/CT) imaging, with a mean maximum standardized uptake value (SUVmax) of the primary lesion at 6.14 ± 1.98 units. All patients received neoadjuvant chemotherapy, and eight received further chemoradiotherapy prior to resection. Mean pre- and post-neoadjuvant treatment serum Ca19-9 was 148.0 ± 146.3 IU/L and 18.0 ± 18.7 IU/L, respectively (p = 0.01). The mean duration of NAT was 5.6 ± 1.7 months. The mean time from completion of NAT to surgery was 13.1 ± 8.3 weeks. The mean lymph node yield was 21.1 ± 10.4 nodes, with one patient found to have 1 lymph node involved. All resections were reported to be R0. The mean length of stay was 11.8 ± 6.2 days. At the time of analysis, one death was reported at 35 months postoperatively. Two cases of recurrence were reported at 16 months (surgical bed) and 33 months (pulmonary). All other patients remain alive and under active surveillance. The current overall survival is 26.6 ± 20.7 months and counting. Complete primary pathological response is uncommon but possible following neoadjuvant treatment in patients with PDAC. Further work to identify the common denominator within this unique cohort may lead to advances in the therapeutic approach and offer hope for patients diagnosed with borderline or locally advanced pancreatic ductal adenocarcinoma.

Enhancing the clinical diagnosis of the acute and subacute phases of autoimmune encephalitis and predicting the risk factors: the potential advantages of 18F-FDG PET/CT

Background2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (18F-FDG PET) could help evaluate metabolic abnormalities by semi-quantitative measurement to identify autoimmune encephalitis (AE). Few studies have been conducted to analyze the prognostic factors of AE. The study aimed to explore the values of diagnosis and treatment evaluation by 18F-FDG PET and preliminarily discussed the potential value in predicting the prognosis of AE patients.MethodsAE patients underwent 18F-FDG PET/CT and magnetic resonance imaging (MRI). There were two steps to analyse 18F-FDG PET imaging data. The first step was visual assessment. The second step was to analyse 18F-FDG PET parameters using Scenium software (Siemens Molecular Imaging Ltd). The mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) of brain relative regional metabolism (BRRM) were quantified in the case and control groups according to the anatomical automatic labeling (AAL) partition. The main statistical method was the Kruskal–Wallis test. Finally, the simple linear regression method was used to analyse the relationships between 18F-FDG PET parameters and the modified Rankin Scale (mRS) scores before and after treatment.ResultsThe results on 18F-FDG PET showed that visual assessment abnormalities were in the mesial temporal lobe (MTL) (70.8%), (mainly infringing on the hippocampus and amygdala), basal ganglia (62.5%), frontal lobes (37.5%), occipital lobes (29.2%), and parietal lobes (12.5%). The positive rate of abnormalities on 18F-FDG PET was more sensitive than that on MRI (95.5% vs 32.2%, p = 0.001). The number of lesions on PET was positively correlated with the mRS scores before and after treatment, and the correlation before treatment was more significant. Before treatment, the SUVmean of the left occipital lobe was the most remarkable (SUVmean, R2 = 0.082, p > 0.05) factor associated with the mRS score, and the correlation was negative. With regard to prognosis, the SUVmax of the MTL was the most notable (R2 = 0.1471, p > 0.05) factor associated with the mRS score after treatment, and the correlation was positive.Conclusions18F-FDG PET could be more sensitive and informative than MRI in the early phases of AE. The common pattern of AE was high MTL metabolism on 18F-FDG PET, which was associated with hypometabolism of the occipital lobe, and the number of lesions on PET before treatment may be significant factors in assessing disease severity. The SUVmax of MTL hypermetabolism may serve as a prognostic biomarker in AE.

Diagnosis value of 18F-Fluoro-d-glucose positron emission tomography-computed tomography in pulmonary hamartoma: a retrospective study and systematic review

PurposeThe diagnosis of pulmonary hamartoma (PH) based on computed tomography (CT) is a challenge, especially in patients with atypical imaging characteristics. This study was aimed at summarizing the imaging characteristic of 18F-Fluoro-d-glucose positron emission tomography-computed tomography (18F-FDG PET-CT) in PH and exploring the application value of PET-CT in the diagnosis of PH.Data and methodsPatients diagnosed with PH who had undergone PET-CT from literature pertaining were retrospectively analyzed, which were cases of publications from the Cochrane Library, PubMed, Excerpta Medica Database (EMBASE), China National Knowledge Infrastructure (CNKI) and Wanfang databases, from 2008 to June 2022. The other 20 cases of the collection were patients from our hospital from 2008 to June 2022. Patients’ symptoms, imaging characteristics of chest CT, PET-CT characteristics, the reason for PET-CT and the complications were analyzed.ResultsIn this retrospective study, a total of 216 patients were diagnosed with PH and had been examined by PET-CT. 20 of the cases were patients of our hospital from January 2008 to June 2022. The other cases were collected from the literature. The mean diameter of most PH lesions is 1.7 ± 1.0 cm. The mean maximum standardized uptake value (SUVmax) of the PH lesions was 1.2 ± 1.1. Most of their SUVmax were lower than internationally recognized cut-off value (SUVmax = 2.5). PET-CT was superior to CT in the diagnosis of PH but there was a correlation of between CT diagnosis and PET-CT diagnosis for the PH lesions. In order to draw the Receiver operating characteristic (ROC), we selected 29 patients with a clear SUVmax value of their PH lesion, and 29 lung cancer patients with clear SUVmax value in our hospital were collected as a control group. ROC curve analysis showed that the area under curve (AUC) of SUVmax was 0.899, and the optimal diagnostic threshold was SUVmax > 2.65. PET-CT could distinguish PH from malignant lesions with a sensitivity of 89.66% by applying a SUVmax of 2.65 as a cut-off in this study.ConclusionPET-CT might be a useful tool to diagnose PH, which shows a better diagnostic sensitivity than CT. But PET-CT can not be used as a single diagnostic approach, which should be combined with other methods and the patients’ history to make the most correct diagnosis.

Prognostic Impact of EBUS TBNA for Lung Adenocarcinoma Patients with Postoperative Recurrences.

Background: The aim of this study was to verify the importance and the timing of endobronchial ultrasound with transbronchial biopsy (EBUS TBNA) among lung adenocarcinoma patients after radical resection. Methods: We retrospectively reviewed consecutive patients with non-small cell lung cancer (NSCLC) who had ever received radical resection from January 2002 to December 2021. The patients were divided into two groups, with and without EBUS TBNA, for diagnosis or staging. Results: Of 2018 patients with NSCLC, after surgical resection of lung tumors, there were 232 with recurrences. Under multivariate Cox regression analysis, patients with recurrences who received EBUS TBNA had a statistically higher mean maximum standardized uptake value (SUVmax) (hazard ratio (HR) = 1.115, confidence interval (CI) = 1.004–1.238, p = 0.042) and better survival (HR = 5.966, CI = 1.473–24.167, p = 0.012). Although KM survival analysis showed no statistically significant difference between groups with and without EBUS TBNA (p = 0.072) of lung adenocarcinoma patients with recurrences, patients with mutated epidermal growth factor receptor (EGFR) showed significantly better survival than wild-type EGFR (p = 0.007). Conclusions: The clinical practice of EBUS TBNA is not only for diagnosis, but also for nodal staging. We found that lung adenocarcinoma patients with recurrences who received EBUS TBNA had better overall survival. Therefore, EBUS TBNA is a reliable and feasible tool that could be used in lung adenocarcinoma patients with recurrences for early diagnosis and for adequate tissue specimens for further molecular analysis.

JS03.5.A Pediatric Neurofibromatosis type 1- associated Malignant Peripheral Nerve Sheath Tumors: a national experience

Abstract Background Malignant peripheral nerve sheath tumors (MPNST) are rare soft tissue sarcomas and although less that 10% occur in the pediatric age, they are the most feared complication in the follow-up of Neurofibromatosis Type 1 (NF1) patients. NF1-children tend to have larger tumors and worse prognosis than non-NF1 patients. There is a lack of data regarding MPNST in pediatric populations with NF1, and the present work aims to characterize a Portuguese population of pediatric NF1 patients who developed a MPNST. Material and Methods Retrospective analysis of all NF1-pediatric patients diagnosed with MPNST between 2000 to 2021, from three centers in Portugal. Patient characteristics, treatment modalities and clinical outcomes were reviewed. Results 12 patients (6 males and 6 females) met the inclusion criteria. 7 had no family history of NF1. Median age at diagnosis was 14.1 years (range 10-18). 5 had been diagnosed previously with Plexiform Neurofibroma and were treated with selumetinib (2) and partial surgery (2). MPNSTs were mostly located in the retroperitoneum (7) and in the proximal lower limbs (2). Only 1 patient had a resectable tumor at diagnosis and 3 patients had metastatic disease. In the FDG-PET scan of evaluated patients (7), the mean maximum standardized uptake value of the main lesion was 6 (range 3.6-9.7).Neoadjuvant ifosfamide plus doxorubicin chemotherapy was used in 4 patients. The median overall survival in this population was 10.3 months (95% CI 0.1-20.6) 2 patients remain alive. Conclusion The prognosis of MPNSTs in NF1 pediatric patients is very poor. In a subset of patients, MPNSTs develop from known Plexiform Neurofibromas. Current surveillance ant treatment protocols need to be improved.

PSMA PET Imaging and Therapy in Adenoid Cystic Carcinoma and Other Salivary Gland Cancers: A Systematic Review.

Simple SummaryAdenoid cystic carcinoma (ACC) and other salivary gland cancers (SGC) are rare conditions with limited treatment options when they recur or spread to other parts of the body. There is increasing interest in the interaction of radioactive labeled proteins 68Gallium- Prostate Specific Membrane Antigen (68Ga-PSMA) with their corresponding receptors on tumor cells (PSMA receptor) which can be detected on scans. This innovation has created diagnostic and therapeutic progress in management of metastatic prostate cancer. These interactions are also found in SGCs though studies are currently limited. Our systematic review aims to collate available published scientific information on this technology to better inform its potential use, pitfalls and its future directions as a diagnostic and therapeutic option in SGCs. We concluded that the 68Ga-PSMA scans can be useful in detecting ACC and SGC not detected on standard radioimaging and that small studies have shown the therapeutic potential of this innovation in advanced or metastatic ACC and SGC.Adenoid cystic carcinoma (ACC) and other salivary gland cancers (SGCs) are rare tumors where application of prostate specific membrane antigen (PSMA) positron emission tomography (PET) and PSMA radioligand therapy have yet to be studied extensively. This review explores the role of PSMA PET imaging and therapy as a theranostic tool for ACC and other SGCs based on current literature. A comprehensive literature search on PubMed and Embase was performed. All relevant studies containing information on PSMA PET imaging in ACC and SGC were included. Ten studies (one prospective, three retrospective, five case reports and one review paper) were included. For ACC, the mean maximum standardized uptake value (SUVmax) for local recurrence and distant metastases ranged from 2.41 to 13.8 and 2.04 to 14.9, respectively. In SGC, the meanSUVmax ranged from 1.2–12.50. Most studies observed PSMA expression positivity on immunohistochemistry (IHC) when there was PSMA PET uptake. PSMA PET was able to detect lesions not detected on standard imaging. Despite the small number of studies and wide intra-patient and inter-tumor variation of PSMA uptake in ACC and SGC, 68Gallium (68Ga)-PSMA PET has promising prospects as a diagnostic and radioligand therapeutic option. Further studies to answer the various theranostics considerations are required to guide its use in the real-world setting.

Prognostic Significance of PD-L1 Expression and Standardized Uptake Values in the Primary Lesions of Stage IV Adenocarcinoma Lung Cancer.

BackgroundThis study evaluated the prognostic ability of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in patients with stage IV adenocarcinoma lung cancer to detect protein death-ligand 1 (PD-L1) expression levels.MethodsIn total, 86 patients with stage IV adenocarcinoma lung cancer underwent 18F-FDG PET/CT imaging and PD-L1 expression evaluation before treatment from February 2019 to November 2020 at Bach Mai Hospital, Hanoi, Vietnam. The assessed patient characteristics in this study included sex, age, smoking status, epidermal growth factor receptor (EGFR) mutation, PD-L1 expression level, survival status, tumor, node, and metastasis (TNM) stage, and metastasis locations.ResultsThe average age was 62.23 ± 9.51 years, and men and women represented 67.4% and 32.6% of the population, respectively. The EGFR mutation rate was 36%. PD-L1 expression was negative (detected in <1% of the tumor) in 40.7% of cases and positive in 59.3% of cases (detected in 1–49% of the tumor in 32.6%; detected in ≥50% of the tumor in 26.7%). The mean maximum standardized uptake value (SUVmax) was 11.09 ± 3.94. SUVmax was significantly higher in PD-L1–positive tumors than in PD-L1–negative tumors (12.24 ± 4.01 and 9.43 ± 3.22, respectively; p = 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of SUVmax was 0.681 (95% confidence interval 0.570–0.793, p = 0.004). Compared with PD-L1–negative cases, SUVmax was significantly different in all PD-L1–positive cases (p = 0.001), weakly PD-L1–positive cases (1–49%, p = 0.005), and strongly PD-L1–positive cases (≥50%, p = 0.003). PD-L1 expression levels were significantly associated with SUVmax (p = 0.001), tumor size (p = 0.022), and EGFR mutation status (p = 0.045).ConclusionsSUVmax in the primary lesions was able to predict PD-L1 expression and may play a role in predicting PD-L1 immunotherapy efficacy in patients with stage IV lung adenocarcinoma.

18F-FDG PET/CT in Late Acquisition Identifies Sites of Active Disease in Treated Takayasu Arteritis.

ObjectiveFew studies have taken advantage of 18F-fluorodeoxyglucose positron emission tomography associated with computed tomography (18F-FDG PET/CT) to personalize patient evaluation and identify sites of more active disease in Takayasu arteritis (TA)–treated patients. This study aimed to evaluate the utility of 18F-FDG PET/CT in late acquisition in identifying sites of active disease in patients under full treatment for TA.MethodsIn this cross-sectional study, patients under full treatment underwent whole-body 18F-FDG PET/CT. Sites of increased 18F-FDG uptake were classified by a score of 3 on the visual scale using the liver uptake as reference. A quantitative analysis was also performed by measuring the maximum standardized uptake value (SUV) of the vascular wall of affected arteries. Disease activity using the National Institutes of Health criteria was also evaluated.ResultsOf the 20 patients, there were 18 female and 2 male patients, with a mean age of 43.6 (±11.58) years and a disease duration of 8.3 (±6.25) years. Thirteen participants (65%) were in inflammatory activity according to the criteria proposed by the National Institutes of Health. All patients received immunosuppressive agents, and one of them received immunobiological treatment. The highest SUV value was 6.2 in the aortic arch, and the lowest was 1.0 in the subclavian artery. The mean maximum SUV did not differ between clinically active and inactive patients. In the visual analysis, all participants had at least 1 vascular site with inflammatory activity, with an uptake ≥2 in relation to the liver. The aortic arch was the most frequently involved site.ConclusionsThis study showed that 18F-FDG PET/CT in late acquisition is an effective imaging method to assess TA activity even in fully treated patients.

P-OGC34 Pandemic paradigms: Early outcomes of radical chemoradiotherapy for patients with operable oesophageal and oesophago-gastric junctional adenocarcinoma

Abstract Background The peak waves of the COVID pandemic necessitated a paradigm shift in surgical management of patients with oesophageal adenocarcinoma due to both pressure on services and high mortality rates for those with COVID undergoing surgery. The Association of Upper GI Surgeons (AUGIS) guidance on treating Upper gastrointestinal cancers in the COVID era made suggestions to treat operable adenocarcinomas using definitive/consolidation chemoradiation (DCRT) over standard neo-adjuvant chemotherapy (NAC) and our unit altered practice accordingly for a cohort of patients. For affected patients we monitored and audited clinical outcomes and the initial results from this are presented here. Methods Patients with oesophageal or oesophago-gastric junctional (O/OGJ) adenocarcinoma with potentially curative disease where initial management was altered from a treatment path which would have included surgery (with or without neoadjuvant therapy) to DCRT discussed at our regional multidisciplinary team (MDT) meeting between 1st February-1st June 2020 were included. Patient demographics, investigations, treatment given and clinical outcomes were prospectively recorded. Results 31 Patients with operable adenocarcinoma of O/OGJ had treatment altered to DCRT (mean age 65.4, [range 43 – 79]), 28 (90%) Male. 1 patient deteriorated prior to starting, leaving 30 who completed DCRT. Of these 4 patients had already had NAC prior to DCRT. Follow up was for a median of 8 (range 4-8) months following start of treatment. Post- vs pre-treatment FDG-PET imaging demonstrated a significant reduction in the mean maximum standardized uptake value (SUVmax) (p = 0.003, Sign test), in all but 3 patients. 11 patients had DCRT alone, (all alive at the time of data collection), of whom 3 patients had no sign of tumour. 19 (56%) patients proceeded to salvage oesophagectomy at a median of 15(range 10-25) weeks after completion of DCRT. 42% of these patients had a complete pathological response to treatment. There was a 5% perioperative mortality rate for this group and 1 patient was found to be unresectable on the day of surgery. At the time the data was reviewed overall survival of the entire cohort was 91%, 56% of whom had no sign of residual or recurrent disease. Conclusions A disease free survival of 56% compares poorly with the literature at the 3-month interval. The long-term follow-up of these patients will only be apparent in the coming months and years. This data does not support the use of this modality in the future and alternate treatment plans should be devised for future pandemics.

Simultaneous FAPI PET/MRI Targeting the Fibroblast-Activation Protein for Breast Cancer.

Background Integrated PET/MRI is a promising modality for breast assessment. The most frequently used tracer, fluorine 18 (18F) fluorodeoxyglucose (FDG), is applied for whole-body staging in advanced breast cancer but has limited accuracy in evaluating primary breast lesions. The fibroblast-activation protein (FAP) is abundantly expressed in invasive breast cancer. FAP-directed PET tracers have recently become available, but results in primary breast tumors remain lacking. Purpose To evaluate the use of FAP inhibitor (FAPI) breast PET/MRI in assessing breast lesions and of FAPI whole-body scanning for lymph node (LN) and distant staging using the ligand gallium 68 (68Ga)-FAPI-46. Materials and Methods In women with histologically confirmed invasive breast cancer, all primary 68Ga-FAPI-46 breast and whole-body PET/MRI and PET/CT examinations conducted at the authors' center between October 2019 and December 2020 were retrospectively analyzed. MRI lesion characteristics and standardized uptake values (SUVs) were quantified with dedicated software. Mann-Whitney U tests were used to compare tumor SUVs across different tumor types. The Pearson correlation coefficient was calculated between SUV and measures of MRI morphologic characteristics. Results Nineteen women (mean age, 49 years ± 9 [standard deviation]) were evaluated-18 to complement initial staging and one for restaging after therapy for distant metastases. Strong tracer accumulation was observed in all 18 untreated primary breast malignancies (mean maximum SUV [SUVmax] = 13.9 [range, 7.9-29.9]; median lesion diameter = 26 mm [range, 9-155 mm]), resulting in clear tumor delineation across different gradings, receptors, and histologic types. All preoperatively verified LN metastases in 13 women showed strong tracer accumulation (mean SUVmax= 12.2 [range, 3.3-22.4]; mean diameter = 21 mm [range, 14-35 mm]). Tracer uptake established or supported extra-axillary LN involvement in seven women and affected therapy decisions in three women. Conclusion This retrospective analysis indicates use of 68Ga fibroblast-activation protein inhibitor tracers for breast cancer diagnosis and staging. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mankoff and Sellmyer in this issue.

First-in-human DR5 PET reveals insufficient DR5 expression in patients with gastrointestinal cancer

BackgroundDeath receptor 5 (DR5) is a promising therapeutic target for cancer therapy. However, many clinical trials of DR5 agonists failed to show significant therapeutic efficacy in patients with cancer. The...

Atorvastatin Promotes Macrocalcification, But Not Microcalcification in Atherosclerotic Rabbits: An 18F-NaF PET/CT Study.

Our study aimed to investigate the effect of atorvastatin on plaque calcification by matching the results obtained by 18F-sodium fluoride (18F-NaF) positron emission tomography (PET)/computed tomography (CT) with data from histologic sections. The rabbits were divided into 2 groups as follows: an atherosclerosis group (n = 10) and an atorvastatin group (n = 10). All rabbits underwent an abdominal aortic operation and were fed a high-fat diet to induce atherosclerosis. Plasma samples were used to analyze serum inflammation markers and blood lipid levels. 18F-NaF PET/CT scans were performed twice. The plaque area, macrophage number and calcification were measured, and the data from the pathological sections were matched with the 18F-NaF PET/CT scan results. The mean standardized uptake value (0.725 ± 0.126 vs. 0.603 ± 0.071, P < 0.001) and maximum standardized uptake value (1.024 ± 0.116 vs. 0.854 ± 0.091, P < 0.001) significantly increased in the atherosclerosis group, but only slightly increased in the atorvastatin group (0.616 ± 0.103 vs. 0.613 ± 0.094, P = 0.384; 0.853 ± 0.099 vs.0.837 ± 0.089, P < 0.001, respectively). The total calcium density was significantly increased in rabbits treated with atorvastatin compared with rabbits not treated with atorvastatin (1.64 ± 0.90 vs. 0.49 ± 0.35, P < 0.001), but the microcalcification level was significantly lower. There were more microcalcification deposits in the areas with increased radioactive uptake of 18F-NaF. Our study suggests that the anti-inflammatory activity of atorvastatin may promote macrocalcification but not microcalcification within atherosclerotic plaques. 18F-NaF PET/CT can detect plaque microcalcifications.

Contribution of 18F-FDG PET/CT in the Differential Diagnosis of Pulmonary Hamartomas and Pulmonary Carcinoids

Objectives:This study aimed to evaluate 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) findings in the differential diagnosis of pulmonary carcinoids and pulmonary hamartomas.Methods: 18F-FDG PET/CT findings of 34 patients with pulmonary carcinoids (12 atypical, 22 typical) and 32 patients with pulmonary hamartomas were retrospectively evaluated. Both mean diameter and mean maximum standardized uptake value (SUVmax) of hamartomas and carcinoids were compared by Mann-Whitney U and Kruskall-Wallis H tests.Results:The mean longest diameter of atypical carcinoids (3.5±1.7 cm) was higher than that of hamartomas (2.1±1 cm) (p=0.038). No significant difference was found between the mean diameter of typical carcinoids and mean diameter of hamartomas (p=0.128). The mean SUVmax of atypical carcinoids (5.97±3.7) and typical carcinoids (4.22±1.7) were higher than those of hamartomas (1.65±0.9) (p=0.002 and p=0.003, respectively). There were collapse/consolidation in 55.8%, bronchiectasis or mucoid impaction in 47%, and air trapping in 14.7% in the peripheral parenchyma of the 34 carcinoids. Collapse/consolidation was detected in a patient with endobronchial hamartoma, and other finding was not found in the parenchyma around hamartomas.Conclusion:The 18F-FDG uptake of pulmonary carcinoids can vary from minimal to intense. 18F-FDG uptake can be seen in pulmonary hamartomas. However, the mean SUVmax of atypical carcinoids and typical carcinoids were higher compared to hamartomas. Pulmonary carcinoid must be suspected in cases with accompanying bronchial obstruction findings in the periphery of the mass.

Imaging findings of granulocyte colony-stimulating factor-producing tumors: a case series and review of the literature

Granulocyte colony-stimulating factor (G-CSF)-producing tumors have an aggressive clinical course. Here, we report five cases of G-CSF-producing tumors and review the literature, focusing on imaging findings related to tumor-produced G-CSF. In addition to our cases, we identified 30 previous reports of G-CSF-producing tumors on which 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, bone scintigraphy, or evaluation of bone marrow MR findings was performed. White blood cell count, serum C-reactive protein, and serum interleukin-6 were elevated in all cases for which these parameters were measured. G-CSF-producing tumors presented large necrotic masses (mean diameter 83.2 mm, range 17–195 mm) with marked FDG uptake (mean maximum standardized uptake value: 20.09). Diffuse FDG uptake into the bone marrow was shown in 28 of the 31 cases in which FDG-PET/CT was performed. The signal intensity of bone marrow suggested marrow reconversion in all seven MRI-assessable cases. Bone scintigraphy demonstrated no significant uptake, except in two cases with bone metastases. Splenic FDG uptake was increased in 8 of 10 cases in which it was evaluated. These imaging findings may reflect the effects of tumor-produced G-CSF. The presence of G-CSF-producing tumors should be considered in patients with cancer who show these imaging findings and marked inflammatory features of unknown origin.

Analysis of the F-18 FDG PET/CT features of pulmonary sclerosing pneumocytoma.

This retrospective study aimed to analyzed the F-18 fluorodeoxyglucose PET/computed tomography (F-18 FDG PET/CT) features of pulmonary sclerosing pneumocytoma (PSP) to improve the understanding and preoperative diagnostic efficacy of this rare disorder. FDG PET/CT images from 11 patients with 22 lesions (including one patient with 12 lesions) proven PSP in our hospital were reviewed. We summarized the PET/CT features of PSP and analyzed the correlation between FDG uptake and tumor size. PET/CT imaging revealed all tumors located in each lobe of the two lungs randomly. All 22 tumors were round or oval nodules; 15 had smooth margins, six were lobulated, six were calcified, and one had a ground-glass halo sign. The mean diameter of these tumors was 19.2 ± 7.8 mm (range: 8-34 mm); the mean maximum standardized uptake value (SUVmax) was 2.8 ± 1.3 (range: 1.1-7.4). Sixteen of the lesions exhibited mild to moderate FDG uptake (mean SUVmax 2.3 ± 0.6), and six of the lesions exhibited intense FDG uptake (mean SUVmax 4.3 ± 1.6). A positive correlation was observed between FDG uptake and tumor size (P <0.05). Single round or ovoid soft-tissue lesions with smooth margins, and mild to moderate FDG uptake on PET/CT images in middle-aged females, suggest a possible diagnosis of PSP. For some atypical cases with intense FDG uptake, a diagnosis of PSP also can be considered. A statistically significant positive correlation was found between SUVmax and PSP lesion size in our study.

Imaging features of fumarate hydratase-deficient renal cell carcinomas: a retrospective study

BackgoundFumarate hydratase-deficient renal cell carcinoma (FH-RCC) is a subtype of RCC that is increasingly recognized pathologically. The aim of this study was to evaluate the imaging features of FH-RCC on computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG PET), and to determine the pre-operative diagnostic potential of imaging.MethodsThis single-site retrospective study included patients with histologically confirmed FH-RCC or with a renal cancer and known germline FH mutation; imaging of the renal mass before treatment with contrast-enhanced CT, contrast-enhanced MRI, or FDG PET/CT between October 2007 and May 2019. Clinical information, pathological data, and imaging features were analyzed and reported descriptively.ResultsSixteen patients with sixteen tumors were included (median age 46 years, interquartile range 38–53 years; 31 % female). Almost all tumors were unifocal (15/16, 94 %). Most tumors had infiltrative margins (14/16, 88 %); few were circumscribed (2/16, 12 %). A large cystic tumor component (> 75 % of tumor volume) was seen in 8/16 (50 %) of tumors. Involvement of renal sinus fat was seen in 13/16 (81 %) of tumors, involvement of the hilar collecting system in 8/16 (50 %), and renal vein tumor thrombus in 6/16 (38 %). All 12 tumors (100 %) imaged with MRI had heterogenous tumor enhancement and heterogenous T2 signal. Of those patients that had diffusion-weighted imaging, 11/11 (100 %) of tumors had diffusion restriction in the solid portions of the tumor. Of the patients who had PET, 3/3 (100 %) tumors showed high metabolic activity with mean maximum standardized uptake value (SUVmax) of 16.4 (range 9.6–21.9). Patients presented with retroperitoneal nodal metastases in 69 % of cases and distant metastases in 75 %. Of those four patients without metastatic disease at presentation, three (75 %) developed metastases within 4 years of diagnosis.ConclusionsIn our study, the majority of tumors (≥ 75 %) were unifocal, had an infiltrative margin, invaded the renal sinus fat, and presented with distant metastases. On MRI, most tumors had heterogenous T2 signal and diffusion restriction in their solid components. The small number of cases that had PET imaging showed high metabolic activity.

Prognostic role of 18F-FDG PET-CT in the prone position in the evaluation of invasive breast carcinoma

Introduction: The objective of this study was to correlate the features of invasive breast carcinoma in 18F-FDG positron emission tomography/computed tomography with histopathological results, findings from other imaging methods, and survival. Methods: This observational single-center study included patients who underwent staging 18F-FDG positron emission tomography/ computed tomography between September 2012 and April 2019; the results were correlated with the findings of other imaging tests and anatomopathological results. Lesions were evaluated for their maximum standardized uptake value on positron emission tomography/computed tomography performed in the prone position. Tumors were classified into three subtypes (luminal, HER2 and triple-negative) based on immunohistochemical analyses. Results: A total of 125 patients with a mean age of 52 years (24–90 years) were analyzed. The primary tumor showed an increased 18F-FDG concentration on positron emission tomography/computed tomography in 122 (97.6%) patients, with a mean maximum standardized uptake value of 7.15 (1.0–32.9 range). The mean maximum standardized uptake value was higher in the triple-negative subtype (11.4; n=24) than in the luminal (6.2; n=89) and HER2 (5.0; n=9) subtypes (p&lt;0.01). Tumors with more aggressive histological and immunohistochemical characteristics showed higher maximum standardized uptake values. Patients with a standardized uptake value greater than 7 in the primary tumor or greater than 6.7 in the axillary lymph nodes had poor overall survival (p=0.03 and p&lt;0.01, respectively). Conclusions: Our study suggests that the maximum standardized uptake value obtained on positron emission tomography/computed tomography in the prone position may correlate with the tumor immunophenotype and overall survival regardless of the treatments performed, and can be used as a prognostic biomarker in invasive breast carcinoma patients.

Differentiating renal pelvic cancer from renal cell carcinoma with 18-fluorodeoxyglucose positron emission tomography-computed tomography.

The differential diagnosis of pelvis renalis cancer (PRC) from renal cell cancer (RCC) is difficult. Because of that, in this study, we compared the standardized uptake value (SUV) with positron emission tomography-computed tomography (PET-CT) of the RCC and PRC. Twenty-one patients (12 males, 9 females; age range: 33-74 years; mean age ± standard deviation [SD]: 57.14 ± 17.6) with suspected primary renal cell cancer as Group 1 and 8 patients (6 male, 2 female; age range, 61-81; mean age ± SD, 71.5 ± 5.65) with suspected renal pelvis cancer as Group 2 detected by conventional imaging techniques (CT, magnetic resonance [MR] imaging, ultrasound, intravenous urogram, CT urography, MR urography) underwent fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT imaging between August 2010 and October 2012. Mean age is 57.14 (33-74) years in Group 1 and 71.5 (61-81) years in Group 2, respectively. The mean maximum SUV (SUVmax) value was 4.6 ± 2.1 in RCC group and 16.6 ± 6.9 in PRC group. At the 18-FDG PET/CT scanning, SUVmax value higher in patients with PRC than in the patients with RCC. It was statistically different (P < 0.001). We suggested that PET/CT can be used for the differential diagnosis of renal pelvis tumor and RCC. However, further studies with larger patient number are needed to confirm our suggestion. To clarify the mechanisms of underlying these differences, molecular advanced molecular studies are needed.