Abnormal Uptake Research Articles

Prevalence and Risk Factors for Retropharyngeal and Retro-Styloid Lymph Node Metastasis in Hypopharyngeal Carcinoma

We evaluated the prevalence and identified the risk factors for retropharyngeal and retro-styloid lymph node metastasis (LNM) in patients with hypopharyngeal carcinoma (HPC). This was achieved using a combination of MR and FDG-PET/CT images. Two board-certified radiation oncologists, who experienced 16 and 18 years in the diagnosis and treatment of head and neck cancers retrospectively reviewed pretreatment FDG-PET/CT images and contrast-enhanced thin-slice CT and MR images of 155 patients with HPC who underwent radiotherapy. Observers assessed these images without prior knowledge of the patient's clinical information and disagreements were resolved by consensus. The radiological diagnostic criteria for lateral retropharyngeal LNM (RPLNM) and retro-styloid LNM (RSLNM) were a short-axis diameter of ≥5 mm and/or necrosis and/or abnormal FDG uptake. Any visible medial RPLN was defined as LNM. RPLNM was confirmed in 20 (13%) patients. Of these, 10 (6%) had ipsilateral RPLNM, 5 (3%) had contralateral RPLNM, and 5 (3%) had bilateral RPLNM. No patients were diagnosed with medial RPLNM. Fisher's exact test revealed tumor site (p = 0.006), T category (p = 0.049), and cervical LNM (p < 0.001) to be significantly associated with RPLNM. Logistic regression analysis revealed posterior wall (PW) tumors (odds ratio [OR]: 4.128, 95% confidence interval [CI]: 1.339-12.727; p = 0.014) and bilateral or contralateral cervical LNM (OR: 11.577, 95% CI: 2.135-62.789; p = 0.005) to be significantly correlated with RPLNM. The RPLNM was found in 9 (32%) of the 28 patients with PW tumors. Of these 9 patients, 2 (7%) had ipsilateral RPLNM, 3 (11%) had contralateral RPLNM, and 4 (14%) had bilateral RPLNM. Fisher's exact test revealed the PW tumors to be significantly associated with contralateral RPLNM (p < 0.001). Retro-styloid LNM (RSLNM) was confirmed in two (1%) patients, both of whom had ipsilateral RSLNM with lymph nodes (LNs) of ≥15 mm in the upper limit of ipsilateral level II. Fisher's exact test revealed the LN of ≥15 mm in the upper limit of ipsilateral level II to be significantly associated with ipsilateral RSLNM (p = 0.001). The RPLNM was identified in 13% of patients with HPC. The PW tumors and bilateral or contralateral cervical LNM were risk factors for RPLNM; particularly, PW tumors were a specific risk factor for contralateral RPLNM. Although the RSLNM was rare, LNs of ≥15 mm in the upper limit of ipsilateral level II were a risk factor for ipsilateral RSLNM.

Positron emission tomography assessment of metacarpal/metatarsal condylar fractures post surgical repair: Prospective study in 14 racehorses.

To assess 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) findings associated with metacarpal/metatarsal condylar fractures at the time of fracture repair and through healing. Prospective descriptive study. Fourteen Thoroughbred racehorses. 18F-NaF PET was performed within 4 days of surgical metacarpal/metatarsal condylar fracture repair, on both the injured and contralateral limb. Follow-up PET scans were offered at 3- and 5-months post fracture repair. Areas of abnormal uptake were assessed using a previously validated grading system. Eight fractures were located in the parasagittal groove (PSG) (six lateral and two medial) and six fractures were located abaxial to the PSG (non-PSG) through the palmar/plantar condyle (all lateral). All horses in the latter group had uptake in the lateral palmar condyle of the contralateral limb suggestive of stress remodeling. Three horses with PSG fractures had uptake in a similar location in the contralateral limb. Horses with lateral condylar fracture only presented minimal or mild uptake in the medial condyle, which is considered atypical in the front limbs for horses in full training. Four horses developed periarticular uptake in the postoperative period suggestive of degenerative joint disease, three of these horses had persistent uptake at the fracture site. These four horses did not return to racing successfully. The findings of this study provide evidence of pre-existing lesions and specific uptake patterns in racehorses suffering from metacarpal/metatarsal condylar fractures. PET has a possible role in the prevention, diagnosis, and postoperative monitoring of metacarpal/metatarsal condylar fractures in racehorses.

A Case of Metastatic Papillary Thyroid Carcinoma in Neck Lymph Nodes Without Primary Tumor in Thyroid Gland.

Metastatic papillary thyroid carcinoma in the lymph nodes without a primary tumor in the thyroid gland is rarely reported. We report the case of a 63-year-old male who had a left neck level II palpable mass. A left cervical mass had previously undergone 2 central needle biopsies, but only atypical cells had been identified. His prior medical history included surgical treatment for prostate cancer 11 years ago. There was no suspicious primary tumor in the endoscopic examination. After the excisional biopsy, the pathologic finding was metastatic papillary carcinoma from the thyroid, and there were no aberrant findings in the thyroid sonography. The patient underwent a complete thyroidectomy, bilateral central neck dissection (CND), and left level IV dissection, along with postoperative radioactive iodine (RAI) therapy. No thyroid lesion and no more positive lymph nodes were found in the final pathology report. Three months later, a radioiodine nuclear scan was performed, although it revealed no abnormal iodine uptake.

Comparison of 18F-FDG PET Findings of Pegfilgrastim-Induced Aortitis With Other Types of Large-Vessel Vasculitis: A Retrospective Observational Study.

To elucidate the PET/CT findings of pegfilgrastim-induced aortitis (PFIA) and compare them with those of other large-vessel vasculitis. We enrolled 45 patients diagnosed with the following: PFIA, n = 8; Takayasu arteritis (TA), n = 12; giant cell arteritis (GCA), n = 6; and immunoglobulin G4-related aortitis (IgG4-A), n = 19. Records of PET/CT performed before treatment initiation were collected. The aorta and its branches were divided into 16 anatomic regions. Presence of abnormal 18F-FDG uptake in each region was determined and measured. The 18F-FDG-positive areas of PFIA were distributed in the regions of the ascending aorta to the suprarenal abdominal aorta, cervical branches of the aorta, and external iliac arteries, similar to those of TA. However, TA had a higher proportion of 18F-FDG-positive areas than PFIA in almost all anatomic regions. These areas of GCA were widespread throughout the entire aorta and the upper and lower limbs, whereas those of IgG4-A were observed from the abdominal aorta to iliac arteries. SUVmax, SUVpeak, metabolic volume, and total lesion glycolysis were higher in GCA than in PFIA, TA, and IgG4-A. Pegfilgrastim-induced aortitis distribution on PET/CT was frequently observed in the aorta, cervical branches, and extra iliac arteries. The low proportion of 18F-FDG-positive areas in PFIA was different from that of TA, GCA, and IgG4-A. These findings may help identify and differentiate various aortitis types in clinical practice.

Increased 18F-FAPI Uptake in Radiation-Induced Liver Injury.

A 51-year-old woman with breast cancer underwent a complete surgical resection and chemoradiotherapy approximately 3 months ago. Follow-up abdominal ultrasound detected a new lesion with decreased echogenicity in the hepatic segment IV/VIII. 18F-FDG PET/CT showed the hepatic lesion without abnormal uptake. The patient was subsequently enrolled in a clinical trial of 18F-FAPI PET/CT to assess the hepatic lesion. An intense 18F-FAPI activity was identified in the hepatic lesion. Finally, pathological analysis combined with imaging follow-up confirmed the diagnosis of radiation-induced liver injury.

327. ANALYSING THE ROLE OF PET-CT IN ESOPHAGEAL CANCER: A SINGLE CENTRE COHORT STUDY

Abstract Background While PET-CT is considered the gold standard imaging investigation in diagnosing esophageal cancer, its role in determining management is controversial. It demonstrates increased sensitivity for detection of occult M1 disease in comparison with endosonography or CT alone, however its accuracy in assessment of histopathologic response to neoadjuvant therapy is unclear. The aim of this study was to evaluate the clinical utility of PET-CT in staging, response evaluation and prognostication in esophageal squamous cell carcinoma (SCC) and adenocarcinoma (AC). Methods Patients with esophageal cancer undergoing treatment with curative intent were studied prospectively. Baseline imaging (PET1) was carried out at diagnosis. Repeat scanning (PET2) was performed at 4 weeks post-completion of neoadjuvant chemotherapy (nCT) or chemoradiation (nCRT). Pathological complete response (pCR) was defined as TRG1, ypN0. Major pathologic response was defined as TRG1–2, ypN0. Metabolic complete response (mCR) was defined as absence of abnormal FDG uptake at the primary site, nodal sites or suspected metastatic sites. The association between 18F-FDG-uptake (SUVmax) and PET-predicted nodal status, histopathologic parameters and survival were determined using univariable and multivariable regression models. Results 730 patients were studied. PET identified CT-occult M1 disease in 2.9% and synchronous neoplasms in 1.4%. The relative reduction in SUVmax was greater among patients treated with nCRT compared with nCT (P = 0.021). SUVmax correlated with pT stage among patients treated with primary surgery (P &amp;lt; 0.001), however 32.3% with AC and 15.8% with SCC who were predicted node negative were pN+. Post neoadjuvant therapy, PET parameters showed modest associations with mCR, but no parameter accurately predicted pCR. Among patients with mCR, 90.9% with AC post-nCT, 84.1% with AC post-nCRT and 54.8% with SCC post-nCRT had residual disease. Lower preoperative SUVmax was independently associated with improved survival in AC, but not SCC. Conclusion PET-CT identifies CT-occult M1 disease or synchronous neoplasms in 4.3% at initial staging. PET-CT poorly predicts ypN status, particularly in AC. After neoadjuvant therapy, PET-CT is poorly predictive of histopathologic response—the majority of patients with an mCR have residual disease. Nonetheless, improvements in SUVmax may reflect a greater chance of achieving major pathologic response and more favourable long-term outcomes in AC.

Deep learning model with collage images for the segmentation of dedicated breast positron emission tomography images.

Dedicated breast positron emission tomography (dbPET) has high contrast and resolution optimized for detecting small breast cancers, leading to its noisy characteristics. This study evaluated the application of deep learning to the automatic segmentation of abnormal uptakes on dbPET to facilitate the assessment of lesions. To address data scarcity in model training, we used collage images composed of cropped abnormal uptakes and normal breasts for data augmentation. This retrospective study included 1598 examinations between April 2015 and August 2020. A U-Net-based model with an uptake shape classification head was trained using either the original or augmented dataset comprising collage images. The Dice score, which measures the pixel-wise agreement between a prediction and its ground truth, of the models was compared using the Wilcoxon signed-rank test. Moreover, the classification accuracies were evaluated. After applying the exclusion criteria, 662 breasts were included; among these, 217 breasts had abnormal uptakes (mean age: 58 ± 14years). Abnormal uptakes on the cranio-caudal and mediolateral maximum intensity projection images of 217 breasts were annotated and labeled as focus, mass, or non-mass. The inclusion of collage images into the original dataset yielded a Dice score of 0.884 and classification accuracy of 91.5%. Improvement in the Dice score was observed across all subgroups, and the score of images without breast cancer improved significantly from 0.750 to 0.834 (effect size: 0.76, P = 0.02). Deep learning can be applied for the automatic segmentation of dbPET, and collage images can improve model performance.

Giant cell carcinoma of the lung with hypertrophic pulmonary osteoarthropathy as a paraneoplastic syndrome: a case report

BackgroundHypertrophic pulmonary osteoarthropathy is a rare syndrome characterized by a triad that includes periostitis, digital clubbing, and painful arthropathy of the large joints, especially large joints in the lower limbs with lung cancer. Herein we describe a case of a giant cell carcinoma of the lung with hypertrophic pulmonary osteoarthropathy as a paraneoplastic syndrome. The tumor was successfully resected, and complete remission of the syndrome was achieved after surgery.Case presentationA 48-year-old man with right fingers and bilateral ankle arthralgias was referred to our hospital. These arthropathies were painful and refractory to the oral administration of several non-steroidal anti-inflammatory drugs; thus, oxycodone hydrochloride hydrate was prescribed. Additionally, the fingers and toes had a clubbed appearance and the tubular bones were shown as double lines on radiographs of both arms and legs, indicating periosteal thickening. A 45-mm mass-like shadow was present on the right upper-to-middle lung field on the chest x-ray, which was confirmed to be a mass in the upper lobe of the right lung on the chest CT scan. An abnormal uptake was observed in the area of the mass on the FDG-PET scan; the standardized uptake value maximum was 11.8. The histologic diagnosis of a bronchoscopic biopsy was an undifferentiated carcinoma, and the clinical diagnosis was non-small cell lung cancer. The clinical stage was c-T2bN0M0 with paraneoplastic syndrome as a hypertrophic pulmonary osteoarthropathy. A right upper lobectomy with an S6 partial resection adjacent to the upper lobe of the right lung and an ND2a-2 lymph node dissection was performed. The postoperative course was uneventful. The pathologic diagnosis was a giant cell lung carcinoma, which was classified as p-T3 (52 mm in diameter) N0M0, stageIIB. A gradual decrease in arthritic pain was observed from the first operative day. No anodyne, including oxycodone, was required approximately 2 months after surgery. No tumor or paraneoplastic syndrome recurrence was observed 2 years postoperatively.ConclusionsHypertrophic pulmonary osteoarthritis may occur as a secondary manifestation of lung malignancies. Thus, the paraneoplastic syndrome should be considered in such cases.

New Developments in Myeloma Treatment and Response Assessment.

Recent innovative strategies have dramatically redefined the therapeutic landscape for treating multiple myeloma patients. In particular, the development and application of immunotherapy and high-dose therapy have demonstrated high response rates and have prolonged remission duration. Over the past decade, new morphologic or hybrid imaging techniques have gradually replaced conventional skeletal surveys. PET/CT using 18F-FDG is a powerful imaging tool for the workup at diagnosis and for therapeutic evaluation allowing medullary and extramedullary assessment. The independent negative prognostic value for progression-free and overall survival derived from baseline PET-derived parameters such as the presence of extramedullary disease or paramedullary disease, as well as the number of focal bone lesions and SUVmax, has been reported in several large prospective studies. During therapeutic evaluation, 18F-FDG PET/CT is considered the reference imaging technique because it can be performed much earlier than MRI, which lacks specificity. Persistence of significant abnormal 18F-FDG uptake after therapy is an independent negative prognostic factor, and 18F-FDG PET/CT and medullary flow cytometry are complementary tools for detecting minimal residual disease before maintenance therapy. The definition of a PET metabolic complete response has recently been standardized and the interpretation criteria harmonized. The development of advanced PET analysis and radiomics using machine learning, as well as hybrid imaging with PET/MRI, offers new perspectives for multiple myeloma imaging. Most recently, innovative radiopharmaceuticals such as C-X-C chemokine receptor type 4-targeted small molecules and anti-CD38 radiolabeled antibodies have shown promising results for tumor phenotype imaging and as potential theranostics.

A preliminary study on the effect of renal function on the metabolism of 18F-FDG in the human cerebellum.

The cerebellum is less affected by normal aging or neurodegenerative diseases, the aim of this paper is to investigate the effect of renal function status on uptake of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) in human cerebellum based on independent creatinine (CRE) or blood urea nitrogen (BUN) levels. A total of 253 patients who underwent 18F-FDG PET/CT scans were included. The patients were divided into groups according to renal function status: 201 patients with normal renal function, 16 patients with increase CRE, 36 patients with decrease CRE, and 31 patients with abnormal BUN. The maximum standardized uptake values were obtained in regions of interest (ROIs) for multiple tissue types (right cerebellum, right lobe of liver, right lung, bone marrow and psoas muscle at the level of the fourth lumbar vertebra). Moreover, the selected normal CRE groups were pair-matched with CRE decrease group with respect to age, sex, body mass index and glucose, respectively. Among 253 patients who met the inclusion/exclusion criteria, the final analysis included 967 ROIs (244 cerebellum, 191 lungs, 230 muscles, 145 bone marrow, and 157 liver) from 18F-FDG PET/CT scans. Among patients grouped by CRE or BUN levels, the uptake of 18F-FDG by cerebellum was significantly decreased in patients with CRE decrease level (P=0.001). There were no statistically significant differences between the other groups. Matched-pair analysis indicated there were no significant changes in outcomes between the CRE decrease group and the age-, sex-, BMI-, and glucose-matched controls compared to pre-matching. In patients with normal renal function and reduced CRE concentration, decrease cerebellar glucose metabolism was observed; however, no abnormal uptake of 18F-FDG was found in the cerebellum and other normal tissues of patients with impaired renal function. Consequently, in the study of cerebellar 18F-FDG metabolism, it may be necessary to consider the influence of blood CRE level.

11C]Choline PET/CT in a Patient with Prostate Cancer Biochemical Recurrence Showing Two Suspicious Findings in the Breast and Liver.

A 79-year-old man with prostate cancer (PCa) was referred to our center to perform a [11C]Choline PET/CT for biochemical recurrence. Positron emission tomography/computed tomography (PET/CT) scan detected PCa recurrence in the prostate gland and several pelvic and abdominal lymph nodes. Two abnormal uptakes were also identified in the right breast and in the liver, respectively. Breast histological findings turned out to be gynecomastia, while the liver lesion resulted in a benign perfusion anomaly at follow-up magnetic resonance imaging (MRI). Although incidental findings were benign in this case, it is important to always investigate abnormal uptakes of [11C]Choline, as it could be an expression of further metastases or synchronous malignancies such as breast cancer and hepatocellular carcinoma.

18F]FDG-PET/CT in Idiopathic Inflammatory Myopathies: Retrospective Data from a Belgian Cohort.

[18F]FDG-PET/CT is a useful tool for diagnosis and cancer detection in idiopathic inflammatory myopathies (IIMs), especially polymyositis (PM) and dermatomyositis (DM). Data deriving from Europe are lacking. We describe [18F]FDG-PET/CT results in a Belgian cohort with IIMs, focusing on patients with PM and DM. All of the cases of IIMs admitted between December 2010 and January 2023 to the Cliniques Universitaires Saint-Luc (Belgium) were retrospectively reviewed. In total, 44 patients were identified with suspected IIMs; among them, 29 were retained for final analysis. The mean age of the retained patients was 48.7 years; 19 patients were female (65.5%). Twenty-two patients had DM and seven had PM. The mean serum creatinine kinase (CK) and the mean CRP levels were 3125 UI/L and 30.3 mg/L, respectively. [18F]FDG-PET/CT imaging was performed for 27 patients, detecting interstitial lung diseases (ILDs) in 7 patients (25.9%), cancer in 3 patients (11.1%), and abnormal muscle FDG uptake compatible with myositis in 13 patients (48.1%). All of the patients who were detected to have ILDs via PET/CT imaging were confirmed using a low-dose lung CT scan. Among the patients who were detected to have abnormal muscle FDG uptake via PET/CT scans (13/28), the EMG was positive in 12 patients (p = 0.004), while the MRI was positive in 8 patients (p = 0.02). We further observed that there was a significantly higher level of CK in the group with abnormal muscle FDG uptake (p = 0.008). Our study showed that PET/CT is useful for detecting cancer and ILDs. We showed that the detection of abnormal muscle uptake via PET/CT was in accordance with EMG and MRI results, as well as with the mean CK value, and that the presence of dyspnea was significantly associated with the presence of ILDs detected via PET/CT imaging (p = 0.002).

Cardiac fludeoxyglucose-18 positron emission tomography in genotype-positive arrhythmogenic cardiomyopathy

BackgroundMyocardial inflammation contributes to the pathogenesis of arrhythmogenic cardiomyopathy (ACM), a clinically and genetically heterogenous disorder. Due to phenotypic overlap, some patients with genetic ACM may be evaluated for an underlying inflammatory cardiomyopathy. However, the cardiac fludeoxyglucose (FDG) positron emission tomography (PET) findings in ACM patients have not been elucidated. MethodsAll genotype-positive patients in the Mayo Clinic ACM registry (n = 323) who received a cardiac FDG PET were included in this study. Pertinent data were extracted from the medical record. ResultsCollectively, 12/323 (4%; 67% female) genotype-positive ACM patients received a cardiac PET FDG scan as part of their clinical evaluation (median age at scan 49 ± 13 years). Amongst these patients, pathogenic/likely pathogenic variants were detected in LMNA (n = 7), DSP (n = 3), FLNC (n = 1) and PLN (n = 1). Of note, 6/12 (50%) had abnormal myocardial FDG uptake, including diffuse (entire myocardium) uptake in 2/6 (33%), focal (1–2 segments) uptake in 2/6 (33%) and patchy (3+ segments) in 2/6 (33%). Median myocardial standardized uptake value ratio was 2.1. Interestingly, LMNA-positive patients accounted for 3 out of 6 (50%) positive studies (diffuse uptake in 2 and focal uptake in 1). ConclusionAbnormal myocardial FDG uptake is common in genetic ACM patients undergoing cardiac FDG PET. This study further supports the role of myocardial inflammation in ACM. Further investigation is needed to determine role of FDG PET in diagnosis and management of ACM and investigate the role of inflammation in ACM.

Preclinical radiolabeling, in vivo biodistribution and positron emission tomography of a novel pyrrolobenzodiazepine (PBD)-based antibody drug conjugate targeting ASCT2

IntroductionAnti-ASCT2 antibody drug conjugate (ADC) MEDI7247 has been under development as a potential anti-cancer therapy for patients with selected relapsed/refractory hematological malignancies and advanced solid tumors by MedImmune. Although promising efficacy was observed in the clinic, pharmacokinetic (PK) analyses observed low exposure of MEDI7247 in phase I hematological patients. To investigate the biodistribution properties of MEDI7247, MEDI7247 and control antibodies were radiolabeled with zirconium-89 and in vitro and in vivo properties characterized. MethodsMEDI7247 (human anti-ASCT2 antibody conjugated with pyrrolobenzodiazepine (PBD)) and MEDI7519 (MEDI7247 without PBD drug conjugate) and an isotype control antibody drug conjugate construct were conjugated with p-isothiocyanatobenzyl-deferoxamine (Df) and radiolabeled with zirconium-89. In vitro studies included determining the radiochemical purity, protein integrity, immunoreactivity (Lindmo analysis), apparent antigen binding affinity for ASCT2-positive cells by Scatchard analysis and serum stability of the radiolabeled immunoconjugates. In vivo studies included biodistribution and PET/MRI imaging studies of the radiolabeled immunoconjugates in an ASCT2-positive tumor model, HT-29 colorectal carcinoma xenografts. ResultsConditions for the Df-conjugation and radiolabeling of antibody constructs were determined to produce active radioimmunoconjugates. In vivo biodistribution and whole body PET/MRI imaging studies of [89Zr]Zr-Df-MEDI7519 and [89Zr]Zr-Df-MEDI7247 radioimmunoconjugates in HT-29 colon carcinoma xenografts in BALB/c nude mice demonstrated specific tumor localization. However, more rapid blood clearance and non-specific localization in liver was observed for [89Zr]Zr-Df-MEDI7247 and [89Zr]Zr-Df-MEDI7519 compared to isotype control ADC. Except for liver and bone, other normal tissues demonstrated clearance reflecting the blood clearance for all three constructs and no other abnormal tissue uptake. Conclusions and advances in knowledgePreclinical biodistribution analyses of [89Zr]Zr-Df-MEDI7247 and [89Zr]Zr-Df-MEDI7519 showed the biodistribution pattern of anti-ASCT2 ADC MEDI7247 was similar to parental MEDI7519, and both antibodies showed specific tumor uptake compared to an isotype control ADC. This study highlights an important role nuclear medicine imaging techniques can play in early preclinical assessment of drug specificity as part of the drug development pipeline.

Comparison of quantitative FDG-PET and MRI in anti-LGI1 autoimmune encephalitis

ObjectivesAnti-leucine glioma-inactivated protein 1 (anti-LGI1) autoimmune encephalitis (AE) presents as subacute memory loss, behavioral changes, and seizures. Diagnosis and treatment delays can result in long term sequelae, including cognitive impairment. 18F-FDG PET/CT may be more sensitive than MRI in patients with AE. Our objective was to determine if anti-LGI1 is associated with a distinct pattern of FDG uptake and whether this pattern persists following treatment.MethodsNineteen18F-FDG PET/CT brain scans (13 pre-treatment, 6 convalescent phase) for 13 patients with anti-LGI1 were studied using NeuroQ™ and CortexID™. The sensitivity of the PET images was compared to MRI. The Z scores of 47 brain regions between the pre-treatment and next available follow-up images during convalescence were compared.ResultsAll 18F-FDG PET/CT scans demonstrated abnormal FDG uptake, while only 6 (42.9%) pre-treatment brain MRIs were abnormal. The pre-treatment scans demonstrated hypermetabolism in the bilateral medial temporal cortices, basal ganglia, brain stem, and cerebellum and hypometabolism in bilateral medial and mid frontal, cingulate, and parietotemporal cortices. Overall, the brain uptake during convalescence showed improvement of the Z scores towards 0 or normalization of previous hypometabolic activity in medial frontal cortex, inferior frontal cortex, Broca’s region, parietotemporal cortex, and posterior cingulate cortex and previous hypermetabolic activity in medial temporal cortices, caudate, midbrain, pons and cerebellum.ConclusionsBrain FDG uptake was more commonly abnormal than MRI in the pre-treatment phase of anti-LGI1, and patterns of dysmetabolism differed in the pre-treatment and convalescent phases. These findings may expedite the diagnosis, treatment, and monitoring of anti-LGI1 patients.

Patterns of recurrence post prostatectomy in the PSMA era: What lessons can we take to daily practice from a high-volume nuclear medicine center?

e17013 Background: PSMA has deeply modified the treatment of prostate cancer, mainly in the biochemical recurrence setting, where the therapeutic plan may be changed in up to two thirds of cases. Unfortunately, this diagnostic tool is still not fully available in many places over the world. Growing evidence from high-volume nuclear medicine centers may guide the development of adapted treatment plans based on sites of relapse according to wide available clinical information. Methods: We retrospectively reviewed 648 Ga68-PSMA-PET-CT scans in the biochemical relapse setting in patients initially treated with prostatectomy. Results were classified either as negative or positive if abnormal SUV uptake was detected in the prostate bed, pelvis, or distant organs. We then classified the patients with positive tests based on sites of relapse according to serum PSA level. Results: Among the 648 analyzed patients, there were 60, 63, and 61 recurrences in prostate bed, pelvis, or distant organs, respectively. For those with serum PSA ≤ 1.0 ng/mL, there was a higher chance of locoregional failure (prostate bed or pelvis), with less than 20% presenting distant metastasis. When assessing patients with serum PSA 1.1-2.0 ng/mL, the rate of distant metastasis increased to 22.7%, while it was found in 40.7% of patients with serum PSA between 2 and 5 ng/mL. Conclusions: PSMA-PET-CT scan is clearly modifying the therapeutic landscape of prostate cancer in different scenarios. Although it is not available in many regions due to high financial costs and logistic barriers, the emerging evidence arising from specialized cancer centers matching the clinical information with tests results may help doctors to make better treatment decisions even without PSMA-PET-CT scans. [Table: see text]

Tumor heterogeneity and treatment response assessment using next generation imaging and liquid biopsy in patients with metastatic castration resistant prostate cancer receiving abiraterone (ANGELA): A single-center prospective observational trial.

5057 Background: Metastatic castration resistant prostate cancer (mCRPC) is a disease of intra-patient tumor heterogeneity which poses obstacles in treatment and response evaluation. With the development of next generation imaging (NGI) and liquid biopsy, precise assessment of heterogeneity has entered a new era. In this study, we used longitudinal NGI (68Ga-PSMA and 18F-FDG PET/CT) and circulating tumor DNA (ctDNA) testing to assess tumor heterogeneity and treatment response in mCRPC patients receiving abiraterone. Methods: ANGELA is a single-center prospective observational trial (NCT05188911). We recruited mCRPC patients who received abiraterone as initial hormonal treatment. Eligible patients should have a life expectancy &gt;12 months. CtDNA testing and NGI were performed at baseline and after 12 weeks of abiraterone (Week 13). Conventional imaging and PSA testing were performed at Week 1 and every 12 weeks. Primary end-point of this study is intra-patient lesion heterogeneity evaluated by 3 dimensions: (1) Imaging heterogeneity: defined as at least 1 lesion with FDG+/PSMA- phenotype at baseline and/or Week 13; (2) Genomic heterogeneity: quantified by ctDNA fraction increase and mutational changes per gene between baseline and Week 13; (3) Response heterogeneity: defined as at least 1 new tumoral lesion with either PSMA or FDG abnormal uptake at Week 13. Secondary end-points are correlations of heterogeneity with conventional-evaluated progression-free survival (PFS) and 2-year overall survival (OS). Results: Between May 20, 2020 and Feb 02, 2021, we included 33 eligible patients in our study. FDG+/PSMA- tumoral lesion was observed in 7/33 (21.2%) and 8/33 (24.2%) of patients at baseline and Week 13, respectively. Notably, 5 of 8 patients with imaging heterogeneity at Week 13 had no FDG+/PSMA- lesion at baseline. For genomic heterogeneity, we detected ctDNA fraction increase in 4/33 patients (12.1%). In addition, we found new gene mutations detected in Week 13 ctDNA testing in 5/33 patients (15.2%), 2 of 5 had ctDNA fraction increase. For response heterogeneity, we observed 15/33 patients (45.5%) patients developed at least 1 new tumoral lesion (FDG+ or PSMA+) at Week 13. We correlated heterogeneity factors with prognosis, and found that detection of new mutated genes (P=0.005 and P&lt;0.001), new PSMA+ lesion (P&lt;0.001 and P&lt;0.001), and new FDG+ lesion (P=0.008 and P&lt;0.0001) at Week 13 were significant predictors of shorter PFS and decreased 2-year OS. Detailed biomarker study for response analysis is still in process. Conclusions: Intra-patient tumor heterogeneity was common among mCRPC patients receiving abiraterone. Combining liquid biopsy with NGI can monitor changes in tumor heterogeneity and indicate early combination therapy. Clinical trial information: NCT05188911 .

A Long-Term Survival Case of Coronary Artery Intimal Sarcoma.

Primary cardiac sarcomas are rare diseases with very poor prognoses. In this report, we present a case of coronary artery intimal sarcoma in a patient who survived for a long time after diagnosis. A 57-year-old female underwent percutaneous coronary intervention of the right coronary artery due to acute myocardial infarction caused by thrombotic occlusion and was diagnosed as having coronary artery intimal sarcoma. She underwent surgical resection and coronary artery bypass surgery of the artery, cryothermy coagulation, and postoperative adjuvant chemotherapy for 1 year. After 3 years, focal recurrence was detected in the caudal region of the left ventricular inferior wall. Radiotherapy was performed. The tumor shrank significantly after radiotherapy. Four years later, there was no significant abnormal uptake on positron-emission tomography/computed tomography. At 7 years after diagnosis, when this case report was submitted, the patient was alive and her performance had maintained a good status. Intimal sarcoma occurring in a coronary artery is extremely rare. The efficacy of treatments for cardiac intimal sarcoma, which include surgical resection, chemotherapy and radiotherapy, has been reported to be limited. To the best of our knowledge, this is the first report of a case of coronary artery intimal sarcoma with long-term survival after comprehensive therapies including surgical resection and radiotherapy.

A solitary osteolytic lesion with pathological fracture in the cervical spine - a case report

BackgroundLangerhans cell histiocytosis (LCH) is a rare disorder. The treatment options vary depending on how many organs are involved and how extensive the disease is. In this report, a case of LCH with isolated 6th cervical vertebra (C6) collapse was presented. This case was treated with anterior corpectomy and instrumented fusion, followed by local radiotherapy (RT), with a good clinical outcome up to postoperative six months.Case presentationThis was a 47-year-old female patient with a complaint of neck pain and bilateral shoulder pain for two months before consultation. She was initially treated with analgesics, but the pain was persistent. Further radiological evaluations revealed an osteolytic lesion within the C6 vertebral body with a pathological fracture. Magnetic resonance imaging (MRI) with contrast of the cervical spine revealed diffused hypointense signal changes on the T1-weighted images and hyperintense signal changes on the T2-weighted images in the C6 vertebral body, with significant contrast-enhanced infiltration signals. Furthermore, in positron emission tomography-computed tomography (PET-CT), focal hypermetabolism and abnormal uptake signals were seen only in the C6 vertebral body. The patient underwent an anterior cervical corpectomy with instrumented fusion. The histopathological results confirmed the diagnosis of LCH. The patient reported significant pain relief on postoperative day one. Moreover, she was treated by local RT at postoperative one month. Good clinical outcomes were achieved in the form of no pain and recovery in neck mobility up to postoperative six months. No evidence of recurrence was observed at the final follow-up.ConclusionsThis case report describes a treatment option for a solitary C6 collapse with LCH managed by anterior corpectomy and instrumented fusion, followed by local RT, with a good clinical outcome at postoperative six months. More studies are needed to elucidate whether such a treatment strategy is superior to surgery or RT alone.

Late recurrent gastric carcinoma 12 years after surgery with attenuation of CD44 variant 9 expression

BackgroundLate recurrence of gastric cancer at 10 years post-gastrectomy is extremely rare, and the underlying mechanism remains unclear. We report a para-aortic lymph node metastasis case that recurred 12 years postoperatively.Case presentationA 44-year-old woman pathologically diagnosed with moderately to poorly differentiated adenocarcinoma with pT2(SS)pN2cM0pStageIIIA according to the Japanese Classification of Gastric Carcinoma (the 13th Edition) underwent laparoscopic distal gastrectomy with D1 + lymph node dissection. She received adjuvant chemotherapy with tegafur-uracil (400 mg/day) for 2 years. At postoperative year (POY) 5, a swollen lymph node was detected in the No.16b1lat lymph node station. However, positron emission tomography (PET) revealed normal uptake, and the levels of tumor markers were within normal limits; hence, the possibility of metastasis was considered low, and the patient was placed under observation. At POY 12, computed tomography revealed an enlargement of the No.16b1lat lymph node station, and PET showed abnormal uptake. Endoscopic ultrasound-guided fine-needle aspiration revealed a moderately differentiated adenocarcinoma. Hence, a diagnosis of recurrence of gastric cancer was made. The patient underwent para-aortic nodal dissection (PAND) of No.16b1lat & int stations. Immunochemical staining results also suggested the recurrence of gastric cancer. However, the expression of CD44 variant 9 (CD44v9), a cancer stem cell marker for gastric adenocarcinoma, was attenuated in the recurrent lesions compared with that in the primary lesions. Postoperatively, she received chemotherapy with tegafur–gimeracil–oteracil (80 mg/day) for 1 year. Bone metastasis was observed at POY 4 after PAND, and the IHC analysis showed a HER2 score of 3 + in a needle biopsy specimen of bone metastasis. The expression of CD44v9 was slightly positive. The patient is being treated with chemotherapy with FOLFOX + trastuzumab.ConclusionsA defense mechanism against reactive oxygen species has been reported as a mechanism causing recurrence of CD44v9-positive gastric cancer. Consequently, CD44v9-positive gastric cancer grows in metastatic organs, repeatedly self-renews, and proliferates to form recurrent lesions. In the present case, the degree of CD44v9 staining in recurrent lesions was suggested to be related to the recurrence time.