The Prognostic Value of Positron Emission Tomography/Computed Tomography in Clinical Stage I Lung Cancer Patients: A Propensity-Match Analysis

Background: The application of positron emission tomography/computed tomography (PET/CT) helps provide accurate clinical staging for lung cancer patients. However, the effects and trends in early-stage lung cancer remain unclear. The aim of this study was to compare differences between clinical stage I lung cancer patients who received PET/CT for staging and those who did not. Methods: Data were obtained from the Taiwan Society of Cancer Registry. There were 6587 clinical stage I lung cancer patients between 2009 and 2014 analyzed in this study. We compared the characteristics of the PET/CT and no PET/CT groups. After propensity score matching, it resulted in both groups having 2649 patients. We measured the overall survival rates of all clinical stage I lung cancer patients and the overall survival rates of patients with PET/CT and without PET/CT. Results: The 1-, 3-, and 5-year survival rates of all clinical stage I lung cancer patients were 97.2%, 88.2%, and 79.0%, respectively. Patients with a larger tumor size tended to receive PET/CT for staging (stage Ib: 38.25% vs. 27.82%, p < 0.0001) and a larger resection (lobectomy: 74.62% vs. 66.61%, p < 0.0001). The 5-year survival rates were 79.8% in the PET/CT group and 78.2% in the no PET/CT group after propensity score matching (p = 0.6528). Conclusions: For clinical stage I lung cancer in Taiwan, patients with larger tumor sizes tend to have PET/CT for staging. Although PET/CT provided more precise clinical staging, these patients still received larger resections and had more pathological migration. However, there was no overall survival rate benefit after PET/CT.

Distinguishing Kikuchi-Fujimoto disease from lymphoma in patients by clinical and PET/CT features

To develop a scheme for distinguishing Kikuchi-Fujimoto disease (KFD) from lymphoma in patients presenting enlarged lymph nodes (LNs) predominantly on the upper side of the diaphragm. From November 2015 to August 2023, 32 KFD patients and 38 lymphoma patients were pathologically confirmed and enrolled in this retrospectively study. Clinical and 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) features were collected. When comparing those PET/CT parameters, we set 5 models with different research objects: (1) all affected LNs; (2) the 5 largest affected LNs in terms of maximum diameter; (3) the 5 largest affected LNs in terms of maximum standard uptake values (SUVmax); (4) the largest affected LNs in terms of maximum diameter; (5) the largest affected LNs in terms of SUVmax. Compared to lymphoma patients, KFD patients were younger; and with higher incidence of fever, arthralgia, abnormal serum white blood cell, lactate dehydrogenase (LDH) and splenomegaly; lower incidence of affected LNs perinodal infiltration, necrosis and conglomeration; more affected LNs in Head and Neck nodes (particularly in level II) and Axillary in KFD (P ˂ .05). PET/CT parameters presented as various difference in each model. Finally, 11 clinical and PET/CT features (age ≤ 34, with fever, arthralgia, abnormal white blood cell, abnormal LDH, and without node necrosis and node conglomeration have a score of 2 each; splenomegaly, perinodal infiltration, median maximum diameter ≤ 20.5 and median SUVmax ≤ 7.1 of affected LNs in model 2 have score of 1 each) were selected as scheme items for distinguishing KFD from lymphoma. Individuals who have a total score > 8, meet the criteria for KFD. Sensitivity and specificity were high: 86.8% (95% CI: 71.9%, 95.5%) and 96.9% (95% CI: 83.7%, 99.5%), AUC = 0.975 (95% CI: 90.5%, 99.6%), respectively. It can effectively distinguish KFD from lymphoma by clinical and PET/CT parameters.

Value of 18 F-FDG PET/CT to Identify Occult Infection in Presumed Aseptic Pseudarthrosis after Spinal Fusion: Correlation with Intraoperative Cultures

Objective  Fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) has gained attention as an emerging tool in case of suspicion of infection on spine, whether native or instrumented. However, the diagnostic performance of 18 F-FDG PET/CT in clinically occult low-grade surgical site infection (SSI) after spinal fusion, an important risk factor for pseudarthrosis, remains unknown. Methods  We retrospectively identified all the presumed aseptic patients with pseudarthrosis confirmed by revision surgery who underwent preoperative 18 F-FDG PET/CT scans performed between April 2019 and November 2022. These patients were presumed aseptic because they did not have clinical signs or laboratory tests suggestive of SSI, preoperatively. The PET/CT images were analyzed in consensus by two nuclear medicine physicians blinded to the clinical, biological, and imaging information. Visual assessment of increased uptake around cage/intervertebral disk space (and/or hardware) higher than background recorded from the first normal adjacent vertebra was interpreted as positive. Image data were also quantitatively analyzed by the maximum standardized uptake value as an index of 18 F-FDG uptake, and the ratio between the uptake around cage/intervertebral disk space (and/or hardware) and background recorded from the first normal adjacent vertebra was calculated. The final diagnosis of infection was based on intraoperative cultures obtained during pseudarthrosis revision surgery. Results  Thirty-six presumed aseptic patients with surgically confirmed pseudarthrosis after spinal fusion underwent preoperative 18 F-FDG PET/CT scans. Cultures of samples from revisions found that 20 patients (56%) were infected. The most frequent isolated bacterium was Cutibacterium acnes ( C. acnes ) in 15 patients (75%), followed by coagulase-negative staphylococci (CNS) in 7 patients (33%). Two patients had co-infections involving both C. acnes and CNS. Of the 36 PET/CT studied in this study, 12 scans were true-negative, 10 true-positive, 10 false-negative, and 4 false-positive. This resulted in sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 50%, 75%, 71%, 55%, and 61%, respectively. Conclusion  In presumed aseptic pseudarthrosis after spinal fusion, 18 F-FDG PET/CT offers good specificity (75%) but low sensitivity (50%) to identify occult SSI. The high prevalence (56%) of SSI, mostly caused by C. acnes (75%), found in our presumed aseptic cohort of patients supports the utility of systematic intraoperative cultures in revision cases for pseudarthrosis.

Imaging of Merkel cell carcinoma of the eyelid: A case report

Merkel cell carcinoma (MCC) is a rare primary neuroendocrine carcinoma commonly found in older adults in areas of the skin that are susceptible to ultraviolet ray damage. The current study reports the case of a 79-year-old woman who presented to the Affiliated Hospital of Zunyi Medical University (Zunyi, China) with a painless lump in the lower eyelid of the left eye accompanied by photophobic tears for 4 months. Head computed tomography (CT) and magnetic resonance imaging (MRI) showed a space-occupying lesion ~2.8×2.4 cm in size outside the left orbital muscle cone, which was poorly demarcated from the surrounding normal tissues. Markedly intense and tortuous walking vascular shadows were observed within the tumor tissues. Fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT revealed increased 18F-FDG uptake in the corresponding lesions. Based on these imaging features, a malignant tumor was suspected. The patient subsequently underwent surgery. Postoperative pathology and immunohistochemistry revealed MCC. The clinical presentation of MCC is usually a painless soft-tissue nodule or mass that grows rapidly over a short period and is flesh-colored, bluish red or purple. A slightly hyperdense mass on CT, with equal T1-weighted and slightly longer T2-weighted MRI signals, and mild enhancement on contrast-enhanced scans, accompanied by significantly enhanced distorted vascular shadows and increased 18F-FDG uptake on PET/CT, are valuable in the diagnosis of eyelid MCC.

18F-FDG PET/CT imaging in pulmonary sarcomatoid carcinoma

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare highly aggressive and poorly differentiated non-small cell carcinoma, and little is known about the information on the usefulness of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). We investigated the clinical and 18F-FDG PET/CT features of PSC.

Methods

We retrospectively analyzed 25 consecutive PSC patients who had undergone 18F-FDG PET/CT. Demographic data, PET/CT findings before treatment, pathological features, and prognosis in these patients were investigated to define correlates between maximal standard uptake value (SUVmax) and clinicopathological parameters.

Results

From March 2017 to January 2023, twenty-five eligible patients with PSC were identified. There were 23 (92%) men, aged 68.5 ± 8.5 (range 56-90) years. Eighteen (72%) patients had a frequent smoking history. The mean size of PSCs was 59.3 ± 18.6 (range 29-97) mm, and 23 (92%) PSCs were Stage IV tumors. 20 (80%) lesions were located in the upper lung and 19 (76%) cases belonged to the peripheral type. Necrotic foci appeared in 21(84%) tumors. 11 (44%) PSCs invaded the pleura. All PSCs were FDG avid, and the mean of SUVmax was 11.8 ± 5.3 (range 4.8-25.5). Metastases were found on PET/CT in 24(96%) patients. The SUVmax of the lesions ≥ 5cm was higher than that of the lesions < 5cm (p=0.004), and the SUVmax of lesions with TTF-1 expression was higher than those of lesions without TTF-1 expression (p=0.009). All of the 25 primary lesions were considered malignant and confirmative, probable, and possible diagnosis of PSC was made in 2 (8%), 4 (16%), and 5(20%) patients, respectively on PET/CT. PSC was not considered in 14 (56%) patients, in PET/CT. The survival of patients with surgery didn't demonstrate a significantly good prognosis as compared with those without surgery (p=0.675).

Conclusion

All PSCs had obvious FDG avidity. Although imaging diagnosis is still difficult, combined clinical and imaging features more than 40% of primary lesions were considered for the possibility of PSC in our group. Early histopathological diagnosis is necessary to help develop a reasonable regimen.

Corrigendum: Predictive value of intratumoral-metabolic heterogeneity derived from 18F-FDG PET/CT in distinguishing microsatellite instability status of colorectal carcinoma

[This corrects the article DOI: 10.3389/fonc.2023.1065744.].

Diagnosis of pancreatic focal nesidioblastosis assisted by dual‑nuclide tracer positron emission tomography/computed tomography: A case report

Nesidioblastosis is a rare cause of hyperinsulinemic hypoglycemia in adults and its clinical features are similar to those of insulinoma with recurrent hypoglycemic attacks. The present study reports the case of a 48-year-old man who visited the Affiliated Hospital of Zunyi Medical University (Zunyi, China) with a 5-year history of recurrent hypoglycemic symptoms such as dizziness and palpitations. Abdominal magnetic resonance imaging (MRI) showed a mass of ~1.2x1.0 cm in the head of the pancreas, which was suspected to be an insulinoma. For confirmation, the patient underwent both fluorine-18-fluorodeoxyglucose (18F-FDG) and gallium-68-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-teraacetic acid-d-Phel-Tyr3-Thr8-OC (68Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT), which showed a moderately increased uptake of 18F-FDG but no uptake of 68Ga-DOTATATE in the corresponding lesion. The patient subsequently underwent surgery to remove the lesion, which was pathologically confirmed as a pancreatic nesidioblastosis. This case showed that nesidioblastosis should be considered a differential diagnosis for insulinoma and that dual nuclear tracer PET/CT imaging is helpful for differentiating between the two. If conventional imaging techniques such as ultrasound, CT and MRI cannot identify the cause of hypoglycemia in future cases, dual-nuclide tracer PET/CT imaging should be considered.

An Intrahepatic Fluorodeoxyglucose (FDG)-PET/CT False-Positive Tumor Secondary to Foreign Body Granuloma Masquerading as Colon Cancer Liver Metastasis: A Case Report

A suture placed next to a dissected liver section during the initial hepatectomy may become an unlikely intrahepatic foreign body granuloma. In this report, we describe a case where a silk suture in the liver section plane placed during initial hepatectomy for synchronous colon cancer metastasis became an intrahepatic foreign body granuloma that exhibited fluorodeoxyglucose (FDG) accumulation on positron emission tomography/computed tomography (PET/CT). The granuloma was resected as the second metachronous liver metastatic lesion. A 73-year-old female was referred for a planned second hepatectomy. She had undergone colectomy and hepatectomy for advanced cancer of the ascending colon and synchronous liver metastasis approximately two years ago. However, two possible liver metastases with FDG accumulation were identified in hepatic segments IV and V after one year and nine months after the initial resection. A second hepatectomy was planned after administering systemic chemotherapy. She underwent a left lobectomy with a middle hepatic vein and partial segment V hepatectomy six months after liver lesion identification. The segment IV lesion was histologically proven to be a liver metastasis adenocarcinoma. The segment V lesion revealed a silk thread on the residual liver side at the initial hepatectomy, which was histologically diagnosed as a foreign body granuloma. The possibility of intrahepatic foreign body granuloma development should be considered in subsequent follow-ups in cases where sutures were applied to the dissected residual liver plane during the initial hepatectomy. Additionally, a thorough second hepatectomy should be considered if recurrence is suspected.

Current status and prospect of PET-related imaging radiomics in lung cancer

Lung cancer is highly aggressive, which has a high mortality rate. Major types encompass lung adenocarcinoma, lung squamous cell carcinoma, lung adenosquamous carcinoma, small cell carcinoma, and large cell carcinoma. Lung adenocarcinoma and lung squamous cell carcinoma together account for more than 80% of cases. Diverse subtypes demand distinct treatment approaches. The application of precision medicine necessitates prompt and accurate evaluation of treatment effectiveness, contributing to the improvement of treatment strategies and outcomes. Medical imaging is crucial in the diagnosis and management of lung cancer, with techniques such as fluoroscopy, computed radiography (CR), digital radiography (DR), computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)/CT, and PET/MRI being essential tools. The surge of radiomics in recent times offers fresh promise for cancer diagnosis and treatment. In particular, PET/CT and PET/MRI radiomics, extensively studied in lung cancer research, have made advancements in diagnosing the disease, evaluating metastasis, predicting molecular subtypes, and forecasting patient prognosis. While conventional imaging methods continue to play a primary role in diagnosis and assessment, PET/CT and PET/MRI radiomics simultaneously provide detailed morphological and functional information. This has significant clinical potential value, offering advantages for lung cancer diagnosis and treatment. Hence, this manuscript provides a review of the latest developments in PET-related radiomics for lung cancer.

Impact of retention index on the neoadjuvant chemotherapy effect and the prognosis in oesophageal cancer

OBJECTIVE

The relationship between retention index calculated from dual-time point 18F-fluorodeoxyglucose positron emission tomography-computed tomography and oesophageal cancer prognosis remains unknown. This study aimed to determine usefulness of retention index as a predictor of long-term prognosis of oesophageal cancer and neoadjuvant chemotherapy efficacy.

METHODS

A total of 151 patients with oesophageal cancer who underwent esophagectomy were evaluated retrospectively in this study. We acquired positron emission tomography scans 60 and 120 min (SUVmax1 and SUVmax2, respectively) after the intravenous administration of 3.7 Mbq/kg 18F-fluorodeoxyglucose. The patients were divided into two groups: high-retention index (retention index ≥29%, 107 patients) and low-retention index (retention index <29%, 44 patients). Retention index was calculated as follows: retention index (%) = [(SUVmax2 - SUVmax1)/SUVmax1] × 100.

RESULTS

The overall survival and relapse-free survival rates in the high-retention index group were significantly lower than those in the low-retention index group (P < 0.001). Our multivariate analysis identified that the high-retention index group contained independent risk factors for overall survival (hazard ratio: 2.44, P = 0.009) and relapse-free survival (hazard ratio: 2.61, P = 0.002). The high-retention index group exhibited a lower partial response rate to neoadjuvant chemotherapy evaluated by computed tomography (P < 0.001) and a lower pathological therapeutic effect in the resected specimen (P = 0.019) than the low-retention index group.

CONCLUSIONS

The retention index was associated with neoadjuvant chemotherapy responses and long-term prognosis for oesophageal cancer.

Fibroblast Activation Protein-Targeted PET/CT With Al18F-NODA-FAPI-04 for In Vivo Imaging of Tendon Healing in Rat Achilles Tendon Injury Models

BACKGROUND

Fibroblast activation protein (FAP) has shown high expression in inflammatory responses and fibrosis.

HYPOTHESIS

We speculated that FAP could serve as a diagnostic and monitoring target in the tendon healing process.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 72 Sprague-Dawley rats were randomly divided into a tendon crush group and a half-partial tendon laceration group. Four rats in each group were injected with radiotracers weekly for 4 weeks after surgery, with aluminum fluoride-labeled 1,4,7-triazacyclononane-N,N',N″-triacetic acid-conjugated FAP inhibitor (Al18F-NODA-FAPI-04) administered on the first day of each week and 18F-fludeoxyglucose (18F-FDG) on the next day. Small animal positron emission tomography (PET) imaging was performed, and tendon tissue was collected for pathology and quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis each week after surgery.

RESULTS

One week after surgery, both radiotracers showed signal concentration at the lesion site, which was the highest radioactive uptake observed during 4 weeks postoperatively, consistent with the severity of the lesion. Consistent trends were observed for inflammatory cytokines during qRT-PCR analysis. Additionally, Al18F-NODA-FAPI-04 PET exhibited a more precise lesion pattern, attributed to its high specificity for naive fibroblasts when referring to histological findings. Over time, the uptake of both radiotracers at the injury site gradually decreased, with 18F-FDG experiencing a more rapid decrease than Al18F-NODA-FAPI-04. In the fourth week after surgery, the maximum standardized uptake values of Al18F-NODA-FAPI-04 in the injured lesion almost reverted to the baseline levels, indicating a substantial decrease in naive fibroblasts and inflammatory cells and a reduction in inflammation and fibrosis, especially compared with the first week. Corresponding trends were also revealed in pathological and qRT-PCR results.

CONCLUSION

Our findings suggest that inflammation is a prominent feature during the early stage of tendon injury. Al18F-NODA-FAPI-04 PET allows accurate localization and provides detailed morphological imaging, enabling continuous monitoring of the healing progress and assessment of injury severity.

Novel Insights From Basic Science in Psoriatic Disease at the GRAPPA 2022 Annual Meeting

Recent basic science advances in psoriatic disease (PsD) were presented and discussed at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 annual meeting. Topics included clinical applications of biomarkers, what the future of biomarkers for PsD may hold, the challenges of developing biomarker research to the point of clinical utility, advances in total-body positron emission tomography/computed tomography imaging, and emerging concepts from single-cell studies in PsD.

Diagnostic performance of 18F-labeled PSMA PET/CT in patients with biochemical recurrence of prostate cancer: a systematic review and meta-analysis

BACKGROUND

After initial treatment of prostate cancer, increases in prostate-specific antigen (PSA) levels commonly signify potential relapse or metastasis. 18F-labeled prostate-specific membrane antigen (PSMA) is considered a promising treatment due to its favorable physical properties.

PURPOSE

To investigate the diagnostic value of 18F-PSMA PET/CT for the recurrence and/or metastasis of biochemical recurrence of prostate cancer (BRPca).

MATERIAL AND METHODS

A comprehensive literature search was conducted in PubMed, EMBASE, Web of Science, and the Cochrane Library databases. Combined sensitivity and specificity values for the use of 18F-PSMA PET/CT in patients with BRPca were obtained. The quality of the studies was tested using the Diagnostic Accuracy Research Quality Assessment tool. Meta-analysis was performed using STATA 15 software, and heterogeneity was subsequently tested.

RESULTS

A total of 16 studies (1162 patients) were enrolled and had significant heterogeneity. The pooled sensitivity, specificity, and AUC values for 18F-PSMA PET/CT in the diagnosis of prostate recurrence and/or metastasis were 0.93 (0.89-0.95), 0.94 (0.85-0.98), and 0.96 (0,94-0.98), respectively. Meta-regression analyses showed that the sources of heterogeneity did not relate to ligands, study designs, or participants. The pooled sensitivity and specificity values of 18F-DCFPyL PET/CT were 0.90 (0.85-0.94) and 0.89 (0.85-0.93), respectively. The pooled sensitivity and specificity values of 18F-PSMA-1007 PET/CT were 0.89 (0.85-0.93) and 0.93 (0.70-0.99), respectively. The per-patient pooled sensitivity and specificity values were 0.92 (0.86-0.96) and 0.83 (0.41-0.97), respectively. The per-lesion pooled sensitivity and specificity values were 0.91 (0.86-0.94) and 0.91 (0.86-0.94), respectively.

CONCLUSION

According to our meta-analysis, 18F-PSMA PET/CT has the potential to be critical for the diagnosis of recurrence and/or metastasis in patients with BRPca.

The Diagnostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Differentiated Thyroid Cancer Patients with Elevated Thyroglobulin/Thyroglobulin Antibody Levels and Negative Iodine Scintigraphy: A Systematic Review and Meta-Analysis

Background: The objective of this study is to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in detecting recurrence in patients with differentiated thyroid cancer (DTC) who have negative whole-body scans (WBSs) but elevated serum thyroglobulin (Tg) or thyroglobulin antibody (TgAb) levels. Methods: This systematic review/meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Diagnostic Test Accuracy criteria (International Prospective Register of Systematic Reviews registration number: CRD42022340924). A comprehensive search of the MEDLINE, EMBASE, and Cochrane databases identified articles reporting the diagnostic accuracy of FDG PET/CT for the detection of recurrence in patients with DTC with negative WBS and elevated serum Tg or TgAb levels published between January 2012 and June 2023. Meta-analyses were performed to determine the diagnostic accuracy of FDG PET/CT on the total target population as well as on subgroups stratified by serum Tg or TgAb, and thyrotropin (TSH) stimulation status at the time of FDG PET/CT. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework was applied to evaluate the quality of evidence and the strength of recommendations to facilitate translation of the meta-analysis results into practical recommendations for clinical guidelines. Results: A total of 24 studies involving 1988 patients were included for analysis. The overall pooled sensitivity and specificity values were 0.87 (95% confidence interval [CI] = 0.83-0.92; I2 = 75%) and 0.84 (CI = 0.80-0.89; I2 = 44%), respectively. Subgroup analyses revealed no significant differences in the diagnostic accuracy of FDG PET/CT in patients stratified by serum Tg or TgAb levels, and TSH stimulation status at the time of PET/CT. Treatment plans were changed following FDG PET/CT imaging in 40% (CI = 34-47%; I2 = 39%) of cases. The quality level of evidence for using FDG PET/CT was moderate in both sensitivity and specificity according to the GRADE system. Conclusion: There is moderate quality evidence demonstrating the high diagnostic accuracy of FDG PET/CT in detecting recurrence in patients with DTC with negative WBS and elevated serum Tg or TgAb levels. This evidence corroborates the current guidelines' endorsement of FDG PET/CT as a diagnostic tool in such patients.

Computed Tomography and 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Imaging Biomarkers of Lung Invasive Non-mucinous Adenocarcinoma: Prediction of Grade 3 Tumour Based on World Health Organization Grading System

AIMS

To evaluate computed tomography (CT) and 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) findings of invasive non-mucinous adenocarcinoma (INMA) of the lung as a predictor of histological tumour grade according to 2021 World Health Organization (WHO) classification.

MATERIALS AND METHODS

This retrospective study included consecutive patients with surgically resected INMA who underwent both preoperative CT and 18F-FDG-PET/CT. A three-tiered tumour grade was performed based on the fifth edition of the WHO classification of lung tumours. CT imaging features and the maximum standardised uptake value (SUVmax) were compared among the three tumour grades.

RESULTS

In total, 214 patients with INMA (median age 70 years; interquartile range 65-76 years; 123 men) were histologically categorised: 36 (17%) as grade 1, 102 (48%) as grade 2 and 76 (35%) as grade 3. Pure solid appearance was more frequent in grade 3 (83%) than in grades 1 (0%) and 2 (26%) (P < 0.001). The SUVmax of the entire tumour was higher in grade 3 than in grades 1 and 2 (P < 0.001). Multivariable analysis revealed that pure solid appearance (odds ratio = 94.0; P < 0.001), round/oval shape (odds ratio = 4.01; P = 0.001), spiculation (odds ratio = 2.13; P = 0.04), air bronchogram (odds ratio = 0.40; P = 0.03) and SUVmax (odds ratio = 1.45; P < 0.001) were significant predictors for grade 3 INMAs.

CONCLUSION

Pure solid appearance, round/oval shape, spiculation, absence of air bronchogram and high SUVmax were associated with grade 3 INMAs. CT and 18F-FDG-PET/CT were potentially useful non-invasive imaging methods to predict the histological grade of INMAs.

Role of Positron Emission Tomography/Computed Tomography in Epithelial Ovarian Cancer

Ovarian cancer (OC) is the most lethal gynecological malignancy with majority of cases diagnosed in advanced stages and associated with high morbidity and mortality. Positron emission tomography/computed tomography (PET/CT) has emerged as an integral part of the management of several nongynecological cancers. We used PubMed search engine using MeSH words "ovarian cancer" and "PET/CT" and reviewed the current status of PET/CT in epithelial OC. Its application related to ovarian tumor including adnexal mass evaluation, baseline staging, as a triaging tool for upfront surgery or neoadjuvant chemotherapy, for response assessment and prognostication, and for relapse detection and treatment planning has been highlighted. we highlight the current guidelines and newer upcoming PET modalities and radiotracers.

Case report:18F-2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography image findings of a dog with gossypiboma

A 13-year-old, spayed, female mixed breed dog that had previously undergone mastectomy and ovariohysterectomy was referred for evaluation of metastasis after surgery. 18F-deoxy-2-D-glucose positron emission tomography/computed tomography (18F-FDG PET-CT) was performed and a soft-tissue mass was observed in the abdominal cavity. The characteristics of the abdominal mass were assessed and screening for metastasis was done with follow-up 18F-FDG PET scans. Uptake of 18F-deoxy-2-D-glucose was higher in the peripheral region and lower in the center of the abdominal mass. Exploratory laparotomy was performed, and the removed abdominal mass was consistent with a gossypiboma, which is a retained surgical sponge composed of non-absorbable material with cotton matrix. This case report describes the characteristics of 18F-FDG PET-CT imaging in a dog with an abdominal gossypiboma, which has not been reported in the veterinary literature before.

A nomogram for predicting the rapid progression of diffuse large B-cell lymphoma established by combining baseline PET/CT total metabolic tumor volume, lesion diffusion, and TP53 mutations

OBJECTIVES

This study aimed to integrate positron emission tomography/computed tomography (PET/CT) metrics and genetic mutations to optimize the risk stratification for diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

The data of 94 primary DLBCL patients with baseline PET/CT examination completed in the Shandong Cancer Hospital and Institute (Jinan, China) were analyzed to establish a training cohort. An independent cohort of 45 DLBCL patients with baseline PET/CT examination from other hospitals was established for external validation. The baseline total metabolic tumor volume (TMTV) and the largest distance between two lesions (Dmax) standardized by patient body surface area (SDmax) were calculated. The pretreatment pathological tissues of all patients were sequenced by a lymphopanel including 43 genes.

RESULTS

The optimal TMTV cutoff was 285.3 cm3 and the optimal SDmax cutoff was 0.135 m-1 . TP53 status was found as an independent predictive factor significantly affecting complete remission (p = 0.001). TMTV, SDmax, and TP53 status were the main factors of the nomogram and could stratify the patients into four distinct subgroups based on their predicted progression-free survival (PFS). The calibration curve demonstrated satisfactory agreement between the predicted and actual 1-year PFS of the patients. The receiver operating characteristic curves showed this nomogram based on PET/CT metrics and TP53 mutations had a better predictive ability than the clinic risk scores. Similar results were identified upon external validation.

CONCLUSIONS

The nomogram based on imaging factors and TP53 mutations could lead to a more accurate selection of DLBCL patients with rapid progression, to increase tailor therapy.

The Correlation Between 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Semiquantitative Parameters and the Clinical Features and Pathological Biological Indexes of Gastric Cancer

Objective: This study explored the application value of the maximum standard uptake value (SUVmax) of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) in gastric cancer. Materials and Methods: Data of 164 patients with gastric cancer who had undergone18F-FDG PET/CT before a biopsy were collected, and the correlation of SUVmax with clinical stage, pathological differentiation degree, human epidermal growth factor receptor-2 (HER-2) status, and Ki-67 index of gastric cancer was analyzed. Results: The SUVmax of poorly differentiated adenocarcinoma was significantly higher than that of moderately differentiated adenocarcinoma and signet-ring cell carcinoma (p < 0.01), and SUVmax in the well-differentiated adenocarcinoma group was higher than that in the signet-ring cell carcinoma group (p < 0.01). The SUVmax in the HER-2 negative group was higher than that in the HER-2 positive group (p < 0.01). The SUVmax was higher in the Ki-67 high expression group than in the low expression group (p < 0.01), and there was a significant positive correlation between the two (p < 0.01). Conclusion: 18F-FDG PET/CT SUVmax can, to some extent, predict the degree of differentiation, HER-2 status, and Ki-67 index of gastric cancer patients.

Endobronchial Squamous Cell Carcinoma Presenting as Long Continuous Bronchial Thickening on 18Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

A 67-year-old man is presented with complaints of chest pain and productive cough for 1½ years. Chest X-ray was suggestive of right upper lobe Koch's lesion. Sputum was positive for mycobacterium tuberculosis. His symptoms got relieved partially by antitubercular treatment but the patient had an aggravation of symptoms for which he was evaluated. Computed tomography (CT) thorax revealed an endobronchial lesion in the right upper lobe bronchus. Bronchoscopy showed a mass in the right main bronchus and biopsy was suggestive of moderately differentiated squamous cell carcinoma (SCC). 18Fluoro-deoxy-glucose positron emission tomography/CT was performed for staging. There would have been chances of coexisting tuberculosis with SCC.

Unusual Diffuse and Heterogeneous FDG Uptake in Appendicular Bone Marrow Space in a Patient with Acute Lymphoblastic Leukemia

We describe a case of F-18-2-fluoro-2-deoxyglucose (FDG) uptake in the appendicular bones on a positron emission tomography/computed tomography (PET/CT) scan in a 20-year-old woman with a diagnosis of acute lymphoblastic leukemia. An FDG PET/CT was performed on this patient because of fever of unknown origin, revealing diffuse and heterogeneous FDG uptake in the bone marrow space of both humeri, femurs, and tibiae. The patient underwent magnetic resonance imaging, which demonstrated bone infarction with heterogeneous high, intermediate, and dark signal intensities on T1- and T2-weighted images in the same areas.

Role of Textural Analysis of Pretreatment 18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Response Prediction in Esophageal Carcinoma Patients

Introduction

Positron emission tomography/computed tomography (PET/CT) is routinely used for staging, response assessment, and surveillance in esophageal carcinoma patients. The aim of this study was to investigate whether textural features of pretreatment 18F-fluorodeoxyglucose (18F-FDG) PET/CT images can contribute to prognosis prediction in carcinoma oesophagus patients.

Materials and Methods

This is a retrospective study of 30 diagnosed carcinoma esophagus patients. These patients underwent pretreatment 18F-FDG PET/CT for staging. The images were processed in a commercially available textural analysis software. Region of interest was drawn over primary tumor with a 40% threshold and was processed further to derive 92 textural and radiomic parameters. These parameters were then compared between progression group and nonprogression group. The original dataset was subject separately to receiver operating curve analysis. Receiver operating characteristic (ROC) curves were used to identify the cutoff values for textural features with a P < 0.05 for statistical significance. Feature selection was done with principal component analysis. The selected features of each evaluator were subject to 4 machine-learning algorithms. The highest area under the curve (AUC) values was selected for 10 features.

Results

A retrospective study of 30 primary carcinoma esophagus patients was done. Patients were followed up after chemo-radiotherapy and they underwent follow-up PET/CT. On the basis of their response, patients were divided into progression group and nonprogression group. Among them, 15 patients showed disease progression and 15 patients were in the nonprogression group. Ten textural analysis parameters turned out to be significant in the prediction of disease progression. Cutoff values were calculated for these parameters according to the ROC curves, GLZLM_long zone emphasis (Gray Level Zone Length Matrix)_long zone emphasis (44.9), GLZLM_low gray level zone emphasis (0.006), GLZLM_short zone low gray level emphasis (0.0032), GLZLM_long zone low gray level emphasis (0.185), GLRLM_long run emphasis (Gray Level Run Length Matrix) (1.31), GLRLM_low gray level run emphasis (0.0058), GLRLM_short run low gray level emphasis (0.005496), GLRLM_long run low gray level emphasis (0.00727), NGLDM_Busyness (Neighborhood Gray Level Difference Matrix) (0.75), and gray level co-occurrence matrix_homogeneity (0.37). Feature selection by principal components analysis and feature classification by the K-nearest neighbor machine-learning model using independent training and test samples yielded the overall highest AUC.

Conclusions

Textural analysis parameters could provide prognostic information in carcinoma esophagus patients. Larger multicenter studies are needed for better clinical prognostication of these parameters.

Diagnostic value of imaging modalities in primary squamous cell carcinoma of the liver

Primary squamous cell carcinoma of the liver (PSCCL) is rare. PSCCL's lack of specific clinical manifestations and laboratory tests necessitate preoperative diagnosis via imaging examination. Conventional ultrasound (US) demonstrates a mass with mixed echogenicity, and contrast-enhanced US shows a circular pattern of "fast forward, fast backward or slow backward, high enhancement." Enhanced computed tomography (CT) showed enhancement in the center or edge of the lesion, and the density of the enhanced lesion was lower than that of the liver tissue in the same layer. Positron emission tomography-CT demonstrates an inhomogeneous low-density mass with increased 18F-FDG metabolism. Magnetic resonance imaging shows low signal intensity on T1-weighed images (T1WI) and high signal on T2-weighed images (T2WI). By summarizing the imaging characteristics of PSCCL, this review aims to improve clinicians' understanding of PSCCL and its diagnosis.

Physiologic 18F-FDG muscle uptake in severe COPD: Implications for accurate lung cancer staging

Recognizing physiologic ¹⁸F-fluorodeoxyglucose (FDG) uptake in severe COPD is crucial to avoid mistaking it for lung cancer metastasis. Correlating ¹⁸F-FDG avid lesions with co-registered computed tomography is essential for accurate lung cancer staging and preventing unnecessary interventions.

Predictive value of intratumoral-metabolic heterogeneity derived from 18F-FDG PET/CT in distinguishing microsatellite instability status of colorectal carcinoma

Purpose/background

Microsatellite instability (MSI) status is a significant biomarker for the response to immune checkpoint inhibitors, response to 5-fluorouracil-based adjuvant chemotherapy, and prognosis in colorectal carcinoma (CRC). This study investigated the predictive value of intratumoral-metabolic heterogeneity (IMH) and conventional metabolic parameters derived from 18F-FDG PET/CT for MSI in patients with stage I-III CRC.

Methods

This study was a retrospective analysis of 152 CRC patients with pathologically proven MSI who underwent 18F-FDG PET/CT examination from January 2016 to May 2022. Intratumoral-metabolic heterogeneity (including heterogeneity index [HI] and heterogeneity factor [HF]) and conventional metabolic parameters (standardized uptake value [SUV], metabolic tumor volume [MTV], and total lesion glycolysis [TLG]) of the primary lesions were determined. MTV and SUVmean were calculated on the basis of the percentage threshold of SUVs at 30%-70%. TLG, HI, and HF were obtained on the basis of the above corresponding thresholds. MSI was determined by immunohistochemical evaluation. Differences in clinicopathologic and various metabolic parameters between MSI-High (MSI-H) and microsatellite stability (MSS) groups were assessed. Potential risk factors for MSI were assessed by logistic regression analyses and used for construction of the mathematical model. Area under the curve (AUC) were used to evaluate the predictive ability of factors for MSI.

Results

This study included 88 patients with CRC in stages I-III, including 19 (21.6%) patients with MSI-H and 69 (78.4%) patients with MSS. Poor differentiation, mucinous component, and various metabolic parameters including MTV30%, MTV40%, MTV50%, and MTV60%, as well as HI50%, HI60%, HI70%, and HF in the MSI-H group were significantly higher than those in the MSS group (all P < 0.05). In multivariate logistic regression analyses, post-standardized HI60% by Z-score (P = 0.037, OR: 2.107) and mucinous component (P < 0.001, OR:11.394) were independently correlated with MSI. AUC of HI60% and our model of the HI60% + mucinous component was 0.685 and 0.850, respectively (P = 0.019), and the AUC of HI30% in predicting the mucinous component was 0.663.

Conclusions

Intratumoral-metabolic heterogeneity derived from 18F-FDG PET/CT was higher in MSI-H CRC and predicted MSI in stage I-III CRC patients preoperatively. HI60% and mucinous component were independent risk factors for MSI. These findings provide new methods to predict the MSI and mucinous component for patients with CRC.

Effectiveness of PET/CT and VATS for detecting and treating internal mammary lymph node metastasis: a case series

OBJECTIVE

We occasionally observed internal mammary lymph node metastases of breast cancer in a clinical setting. However, unlike a standard treatment in axillary metastasis, surgical resection for internal mammary lymph node metastasis is not prevalent because of unclear safety and benefits. Thus, we aimed to evaluate the diagnostic ability and clinical outcomes of positron emission tomography/computed tomography and video-assisted thoracoscopic surgery.

METHODS

We retrospectively investigated 34 patients with breast cancer with abnormal 18F-fluorodeoxyglucose uptake in internal mammary lymph nodes, at a single centre, between January 2015 and June 2022 and identified 11 female patients (mean age ± SD, 51.5 ± 12.9 years) who underwent video-assisted thoracoscopic surgery resection. Positron emission tomography/computed tomography was used to determine the clinical stage. We reviewed the surgical pathology of eleven and two patients who underwent direct-view internal mammary lymph node resection to calculate the positive predictive value of positron emission tomography/computed tomography.

RESULTS

Ipsilateral fluorodeoxyglucose accumulation was observed, with an average maximum standardized uptake value of 8.9 (range, 3.1-24.0). No perioperative complications occurred, and all patients who underwent video-assisted thoracoscopic surgery alone were discharged from the hospital on post-operative day 2 or 3. The estimated positive predictive value was 80%. All patients were alive, and seven of nine patients with metastasis were relapse-free, at a mean follow-up period of 17.9 months (range, 1-51). However, two patients had recurrence at 16 and 14 months after surgery for internal mammary lymph node relapse.

CONCLUSIONS

Radiotherapy is the standard treatment for suspected internal mammary lymph node metastasis detected using positron emission tomography/computed tomography; however, we could safely perform minimally invasive video-assisted thoracoscopic surgery resection, leading to a definite pathological diagnosis.

Solitary Cardiac Metastasis from Esophageal Cancer

A 72-year-old woman with past medical history of rectal cancer resection (adenocarcinoma, pT3N1aM0) presented with a 2-month history of dysphagia. Imaging studies found a thoracic esophageal cancer, for which subtotal esophagectomy with gastric conduit reconstruction via retrosternal route followed by chemoradiotherapy were performed (squamous cell carcinoma, pT4N1M0, RM1). Seven months after the esophagectomy, a contrast-enhanced computed tomography (CT) demonstrated a new asymptomatic mass inside the right atrium. A thrombus or a tumorous lesion was suspected. Positron emission tomography (PET)/CT showed abnormal uptake in the mass. After a thorough discussion by a multidisciplinary oncology group, we performed 1-week anticoagulant therapy first, resulting in mass enlargement. Then tumorectomy was carried out. The final pathological findings revealed that the mass was squamous cell carcinoma, yielding the diagnosis of cardiac metastasis from esophageal cancer. The patient's postoperative course was unremarkable. PET/CT may help to estimate malignancy and to omit invasive heart surgery.

An Automated Method for Artifical Intelligence Assisted Diagnosis of Active Aortitis Using Radiomic Analysis of FDG PET-CT Images

The aim of this study was to develop and validate an automated pipeline that could assist the diagnosis of active aortitis using radiomic imaging biomarkers derived from [18F]-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) images. The aorta was automatically segmented by convolutional neural network (CNN) on FDG PET-CT of aortitis and control patients. The FDG PET-CT dataset was split into training (43 aortitis:21 control), test (12 aortitis:5 control) and validation (24 aortitis:14 control) cohorts. Radiomic features (RF), including SUV metrics, were extracted from the segmented data and harmonized. Three radiomic fingerprints were constructed: A-RFs with high diagnostic utility removing highly correlated RFs; B used principal component analysis (PCA); C-Random Forest intrinsic feature selection. The diagnostic utility was evaluated with accuracy and area under the receiver operating characteristic curve (AUC). Several RFs and Fingerprints had high AUC values (AUC > 0.8), confirmed by balanced accuracy, across training, test and external validation datasets. Good diagnostic performance achieved across several multi-centre datasets suggests that a radiomic pipeline can be generalizable. These findings could be used to build an automated clinical decision tool to facilitate objective and standardized assessment regardless of observer experience.

Oxidized Regenerated Cellulose can be a Cause of False Tumor Recurrence on PET/CT in Patients with Lung Cancer Treated Surgically

Objectives

Regular follow-up of patients with lung cancer treated surgically is crucial to detect local recurrence or distant metastasis of the tumor. Postoperative follow-ups are performed with thorax computed tomography (CT) and, if necessary, positron emission tomography (PET)/CT. Sometimes, inflammatory tissue reactions due to the materials used during the surgery for hemostasis may cause the appearance of tumor recurrence in imaging modalities. In this study, we presented that oxidized regenerated cellulose (ORC) used intraoperatively may cause false tumor recurrence on PET/CT.

Methods

The records of patients who had local tumor recurrence after lung cancer surgery was reviewed retrospectively. Inclusion criteria were the presence of local recurrence of cancer on PET/CT, specification of using ORC in the surgical notes, and histopathological diagnosis of the recurrence site of tumor was reported as a foreign body reaction. Data of patients were collected according to age, gender, surgery performed, adjuvant therapy status, resolution status and time ORC, and standard uptake value of ¹⁸F-fluorodeoxyglucose on PET/CT.

Results

Eleven patients (1 female, 10 males) who met the criteria were included in the study. The median age was 64. Histopathological results of all patients were reported as foreign body reactions. The median detection time of PET/CT positivity after surgery was 139 days (range: 52-208 days). False tumor recurrence was resolved in 8 patients (72.7%) in their control radiological examinations and median resolution time was 334 days (range: 222-762 days). The median maximum standard uptake value of the lesions was 6.2 (1.7-11) on the PET/CT.

Conclusion

ORC used intraoperatively in patients undergoing surgery for lung cancer may cause false tumor recurrence in imaging modalities in postsurgical follow-ups. When tumor recurrence is suspected in the follow-up of these patients, histopathological confirmation is necessary to prevent unnecessary operations and treatments.

Ga-68-Edotreotide Positron Emission Tomography/Computed Tomography Somatostatin Receptors Tumor Volume Predicts Outcome in Patients With Primary Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

We retrospectively aimed to assess the prognostic significance of somatostatin receptor (SSTR) standardized uptake value (SUVmax_sstr), SSTR representative tumor volume (RTV_sstr) and total lesion SSTR expression (TL_sstr) obtained by [⁶⁸Ga]Ga-edotreotide PET/CT ([⁶⁸Ga]Ga-SSTR PET/CT) in patients with primary gastroenteropancreatic neuroendocrine tumors (GEP-NET) before surgery.

MATERIAL AND METHODS

We analyzed patients who underwent [⁶⁸Ga]Ga-SSTR PET/CT 3-6 weeks before surgery from February 2020 to April 2022. The mean SUVmax_sstr value, the RTV_sstr (cm3; 42% threshold) and the TL_sstr (g) were registered. Thereafter the patients were followed up 10.3 months (range 3-27). The PET/CT results were compared to the event free survival (EFS).

RESULTS

Forty-two patients (61 ± 13 years) have been enrolled. At multivariate analysis only RTV_sstr values were predictive. The Kaplan-Meier survival analysis for RTV_sstr showed a significant better EFS in patients presenting lower values as compared to those having greater (P = .003, log-rank test). SUVmax_sstr was not suitable for predicting EFS, TL_sstr mildly.

CONCLUSION

RTV_sstr represents a valuable volumetric parameter able to predict the outcome in GEP-NET patients who underwent surgery. The magnitude of the SSTR representative tumor burden holds a predominant value for determining the response to therapy in GEP-NET patients before surgery, rather than the maximal SSTR representation at single voxel.

Comprehensive Analysis of Fibroblast Activation Protein Expression in Interstitial Lung Diseases

Rationale: Sustained activation of lung fibroblasts and the resulting oversynthesis of the extracellular matrix are detrimental events for patients with interstitial lung diseases (ILDs). Lung biopsy is a primary evaluation technique for the fibrotic status of ILDs, and is also a major risk factor for triggering acute deterioration. Fibroblast activation protein (FAP) is a long-known surface biomarker of activated fibroblasts, but its expression pattern and diagnostic implications in ILDs are poorly defined. Objectives: The present study aims to comprehensively investigate whether the expression intensity of FAP could be used as a potential readout to estimate or measure the amounts of activated fibroblasts in ILD lungs quantitatively. Methods: FAP expression in human primary lung fibroblasts as well as in clinical lung specimens was first tested using multiple experimental methods, including real-time quantitative PCR (qPCR), Western blot, immunofluorescence staining, deep learning measurement of whole slide immunohistochemistry, as well as single-cell sequencing. In addition, FAP-targeted positron emission tomography/computed tomography imaging PET/CT was applied to various types of patients with ILD, and the correlation between the uptake of FAP tracer and pulmonary function parameters was analyzed. Measurements and Main Results: Here, it was revealed, for the first time, FAP expression was upregulated significantly in the early phase of lung fibroblast activation event in response to a low dose of profibrotic cytokine. Single-cell sequencing data further indicate that nearly all FAP-positive cells in ILD lungs were collagen-producing fibroblasts. Immunohistochemical analysis validated that FAP expression level was closely correlated with the abundance of fibroblastic foci on human lung biopsy sections from patients with ILDs. We found that the total standard uptake value (SUV) of FAP inhibitor (FAPI) PET (SUVtotal) was significantly related to lung function decline in patients with ILD. Conclusions: Our results strongly support that in vitro and in vivo detection of FAP can assess the profibrotic activity of ILDs, which may aid in early diagnosis and the selection of an appropriate therapeutic window.

Incidentally Detected Gastrointestinal Stromal Tumor in a Patient with Carcinoma Prostate: 68Ga-Prostate-Specific Membrane Antigen Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Uptake of 68Ga-prostate-specific membrane antigen (PSMA) in various nonprostatic tumors is well documented in the literature. We present a case of a gastrointestinal stromal tumor, incidentally detected on 68Ga-PSMA positron emission tomography/computed tomography imaging in a patient who underwent imaging for a suspected recurrence of carcinoma prostate.

Imaging Acute Myocarditis with 68Ga-DOTANOC PET/CT

Somatostatin receptor (SSTR) imaging is a useful method in the diagnosis of acute myocarditis. We present a case of a 54-year-old male with a clinical diagnosis of acute myocarditis in whom, 68Ga-DOTANOC positron emission tomography/computed tomography PET/CT showed diffuse left ventricular myocardial uptake. SSTR imaging can act as a surrogate marker of active inflammation. SSTR imaging is useful in deciding site of biopsy, assessing response to therapy and for prognostication.

Analysis of the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft infection

BACKGROUND

As a result of constantly improving surgical methods, an increasing number of patients have medical devices implanted in the cardiovascular system (including vascular grafts and endografts). Such patients are characterised by their high risk of infectious complications due to the possibility of biofilm formation on implanted material. This work aims to analyse the utility of 2-[18F]FDG PET/CT in diagnosing vascular graft and endograft infections.

MATERIAL AND METHODS

The study was undertaken on a group of 58 patients, of whom 34 were in the study group, and 24 were in the control group. The 2-[18F]FDG PET/CT study was conducted in the Nuclear Medicine Department at the University Hospital of Lublin. The inclusion criteria for the study group were the presence of a vascular graft or endograft that encompasses the aorta, and strong clinical suspicion of its infection. The inclusion criteria for the control group were the presence of a vascular graft or endograft in the large arteries and the absence of signs of its infection on 2-[18F]FDG PET/CT, as well as the absence of clinically apparent signs and symptoms during six months of observation after 2-[18F]FDG PET/CT. All patients found in the database that met the criteria were included.

RESULTS

Vascular endografts were more common in the control group than in the study group. However, in the case of infection of the vascular endograft, signs of infection in 2-[18F]FDG PET/CT were more severe. Images in the study group were divided into three groups that represent image patterns based on CT and PET characteristics. The first pattern (P1) was recognised in six patients. The second (P2) and third (P3) were visible in 11 and 17 patients, respectively.

CONCLUSIONS

Comparative analysis of the study and control groups demonstrates the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft/endograft infection.

18F-Flurodeoxyglucose Positron Emission Tomography/Computed Tomography Findings in a Rare Case of Trichoptysis

Trichoptysis or coughing of hairs is a rare symptom, but is pathognomonic for a teratoma with tracheobronchial communication. We present such a rare case with 18F-flurodeoxyglucose positron emission tomography/computed tomography (PET-CT) imaging findings in a 20-year-old female. The diagnosis was made with PET-CT and she underwent curative surgical resection after that.

Computer-aided diagnostic models to classify lymph node metastasis and lymphoma involvement in enlarged cervical lymph nodes using PET/CT

BACKGROUND

It is a clinical problem to identify histological component in enlarged cervical lymph nodes, particularly in differentiation between lymph node metastasis and lymphoma involvement.

PURPOSE

To construct two kinds of deep learning (DL)-based computer-aided diagnosis (CAD) systems including DL-convolutional neural networks (DL-CNN) and DL-machine learning for pathological diagnosis of cervical lymph nodes by positron emission tomography (PET)/computed tomography (CT) images.

METHODS

We collected CT, PET, and PET/CT images series from 165 patients with enlarged cervical lymph nodes receiving examinations from January 2014 to June 2018. Six CNNs pretrained on ImageNet as DL architectures were used for two kinds of DL-based CAD models, including DL-CNN and DL-machine learning models. The DL-CNN models were constructed via transfer learning for classification of lymphomatous and metastatic lymph nodes. The DL-machine learning models were developed by DL-based features extractors and support vector machine (SVM) classifier. As for DL-SVM models, we also evaluate the effect of handcrafted radiomics features in combination of DL-based features.

RESULTS

The DL-CNN model with ResNet50 architecture on PET/CT images had the best diagnostic performance among all six algorithms with an area under the receiver operating characteristic curve (AUC) of 0.845 and accuracy of 78.13% in the testing cohort. The DL-SVM model on ResNet50 extractor showed great performance for the testing cohort with an AUC of 0.901, accuracy of 86.96%, sensitivity of 76.09%, and specificity of 94.20%. The combination of DL-based and handcrafted features yielded the improvement of diagnostic performance.

CONCLUSIONS

Our DL-based CAD systems on PET/CT images were developed for classifying metastatic and lymphomatous involvement with favorable diagnostic performance in enlarged cervical lymph nodes. Further clinical practice of our systems may improve quality of the following therapeutic interventions and optimize patients' outcomes.

Positron emission tomography - Computed tomography for staging of mediastinal lymph nodes in patients with non-small cell lung cancer

Background

The tumor involvement of lymph nodes (LN) in N2 station is a very important factor for the further therapy decision and the prognosis of lung cancer patients. Today, integrated positron emission tomography-computed tomography (PET-CT) is considered to be the new standard in the staging of bronchial carcinoma. The aim of this study is to investigate the correctness of the clinical staging of the mediastinal LNs in operated patients and to investigate the sensitivity and specificity of the PET-CT examination for mediastinal LNs.

Subjects and Methods

In the years 2010-2014, 359 patients underwent surgery for bronchial carcinoma. The histological examination of all mediastinal and hilar LNs was used as a reference to the data from the PET-CT examinations. The correctness of the PET staging, overestimation, and underestimation for the N stage was analyzed. In addition, the "sensitivity," "specificity," and "overall accuracy" of the PET-CT examination with regard to the N2 LNs were calculated.

Results

It was found that in 8.9% the staging of the mediastinal N2/N3 LN stations was rated too high by the PET and in 11.2% too low. The study showed a sensitivity of 47.37%, a specificity of 90.07%, and an accuracy of 81.01% for the mediastinal LNs.

Conclusion

Our study confirms the limited ability of integrated PET-CT in staging the mediastinal LNs. We, therefore, recommend a histological examination of the LNs in patients with PET-positive N2 LNs to avoid false-positive results and to initiate correct therapy.

Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET)/Computed Tomography Features of Atypical Teratoid/Rhabdoid Tumors: Case Series and Review

Purpose: The purpose of this article is to explore the clinical and neuroradiologic properties of atypical teratoid/rhabdoid tumors. Methods: Data from 6 pediatric patients with atypical teratoid/rhabdoid tumors, which mainly contained the features of magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), was retrospectively analyzed. Follow-up was conducted in all patients through clinic services and/or telephone consultation. Results: The patients included 4 males and 2 females, aged from 3.2 to 83.1 months at the initial diagnosis. All patients had MRI scans. Two patients underwent ¹⁸F-fluorodeoxyglucose PET/CT scintigraphy preoperatively and 4 postoperatively. All primary lesions were located in the cranial cavity and the average diameter of lesions was 37.2 mm. Cerebrospinal fluid spread on enhanced T1-weighted images were found in 2 patients. Multiple metastases were found on MRI and PET/CT scans, which were located at cranial cavity, spinal cord, lung and lymph node. The primary and metastatic lesions showed evident uptake of ¹⁸F-fluorodeoxyglucose. Two patients underwent total tumor removal, and 4 patients underwent subtotal removal. None of the patients received shunt surgery. Follow-up was performed in all 6 patients. One patient survived event-free 38.4 months after resection. The mean overall survival of the remaining 5 patients was 5.1 months. Conclusion: We identified specific PET/CT and MRI features that can facilitate the recognition of atypical teratoid/rhabdoid tumors prior to biopsy.

Omicron Variant of COVID-19: Imaging Pattern on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

We report a case of omicron infection in a biopsy-proven case of carcinoma breast sent for staging F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) during the omicron COVID wave. FDG PET/computed tomography (CT) revealed increased FDG uptake in nasopharyngeal, oropharynx, and tonsillar regions and bilateral cervical lymph nodes along with uptake in primary carcinoma and locoregional lymph nodes. Based on the clinical history and specific pattern of FDG PET/CT findings (as suggested by SNMMI Taskforce), COVID history and reverse transcription polymerase chain reaction positivity was elicited.

Ga-68 Prostate-Specific Membrane Antigen-HBED-CC Positron Emission Tomography/Computed Tomography in Anaplastic Thyroid Carcinoma

Purpose

Anaplastic thyroid carcinoma (ATC) is the most aggressive thyroid cancer and there is no established treatment that works well. The study was conducted to see prostate-specific membrane antigen (PSMA) expression in ATC as a stepping stone to study its role in potential theranostics.

Materials and Methods

Pathologically proven ATC patients were prospectively included in this study. Ga-68-PSMA positron emission tomography/computed tomography (PET/CT) was done to look for PSMA expression in local and distant sites 45-60 mins after injecting 2-3mCi of tracer.

Results

Twenty patients were enrolled in this study. Nodal metastases were seen in all patients, while distant metastases were seen in 17/20. The mean SUVmax of primary lesion was 6.72 ± 4.6. Mean SUVmax of node and lung lesions was 5.7 ± 5.6 and 2.9 ± 1.98, respectively. Mean SUVmax of liver, mediastinum, and parotid gland was 5.95 ± 3.03, 1.54 ± 0.68, and 9.03 ± 3.75, respectively. Mean Tumor to background ratio (liver = TBRl; mediastinum = TBRm; parotid = TBRp) were 1.21, 4.49 and 0.78, respectively.

Conclusion

ATC showed variable PSMA expression on Ga-68-PSMA-PET/CT and this attribute may be potentially useful in ATC theranostics.

68Ga-Tetraazacyclododecane Tetraacetic Acid-DPhe1-Tyr3-Octreotate Positron Emission Tomography/Computed Tomographic Findings of Large-Cell Neuroendocrine Carcinoma of the Lung in a Child

Primary lung cancers in children are rare, and most children are diagnosed incidentally while being investigated for another medical problem. The diagnosis of primary lung tumors in children is very difficult because many children are asymptomatic until the advanced stages of the disease and nonspecific imaging findings. Although the usage of 68Ga-tetraazacyclododecane tetraacetic acid-DPhe1-Tyr3-octreotate (68Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT) in adult patients is well known, it is a relatively new imaging modality for the pediatric patient group. Herein, we presented a unique case of large-cell neuroendocrine carcinoma of the lung in a child on 68Ga-DOTATATE PET/CT.

Improvement of liver metabolic activity in people with advanced HIV after antiretroviral therapy initiation

OBJECTIVE

Evaluating hepatic metabolic changes in people with HIV (PWH) with advanced disease, before and after antiretroviral therapy (ART) initiation, using [ 18 F]-fluorodeoxyglucose (FDG) PET-computed tomography (PET/CT). FDG PET/CT noninvasively quantifies glucose metabolism in organs.

DESIGN/METHODS

Forty-eight viremic PWH (CD4 + cell counts <100 cells/μl) underwent FDG PET/CT at baseline and approximately 6 weeks after ART initiation (short-term). Twenty-seven PWH participants underwent follow-up scans 2 years after treatment (long-term). FDG PET/CT scans from 20 healthy controls were used for comparison. Liver FDG uptake was quantified from the PET/CT scans. Imaging findings as well as clinical, laboratory, and immune markers were compared longitudinally and cross-sectionally to healthy controls.

RESULTS

Liver FDG uptake was lower at baseline and short-term in PWH compared with controls ( P  < 0.0001). At the long-term scan, liver FDG uptake of PWH increased relative to baseline and short-term ( P  = 0.0083 and 0.0052) but remained lower than controls' values ( P  = 0.004). Changes in FDG uptake correlated negatively with levels of glucagon, myeloperoxidase, sCD14, and MCP-1 and positively with markers of recovery (BMI, albumin, and CD4 + cell counts) ( P  < 0.01). In multivariable analyses of PWH values across timepoints, BMI and glucagon were the best set of predictors for liver FDG uptake ( P  < 0.0001).

CONCLUSION

Using FDG PET/CT, we found decreased liver glucose metabolism in PWH that could reflect hepatocytes/lymphocytes/myeloid cell loss and metabolic dysfunction because of inflammation. Although long-term ART seems to reverse many hepatic abnormalities, residual liver injury may still exist within 2 years of treatment initiation, especially in PWH who present with low nadir CD4 + cell counts.

Ectopic papillary thyroid carcinoma mimicking distant metastatic tissue

We report a case of a 50-year-old woman presenting with a solid nodule in each lung. She was previously suspected of having lung cancer and distant pulmonary metastasis on the basis of imaging findings. Surgical pathology revealed that the left lung nodule was adenocarcinoma, but the contralateral nodule was papillary thyroid carcinoma (PTC). We subsequently performed total thyroidectomy, and the histological findings of the resected specimen showed no suspicious tumor tissue. Overall, the results led to a diagnosis of ectopic intrapulmonary PTC with synchronous lung adenocarcinoma. Ectopic intrapulmonary PTC is a rare but true phenomenon that may be easily mistaken for pulmonary metastasis in daily practice. It is important to improve the recognition of ectopic intrapulmonary thyroid tumors to avoid misdiagnosis.

Inflammatory Blood Parameters as Biomarkers for Response to Immune Checkpoint Inhibition in Metastatic Melanoma Patients

Objectives: We aimed to investigate whether inflammatory parameters in peripheral blood at baseline and during the first six months of treatment could predict the short- and long-term outcomes of metastatic melanoma patients treated with immune checkpoint inhibitors (ICIs). Methods: This single-center retrospective study considered patients with metastatic melanoma treated with either single or dual checkpoint inhibition. Blood sample tests were scheduled together with 18F-2-fluor-2-desoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) scans at baseline and at three and six months after initiation of ICI treatment. The short-term response to ICIs was assessed using FDG-PET/CT scans. The long-term response to ICIs was assessed using the overall survival OS and progression-free survival PFS as endpoints. Results: A total of 100 patients with metastatic melanoma were included (female, n = 31; male, n = 69). The median age was 68 years (interquartile range (IQR): 53−74 years). A total of 82% of the cohort displayed a disease control (DC), while 18% presented a progressive disease (PD) after six months of ICIs. Patients with DC after six months of ICIs showed a lower median of the neutrophils-to-lymphocytes ratio (NLR) toward patients with PD, with no significant prediction power of NLR neither in the short nor in the long term. The count of neutrophils at the baseline time point (TP 0) (p = 0.037) and erythrocytes three months after treatment start (TP 1) (p = 0.010) were strong predictive parameters of a DC six months after treatment start. Erythrocytes (p < 0.001) and lymphocytes (p = 0.021) were strong biomarkers predictive of a favorable OS. Erythrocytes (p = 0.013) and lymphocytes (p = 0.017) also showed a significant prediction power for a favorable PFS. Conclusions: Inflammatory blood parameters predicted the short- and long-term response to ICIs with a strong predictive power. Our results suggested the validation of inflammatory blood parameters as biomarkers that predict immunotherapies’ efficacity in metastatic melanoma patients. However, confounding factors that interfere with myelopoiesis should also be taken into consideration.

A Rare Case of Incidental Finding of Cervical Spinal Cord Hemangioblastoma by 68Ga-DOTATOC Positron Emission Tomography/Computed Tomography Scan

Hemangioblastomas are rare vascular tumors of the central nervous system usually related to other pathological conditions, such as Von Hippel Lindau Syndrome (VHLS) and polycythemia. We describe a case of a 65-year-old man with a neuroendocrine tumor of the ileum presenting with cervical pain who underwent a 68Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) scan that incidentally underlines the presence of hemangioblastoma of the cervical spinal cord. The patient does not have a family history of VHLS nor does he suffer from polycythemia and he is currently waiting for genetic testing. Despite being rare, hemangioblastomas could be possible findings of central nervous system incidentaloma at 68Ga-DOTATOC PET/CT scan, especially in patients with anamnesis with possible related condition.

Ga-68 Chemokine Receptor-4 PET/CT Imaging in Schminke Type of Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma is a rare malignancy of the head-and-neck region. It is associated with Epstein-Barr virus infection and smoking. Its association with breast cancer is also infrequent. Chemokine receptor (CXCR)-4 imaging is a newer agent for imaging many malignancies with a good diagnostic value. We present a case of a young female diagnosed with left breast carcinoma in whom Ga-68 CXCR-4 PET/CT demonstrated tracer avid lesion in the nasopharynx. Biopsy of the nasopharyngeal lesion revealed Schminke type of lymphoepithelial cancer, indicating CXCR-4 PET/CT as a potential imaging modality for lymphoepithelial malignancy.