Predictive [18F]-FDG PET/CT-Based Radiogenomics Modelling of Driver Gene Mutations in Non-small Cell Lung Cancer.

RATIONALE AND OBJECTIVES: To investigate whether [18F]-FDG PET/CT-derived radiomics may correlate with driver gene mutations in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: In this IRB-approved retrospective study, 203 patients with surgically treated NSCLC who underwent subsequent genomic analysis of the primary tumour at our institution between December 2004 and January 2014 were identified. Of those, 128 patients (mean age 62.4 ± 10.8 years; range: 35-84) received preoperative [18F]-FDG PET/CT as part of their initial staging and thus were included in the study. PET and CT image segmentation and feature extraction were performed semi-automatically with an open-source software platform (LIFEx, Version 6.30, lifexsoft.org). Molecular profiles using different next-generation sequencing (NGS) panels were collected from a web-based resource (cBioPortal.ca for Cancer genomics). Two statistical models were then built to evaluate the predictive ability of [18F]-FDG PET/CT-derived radiomics features for driver gene mutations in NSCLC. RESULTS: More than half (68/128, 53%) of all tumour samples harboured three or more gene mutations. Overall, 55% of tumour samples demonstrated a mutation in TP53, 26% of samples had alterations in KRAS and 17% in EGFR. Extensive statistical analysis resulted in moderate to good predictive ability. The highest Youden Index for TP53 was achieved using combined PET/CT features (0.70), for KRAS using PET features only (0.57) and for EGFR using CT features only (0.60). CONCLUSION: Our study demonstrated a moderate to good correlation between radiomics features and driver gene mutations in NSCLC, indicating increased predictive ability of genomic profiles using combined [18F]-FDG PET/CT-derived radiomics features.

The [18F]F-FDG PET/CT Radiomics Classifier of Histologic Subtypes and Anatomical Disease Origins across Various Malignancies: A Proof-of-Principle Study.

We aimed to investigate whether [18F]F-FDG-PET/CT-derived radiomics can classify histologic subtypes and determine the anatomical origin of various malignancies. In this IRB-approved retrospective study, 391 patients (age = 66.7 ± 11.2) with pulmonary (n = 142), gastroesophageal (n = 128) and head and neck (n = 121) malignancies were included. Image segmentation and feature extraction were performed semi-automatically. Two models (all possible subset regression [APS] and recursive partitioning) were employed to predict histology (squamous cell carcinoma [SCC; n = 219] vs. adenocarcinoma [AC; n = 172]), the anatomical origin, and histology plus anatomical origin. The recursive partitioning algorithm outperformed APS to determine histology (sensitivity 0.90 vs. 0.73; specificity 0.77 vs. 0.65). The recursive partitioning algorithm also revealed good predictive ability regarding anatomical origin. Particularly, pulmonary malignancies were identified with high accuracy (sensitivity 0.93; specificity 0.98). Finally, a model for the synchronous prediction of histology and anatomical disease origin resulted in high accuracy in determining gastroesophageal AC (sensitivity 0.88; specificity 0.92), pulmonary AC (sensitivity 0.89; specificity 0.88) and head and neck SCC (sensitivity 0.91; specificity 0.92). Adding PET-features was associated with marginal incremental value for both the prediction of histology and origin in the APS model. Overall, our study demonstrated a good predictive ability to determine patients' histology and anatomical origin using [18F]F-FDG-PET/CT-derived radiomics features, mainly from CT.

Up-to-date review into the evolving world of bariatric interventions: a guide for radiologists.

Obesity is a worldwide health concern leading to several chronic health problems and comorbidities. Its treatment requires a multidisciplinary approach where lifestyle changes are fundamental. Additionally, in the past decade, the use of different surgical procedures of various levels of complexity has grown, with the objective of reducing the gastric capacity, creating diversions, or a combination of both. The aim of this article is to review and illustrate the major types of bariatric surgical techniques, their normal post-surgical anatomy, and the possible associated complications, to aid the radiologist in their assessment and timely diagnosis.

Role of FDG PET/CT in Patients With Lymphoma Treated With Chimeric Antigen Receptor T-Cell Therapy: Current Concepts.

Chimeric antigen receptor (CAR) T-cell therapy is a cellular therapy in which the patient's T cells are enhanced to recognize and bind to specific tumor antigens. CAR T-cell therapy was initially developed for the treatment of leukemia, but its current main indication is the treatment of relapsed or refractory non-Hodgkin lymphoma. FDG PET/CT plays a fundamental role in the diagnosis, staging, therapy response assessment, and recurrence evaluation of patients with metabolically active lymphoma. Consistent with the examination's role in lymphoma management, FDG PET/CT is also the imaging modality of choice to evaluate patients before and after CAR T-cell therapy, and evidence supporting its utility in this setting continues to accumulate. In this article, we review current concepts in CAR T-cell therapy in patients with lymphoma, emphasizing the critical role of FDG PET/CT before and after therapy. A framework is presented that entails performing FDG PET/CT at four time points over the course of CAR T-cell therapy: pretherapy at baseline at the time of decision to administer CAR T-cell therapy and after any bridging therapies and posttherapy 1 and 3 months after infusion. PET parameters assessed at these time points predict various patient outcomes.

Association of PSMA PET-derived Parameters and Outcomes of Patients Treated for Oligorecurrent Prostate Cancer.

Background Prostate-specific membrane antigen (PSMA) PET is useful in the early detection of oligorecurrent prostate cancer (PCa), but whether PSMA PET parameters can be used to identify patients who would benefit from metastasis-directed therapy (MDT) with radiation or surgery remains uncertain. Purpose To assess the association of PSMA PET parameters with outcomes of patients with oligorecurrent PCa after MDT. Materials and Methods In this retrospective analysis of a single-center phase II trial that enrolled patients with biochemical recurrence of PCa after maximal local therapy and with no evidence of disease at conventional imaging, patients underwent PSMA PET (between May 2017 and November 2021), and unveiled recurrences were treated with MDT. Maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean) and PSMA tumor volume derived using thresholds of 2.5 (SUVmean2.5) and 41% (SUVmean41%), respectively, were recorded for sites of recurrence on PSMA PET scans, and a molecular imaging PSMA score was assigned. These parameters were also corrected for smooth filter and partial volume effects, and the PSMA score was reassigned. Cox proportional hazards models were used to evaluate the relationship between PSMA PET parameters and outcomes. Results A total of 74 men (mean age, 68.3 years ± 6.6 [SD]) with biochemical recurrence of PCa were included. PSMA PET revealed 145 lesions in the entire cohort, of which 125 (86%) were metastatic lymph nodes. Application of the correction factor changed the PSMA score in 88 of 145 lesions (61%). Mean SUVmax, SUVmean2.5, and SUVmean41% were associated with lower risk of biochemical progression (hazard ratio [HR] range, 0.77-0.95; 95% CI: 0.61, 1.00; P = .03 to P = .04). For corrected parameters, mean SUVmax, mean SUVmean2.5, mean SUVmean41%, mean PSMA score, maximum SUVmean2.5, maximum SUVmean41%, and maximum PSMA score were associated with a lower risk of biochemical progression (HR, 0.61-0.98; 95% CI: 0.39, 1.00; P = .01 to P = .04). Conclusion Measured and corrected PSMA PET parameters were associated with biochemical progression in men with oligorecurrent PCa treated with MDT. Clinical trial registration no. NCT03160794 © RSNA, 2023 See also the editorial by Civelek in this issue.

Impact of the COVID-19 Pandemic on Staging Oncologic PET/CT Imaging and Patient Outcome in a Public Healthcare Context: Overview and Follow Up of the First Two Years of the Pandemic.

To assess the impact of the COVID-19 pandemic on the diagnosis, staging and outcome of a selected population throughout the first two years of the pandemic, we evaluated oncology patients undergoing PET/CT at our institution. A retrospective population of lung cancer, melanoma, lymphoma and head and neck cancer patients staged using PET/CT during the first 6 months of the years 2019, 2020 and 2021 were included for analysis. The year in which the PET was performed was our exposure variable, and our two main outcomes were stage at the time of the PET/CT and overall survival (OS). A total of 1572 PET/CTs were performed for staging purposes during the first 6 months of 2019, 2020 and 2021. The median age was 66 (IQR 16), and 915 (58%) were males. The most prevalent staged cancer was lung cancer (643, 41%). The univariate analysis of staging at PET/CT and OS by year of PET/CT were not significantly different. The multivariate Cox regression of non-COVID-19 significantly different variables at univariate analysis and the year of PET/CT determined that lung cancer (HR 1.76 CI95 1.23-2.53, p < 0.05), stage III (HR 3.63 CI95 2.21-5.98, p < 0.05), stage IV (HR 11.06 CI95 7.04-17.36, p < 0.05) and age at diagnosis (HR 1.04 CI95 1.02-1.05, p < 0.05) had increased risks of death. We did not find significantly higher stages or reduced OS when assessing the year PET/CT was performed. Furthermore, OS was not significantly modified by the year patients were staged, even when controlled for non-COVID-19 significant variables (age, type of cancer, stage and gender).

Corrigendum: Standardized classification schemes in reporting oncologic PET/CT.

[This corrects the article DOI: 10.3389/fmed.2022.1051309.].

Asymptomatic Penetrating Atherosclerotic Ulcer Findings on 18 F-FDG PET/CT.

ABSTRACT: We present a case of an 84-year-old man with a history of smoking, hypertension, and coronary artery disease with an incidental spiculated left apical pulmonary nodule, suspicious for a stage I non-small cell lung cancer. 18 F-FDG PET/CT performed for staging, which confirmed a small metabolically active pulmonary nodule. As an incidental finding, there was focal FDG uptake in the proximal descending aorta corresponding to a partially thrombosed outpouching of the aortic wall, in keeping with a penetrating atherosclerotic ulcer.

[18F]-FDG PET in anal canal cancer: a systematic review and meta-analysis.

PURPOSE: To provide comprehensive data on the diagnostic and prognostic value of [18F]-FDG PET (PET) in anal canal cancer patients. METHODS: This study was designed following the PRISMA-DTA guidelines. For the meta-analysis, published original articles (until December 2022) that met the following criteria were included: Evaluated PET for locoregional and/or distant disease detection in patients with histopathology-proven anal canal cancer; Compared PET with a valid reference standard; Provided crude data to calculate meta-analytic estimates. Diagnostic measurements from subgroups were calculated in evaluating primary tumour detection, T stage, lymph node and distant metastases. Articles providing prognostic information on PET were also reported as a systematic review. For pooled meta-analytic calculations, the hierarchical method was used. The bivariate model was conducted to find the summary estimates. Analyses were performed using STATA 16. RESULTS: After the screening, 28 studies were eligible to enter the meta-analytic calculations, and data from 15 were reported descriptively. For distinguishing T3/T4 from other T-stages, PET had pooled sensitivity and specificity of 91%(95%CI:72%-97%) and 96%(95%CI:88%-98%), respectively. The sensitivity and specificity for detecting metastatic (regional and/or distant) disease were 100% (95%CI:82%-100%) and 95% (95%CI:90%-98%), respectively. For therapy response assessment, the sensitivity and specificity of PET were 96%(95%CI:78%-99%) and 86%(95%CI:75%-93%), respectively. Higher pre-treatment total metabolic tumour volume was predictive of poorer survival. Conversely, for those achieving complete metabolic response, the 2-year PFS was 94%(95%CI:91%-97%) versus 51%(95%CI:42%-59%) for others (p-value < 0.001). CONCLUSION: PET may be a useful tool for anal canal cancer therapy planning and provides valuable prognostic information.

Oligometastasis in Prostate Cancer: Can We Learn from Those "Excluded" from a Phase 2 Trial?

We conducted and previously published a phase 2 trial of metastasis-directed therapy (MDT) in men with recurrence of prostate cancer at a low prostate-specific antigen level following radical prostatectomy and postoperative radiotherapy. All patients had negative conventional imaging and underwent prostate-specific membrane antigen (PSMA) positron emission tomography (PET). Patients without visible disease (n = 16) or with metastatic disease not amenable to MDT (n = 19) were excluded from the interventional study. The remaining patients with disease visible on PSMA-PET received MDT (n = 37). We analyzed all three groups to identify distinct phenotypes in the era of molecular imaging-based characterization of recurrent disease. Median follow up was 37 mo (interquartile range 27.5-43.0). There was no significant difference in time to the development of metastasis on conventional imaging among the groups; however, castrate-resistant prostate cancer-free survival was significantly shorter for patients with PSMA-avid disease not amenable to MDT (p = 0.047). Our findings suggest that PSMA-PET findings can help in discriminating diverging clinical phenotypes among men with disease recurrence and negative conventional imaging after local therapies with curative intent. There is a pressing need for better characterization of this rapidly growing population of patients with recurrent disease defined by PSMA-PET to derive robust selection criteria and outcome definitions for ongoing and future studies. Patient summary: In men with prostate cancer with rising PSA levels following surgery and radiation, a newer type of scan called PSMA-PET (prostate-specific membrane antigen positron emission tomography) can be used to characterize and differentiate the patterns of recurrence, and inform future cancer outcomes.

99mTc-MAA accumulation within tumor in preoperative lung perfusion SPECT/CT associated with occult lymph node metastasis in patients with clinically N0 non-small cell lung cancer.

BACKGROUND: 99mTc-MAA accumulation within the tumor representing pulmonary arterial perfusion, which is variable and may have a clinical significance. We evaluated the prognostic significance of 99mTc-MAA distribution within the tumor in non-small cell lung cancer (NSCLC) patients in terms of detecting occult nodal metastasis and lymphovascular invasion, as well as predicting the recurrence-free survival (RFS). METHODS: Two hundred thirty-nine NSCLC patients with clinical N0 status who underwent preoperative lung perfusion SPECT/CT were retrospectively evaluated and classified according to the visual grading of 99mTc-MAA accumulation in the tumor. Visual grade was compared with the quantitative parameter, standardized tumor to lung ratio (TLR). The predictive value of 99mTc-MAA accumulation with occult nodal metastasis, lymphovascular invasion, and RFS was assessed. RESULTS: Eighty-nine (37.2%) patients showed 99mTc-MAA accumulation and 150 (62.8%) patients showed the defect on 99mTc-MAA SPECT/CT. Among the accumulation group, 45 (50.5%) were classified as grade 1, 40 (44.9%) were grade 2, and 4 (4.5%) were grade 3. TLR gradually and significantly increased from grade 0 (0.009 ± 0.005) to grade 1 (0.021 ± 0.005, P < 0.05) and to grade 2-3 (0.033 ± 0.013, P < 0.05). The following factors were significant predictors for occult nodal metastasis in univariate analysis: central location, histology different from adenocarcinoma, tumor size greater than 3 cm representing clinical T2 or higher, and the absence of 99mTc-MAA accumulation within the tumor. Defect in the lung perfusion SPECT/CT remained significant at the multivariate analysis (Odd ratio 3.25, 95%CI [1.24 to 8.48], p = 0.016). With a median follow-up of 31.5 months, the RFS was significantly shorter in the defect group (p = 0.008). Univariate analysis revealed that cell type of non-adenocarcinoma, clinical stage II-III, pathologic stage II-III, age greater than 65 years, and the 99mTc-MAA defect within tumor as significant predictors for shorter RFS. However, only the pathologic stage remained statistically significant, in multivariate analysis. CONCLUSION: The absence of 99mTc-MAA accumulation within the tumor in preoperative lung perfusion SPECT/CT represents an independent risk factor for occult nodal metastasis and is relevant as a poor prognostic factor in clinically N0 NSCLC patients. 99mTc-MAA tumor distribution may serve as a new imaging biomarker reflecting tumor vasculatures and perfusion which can be associated with tumor biology and prognosis.

Prognostic Value of Sarcopenia and Metabolic Parameters of 18F-FDG-PET/CT in Patients with Advanced Gastroesophageal Cancer.

We investigated the prognostic value of sarcopenia measurements and metabolic parameters of primary tumors derived from 18F-FDG-PET/CT among patients with primary, metastatic esophageal and gastroesophageal cancer. A total of 128 patients (26 females; 102 males; mean age 63.5 ± 11.7 years; age range: 29-91 years) with advanced metastatic gastroesophageal cancer who underwent 18F-FDG-PET/CT as part of their initial staging between November 2008 and December 2019 were included. Mean and maximum standardized uptake value (SUV) and SUV normalized by lean body mass (SUL) were measured. Skeletal muscle index (SMI) was measured at the level of L3 on the CT component of the 18F-FDG-PET/CT. Sarcopenia was defined as SMI < 34.4 cm2/m2 in women and <45.4 cm2/m2 in men. A total of 60/128 patients (47%) had sarcopenia on baseline 18F-FDG-PET/CT. Mean SMI in patients with sarcopenia was 29.7 cm2/m2 in females and 37.5 cm2/m2 in males. In a univariable analysis, ECOG (<0.001), bone metastases (p = 0.028), SMI (p = 0.0075) and dichotomized sarcopenia score (p = 0.033) were significant prognostic factors for overall survival (OS) and progression-free survival (PFS). Age was a poor prognostic factor for OS (p = 0.017). Standard metabolic parameters were not statistically significant in the univariable analysis and thus were not evaluated further. In a multivariable analysis, ECOG (p < 0.001) and bone metastases (p = 0.019) remained significant poor prognostic factors for OS and PFS. The final model demonstrated improved OS and PFS prognostication when combining clinical parameters with imaging-derived sarcopenia measurements but not metabolic tumor parameters. In summary, the combination of clinical parameters and sarcopenia status, but not standard metabolic values from 18F-FDG-PET/CT, may improve survival prognostication in patients with advanced, metastatic gastroesophageal cancer.

Standardized classification schemes in reporting oncologic PET/CT.

The imaging report is essential for the communication between physicians in patient care. The information it contains must be clear, concise with evidence-based conclusions and sufficient to support clinical decision-making. In recent years, several classification schemes and/or reporting guidelines for PET have been introduced. In this manuscript, we will review the classifications most frequently used in oncology for interpreting and reporting 18F-FDG PET imaging in lymphoma, multiple myeloma, melanoma and head and neck cancers, PSMA-ligand PET imaging for prostate cancer, and 68Ga-DOTA-peptide PET in neuroendocrine tumors (NET).

18F-FDG PET/CT Evaluation of Thymomas: a Pictorial Review.

The World Health Organization classification divides thymomas according to morphology, epithelial component, and cell atypia. They are grouped into 3 large subgroups: low-risk thymomas (types A, AB, and B1), high-risk thymomas (types B2 and B3), and thymic carcinomas. Tumor subtype represents an independent prognostic factor, which determines therapeutic decision. All thymomas show some degree of 18F-FDG uptake, which tends to increase with the grade of malignancy; this is related to glucose transporter 1 (GLUT1) expression. This review collects all types of thymomas with illustrative images and provides a guide to get familiar with histological characteristics of the lesions and have them in mind because, even imaging findings can overlap among subtypes, certain characteristics can be combined to make an accurate diagnosis based on 18F-FDG PET-CT findings.

Rosai-Dorfman Disease: Importance of 18F FDG PET/CT to Determine Extension and Extranodal Involvement.

Rosai-Dorfman disease or sinus histiocytosis with lymphadenopathy is a rare benign histiocytic proliferative disorder of unknown etiology first described in 1969. It typically affects older females and most common presentation is with massive lymphadenopathy and nonspecific systemic symptoms; therefore, it is often confused with lymphoproliferative disorders [1, 2]. We present the case of a 69-year-old woman with nasal obstruction as only complaint. Laboratory tests showed normal leukocyte count with elevated ANC (absolute neutrophil count), normal RBC count with normal MCV (mean corpuscular volume) and MCH (mean corpuscular hemoglobin), elevated ESR (erythrocyte sedimentation rate), and normal IgG, IgA, and IgM values. Evaluation revealed a nasopharyngeal mass, which was biopsied and reported emperipolesis with positive CD68 and S-100; typical and differential findings of this disease [1, 2]. 18F FDG PET/CT was performed to determine the extent and involvement of the disease. Considering the presence of few symptoms and no significant laboratory abnormality, treating physicians decided to start a regimen of corticosteroids (prednisolone) for a period of 4 months, after which a follow-up with 18F FDG PET/CT will be performed.

Evaluación mediante ultrasonido de las glándulas paratiroides / Ultrasound Evaluation of the Parathyroid Glands

La principal indicación para el estudio de las glándulas paratiroides son las masas y, específicamente, la sospecha de adenomas, que son la patología más frecuente. Entre las diferentes modalidades diagnósticas disponibles, las de mayor sensibilidad para su detección son el ultrasonido y la gammagrafía con sestamibi, que en conjunto alcanzan la mayor especificidad para el diagnóstico. La evaluación mediante ultrasonido de las glándulas paratiroides tradicionalmente se ha considerado compleja y operador-dependiente; sin embargo, con las nuevas tecnologías de alta resolución es mucho más sencilla y nos obligamos a identificarlas en forma rutinaria, sean normales o patológicas. En este trabajo se hace una revisión sobre la anatomía normal, las técnicas de exploración y los hallazgos normales y anormales en ultrasonido de paratiroides para realizar un abordaje sencillo en la práctica diaria.

The main indication for the study of the parathyroid glands is the suspicion of masses and specifically the suspicion of adenomas, which are the most frequent pathology. Among the different diagnostic modalities available, the most sensitive for detection are ultrasound and Sestamibi scintigraphy, which together achieve the highest specificity for diagnosis. Ultrasound evaluation of the parathyroid glands has traditionally been considered complex and operator dependent, but with the new high resolution technologies it is much simpler and we are obliged to identify them routinely, whether normal or pathological. In the present work, a review is made on the normal anatomy, exploration techniques and normal and abnormal findings in parathyroid ultrasound to perform a simple and practical approach to daily practice.