RPS 2016 - The evolving landscape of imaging for neuroendocrine tumours and sarcomas

Author Block: P. Summer¹, P. Sorgo¹, P. M. Sbeghen², A. Y. Yasin¹, S. Pötter-Lang¹, N. Bastati-Huber¹, A. Ba-Ssalamah¹, U. I. Attenberger¹; ¹Vienna/AT, ²Verona/IT
Purpose: Intrapancreatic ectopic spleen (IPES) is a benign entity that often mimics pancreatic neuroendocrine tumors (NETs) on imaging. Conventional CT, ECCM-MRI, Ga-68 DOTA-NOC PET/CT, and Tc-99m HDRBC SPECT have important diagnostic limitations. Superparamagnetic iron oxide (SPIO)–enhanced MRI may allow reliable noninvasive differentiation. We evaluated the diagnostic performance of multimodal imaging with emphasis on SPIO-MRI.
Methods or Background: This retrospective study included 23 patients (10 NET, 13 IPES; mean age 59 ± 14 years) who underwent ECCM-MRI and SPIO-MRI. Subsets also had CECT (n=22), Ga-68 DOTA-NOC PET/CT (n=13), and Tc-99m HDRBC SPECT (n=6). Two blinded abdominal radiologists assessed qualitative and quantitative imaging features and diagnostic confidence. ROC analyses were performed to evaluate modality performance.
Results or Findings: NETs were significantly larger than IPES (1.9 vs. 1.3 cm, p<0.05). ECCM-MRI and CECT showed overlapping enhancement patterns with low accuracy (~50%). Ga-68 DOTA-NOC PET/CT demonstrated higher uptake in NETs compared with IPES (SUVmax 82 vs. 36, p=0.06), but with poor discriminatory value. Tc-99m HDRBC SPECT was inconclusive due to limited spatial resolution. In contrast, all IPES lesions showed marked T2/T2* signal loss after SPIO administration, whereas NETs remained unchanged. Both readers achieved 100% accuracy, with excellent interobserver agreement (κ=0.95, ICC=0.91). ROC analysis confirmed SPIO-MRI as the only modality with near-perfect diagnostic performance (AUC 0.79–1.00, p<0.001).
Conclusion: SPIO-enhanced MRI enables confident, noninvasive differentiation between IPES and NET, clearly outperforming conventional imaging and nuclear medicine techniques. It should be implemented as the preferred next step in suspected IPES to avoid unnecessary interventions.
Limitations: This retrospective, single-center study included a small cohort with uneven availability of comparator imaging modalities, limiting generalizability. The reported 100% accuracy of SPIO-MRI requires prospective validation in larger, multicenter cohorts.
Funding for this study: No funding.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Protocol Number: 1441/2016

Author Block: L. Carone, M. G. Di Niso, S. Kalantari, M. Zacchino, F. Sirchia, L. Preda; Pavia/IT
Purpose: NF1 is a rare inherited genetic syndrome characterized by wide phenotypic variability and a predisposition to tumor development. In recent years, WB-MRI has emerged as a valuable imaging tool for the comprehensive evaluation of multisystem alterations associated with NF1 and for the early detection of incidental findings of potential clinical relevance. This prospective, monocentric observational study aimed to assess the role of WB-MRI in the characterization of clinically relevant radiological findings (ONCO-RADS) in adult NF1 patients, promoting a tailored approach.
Methods or Background: Since July 2024, 20 adult patients with NF1 (mean age 36 years, range 18–68) referred to the Medical Genetics Unit of Policlinico San Matteo, Pavia, underwent WB-MRI from head to toe. Each case was discussed by a multidisciplinary team to evaluate disease-related alterations and define appropriate management.
Results or Findings: Plexiform neurofibromas (PN), with variable size and location, were identified in 11/20 patients (55%), of which 6 were newly diagnosed.
Other extracranial findings included cutaneous and subcutaneous neurofibromas (100%), skeletal alterations (60%), thyroid nodules (20%), splenomegaly (15%), diffuse neurofibromas (15%), and bullous dystrophy (5%).
In one patient, an early-stage malignant lung tumor was diagnosed, allowing timely treatment. In another patient with a symptomatic inoperable PN, experimental treatment with Selumetinib was proposed.
Conclusion: This case series confirms the established role of WB-MRI as a safe tool for surveillance and multidisciplinary management of NF1-related manifestations, enabling the detection of previously unknown and clinically relevant lesions.
Limitations: Small cohort study; limited observation period; only preliminary restults are avalaible..
Funding for this study: No
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: L. Alonzo¹, R. Cannella¹, R. Laudicella², V. Benfante¹, P. Purpura¹, G. Micci¹, M. Galia¹, G. Brancatelli¹, P. Alongi¹; ¹Palermo/IT, ²Messina/IT
Purpose: The diagnosis of Neuroendocrine Tumors (NETs) can be challenging because of small lesion size, indolent growth, and variable metabolic activity, particularly in cases of unknown primary origin (CUP-NETs). Early and accurate identification of the primary lesion is essential for therapeutic decisions, including surgery, peptide receptor radionuclide therapy (PRRT), or somatostatin analogues.
This systematic review investigated the diagnostic accuracy and clinical impact of molecular imaging, with particular emphasis on PET/CT with radiolabeled somatostatin analogs, in patients with suspected NETs and CUP-NETs.
Methods or Background: A comprehensive search of PubMed and Scopus was performed following PRISMA guidelines. Twenty-one clinical studies published between 2010 and 2024 were included, encompassing 1,857 patients (420 CUP-NETs and 452 suspected NETs). Extracted data included study design, radiotracers, detection rates, and changes in patient management. Methodological quality was assessed using CASP tools.
Results or Findings: PET/CT with [68Ga]Ga-DOTA-peptides consistently outperformed conventional [111In]Pentetreotide SPECT. Reported detection rates for primary tumors in CUP-NETs ranged from 38% to 83% with PET/CT, compared with less than 10% with SPECT. In suspected NETs, PET/CT achieved sensitivity up to 95% and specificity above 85%, leading to therapeutic changes in up to one-third of cases. Additional diagnostic yield was provided by dual-tracer protocols combining [68Ga]Ga-DOTATATE with [18F]FDG and by newer tracers such as [18F]DOPA and [18F]-OC, particularly for aggressive variants and rare subtypes (e.g., paragangliomas, insulinomas). Detection of unknown primaries frequently enabled curative surgery or more tailored systemic treatment.
Conclusion: [68Ga]Ga-DOTA-peptide PET/CT is a key tool in the diagnostic evaluation of suspected and unknown primary NETs. Beyond its superior sensitivity compared with conventional imaging, it significantly influences clinical decision-making and should be integrated into standard diagnostic algorithms.
Limitations: Several retrospective, single-center, and with small sample sizes articles, which may limit generalizability.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: F. Schön, P. Günther, A. Weidlich, J. Kirchberg, M-L. Kromrey, R-T. Hoffmann, H. Fritzsche, J-P. Kühn; Dresden/DE
Purpose: This study investigated the potential of quantitative magnetic resonance imaging (MRI) to differentiate benign from malignant soft tissue tumors.
Methods or Background: Between 10/2022 and 01/2025, patients with soft tissue tumors were prospectively enrolled for quantitative MRI prior to histopathological confirmation. All 3.0T MRI examinations included chemical shift-encoded MRI, T1-/T2-mapping, and diffusion-weighted imaging (intravoxel incoherent motion [IVIM]). All MRI datasets were post-processed to generate R2*-, PDFF- (proton density fat fraction), T1-/T2-maps, and Diffusion (IVIM D), Pseudo-Diffusion (IVIM D*), Perfusion-Fraction (IVIM f). Histopathological diagnosis was defined as standard of reference. Mean values of two readers of each map were compared using Mann-Whitney U tests. A logistic regression model was established to predict malignancy.
Results or Findings: Fifty-nine patients (30 women; mean age 59.1+/-15.5 years) were examined, including 23 with malignant and 36 with benign tumors. Malignant tumors revealed significantly lower values for R2* (13.5+/-25.9 vs. 42.7+/-29.2; p<0.001), PDFF (29.3+/-38.1 vs. 60.2+/-42.4; p=0.003), IVIM D (1221.5+/-716.6 vs. 683.4+/-810.7; p=0.007), and IVIM D* (26.0+/-48.2 vs. 107.0+/-170.6; p=0.004) compared to benign tumors. In contrast, T1 relaxation times were significantly higher (1843.0+/-1065.4 vs. 1113.6+/-948.3; p=0.031). No significant differences were observed for IVIM f and T2 relaxation times (p>0.05). Univariate logistic regression analyses identified R2*, PDFF, IVIM D, and T1 as predictors for malignancy (p<0.05). Following backward elimination, R2* remained as independent variable in the multivariate model (p=0.002; odds ratio=0.96), yielding an AUC of 0.800 with a Youden-Index of 0.539.
Conclusion: By enabling non-invasive differentiation of soft tissue tumors, quantitative MRI - particularly through the independent predictive value of R2* - may serve as a valuable tool to determine lesion dignity in clinical practice.
Limitations: Limited sample size and single-center setting.
Funding for this study: This work was supported by the Clinical Scientist Program MeDDrive of the University Medicine Dresden.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approved by the local ethics committee of the Technical University Dresden (BO-EK-342072022_2)

Author Block: A. K. Nawaz, S. Ahmed, K. Siddique; Lahore/PK
Purpose: - To illustrate diverse diverse CT appearances of pulmonary metastasis in osteosarcoma.
- To correlate imaging appearances with their frequency in clinical cohort.
- To highlight the role of CT in staging, surveillance and treatment response assessment.
Methods or Background: Lungs are the most common site of metastasis in osteosarcoma. While soft tissue and calcified nodules are well known, atypical patterns such as cavitary, pleural or endobronchial disease are often underappreciated. Pulmonary metastasis in osteosarcoma are not just nodules - they represent a spectrum every radiologist must recognize.
For this purpose, we retrospectively reviewed chest CTs of 46 patients with histologically confirmed osteosarcoma and pulmonary metastasis betrween 2023-2025. Imaging appearances were categorized into six groups: soft tissue nodules, calcified nodules, cavitary lesions, pleural involvement, endobronchial disease and mass like lesions.
Results or Findings: Soft tissue nodules were frequent finding, observed in 15 patients (32.6%). Calcified metastases were present in 14 (30.4%), pleural involvement in 11 (23.9%) and mass like lesions or consolidations in 5 (10.8%). Cavitary lesions and endobronchial disease were less common, identified in 2 patients each (4.3%).
Conclusion: Pulmonary metastases in osteosarcoma demonstrate a wide CT spectrum. Beyond the classic nodule, recognizing calcified, cavitary, pleural and airway patterns is essential for accurate staging, guiding treatment decisions and monitoring disease progression.
Limitations: None
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective anonymized review was conducted in accordance with our institutional IRB guidelines. No additional patient consent was required.

Author Block: A. K. Nawaz, M. Nawab, A. Usman, K. Siddique; Lahore, Pakistan/PK
Purpose: Ewing sarcoma is typically a bone tumor, but extra skeletal forms, though uncommon, can occur in diverse anatomical sites. Early recognition of these rare presentations is essential for accurate diagnosis and management. The objective of this study was to analyze the anatomical distribution and imaging characteristics of 12 histologically proven extra skeletal Ewing sarcoma cases from 2020–2025.
Methods or Background: In this retrospective study, we analyzed 208 cases of histologically proven cases of Ewing Sarcoma from January 20202 to January 2025. From these 208 cases, 12 extra skeletal cases were identified after excluding lesions in the upper limb, lower limb, mandible, and thorax. Demographic, anatomical, and imaging data were reviewed.
Results or Findings: Extra skeletal disease represented 5.8% of the cohort. Sites included: head & neck (5, 41.7%), pelvis (3, 25%), abdomen/retroperitoneum (2, 16.7%), thyroid (1, 8.3%), and uterus (1, 8.3%). Patients ranged from 14–32 years; male-to-female ratio was 1.3:1. Imaging revealed well-defined soft tissue masses without bone involvement.
Conclusion: Although rare, extra skeletal Ewing sarcoma can involve head & neck, pelvis, abdomen, thyroid, and uterus. Recognizing these histologically proven atypical sites is vital for timely diagnosis and guiding therapy. This five-year review highlights their frequency, distribution, and imaging features, emphasizing the need for awareness among radiologists and oncologists.
Limitations: None
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective anonymized review was conducted in accordance with our institutional IRB guidelines. No additional patient consent was required.

Author Block: B. J. Kim, M. J. Kim, J. Y. Kim; Daegu/KR
Purpose: To date, there are no studies examining radiologic findings based on histologic patterns of primary hepatic angiosarcoma. This study aims to elucidate radiologic findings of primary hepatic angiosarcoma according to distinct histologic patterns.
Methods or Background: From January 2010 to October 2024, a cohort of 17 patients was included in this study. All patients were pathologically diagnosed with primary hepatic angiosarcoma and underwent CT with or without MRI. Histologic patterns were categorized into mass-forming and non-mass forming groups. The mass-forming type was subdivided into vasoformative and non-vasoformative (epithelioid, spindled) patterns, while the non-mass forming type was divided into sinusoidal and peliotic patterns. Two radiologists independently reviewed the CT and MRI images, categorizing the lesions into diffusely infiltrating and mass-forming types. Additionally, the presence of hypervascular portions and targetoid patterns was analyzed. The correlation between histologic patterns and radiologic findings was assessed using Fisher’s exact test.
Results or Findings: The mass-forming pattern was observed in 13 patients (76.5%), while the non-mass-forming pattern was identified in 4 patients (23.5%). There was a significant correlation (P<.05) between the radiologically classified patterns of diffusely infiltrating and mass-forming lesions and their pathological counterparts. However, the pathological classification of vasoformative and non-vasoformative lesions did not show a significant correlation with the presence of a hypervascular portion on imaging.
Conclusion: The pathological classification of hepatic angiosarcoma into mass-forming and non-mass-forming patterns closely corresponds to the radiological classification of mass-forming and diffusely infiltrating lesions, indicating that pathological findings are well reflected in imaging characteristics.
Limitations: Due to its retrospective design and relatively small number of patients, there may be inherent selection and sampling biases, and in cases with mixed histologic patterns, both histologic classification and radiologic interpretation were based on the predominant component, potentially limiting accuracy.
Funding for this study: The histologic pattern of primary hepatic angiosarcoma may be reflected in imaging as diffusely infiltrating or mass-forming appearances.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: M. Ben salah Faria, G. Raia, F. Peier, L. Widmer, H. Thoeny; Fribourg/CH
Purpose: Our systematic review and meta-analysis aim to evaluate the diagnostic performance of Node Reporting and Data System 1.0 (Node-RADS) for identifying lymph node (LN) metastases, using histopathology as a reference standard, across a range of abdominal and pelvic malignancies.
Methods or Background: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, ScienceDirect and Cochrane Library databases were systematically searched until August 2025. We included studies analysing patients diagnosed with an abdominal or pelvic malignancy, who underwent contrast-enhanced CT or MRI for loco-regional work-up, with LN assessment by Node-RADS, associated with LN histopathological analysis. Study quality was assessed by modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Diagnostic performance was estimated by the random-effects model. Forest plots of pooled sensitivity and specificity were generated for two different Node-RADS thresholds.
Results or Findings: Eighteen retrospective studies were included, comprising 10 using CT and 8 using MRI. These studies covered a variety of malignancies: gynecologic (endometrial, ovarian, cervical), urologic (prostate, bladder, renal), and gastrointestinal cancers (colon, rectal, gastric, cholangiocarcinoma, periampullary). When applying a Node-RADS threshold of ≥3 to define malignant LN, the pooled sensitivity and specificity were 0.80 (95%CI, 0.69-0.87) and 0.79 (95%CI, 0.68-0.87), respectively. For a threshold of ≥4, sensitivity decreased to 0.60 (95%CI, 0.50-0.69), while specificity improved to 0.94 (95%CI, 0.90-0.96). The hierarchical summary receiver operating characteristic (HSROC) analysis showed area under the curves (AUCs) of 0.85 (95%CI, 0.79-0.89) and 0.87 (95%CI, 0.80-0.92) for thresholds ≥3 and ≥4, respectively.
Conclusion: Node-RADS score demonstrated reliable diagnostic performance in assessing lymph node malignancy across abdomino-pelvic malignancies, allowing a standardized approach that enhances reproducibility and supports clinical decision-making in oncologic staging.
Limitations: Heterogeneity of the included studies, which are of retrospective design.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: