FDG PET/CT in Papillary Intralymphatic Angioendothelioma of the Spleen.

Splenic papillary intralymphatic angioendothelioma is extremely rare. We describe FDG PET/CT and MRI findings of splenic papillary intralymphatic angioendothelioma in a young adult. The splenic tumor showed hypodensity and increased FDG uptake with SUV max of 4 on PET/CT, heterogeneous signal intensity with internal hypointense stellate scars on T2-weighted image, and progressive centripetal enhancement on dynamic contrast-enhanced T1-weighted images. This case indicates that papillary intralymphatic angioendothelioma should be included in the differential diagnosis of FDG-avid splenic lesions.

Jiao B ，Liu H ，Ma X ，Dong A ，Zhao H ... -  《-》

Diagnostic ability of [(18)F]FDG PET/CT for distinguishing benign from malignant spleen lesions.

[18F]Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a non-invasive imaging modality used in the differential diagnosis of splenic lesions, although ideal parameters and thresholds remain unclear. The present study evaluated the ability of [18F]FDG PET/CT, including its visual and quantitative parameters, to differentiate between benign and malignant splenic lesions. Patients who underwent [18F]FDG PET/CT following the detection of splenic lesions on contrast-enhanced CT were retrospectively analysed. Visual parameters assessed on [18F]FDG PET/CT included whole spleen uptake intensity, lesion multiplicity, and lesion uptake, and quantitative parameters included maximum standardised uptake value (SUVmax), lesion-to-background ratio (LBR), metabolic tumour volume (MTV), total lesion glycolysis (TLG), and lesion size. Parameters differentiating between benign and malignant lesions were evaluated by Pearson's chi-square test, Mann-Whitney U-test, and receiver operating characteristics (ROC) curve analysis. Splenic lesion uptake (p = 0.001) was the only visual parameter significantly distinguishing between benign and malignant lesions. ROC curve analysis demonstrated that SUVmax had the largest area under the ROC, 0.91 (p < 0.001), with an optimal cut-off > 5.3 having a sensitivity of 90.3% and a specificity of 80.6%. Subgroup analysis of malignant lesions showed that SUVmax (p = 0.013), LBR (p = 0.012), and TLG (p  = 0.034) were significantly higher in splenic lymphomas than in splenic metastases. Of the [18F]FDG PET/CT parameters investigated, SUVmax had the highest accuracy in diagnosing malignant splenic lesions and was significantly higher in splenic lymphomas than in splenic metastases. Visual determination of [18F]FDG uptake by splenic lesions may be an easily evaluated parameter. SUVmax and visual grade of [18F]FDG PET/CT help to differentiate spleen lesions. [18F]FDG PET/CT is useful for discriminating between benign and malignant spleen lesions. Many splenic lesions are difficult to diagnose on anatomical imaging, with histopathologic analyses are required. SUVmax of PET/CT provided the diagnostic ability to differentiate between benign and malignant splenic lesions. More than normal spleen uptake can be a convenient parameter to diagnose malignant spleen lesions.

Lee DY ，Kim YI ，Ryu JS 《-》

Is there a comparable Mp-MRI for incidental prostate uptake on 18 F-FDG PET/CT?

Although 18 F-FDG-PET/CT is helpful in defining many types of cancer, localized prostate cancer should not be treated with this technique. This study describes the use of multi-parametric MRI (mpMRI) to characterize incidental 18 F-FDG uptake in the prostate. While 18 F-FDG-PET/CT is useful for characterizing a variety of cancers, it is not advised for prostate cancer that is localized. This work investigates the use of mpMRI to describe incidental 18 F-FDG uptake in the prostate.mpMRI included T2-weighted (T2W), dynamic contrast enhancement (DCE), and apparent diffusion coefficient (ADC) sequences. Patients were classified according to PI-RADS (Prostate Imaging Reporting and Data System) version 2.1 by an experienced uroradiologist, and 18 F-FDG-PET was evaluated to determine whether the area of involvement on CT had a counterpart in mpMRI. A biopsy was performed on 30 of the 92 patients. These patients' maximum standardized uptake values (SUVmax) 6 < and ≥ 6, PS(PSA) density 0.15 < and ≥ 0.15, PSA level, uptake pattern (focal involvement/diffuse involvement), and PI-RADS scores were compared. P < .05 was considered statistically significant. Logistic regression was used to analyze PI-RADS score groups age, PSA, PSA density and SUVmax. In the study, 92 patients with incidental 18 F-FDG-PET/CT prostate uptake were examined. Median age was 66, PSA median was 3.6 ng/ml (range: 0-3198 ng/ml). Notably, in 70.6% of cases, PET/CT uptake didn't correlate with mp-MRI findings. Among PI-RADS 3-4-5 patients (29.3%), there was a correlation. Biopsies in 30 patients revealed 43.3% benign, 56.7% malignant. Significant differences between benign and malignant cases were observed in PSA density, PI-RADS scores, and PSA levels (p < .05), while SUVmax and uptake pattern were not significant. In multivariate logistic regression analysis, PI-RADS score groups were found to be independent risk factors for predicting malignancy. Our study showed that incidental 18 F-FDG-PET/CT prostate uptake was detected and that high PSA density values, PI-RADS scores, and PSA values, such as in routine patients, and not PET-CT findings such as SUVmax and uptake pattern, were more predictive of malignancy.

Şam Özdemir M ，Kaya N ，Savun M ，Keskin ET ，Yüzkan S ，Arslan FZ ，Budak B ，Omak Ö ，Yardımcı AH ，Özdemir H ... -  《World Journal of Surgical Oncology》

Desmoplastic Small Round Cell Tumor: a study of CT, MRI, PET/CT multimodal imaging features and their correlations with pathology.

Exploring the computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT Multimodal Imaging Characteristics of Desmoplastic Small Round Cell Tumor (DSRCT) to enhance the diagnostic proficiency of this condition. A retrospective analysis was performed on clinical data and multimodal imaging manifestations (CT, MRI, FDG-PET/CT) of eight cases of DSRCT. These findings were systematically compared with pathological results to succinctly summarize imaging features and elucidate their associations with both clinical and pathological characteristics. All eight cases within this cohort exhibited abdominal-pelvic masses, comprising six solitary masses and two instances of multiple nodules, except for one case located in the left kidney, the remaining cases lacked a clear organ source. On plain images, seven cases exhibited patchy areas of low density within the masses, four cases showed calcification within the masses. Post-contrast imaging displayed mild-to-moderate, uneven enhancement. Larger masses displayed patchy areas without significant enhancement at the center. In the four MRI examinations, T1-weighted images exhibited uneven, low signal intensity, while T2-weighted images demonstrated uneven high signal intensity. Imaging unveiled four cases of liver metastasis, four cases of ascites, seven cases of lymph node metastasis, three cases of diffuse peritoneal thickening, and one case involving left ureter invasion with obstruction. In the FDG-PET/CT examinations of seven cases, multiple abnormal FDG accumulations were observed in the abdominal cavity, retroperitoneum, pelvis, and liver. One postoperative case revealed a new metastatic focus near the colonic hepatic region. The range of maximum standardized uptake values (SUVmax) for all lesions are 6.62-11.15. DSRCT is commonly seen in young men, and the imaging results are mostly multiple lesions with no clear organ source. Other common findings include intratumoral calcification, liver metastasis, ascites, peritoneal metastasis, and retroperitoneal lymph node enlargement. The combined use of CT, MRI and FDG-PET/CT can improve the diagnostic accuracy and treatment evaluation of DSRCT. However, it is imperative to underscore that the definitive diagnosis remains contingent upon pathological examination.

Xu K ，Chen Y ，Shen W ，Liu F ，Wu R ，Ni J ，Wang L ，Chen C ，Zhu L ，Zhou W ，Zhang J ，Zuo C ，Wang J ... -  《BMC MEDICAL IMAGING》

Evaluating 64Cu-DOTA-rituximab as a PET agent in patients with B-cell lymphoma: a head-to-head comparison with 18F-fluorodeoxyglucose PET/computed tomography.

This study aimed to evaluate the biodistribution of 64Cu-DOTA-rituximab and its diagnostic feasibility for lymphoma using CD20-targeted 64Cu-DOTA-rituximab PET/computed tomography (PET/CT). A prospective study involving six patients diagnosed with lymphoma was conducted between January 2022 and January 2023. These patients underwent 18F-fluorodeoxyglucose (18F-FDG) and 64Cu-DOTA-rituximab PET/CT scans. 64Cu-DOTA-rituximab PET/CT images were acquired at 1, 24, and 48 h after administering 64Cu-DOTA-rituximab to assess the biodistribution and dosimetry over time. The observed lymph nodes were categorized into specific regions, including cervical and supraclavicular, axillary and infraclavicular, mediastinal, hilar, abdominal paraaortic and retroperitoneal, iliac, mesenteric, and inguinal regions, to compare the diagnostic ability of 18F-FDG and 64Cu-DOTA-rituximab PET/CT in detecting lymphoma lesions. Furthermore, the tumor-to-background ratio was calculated and compared with the maximum standardized uptake (SUVmax) of the tumors and the mean standardized uptake (SUVmean) of normal organs. Internal radiation dosimetry was determined using the OLINDA/EXM software. 64Cu-DOTA-rituximab uptake in lymph nodes associated with lymphoma progressively increased from 1 to 48 h after injection. In contrast, 64Cu-DOTA-rituximab uptake in normal organs, such as blood, lung, kidney, bladder, muscle, bone, and brain, decreased over time, whereas it increased in the liver and spleen. When it comes to the comparison between 64Cu-DOTA-rituximab and 18F-FDG, the SUVmax of tumors was higher on 64Cu-DOTA-rituximab PET/CT (18.1 ± 8.3) than on 18F-FDG PET/CT (5.2 ± 1.5). Additionally, the tumor-to-background ratio, measured using the SUVmean of normal muscles, was higher on 64Cu-DOTA-rituximab PET/CT (55.7 ± 31.0) than on 18F-FDG PET/CT (8.6 ± 2.8). No adverse events related to 64Cu-DOTA-rituximab injection were reported. The results of this study demonstrate the feasibility of using 64Cu-DOTA-rituximab PET/CT to evaluate the CD20 expression. The increased 64Cu-DOTA-rituximab uptake in lymph nodes associated with tumors, higher SUVmax, and tumor-to-muscle ratios observed with 64Cu-DOTA-rituximab PET/CT compared with 18F-FDG PET/CT, highlight the diagnostic potential of this imaging modality.

Lee I ，Byun BH ，Kim BI ，Choi CW ，Kang HJ ，Kang CS ，Woo SK ，Lee KC ，Kang JH ，Lim I ... -  《-》