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Purpose: Recurrence is the main cause of tumor-related death of retroperitoneal liposarcoma (RPLPS). Different recurrence pattern was determined by variant subtype of retroperitoneal liposarcoma which displayed diverse presentations on 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). This study aims to analyze the characteristics of different histologic subtypes of RPLPS on 18F-FDG PET/CT and their associations with recurrence and prognosis.Methods: Clinical-pathological information, 18F-FDG PET/CT, recurrence and progression free survivals (PFS) of 83 patients with RPLPS were collected. Maximum, and peak standardized uptake value (SUVmax and SUVpeak, respectively) and mean CT value (CTmean) of tumors were measured; their correlations with histologic subtype were analyzed. The predictability of SUVmax and CTmean for histologic subtype was evaluated using the receiver operating characteristics (ROC) curve analysis. ROC curve was also performed to analyze the predictive value of SUVmax and peak SUV (SUVpeak) for recurrence. The Kaplan-Meier analysis was performed to analyze whether SUVmax and SUVpeak were risk factors for recurrence. Results: Regarding the histology, 30.1% patients were well-differentiated liposarcoma (WDLPS), 56.6% patients were dedifferentiated liposarcoma (DDLPS), 12.0% patients were myxoid/round cell liposarcoma(MLPS), and 1.2% patients were pleomorphic liposarcoma (PMLPS). SUVmax of DDLPS were significantly higher than those of WDLPS (P < 0.001) and MLPS(P = 0.001). CTmean of WDLPS was significantly lower than those of MLPS (P = 0.001) and DDLPS (P < 0.001). ROC curve suggested 5.1 as an approximate cutoff value of SUVmax for distinguishing DDLPS from non-DDLPS (sensitivity = 76.8%, specificity = 88.0%), and 12.3Hu as cutoff value of CTmean for distinguishing WDLPS from non-WDLPS (sensitivitty = 94.1%, specificity = 54.5%). When the cut-off values of SUVmax and SUVpeak were set at 10.7 and 6.9 respectively, the maximum performances for predicting recurrence were obtained. Kaplan-Meier analyses showed that histologic subtype, SUVmax, and SUVpeak were risk factors that associated with recurrence-free survival (P = 0.02, ＜0.001, and 0.001, respectively).Conclusions: The SUV value and CT features on 18F-FDG PET/CT imaging may increase the confidence in diagnosis and subtype distinguish of RPLPS. When inflammatory liposarcoma was excluded, patients with SUVmax > 10.7 or SUVpeak > 6.9 suggest a poor prognosis.

Objective The aim of this study was to analyze the computed tomography (CT), fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), and clinical findings of pulmonary epithelioid hemangioendothelioma. Methods Eighteen patients were included. We reviewed CT and PET/CT features and clinical information. Spearman correlation analysis was used to reveal the correlation between lesion size and maximum standardized uptake values (SUVmax). Results Eleven patients complained of different symptoms. The serum levels of tumor markers were elevated in 8 patients (44.4%). Multiple lesions were shown in 14 cases (77.8%). Eleven cases (61.1%) presented as bilateral multiple perivascular lesions. The size of the largest nodule was less than 20 mm in diameter in 11 cases (61.1%). Eleven cases underwent PET/CT examination, and 8 cases (72.7%) had increased FDG uptake. There was a positive correlation (Spearman correlation coefficient, 0.56; P = 0.009) between lesion size and SUVmax. Extrapulmonary involvement was shown in 7 cases, including the liver and bone. Conclusions Pulmonary epithelioid hemangioendothelioma on CT scan usually showed multiple bilateral perivascular lung nodules, generally measuring less than 20 mm in diameter. Lesions usually showed increased FDG uptake on PET/CT scans. There was a positive correlation between lesion size and SUVmax. The liver and bone were the most frequently involved extrapulmonary organs.

Background Previous reports suggested that CD133-positive cells had biological features of cancer stem cells (CSCs). Furthermore, CD133 expression was reported as an unfavorable prognostic factor in patients. Therefore, a new radiolabeled probe, 99mTc labeled AC133 antibody which binding with CD133 specifically, was developed to noninvasively detect CSCs by SPECT in vivo. Methods CD133 expression was evaluated by flow cytometry in three colon cancer cell lines (HCT116, Lovo and DLD1). AC133 antibody and control IgG were conjugated with succinimidyl-6-hydrazinonicotinate hydrochloride (SHNH), and then labeled with 99mTc. The new radiolabeled probe was named as 99mTc-SHNH-AC133. The vitro cell binding assays, series SPECT imaging and biodistribution analyses were performed. Flow cytometry, immunofluorescence staining of tumor tissues were carried to verify the in-vivo imaging results. Results 99mTc-SHNH-AC133 was labeled with a high radiochemical purity (97.7±2.4%, N.=3) and specific activity (4.07 MBq/µg). Cellular experiments showed that the labeled AC133 antibody retained with a high binding affinity on CD133-positive cells (HCT116 and Lovo cells). Biodistribution analyses showed high tumor uptake of the tracer in HCT116 and Lovo xenografts (8.82±0.73 and 7.37±0.26 %ID/g, respectively, N.=4) and high tumor-to-muscle ratios (13.18±2.84 and 11.13±0.53, respectively, N.=4) at 36 h after injection, resulting in high contrast SPECT images with high specific tumor uptake. However, the tumor bearing CD133-negative cell (DLD1 cells) showed no obvious uptake of 99mTc-SHNH-AC133 both in-vitro cell binding and in-vivo imaging study. Moreover, the tumor uptake of 99mTc-SHNH-AC133 in positive tumor models was significantly reduced by pre-injection of excess unlabeled AC133 antibody. Flow cytometric analysis and immunofluorescence staining confirmed the CD133 expression in tumors, which correlated well with the in-vivo results. Conclusions This study showed that 99mTc-SHNH-AC133 exhibited high uptake in CD133-positive tumors. The high specificity and good tumor targeting properties of 99mTc-SHNH-AC133 may provide a new method to track or locate CSCs.