Diagnostic performance and prognostic value of preoperative (18)F-FDG PET/CT in renal cell carcinoma patients with venous tumor thrombus.

To observe the diagnostic efficacy of preoperative fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) upon venous tumor thrombus (VTT) in patients with renal cell carcinoma (RCC), and investigate the prognostic value of imaging parameters integrated with clinicopathological characteristics in patients with VTT after nephrectomy with tumor thrombectomy. Patients with newly diagnosed RCC who underwent 18F-FDG PET/CT were reviewed retrospectively. The diagnostic efficacy of 18F-FDG PET/CT in VTT was analyzed. Logistic regression analysis was carried out to identify the clinical variables and PET/CT variables (including maximum standardized uptake value (SUVmax) of primary tumor, VTT SUVmax and primary tumor size) for differentiating early VTT (Mayo 0-II) from advanced VTT (Mayo III-IV). Cox proportional hazard analyses were used to evaluate clinicopathological factors and PET/CT factors (including distant metastasis, primary tumor SUVmax, VTT SUVmax and primary tumor size) for disease-free survival (DFS) in patients with VTT after operation. A total of 174 eligible patients were included in this study, including 114 men (65.5%) and 60 women (34.5%), with a median age of 58 years (range, 16-81 years). The distribution of pathological tumor stage (T stage) was 56 (T1), 17 (T2), 95 (T3), and 6 cases (T4), respectively. According to WHO/ISUP grade, except for 4 cases of chromophobe cell RCC, there were 14 patients (8.0%) of grade 1, 59 patients (33.9%) of grade 2, 74 patients (42.5%) of grade 3 and 23 patients (13.2%) of grade 4. The median maximum diameter of the primary tumor on PET/CT was 7.3 cm (5.0-9.5 cm). The distal metastasis was observed in 46 patients (26.4%). Sixty-one cases (35.1%) were confirmed with VTT by pathology. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 18F-FDG PET/CT imaging were 96.7, 99.1, 98.3, 98.3, and 98.2%, in detecting VTT, respectively, and 70.0, 100.0, 94.9, 100.0, and 94.2%, in evaluating the level of VTT, respectively. Elevated VTT SUVmax (≥5.20) could significantly distinguish the early VTT group and advanced VTT group (P = 0.010). In the prognosis analysis, elevated VTT SUVmax (≥4.30) (P = 0.018, HR 3.123, 95% CI 1.212-8.044) and distant metastasis (P = 0.013, HR 3.344, 95% CI 1.293-8.649) were significantly independent predictors for DFS. Preoperative 18F-FDG PET/CT has a high diagnostic efficacy in detecting VTT and evaluating its level in RCC patients. Those patients with elevated VTT SUVmax should be carefully monitored to detect the possibility of disease progression after operation.

Chen S ，Zhao Y ，Tang Q ，Wu C ，Wang A ，Ma L ，Zhang X ，Chen J ，Gao Y ，Liao X ，Feng N ，Fan Y ，Zhang J ，Li X ，Liu M ... -  《-》

Elevated tumor-to-liver standardized uptake value ratio (TLR) from preoperative (18)F-FDG PET/CT predicts poor prognosis of patients with clear cell renal cell carcinoma after nephrectomy.

To assess the potential of using preoperative 18F-FDG PET/CT to predict the prognosis of patients with clear cell renal cell carcinoma (ccRCC) after nephrectomy. Sixty-nine patients with newly diagnosed ccRCC who underwent 18F-FDG PET/CT prior to surgery were retrospectively reviewed. The metabolic parameters of maximum standardized uptake value (SUVmax) and tumor-to-liver ratio (TLR) from 18F-FDG PET/CT were obtained. Clinicopathological characteristics, including the World Health Organization/the International Society of Urological Pathology (WHO/ISUP) grade, pathological tumor node metastasis (pTNM) stage, venous tumor thrombus, and so on, were acquired. Univariate and multivariate Cox proportional hazards analyses were performed to identify the prognostic factors for disease-free survival (DFS). Of the 69 patients, 25 patients (36.2%) experienced disease progression during the follow-up period. In univariate analysis, the primary tumor size (>4.85 cm), pTNM stage (Ⅲ/Ⅳ), WHO/ISUP grade (G3/4), venous tumor thrombus, adjuvant therapy, SUVmax (>3.55), and TLR (>1.66) were found to correlate with the incidence of decreased DFS (P < 0.05). In multivariate analysis, TLR (P = 0.007, HR: 5.489, 95%CI: 1.605-18.774) and pTNM stage (P = 0.024, HR: 10.385, 95%CI: 1.361-79.238) were revealed to serve as independent prognostic predictors for DFS after adjustment for other variables. Only 3 cases (8.3%) with normal TLR showed disease progression, while 22 cases (66.7%) with elevated TLR experienced disease progression. ccRCC patients with preoperatively elevated TLR (>1.66) and high pTNM stages (Ⅲ/Ⅳ) had significantly unfavorable survival outcomes. These patients should be carefully monitored to detect the possibility of disease progression after nephrectomy as early as possible.

Wu C ，Cui Y ，Zhao Y ，Chen X ，Liao X ，Di L ，Yin L ，Liu M ，Wang R ... -  《-》

Diagnostic value of (18)F-FDG PET/CT versus contrast-enhanced MRI for venous tumour thrombus and venous bland thrombus in renal cell carcinoma.

The purpose of this study was to compare the ability of 18F-FDG PET/CT and contrast-enhanced MRI (CEMRI) to detect and grade venous tumour thrombus (VTT) and venous bland thrombus (VBT) in RCC and assess invasion of the venous wall by VTT. The PET/CT and CEMRI data of 41 patients with RCC were retrieved. The difference in maximum standardized uptake value (SUVmax) between VTT and VBT was analysed. According to their pathological diagnosis, the patients were divided into those with and without venous wall invasion. The PET/CT and CEMRI features, including the SUVmax of the primary lesion and VTT, maximum venous diameter, complete occlusion of the vein by VTT, and VTT morphology, were compared between the two groups. All 41 patients had VTT, and eleven of the 41 patients had VBT. The mean SUVmax of the VTT (6.33 ± 4. 68, n = 41) was significantly higher than that of the VBT (1.37 ± 0.26, n = 11; P < 0.001). Ten of the 11 cases of VBT were correctly diagnosed by 18F-FDG PET/CT, and all 11 were diagnosed by CEMRI. Both 18F-FDG PET/CT and CEMRI can effectively detect VTT and distinguish VTT from VBT. 18F-FDG PET/CT is less effective in grading VTT than CEMRI. Complete venous occlusion by VTT indicates venous wall invasion.

Zhu AH ，Hou XY ，Tian S ，Zhang WF ... -  《Scientific Reports》

Noninvasive evaluation of tumor immune microenvironment in patients with clear cell renal cell carcinoma using metabolic parameter from preoperative 2-[(18)F]FDG PET/CT.

Nowadays, it is necessary to explore effective biomarkers associated with tumor immune microenvironment (TIME) noninvasively. Here, we investigated whether the metabolic parameter from preoperative 2-[18F]FDG PET/CT could provide information related to TIME in patients with clear cell renal cell carcinoma (ccRCC). Ninety patients with newly diagnosed ccRCC who underwent 2-[18F]FDG PET/CT prior to surgery were retrospectively reviewed. The immunological features included tumor-infiltrating lymphocytes (TILs) density, programmed death-ligand 1 (PD-L1) expression, and tumor immune microenvironment types (TIMTs). TIMTs were classified as TIMT I (positive PD-L1 and high TILs), TIMT II (negative PD-L1 and low TILs), TIMT III (positive PD-L1 and low TILs), and TIMT IV (negative PD-L1 and high TILs). The relationship between maximum standardized uptake value (SUVmax) in the primary lesion from 2-[18F]FDG PET/CT and immunological features was analyzed. Cox proportional hazards analyses were performed to identify the prognostic factors for disease-free survival (DFS) after nephrectomy. Tumors with high TILs infiltration showed remarkable correlation with elevated SUVmax and aggressive clinicopathological characteristics, such as high World Health Organization/International Society of Urological Pathology (WHO/ISUP) grade. PD-L1 expression on tumor cells was positively associated with WHO/ISUP grade and negatively correlated with body mass index (BMI). However, no correlation was observed between SUVmax and PD-L1 expression, regardless of its spatial tissue distribution. SUVmax of TIMT I and IV was higher than that of TIMT II, but there was remarkable difference merely between TIMT II and IV. In multivariate analysis, SUVmax (P = 0.022, HR 3.120, 95% CI 1.175-8.284) and WHO/ISUP grade (P = 0.046, HR 2.613, 95% CI 1.017-6.710) were the significant prognostic factors for DFS. Six cases (16.2%) with normal SUVmax showed disease progression, while 25 cases (71.4%) with elevated SUVmax experienced disease progression. Conversely, the immunological features held no prognostic value. Our findings demonstrated that 2-[18F]FDG PET/CT could provide metabolic information of TIME for ccRCC patients and develop image-guided therapeutic strategies accordingly. Patients with elevated preoperative SUVmax should be seriously considered, and perioperative immunotherapy might be beneficial for them.

Wu C ，Cui Y ，Liu J ，Ma L ，Xiong Y ，Gong Y ，Zhao Y ，Zhang X ，Chen S ，He Q ，Zhang J ，Liu M ，Fan Y ... -  《-》

2-[(18)F]FDG PET/CT parameters associated with WHO/ISUP grade in clear cell renal cell carcinoma.

Zhao Y ，Wu C ，Li W ，Chen X ，Li Z ，Liao X ，Cui Y ，Zhao G ，Liu M ，Fu Z ... -  《-》