Negative Predictive Value Of 18F-FDG Research Articles

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

BackgroundTo 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.MethodsPatients 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.ResultsA 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.ConclusionPreoperative 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.

The Role of 18F-FDG PET/CT in Predicting the Neoadjuvant Treatment Response in Patients with Locally Advanced Breast Cancer

Purpose: Patients with locally advanced breast cancer (LABC) should be treated with neoadjuvant chemotherapy (NAC). Pathological complete response (pCR) is related to better disease-free survival (DFS). The best strategy for assessing the efficacy of NAC has not been established yet, but several studies have shown that 18F-FDG PET/CT is a potential imaging tool for assessing pCR. The aim of this study is to investigate the merits of 18F-FDG PET/CT imaging in predicting pCR in both axillary and breast tissue and to establish a threshold maximum standard uptake value (SUVmax) for predicting the response after completion of NAC. Methods: A total of 186 LABC patients, treated with an NAC regimen according to tumor subtype, were retrospectively analyzed in this study. All patients underwent 18F-FDG PET/CT imaging before and after completion of NAC. PET parameters were measured in the most FDG avid breast tissue and axillary lymph nodes. We analyzed the correlation between the tumor SUVmax of the PET/CT response and the pCR after surgery. DFS was also evaluated with respect to pCR. Results: Higher pCR rates were significantly associated with a higher tumor grade, an initial Ki-67 ≥20% (p = 0.03 and p = 0.003, respectively), a triple-negative subtype (32.9%), and a human epidermal growth factor receptor 2 (HER-2)-positive subtype (24.7%) (p < 0.001). There was a significant correlation between the pCR and a complete response in 18F-FDG PET/CT (p < 0.001). The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 18F-FDG PET/CT to determine the pCR after NAC were 100%, 72.2%, 85%, 75.2%, and 100%, respectively. We demonstrated a 1.1 cutoff SUVmax for breast tumors after NAC (OR: 3.94, 95% CI: 1.14–5.05, p = 0.004), the 18F-FDG PET/CT response to NAC (OR: 0.50, 95% CI: 0.25–0.99, p = 0.003), and the molecular subtype of breast tumors (OR: 0.58, 95% CI: 0.38–0.88, p = 0.011). Conclusion: Our results confirm that 18F-FDG PET/CT is a useful method for predicting the NAC response in LABC.

Diagnostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography Computed Tomography in Prosthetic Pulmonary Valve Infective Endocarditis

ObjectivesThe aim of this study was to assess the diagnostic performances of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in congenital heart disease (CHD) patients with pulmonary prosthetic valve or conduit endocarditis (PPVE) suspicion. BackgroundPPVE is a major issue in the growing CHD population. Diagnosis is challenging, and usual imaging tools are not always efficient or validated in this specific population. Particularly, the diagnostic yield of 18F-FDG PET/CT remains poorly studied in PPVE. MethodsA retrospective multicenter study was conducted in 8 French tertiary centers. Children and adult CHD patients who underwent 18F-FDG PET/CT in the setting of PPVE suspicion between January 2010 and May 2020 were included. The cases were initially classified as definite, possible, or rejected PPVE regarding the modified Duke criteria and finally by the Endocarditis Team consensus. The result of 18F-FDG PET/CT had been compared with final diagnosis consensus used as gold-standard in our study. ResultsA total of 66 cases of PPVE suspicion involving 59 patients (median age 23 years, 73% men) were included. Sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT in PPVE suspicion were respectively: 79.1% (95% CI: 68.4%-91.4%), 72.7% (95% CI: 60.4%-85.0%), 91.9% (95% CI: 79.6%-100.0%), and 47.1% (95% CI: 34.8%-59.4%). 18F-FDG PET/CT findings would help to correctly reclassify 57% (4 of 7) of possible PPVE to definite PPVE. ConclusionsUsing 18F-FDG PET/CT improves the diagnostic accuracy of the Duke criteria in CHD patients with suspected PPVE. Its high positive predictive value could be helpful in routine to shorten diagnosis and treatment delays and improve clinical outcomes.

Abstract PS1-30: A prospective phase II trial to evaluate the feasibility of omit sentinel lymph node biopsy after integrate18F-FDG dedicated axillary PET in early breast cancer: SOAPET trial

Abstract Purpose: Sentinel Lymph Node Biopsy (SLNB) is currently the standard of care in clinical node negative (cN0) early breast cancer. The aim of this study is to evaluate the negative predictive value of 18F-FDG dedicated axillary PET (DA-PET) and to verify whether SLNB can be omitted in patients with negative preoperative axillary assessment. Patients and Methods: SOAPET is a prospective phase II trial consisted of 2 stages (NCT04072653). In the first stage, cN0 patients detected by clinical examination, received routinely axillary imaging evaluation (ultrasound and CT etc) and DA-PET, then received SLNB. In the second stage, SLNB will be omitted in the patients with negative preoperative axillary assessment after integrate DA-PET. Now we report the results of the first stage, the primary outcome is negative predictive value (NPV) of DA-PET to detect non-macrometastases of lymph nodes. Results: From Sep 9, 2019 to May 30, 2020, 224 patients were screened, and 189 patients with invasive breast cancer (180 invasive ductal carcinoma, 9 invasive lobular carcinoma) received DA-PET followed by surgical operations with definitive pathological reports. Media tumour size was 2.2cm, 120 HR+HER2-, 23 HR+HER2+, 27 HR-HER2+, 19 HR-HER2-. 40 patients had at least 1 macrometastases lymph nodes (8 patients had over 3 nodes involved), and 16 patients had only micrometastasis nodes. Among 131 patients with DA-PET negative (maxSUV&amp;lt;0.27), 16 patients had macrometastases lymph nodes and 11 patients had micrometastasis diseases. For 58 patients with DA-PET positive (maxSUV&amp;gt;=0.27), 24 patients had macrometastases and 5 patients had micrometastasis nodes. The NPV of DA-PET was 87.8%. The NPV of ultrasound was 86.3%. When combine axillary imaging evaluation with ultrasound and DA-PET, 100 patients were screened out with both DA-PET and ultrasound negative, among which 9 patients had macrometastases and 9 patients had micrometastasis nodes, the NPV was 91%. Conclusions: DA-PET can be used to identify cN0 patients, reducing the false negative rate &amp;lt; 10%. The second stage of SOAPET trial is ongoing to validate the safety of omitting SLNB according to preoperational axillary evaluation when integrating DA-PET. Key words: Breast cancer, Sentinel lymph node biopsy; Dedicated PET;18F-FDG; Table 1: Axillary lymph node detection efficiency of ultrasound and DA-PETAxillary imaging assessmentPatients nmacrometastasesmicrometastasis onlyultrasound*4016US-neg1241712US-det46144US-met1990DA-PET**negative1311611positive58245*:US-neg: no lymph nodes detected by ultrasound;US-det: lymph nodes detected by ultrasound;US-met: suspected metastatic lymph nodes detected by ultrasound**:Maximum single-voxel Standard Uptake Value (maxSUV) cutoff value of DA-PET was set at 0.27 (&amp;lt;0.27 is negative) Table 2: Intergrate axillary imaging assessment with ultrasound and DA-PETmacrometastases+-axillary imaging assessment+315889-*99110040149189*:no lymph nodes detected by ultrasound and maxSUV in DA-PET &amp;lt; 0.27 Citation Format: Junjie Li, Jingyi Cheng, Guangyu Liu, Yifeng Hou, Genghong Di, Benlong Yang, Yizhou Jiang, Liang Huang, Sheng Chen, Yan Wang, Keda Yu, Zhimin Shao. A prospective phase II trial to evaluate the feasibility of omit sentinel lymph node biopsy after integrate18F-FDG dedicated axillary PET in early breast cancer: SOAPET trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-30.

Diagnostic value of sentinel lymph node scintigraphy and 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in the detection of metastatic lymph nodes in patients with early-stage cervical cancer.

Cervical cancer is staged clinically using the International Federation of Gynaecology and Obstetrics staging system. Although lymph node status does not form part of the staging, it has important prognostic and potential therapeutic implications. The aim of the study was to evaluate the role of sentinel lymph node (SLN) scintigraphy and 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in detecting lymph node metastases in patients with early-stage cervical cancer. Thirty-six patients with early-stage cervical cancer underwent SLN detection during primary operation. Of the 36 patients, 28 patients underwent 18F-FDG PET/CT before surgery. The 18F-FDG PET/CT images were analyzed with the histopathological findings as the reference standard. The diagnostic performance of 18F-FDG PET/CT in the detection of nodal disease was reported in terms of accuracy value. The SLN detection rate was the highest (91.7%) using the combined method (lymphoscintigraphy, intraoperative gamma probe, and blue dye). Seven of the thirty-six patients had lymph node involvement (19.4%), of which five had preoperative 18F-FDG PET/CT imaging. On overall patient-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of 18F-FDG PET/CT were 40.0%, 78.3%, 28.6%, 85.7%, and 71.4%, respectively. The combination of radiolabeled nanocolloid with blue dye is safe and reliable and allows successful detection of SLNs in patients with early-stage cervical cancer in a population with high prevalence of human immunodeficiency virus. The specificity and NPV of 18F-FDG PET/CT are high and can be used in conjunction with SLN biopsy.

18F-FDG PET/CT in the Diagnostic and Treatment Evaluation of Pediatric Posttransplant Lymphoproliferative Disorders.

We aimed to evaluate the diagnostic performance of 18F-FDG PET/CT for the detection of posttransplantation lymphoproliferative disorder (PTLD) in a pediatric population and explore its feasibility during response assessment. Methods: This retrospective study included 28 pediatric transplant recipients who underwent a total of 32 18F-FDG PET/CT scans due to clinical suspicion of PTLD within an 8-y period. Pathology reports and 2 y of follow-up were used as the reference standard. Twenty-one response assessment 18F-FDG PET/CT scans were reevaluated according to the Lugano criteria. Results: The diagnosis of PTLD was established in 14 patients (49%). Sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT for the detection of PTLD in children with a clinical suspicion of this disease were 50% (7/14), 100% (18/18), 100% (7/7), and 72% (18/25), respectively. False-negative results occurred in patients with PTLD in the Waldeyer's ring, cervical lymph nodes, or small bowel with either nondestructive or polymorphic PTLD. Two of 5 interim 18F-FDG PET/CT scans and 3 of 9 end-of-treatment 18F-FDG PET/CT scans were false-positive. Conclusion:18F-FDG PET/CT had good specificity and positive predictive value but low to moderate sensitivity and negative predictive value for the detection of PTLD in a 28-pediatric-patient cohort with a clinical suspicion of this disease. False-negative results were confirmed in the Waldeyer's ring, cervical lymph nodes, and small bowel with either nondestructive or polymorphic PTLD subtypes. 18F-FDG PET/CT appears to have a limited role in the response assessment setting of pediatric PTLD, given the observed high proportions of false-positives both at interim and at end-of-treatment evaluations.

Diagnostic value of 18F-FDG PET/CT and tumor markers (CEA, CA19-9, CA24-2) in recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma

Objective To evaluate the diagnostic value of 18F-FDG PET/CT and tumor markers (CEA,CA19-9,CA24-2) in detection for recurrence and metastasis of postoperative colorectal moderately differentiated adenocarcinoma. Methods Fifty-five patients were enrolled in this study. All of the patients were tested with serum CEA within 2 weeks when they underwent 18F-FDG PET/CT scan, and some patients were tested with serum CA19-9 and CA24-2 simultaneously. According to the pathology and clinical results of their follow-up, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT and tumor markers were calculated based on different divided groups, respectively. Results According to the pathology and the results of their clinical follow-up, the sensitivity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 68.09%, 28.57%, 40.00% and 74.47%, respectively. The specificity of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 50.00%, 66.67%, 71.43% and 50.00%, respectively. The positive predictive valueof 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 95.74%, 88.89%, 85.71%, 88.89% and 89.74%, respectively. The negative predictive value of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 75.00%, 26.67%, 11.42%, 17.24%, 25.00%, respectively. The accuracy of 18F-FDG PET/CT, CEA, CA19-9, CA24-2 and the combination of those three tumor markers were 92.73%, 65.47%, 32.65%, 44.68% and 70.91%, respectively. There were 2 cases of false positive and 2 cases of false negative in 18F-FDG PET/CT. Conclusion 18F-FDG PET/CT has high value in detecting recurrence and metastasis of postoperative colorectal carcinoma. Tumor markers have the positive value to imply the recurrence and metastasis of postoperative colorectal carcinoma and are useful to indicate when to perform the 18F-FDG PET/CT. The combination of tumor markers could improve the diagnostic efficiency to some extent.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in restaging and prognosis of recurrent melanoma after curative surgery.

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography–computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan–Meier method and Cox regression analysis. 18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74–0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05). 18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

Clinical Impact of 18F-FDG PET/CT on the Management of Gynecologic Cancers: One Center Experience.

Objective(s):We aim to investigate the clinical impact of 18F-FDG PET/CT in managing patients with gynecological malignancies and pelvic or extrapelvic lymph nodes that are of equivocal significance on conventional imaging.Methods:We retrospectively evaluated 18F-FDG PET/CT scans of patients with gynecologic tumors who were referred to King Hussein Cancer Center from January 2010 to August 2014. PET/CT results were compared with MRI and CT findings. We evaluated sensitivity and specificity of 18F-FDG PET/CT, its role in changing treatment plan and its positive predictive value (PPV) and negative predictive value (NPV).Results: Ninety seven patients (mean age: 49 years) underwent 18F-FDG/PET in the study period (40 cervical, 37 endometrial and 20 ovarian cancers). PET/CT scan provided additional information in 23 patients; upstaging 4.1% (4 patients; 3 true positive) and down staging in 19.5% (19 patients; 15 true negative). As a result, treatment strategy was changed from curative to palliative in three patients, and modification of radiation field or additional curative therapy was implemented following exclusion of distant metastasis in 11 patients. Mean follow up time for the whole cohort was 35 months (range 6 - 60 months). NPV of 18F-FDG PET/CT in detecting extrapelvic lymphadenopathy was 83.3%.Conclusion: 18F-FDG PET/CT has high clinical impact in management of gynaecological cancers as it alters the treatment plan in a substantial number of patients who had equivocal findings on conventional imaging, as well as it offers excellent validity in lymph nodes staging.

Clinical Value of Combining 18F-FDG PET/CT and Routine Serum Tumor Markers in The Early Detection of Recurrence Among Follow-up Patients Treated for Cervical Squamous Cell Carcinoma.

Objective: The purpose of this retrospective study was to investigate the role of 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET/CT) and evaluate if combined elevated serum tumor markers levels improve the accuracy of 18F-FDG PET/CT in detecting recurrence of cervical squamous cell carcinoma.Methods: A total number of 42 patients who were treated for cervical squamous cell carcinoma and had underwent 18F-FDG PET/CT for suspected recurrence of cervical cancer were retrospectively reviewed in this study and their clinical, pathological and serological data were collected and analyzed. The clinical value of combining 18F-FDG PET/CT with serum tumor markers was investigated.Results: Among the 42 patients, 18F-FDG PET/CT was true positive in 25 (59.5%), false positive in 5 (11.9%), true negative in 12 (28.5%) and false negative in none. The overall patient-based sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 18F-FDG PET/CT in detecting recurrent cervical cancer were 100%, 70.6, 88.1%, 83.3%, and 100%, respectively. The accuracy of 18F-FDG PET/CT with combined squamous cell carcinoma antigen (SCC Ag) and carcinoembryonic antigen (CEA) elevation was 100% compared to only SCC Ag elevation and only CEA elevation, 90% and 33.3%, respectively. The positive predictive value of a positive 18F-FDG PET/CT with combined SCC Ag and CEA elevation was 100% for detection of recurrent cervical cancer. Also, the negative predictive value of a negative 18F-FDG PET/CT combined with normal SCC Ag and CEA levels was 100%.Conclusion: 18F-FDG PET/CT is highly sensitive in the diagnosis of recurrent cervical cancer. When 18F-FDG PET/CT is associated with both SCC Ag and CEA elevation or only SCC Ag elevation, the accuracy is increased but not when associated with only CEA elevation. Positive 18F-FDG PET/CT associated with both tumor markers elevation can precisely predict recurrence. Moreover, normal levels of both tumor markers with a negative 18F-FDG PET/CT result may clinically reassure that a recurrence is absent.

Prognostic Importance of Bone Marrow Uptake on Baseline 18F-FDG Positron Emission Tomography in Diffuse Large B Cell Lymphoma.

To define the role of 18F-flourodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the detection of bone marrow (BM) involvement in patients with diffuse large B cell lymphoma (DLBCL). Fifty-four (mean age: 55.5 ± 18.3 years, 20 female and 34 male) DLBCL patients who underwent pretreatment 18F-FDG PET/CT were included to the study. Focal or diffuse BM 18F-FDG uptake that is higher than mediastinal blood pool uptake was accepted as positive. After staging of disease by CT and 18F-FDG PET/CT, all the patients received R-CHOP treatment after diagnostic blinded bone marrow biopsy (BMB). Presence of positive BM uptake in 18F-FDG PET/CT and histopathological examination results of BMBs were analyzed by Chi-square test. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 18F-FDG PET/CT in the detection of BM involvement were calculated. Prognostic importance of the presence of BM 18F-FDG uptake was analyzed by Kaplan-Meier analysis. BM 18F-FDG uptake was detected in 8 patients. Histopathological examination of BMB revealed BM involvement in 6 out of 8 patients. BMB was negative in all patients who have no 18F-FDG uptake in the evaluation of PET/CT images. Sensitivity, specificity, accuracy, PPV, and NPV of 18F-FDG PET/CT in the detection of BM involvement were calculated as 100%, 96%, 96%, 75%, and 100%, respectively. In the Kaplan-Meier analysis, we found that presence of pretreatment 18F-FDG uptake in BM has a prognostic importance. Whereas mean time to progression (TTP) in patients with BM uptake was 32.25 ± 10.9 months and mean TTP in those without was 51.69 ± 3.6 months (p = 0.013). BM uptake in pretreatment 18F-FDG PET/CT is an important prognostic factor in DLBCL patients. Moreover, in consideration of high NPV, 18F-FDG PET/CT could eliminate unnecessary BMB in FDG-negative patients.

Comparison of imaging features of 18F-FDG PET/CT in malignant pleural effusion and tuberculosis pleural effusion

Objective To compare the imaging features of 18F-FDG PET/CT in malignant pleural effusion (MPE) and tuberculosis pleural effusion (TPE). Methods From January 2012 to December 2014, 93 patients (52 males, 41 females, and average age (66.7±12.7) years) with unexplained pleural effusion who underwent 18F-FDG PET/CT were retrospectively studied. MPE and TPE were confirmed by histology, cytology or clinical follow-up. Lesion SUVmax and T/NT were calculated. Both lesion size and density (in Hounsfield units) of pleural abnormalities on CT images were measured. The difference of images between MPE and TPE was analyzed. Diagnostic efficiency of 18F-FDG PET/CT for detecting MPE and TPE were estimated. Two-sample t test and χ2 test were used to analyze the data. Results The lesion SUVmax of 66 patients with MPE and 27 patients with TPE was higher than that in normal tissues (7.72±6.50, 8.43±4.92; t=7.81 and 7.15, both P 0.05). T/NT was not significantly different between MPE and TPE (5.40±4.29, 5.20±2.73 respectively, t=-0.22, P>0.05) either. The uptake features of 18F-FDG were different between MPE and TPE (χ2=29.3, P<0.01). When the nodular 18F-FDG uptake increase in pleura was taken as the malignancy, diffuse 18F-FDG uptake increase in pleura as tuberculosis, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 78.8%(52/66), 81.5%(22/27), 91.2%(52/57), 61.1%(22/36), respectively, for differentiation of MPE from TPE. Primary cancers were found in 43 patients. When the nodular uptake increase in pleura, or primary cancer associated with increased pleural uptake found by PET was taken as the malignancy, the above mentioned parameters were 95.5%(63/66), 81.5%(22/27), 92.6%(63/68), 88.0%(22/25), respectively. Conclusions The 18F-FDG uptake in MPE and TPE is higher than that in normal tissues. 18F-FDG PET/CT is helpful in the search for the primary tumor of MPE. Qualitative method of 18F-FDG PET/CT has a good value in the differentiation of MPE from TPE. Key words: Pleural effusion; Neoplasms; Tuberculosis; Tomography, emission-computed; Tomography, X-ray computed; Deoxyglucose

Value of Dedicated Head and Neck 18F-FDG PET/CT Protocol in Detecting Recurrent and Metastatic Lesions in Post-surgical Differentiated Thyroid Carcinoma Patients with High Serum Thyroglobulin Level and Negative 131I Whole-body Scan.

Objective(s):In clinical practice, approximately 10-25% of post-surgical differentiated thyroid carcinoma (DTC) patients with high serum thyroglobulin (Tg) and negative 131I whole-body scan (WBS) have poor prognosis due to recurrent or metastatic lesions after radioactive iodine treatment. The purpose of this study was to evaluate the value of 18F-FDG PET/CT scan in DTC patients with high serum Tg level and negative 131I WBS.Methods:69 post-surgical DTC patients with high serum Tg level and negative post ablation 131I WBS were enrolled in this study. All DTC patients underwent head and neck ultrasound, CT scan and whole-body 18F-FDG PET/CT, based on the dedicated head and neck protocol.Results:Overall, 92 lesions were detected in 43 (62.3%) out of 69 patients with positive 18F-FDG PET/CT scan, compared to only 39 lesions detected on CT scan in 26 (37.7%) out of 69 patients. The sensitivity, accuracy and negative predictive value of 18F-FDG PET/CT were 88%, 87% % and 76%, respectively, which were significantly higher than those of CT scan (67.2%, 54.3% and 48.8%, respectively) (P<0.01). Specificity and positive predictive value of 18F-FDG PET/CT (90.5% and 95.2%, respectively) were similar to those of CT scan (95.2% and 96.2%, respectively) (P>0.05). The maximum standardized uptake value (SUVmax) threshold was 4.5 with a good diagnostic value (sensitivity of 92.3% and specificity of 100%). The dedicated head and neck 18F-FDG PET/CT protocol altered the treatment plan in 33 (47.8%) out of 69 DTC patients with high serum Tg level and negative 131I WBS.Conclusion:Dedicated head and neck 18F-FDG PET/CT protocol showed a higher diagnostic value, compared to CT scan and played an important role in detecting recurrent or metastatic lesions in post-surgical DTC patients with high serum Tg level and negative 131I WBS.

Comparison of ¹⁸F-FDG PET/CT and large-scale DWI for evaluation of non-Hodgkin lymphoma bone marrow infiltration

To compare the diagnostic value of ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and large-scale diffusion weighted imaging (DWI) for evaluation of non-Hodgkin lymphoma (NHL) bone marrow (BM) infiltration. A total of 79 patients with pathologically diagnosed NHL underwent ¹⁸F-FDG PET/CT, large scale DWI and BM pathological examination. BM examination as the "gold standard", the performance (the sensitivity, specificity, accuracy, positive and negative predictive value) of ¹⁸F-FDG PET/CT and large scale DWI for evaluation of BM infiltration was compared and the risk of BM infiltration of different subtypes and sources of NHL was analyzed. 25 of 79 cases were diagnosed as BM infiltration by pathological examination with 57 BM sites. Abnormal high BM metabolisms were identified in 22 cases with 56 BM sites by ¹⁸F-FDG PET/CT and 25 cases with 58 BM sites by large-scale DWI. The sensitivity, specificity, accuracy, positive and negative predictive value of ¹⁸F-FDG PET/CT were 80.0%, 96.3%, 91.1%, 90.9%, 91.2%, respectively. And they were 84.0%, 92.6%, 89.9%, 84.0%, and 92.6% by large-scale DWI, respectively. A receiver operating characteristic (ROC) analysis demonstrated that there was no statistical difference in ¹⁸F-FDG PET/CT and large-scale DWI (P>0.05). The area under ROC curve for ¹⁸F-FDG PET/CT and large-scale DWI were 0.911 and 0.883 respectively. The incidences of BM infiltration in aggressive NHL patients by ¹⁸F-FDG PET/CT (21/69, 30.4%) and large-scale DWI (23/69, 33.3%) were higher than those (PET/CT: 10.0%; large-scale DWI: 20.0%; P>0.05) in indolent NHL patients. ¹⁸F-FDG PET/CT and large-scale DWI had important clinical value in diagnosing BM infiltration of NHL. A combination of ¹⁸F-FDG PET/CT, large-scale DWI and pathological examination could improve the positive rate of BM infiltration in NHL.

Detection of nodal metastases by 18F-FDG PET/CT in apparent early stage ovarian cancer: A prospective study

BackgroundThe rate of nodal metastases in ovarian cancer macroscopically confined to the pelvis is about 15%–20%. Systematic pelvic and aortic lymphadenectomy improves staging but it is associated with increased morbidity and costs. The purpose of this study was to evaluate the role of 18F-FDG PET/CT in the pre-operative nodal metastases detection in ovarian cancer grossly confined to the pelvis. MethodsFrom 2006 to 2012, 68 consecutive women with epithelial ovarian cancer confined to the pelvis underwent 18F-FDG PET/CT followed by surgery inclusive of systematic pelvic and aortic lymphadenectomy (SAPL). 18F-FDG PET/CT images were analyzed and correlated to histological examination. ResultsTwenty-six women underwent bilateral and 42 unilateral SAPL with 3165 nodes removed and analyzed. Median number of dissected nodes was 42 (range 16–91). Twelve women (17.6%) had nodal metastases. 18F-FDG PET/CT correctly identified 10 patients with nodal involvement. Sensitivity, specificity, accuracy, positive and negative-predictive value of 18F-FDG PET/CT in detecting nodal metastases were 83.3%, 98.2%, 95.6%, 90.9% and 96.5%, respectively, on overall patient-based, and 75.5%, 99.4%, 98.1%, 87.5% and 98.6%, respectively, on nodal lesion site-based analysis. Conclusion18F-FDG PET/CT is an accurate tool for the detection of nodal metastases. Metabolic imaging could be used to select women who could benefit from systematic lymphadenectomy. The high negative predictive value allows avoidance of SAPL in the vast majority of women, minimizing operative and post surgical complications. Further larger prospective investigation is required to confirm our data.