Early SUVmax Research Articles

18F-FDG PET/CT for early prediction of pathological complete response in breast cancer neoadjuvant therapy: a retrospective analysis.

Neoadjuvant treatment has been developed as a systematic approach for patients with early breast cancer and has resulted in improved breast-conserving rate and survival. However, identifying treatment-sensitive patients at the early phase of therapy remains a problem, hampering disease management and raising the possibility of disease progression during treatment. In this retrospective analysis, we collected 2-deoxy-2-[F-18] fluoro-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) images of primary tumor sites and axillary areas and reciprocal clinical pathological data from 121 patients who underwent neoadjuvant treatment and surgery in our center. The univariate and multivariate logistic regression analyses were performed to investigate features associated with pathological complete response (pCR). An 18F-FDG PET/CT-based prediction model was trained, and the performance was evaluated by receiver operating characteristic curves (ROC). The maximum standard uptake values (SUVmax) of 18F-FDG PET/CT were a powerful indicator of tumor status. The SUVmax values of axillary areas were closely related to metastatic lymph node counts (R = 0.62). Moreover, the early SUVmax reduction rates (between baseline and second cycle of neoadjuvant treatment) were statistically different between pCR and non-pCR patients. The early SUVmax reduction rates-based model showed great ability to predict pCR (AUC = 0.89), with all molecular subtypes (HR+HER2-, HR+HER2+, HR-HER2+, and HR-HER2-) considered. Our research proved that the SUVmax reduction rate of 18F-FDG PET/CT contributed to the early prediction of pCR, providing rationales for utilizing PET/CT in NAT in the future.

Evaluation of the Diagnostic Performance of F18-Fluorodeoxyglucose-Positron Emission Tomography, Dynamic Susceptibility Contrast Perfusion, and Apparent Diffusion Coefficient in Differentiation between Recurrence of a High-grade Glioma and Radiation Necrosis.

Differentiation between recurrence of brain tumor and radiation necrosis remains a challenge in current neuro-oncology practice despite recent advances in both radiological and nuclear medicine techniques. The purpose of this study was to compare the diagnostic performance of dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI), apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging, and F18-fluorodeoxyglucose-positron emission tomography (F18-FDG-PET) in the differentiation between the recurrence of a high-grade glioma and radiation necrosis. Patients with a diagnosis of high-grade glioma (WHO Grades III and IV) who had undergone surgical resection of the tumor followed by radiotherapy with or without chemotherapy were included in the study. DSC perfusion, diffusion-weighted MRI, and PET scan were acquired on a hybrid PET/MRI scanner. For each lesion, early and delayed tumor-to-brain ratio (TBR), early and delayed maximum standardized uptake value (SUVmax), normalized ADC ratio, and normalized relative cerebral blood volume (rCBV) ratio were calculated and the pattern of lesional enhancement was noted. The diagnosis was finalized with either histopathological examination or the characteristics on follow-up imaging. The statistical analysis using the receiver operator characteristic curves was done to determine the diagnostic performance of DSC perfusion, 18-F FDG-PET, and ADC in differentiation between tumor recurrence and radiation necrosis. Fifty patients were included in the final analysis, 32 of them being men (64%). A cutoff value of early TBR >0.8 (sensitivity of 100% and specificity of 80%), delayed TBR >0.93 (sensitivity of 92.3% and specificity of 80%), early SUVmax >10.2 (sensitivity of 76.9% and specificity of 80%), delayed SUVmax >13.2 (sensitivity of 61.54% and specificity of 100%), normalized rCBV ratio >1.21 (sensitivity of 100% and specificity of 60%), normalized ADC ratio >1.66 (sensitivity of 38.5% and specificity of 80%), and Grade 3 enhancement (sensitivity of 100% and specificity of 60%) were found to differentiate recurrence from radiation necrosis. Early TBR had the highest accuracy (94.44%), while ADC ratio had the lowest accuracy (50%). A combination of early TBR (cutoff value of 0.8), late TBR (cutoff value of 0.93), and rCBV ratio (cutoff value of 1.21) showed a sensitivity of 100%, specificity of 92.3%, positive predictive value of 88.9%, negative predictive value of 93.7%, and an accuracy of 96.6% in discrimination between radiation necrosis and recurrence of tumor. F18-FDG-PET and DSC perfusion can reliably differentiate tumor recurrence from radiation necrosis, with early TBR showing the highest accuracy. ADC demonstrates a low sensitivity, specificity, and accuracy in differentiating radiation necrosis from recurrence. A combination of early TBR, delayed TBR, and rCBV may be more useful in discrimination between radiation necrosis and recurrence of glioma, with this combination showing a better diagnostic performance than individual parameters or any other combination of parameters.

The differential diagnostic value of dual-phase 18F-DCFPyL PET/CT in prostate carcinoma

ObjectiveBinding of 18F-DCFPyL at prostate cancer (PC) cells increases over time. The dual-phase protocol may be helpful in separating benign lesions from malignant ones associated with prostate cancer. The purpose of this study was to retrospectively analyze the incremental diagnostic value of 18F-DCFPyL dual-time imaging in patients with prostate cancer.Method114 prostate-related malignant lesions and 43 benign lesions in 38 patients with prostate cancer were retrospectively analyzed. Maximum standardized uptake value (SUVmax) for benign and prostate-related malignant lesions were calculated at min 60 and min 120 of PET/CT imaging. In order to calculate SUV ratio, the SUVmax of left gluteus maximus was measured at the same time. The difference of SUVmax metrics and SUV ratio between malignant and benign lesions was statistically analyzed, the cut-off value of ROC curve was calculated, and the diagnostic efficacy of SUVmax index and SUV ratio at two time points was compared.ResultsSUVmax metrics and SUV ratio of early and delayed imaging of PC-related malignant lesions were significantly higher than those of benign lesions (p < 0.05). In terms of individual indicators, the highest accuracy and sensitivity was in the delayed SUV ratio (89.2% and 94.7%), the best specificity was in the early SUVmax (93.0%). When the individual and combined indicators were compared together, the SUV ratio in the delay period still showed the best diagnostic sensitivity and accuracy, and the best specificity were SUVmax early and ▵SUVmax, SUVmax early and RI.ConclusionsUptake of 18F-DCFPyL increased over time in prostate-associated malignant lesions compared with benign tissue. For single-phase imaging, 2-hour (delayed) imaging has better diagnostic performance. However, the dual-phase imaging (1 and 2 h) are helpful in the differential diagnosis of prostate-associated malignant lesions and benign lesions.

Prognostic Value of Neutrophil-to-Lymphocyte Ratio and Early Standardized Uptake Value Reduction in Patients With Breast Cancer Receiving Neoadjuvant Chemotherapy.

We investigated the treatment response and prognosis using the neutrophil-to-lymphocyte ratio (NLR) and standardized uptake value (SUV) of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in neoadjuvant settings. Baseline NLR and maximum SUV (SUVmax) were retrospectively analyzed in 273 females with breast cancer who received neoadjuvant chemotherapy followed by surgery. Of these, 101 patients underwent 18F-FDG PET after 3-4 neoadjuvant chemotherapy cycles, which allowed the measurement of ΔSUVmax, an early reduction in SUVmax. NLR and early SUVmax reduction (ΔSUVmax) were classified as low and high, respectively, relative to the median values. The mean NLR was lower, and the mean ΔSUVmax was higher in patients with pathologic complete response (pCR) than in those with residual tumors. The ΔSUVmax was an independent variable associated with pCR. Furthermore, the high NLR group had poor recurrence-free survival (RFS) and overall survival. Among patients with ΔSUVmax data, high NLR (adjusted hazard ratio, 2.82; 95% confidence intervals [CI], 1.26-6.28; P = 0.016) and low ΔSUVmax (adjusted hazard ratio, 2.39; 95% CI, 1.07-5.34; P = 0.037) were independent prognostic factors for poor RFS. The categorization of the patients into four groups according to the combination of NLR and ΔSUVmax showed that patients with high NLR and low ΔSUVmax had significantly poorer RFS. Baseline NLR and ΔSUVmax were significantly associated with the prognosis of patients with breast cancer who received neoadjuvant chemotherapy. These results suggest that metabolic non-responders with defective immune systems have worse survival outcomes.

Prognostic value of metabolic parameters measured by pretreatment dual-time-point 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with intrahepatic or perihilar cholangiocarcinoma: A STROBE study.

The purpose of this study was to determine the glucose metabolism at delay phase measured by pretreatment dual-time-point 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/ computed tomography (CT) provides prognostic information independent of well-known prognostic factors in patients with intrahepatic or perihilar cholangiocarcinoma (ICC or PCC).From July 2012 to December 2017, 55 patients (men 27, women 28, mean age 68 ± 11 years) with pathologically proven ICC or PCC were enrolled in this retrospective study. The dual-time-point 18F-FDG PET/CT as part of a staging workup was performed in all patients. The patient's data includes age, sex, serum CA19-9, presence of LN or distant metastasis, early SUVmax (early maximum standardized uptake value [eSUV]), delay SUVmax (delay maximum standardized uptake value [dSUV]), retention index of SUVmax (percent change of maximum standardized uptake values [ΔSUV]), neutrophil to lymphocyte ratio (NLR) and histopathology including pCEA, p53, Ki-67 index. The analysis of the relationship between metabolic parameters and survival was done using the Kaplan–Meier curve and Cox proportional hazards regression model.Median survival for all patients was 357 days. Median early and delay SUVmax was 5.2 (range: 2.0–21.4) and 6.5 (range 2.7–24.5), respectively. The overall survival was found to be significantly related to eSUV, dSUV, ΔSUV, age, serum CA19-9 and NLR in univariate analysis. In multivariate analysis, dSUV (P = .014, 95%CI; 1.30–10.7, HR 3.74) and ΔSUVmax (P = .037, 95%CI; 1.05–6.12, HR 2.5) were independent factors of overall survival. Kaplan–Meier curve analysis clearly showed the significant difference of overall survival between 2 groups (high eSUV, low eSUV + high ΔSUV vs low eSUV and ΔSUV, P < .001) among the comparisons of the SUV parameters on FDG PET. In the receiver operating characteristic analysis using combinations of the SUV parameters, the 2 groups [eSUV + ΔSUV (P = .0001, area under the curve [AUC] 0.68) and dSUV + ΔSUV (P = .0002, AUC 0.71)] showed significantly larger AUC than the other groups applying eSUV or dSUV alone (AUC 0.61 and AUC 0.68).dSUV and ΔSUV on pretreatment dual-time-point 18F-FDG PET/CT can be useful parameters in the prediction of survival in patients with ICC or PCC.

Early SUVmax is the best predictor of axillary lymph node metastasis in stage III breast cancers.

Although fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission/computed tomography (PET/CT) imaging has been investigated for its ability to evaluate lymph node metastasis of breast cancer, few comparative analyses have evaluated the preoperative and postoperative regional lymph node metastasis of breast cancer by dual-phase imaging, especially in patients with stage III (N2) disease. The clinical, pathological, and imaging data of 40 patients with stage III (N2) breast cancer were retrospectively analyzed. All patients underwent dual-time point 18F-FDG imaging before surgery and postoperative pathology examinations were obtained. The short-axis lymph node diameter was measured, and the maximum standardized uptake value (SUVmax) and the percentage difference of SUVmax between dual-phase (ΔSUVmax) were calculated to compare metastatic and non-metastatic lymph nodes on dual-time point images. A total of 398 axillary lymph nodes were inspected, and 209 lymph nodes were matched with those on PET/CT images, including 97 metastatic and 112 non-metastatic lymph nodes. The SUVmax values were significantly different between metastatic and non-metastatic lymph nodes, in both the early and delayed scans (P<0.001). For metastatic lymph nodes, the SUVmax value on the delayed scan (6.17±2.62) was significantly higher compared with the early scan (5.45±1.35; ΔSUVmax =0.08±0.21, P<0.001). Moreover, the SUVmax values were not significantly different between the delayed (2.82±0.91) and early scans (2.79±0.72; ΔSUVmax=-0.00±0.11, P=0.77). The short diameters were not significantly different between metastatic and non-metastatic lymph nodes (P=0.12), and the SUVmax values of metastatic lymph nodes with short diameters of >4.00 and ≤6.00 mm were not significantly different between the early and delayed scans (P=0.06). However, the SUVmax values of metastatic lymph nodes with short diameters of >6.00 and ≤8.00 mm (7.11±0.19 vs. 5.96±0.08) and short diameters of >8.00 and ≤10.00 mm (10.76±0.35 vs. 6.82±0.50) were higher on the delayed scan versus the early scan, respectively (P<0.01 for each comparison). The difference between the ΔSUVmax values among the three subgroups was statistically significant (F=78.98, P<0.001).The receiver operating characteristic (ROC) curve analysis of the lymph nodes showed that the area under the curve (AUC) of the early and delayed PET/CT scans was 0.961 (0.925-0.983, P=0.013) and 0.897 (0.847-0.934, P=0.022), respectively. The ROC curves of the early and delayed scans were also significantly different (z=4.46, P<0.001). AUC of the ΔSUVmax for the early scan was significantly lower compared with delayed scans (z=8.95 vs. 9.13, respectively; P<0.001). Dual-time point 18F-FDG PET imaging significantly improved the prediction and detection of axillary lymph node metastasis, compared with prediction based on size of lymph node alone, in patients with stage III breast cancer. We found that lymph nodes with continuously increased SUVmax values tended to show metastasis, and early SUVmax assessment offers the best capacity for prediction of axillary lymph node metastasis.

Dual time point [18F]Flurodeoxyglucose (FDG) Positron Emission Tomography (PET)/Computed Tomography (CT) with water gastric distension in differentiation between malignant and benign gastric lesions

ObjectivesTo assess diagnostic accuracy and added value of dual time point 18F-FDG PET/CT after gastric distention using oral water in differentiating malignant from benign gastric lesions. MethodsPatients (n = 30, 19 males, mean age 58.6 ± 16.4 years). All patients are known or suspected oncology patients. All patients underwent whole body 18F-FDG PET/CT scan and 2 h delayed PET/CT abdominal images following oral water gastric distension. The best cut off values for early SUVmax (SUVmax1), delayed SUVmax (SUVmax2) and SUVmax2-SUVmax1 (ΔSUVmax) to differentiate benign from malignant lesions were set based on ROC analysis. Data analyzed included in addition; age, sex and 18F-FDG uptake pattern in delayed images. Suspicious gastric lesions were correlated with biopsy in 18 patients (60 %) and with clinical and follow-up imaging (18F-FDG PET/CT, CT or MRI) in 12 patients (40 %). Unpaired t-test was used to compare the mean deference in continuous variables between patients with gastric malignancy and those with benign gastric lesions. Fisher’s exact test was used to analyze categorical variables. Logistic regression analysis was performed to identify the most powerful factors to predict malignant lesions. ResultsFifteen patients (50 %) had confirmed malignant gastric lesions. Patients with confirmed gastric malignancy were older (65 ± 13 vs 52 ± 17; p = 0.023) and had significantly higher mean ΔSUVmax (1.29 ± 1.76 vs −0.89 ± 1.59; p = 0.003). The mean SUVmax1 (6.99 ± 6.66 vs 5.31 ± 2.53; p = 0.367) and SUVmax2 (8.29 ± 7.41 vs 4.44 ± 3.34; p = 0.077) although both higher in patients with malignant lesions, they did not reach statistical significance. Sensitivity, specificity, PPV, NPV, and accuracy to detect malignant gastric lesions were highest for lesions with localized uptake pattern in delayed images post water oral contrast as well as for lesions with ΔSUVmax>0. Regression analysis revealed both variables as independent predictors for malignant lesions with odd ratios of 22.9 and 9.5 respectively and final model Chi-Square of 19.9 (p < 0.0001). The model correctly identified 12/15 (80 %) malignant lesions and 13/15 (86.7 %) benign lesions with 2 false positives confirmed as chronic active gastritis with helicobacter pylori and 3 false negatives including 1 signet ring gastric cancer and 1 low grade gastrointestinal stromal tumor (GIST), both with poor 18 F-FDG uptake. ConclusionLocalized uptake pattern in delayed PET/CT images following gastric distention with oral water contrast as well as ΔSUVmax>0 are powerful independent variables to identify malignant gastric lesions with fairly high sensitivity and reasonable accuracy. Malignancies with inherently low 18F-FDG avidity are the main cause of false negatives while active gastritis is the main cause of false positives.

Using neighborhood gray tone difference matrix texture features on dual time point PET/CT images to differentiate malignant from benign FDG-avid solitary pulmonary nodules

ObjectiveLung cancer usually presents as a solitary pulmonary nodule (SPN) on diagnostic imaging during the early stages of the disease. Since the early diagnosis of lung cancer is very important for treatment, the accurate diagnosis of SPNs has much importance. The aim of this study was to evaluate the discriminant power of dual time point imaging (DTPI) PET/CT in the differentiation of malignant and benign FDG-avid solitary pulmonary nodules by using neighborhood gray-tone difference matrix (NGTDM) texture features.MethodsRetrospective analysis was carried out on 116 patients with SPNs (35 benign and 81 malignant) who had DTPI 18F-FDG PET/CT between January 2005 and May 2015. Both PET and CT images were acquired at 1 h and 3 h after injection. The SUVmax and NGTDM texture features (coarseness, contrast, and busyness) of each nodule were calculated on dual time point images. Patients were randomly divided into training and validation datasets. Receiver operating characteristic (ROC) curve analysis was performed on all texture features in the training dataset to calculate the optimal threshold for differentiating malignant SPNs from benign SPNs. For all the lesions in the testing dataset, two visual interpretation scores were determined by two nuclear medicine physicians based on the PET/CT images with and without reference to the texture features.ResultsIn the training dataset, the AUCs of delayed busyness, delayed coarseness, early busyness, and early SUVmax were 0.87, 0.85, 0.75 and 0.75, respectively. In the validation dataset, the AUCs of visual interpretations with and without texture features were 0.89 and 0.80, respectively.ConclusionCompared to SUVmax or visual interpretation, NGTDM texture features derived from DTPI PET/CT images can be used as good predictors of SPN malignancy. Improvement in discriminating benign from malignant nodules using SUVmax and visual interpretation can be achieved by adding busyness extracted from delayed PET/CT images.

Impact of 18F-FDG PET/CT Dual Time Point Imaging in Lymphoma Patients with Lung Lesions.

The aim of: this prospective study was to assess the role of dual time imaging PET/CT study in characterization of the lung lesions in lymphoma patients with lung lesion. Patients and methods: The study was conducted on 28 lymphoma patients. Scan 1 (early image) was performed at 50 min and scan 2 (delayed image) at 110 min after FDG IV injection. The majority of final decisions were reached based on clinical and radiological follow up and the minority was pathologically based. SUV max was calculated at early and delayed images. The difference between early and delayed SUV max (D-SUV max) and the retention index (RI-SUV max) were estimated. Then their cut-off values were evaluated using area under the curve (AUC) from receiver operating characteristic (ROC) analysis. Also, the median quantitative analysis for these parameters was used. Results: Thedelayed SUV max cut-off value of 4.9 giving sensitivity of 90% and specificity of 72% (P=0.004). The cut-off value of D-SUV max of 0.55 yielding a sensitivity of 90% and specificity of 78% (P=0.001). Using 7.5% as a cut-off value of RI-SUV max had sensitivity of 80% and specificity of 67% (P=0.04). The delayed SUV max and D-SUV max had AUCs (0.825 & 0.894 respectively) which is statistically greater than of early SUV max (0.789). The D-SUV max has the largest AUC between the four indices. The median quantitative analysis for Delayed-SUV max was 4.9 (P=0.003), D-SUV max was 0.50 (P=0.001), RI-SUV max was 0.75 (P=0.01). Conclusion: The delayed time point PET/CT imaging is additive technique with higher sensitivity and specificity to characterize lung lesions in lymphoma patients.

Additional prognostic value of metabolic parameters measured by dual time point pretreatment F-18 FDG PET/CT in patients with intrahepatic cholangiocarcinoma.

e15598 Background: The aim of this retrospective study was to determine whether delayed glucose metabolism assessed by dual time point F-18 FDG PET/CT provides additional prognostic information independent of established prognostic factors in patients with intrahepatic cholangiocarcinoma (IHCC). Methods: We reviewed retrospectively the medical records of 96 patients (men 57, women 39, mean age 66 ± 10 years) with pathologically proven IHCC. They underwent dual time point F-18 FDG PET/CT as part of a pretreatment workup from July 2012 to December 2017. For the analysis, patients were classified by age, sex, stage, serum CA19-9, early SUVmax (eSUV), delayed SUVmax (dSUV), delta SUVmax (ΔSUV, difference between early and delayed SUVmax) and histopathology (pCEA, p53, Ki-67 index). The relationship between FDG uptake and survival was analyzed using the Kaplan-Meier with log-Rank test and Cox’s proportional-hazard regression methods. Results: Median survival for all 96 study subjects was 303 days and median SUVmax was 7.2 (range: 2.5 – 21.7). The survival was found to be significantly related to eSUV ( p &lt; 0.0001), age ( p = 0.017), LN metastasis ( p = 0.03) and p53 index ( p = 0.04) and multivariate analysis study revealed that the patients with a higher SUVmax ( p = 0.0001, 95%CI = 1.80 to 5.89, HR = 3.26), prescence of LN metastasis ( p = 0.031), higher age ( p = 0.044) and a higher p53 index ( p = 0.007) showed worse overall survival. In addition, we carried out a subgroup analysis targeting the 55 patients with delayed SUVmax to evaluate a prognostic value of delayed image parameter. In univariate analysis, dSUV (cut-offvalue 7.3, p = 0.0006) and ΔSUV (cut-off value 3.2, p = 0.035), age ( p &lt; 0.0001) and sCA19-9 ( p = 0.018) showed significant correlation and dSUV was an independent factor of overall survival in multivariate analysis. ( p = 0.014, 95%CI = 1.30 to 10.7, HR = 3.74) And then, we analyzed combinations of eSUV, dSUV and ΔSUV each other to evaluate additional prognostic information. The result revealed that higher dSUV ( p = 0.0001, AUC = 0.68) and ΔSUV ( p = 0.0002, AUC = 0.71) showed a poorer overall survival although the eSUV of IHCC was low. Conclusions: Higher delayed SUVmax and ΔSUVmax on pretreatment dual time point F-18 FDG PET/CT can predict poorer survival and additional information of risk stratification in patients with IHCC.

Predictive value of dual-time 18F-FDG PET/CT to distinguish primary lung and metastatic adenocarcinoma in solitary pulmonary nodule.

Distinction between primary lung adenocarcinoma and metastatic adenocarcinoma from extrapulmonary origin in solitary pulmonary nodule (SPN) is crucial for cancer treatment. We investigated the predictive role of dual-time-point 18F-FDG PET/CT to distinguish primary and metastatic lung adenocarcinoma in SPN. A total of 96 consecutive patients with newly diagnosed SPN and biopsy-proven adenocarcinoma were enrolled in this study, retrospectively (54 male; 42 female; age 59.68 ± 8.2 years). They all underwent dual-time-point 18F-FDG PET/CT at 60 minutes (early) for whole body and 120 minutes (delayed) for chest region after FDG injection. Maximum standardized uptake values (early SUVmax and delayed SUVmax) and retention index (RI) were acquired for analysis. Final pathology results were confirmed by surgical specimens. Metastatic adenocarcinoma showed significantly higher early SUVmax, delayed SUVmax, and RI compared to primary lung adenocarcinoma. Delayed SUVmax and RI presented superior diagnostic performance for prediction of metastatic adenocarcinoma than early 18F-FDG PET/CT. Among metastatic adenocarcinoma, metastasis from colorectal origin showed significantly higher RI than from other origins. In addition, RI significantly predicted metastatic adenocarcinoma from colorectal cancer than early or delayed SUVmax. Dual-timepoint 18F-FDG PET/CT can be useful to distinguish primary and metastatic lung adenocarcinoma in SPN. Furthermore, it may also be useful to predict metastatic adenocarcinoma from colorectal origin.

18F- FDG PET/CT helps differentiate autoimmune pancreatitis from pancreatic cancer

Background18F-FDG PET/CT could satisfactorily show pancreatic and extra-pancreatic lesions in AIP, which can be mistaken for pancreatic cancer (PC). This study aimed to identify 18F-FDG PET/CT findings that might differentiate AIP from PC.MethodsFDG-PET/CT findings of 26 AIP and 40 PC patients were reviewed. Pancreatic and extra-pancreatic lesions related findings, including maximum standardized uptake values (SUVmax) and patterns of FDG uptake, were identified and compared.ResultsAll 26 patients with AIP had increased pancreatic FDG uptake. Focal abnormal pancreatic FDG activities were found in 38/40 (95.00%) PC patients, while longitudinal were found in 18/26 (69.23%) AIP patients. SUVmax was significantly different between AIP and PC, both in early and delayed PET/CT scans (p < 0.05). AUCs were 0.700 (early SUVmax), 0.687 (delayed SUVmax), 0.683 (early lesions/liver SUVmax), and 0.715 (delayed lesion/liver SUVmax). Bile duct related abnormalities were found in 12/26 (46.15%) AIP and 10/40 (25.00%) PC patients, respectively. Incidentally, salivary and prostate gland SUVmax in AIP patients were higher compared with those of PC patients (p < 0.05). In males,an inverted “V” shaped high FDG uptake in the prostate was more frequent in AIP than PC patients (56.00%, 14/25 vs. 5.71%, 2/35). Increased FDG activity in extra-pancreatic bile duct was present in 4/26 of AIP patients, while was observed in none of the PC patients. Only in AIP patients, both diffuse pancreatic FDG accumulation and increased inverted “V” shaped FDG uptake in the prostate could be found simultaneously.Conclusions18F-FDG PET/CT findings might help differentiate AIP from PC.

Unusual Presentation of Bronchiolitis Obliterans Organizing Pneumonia Mimicked Pulmonary Metastases: A Case Report

SESSION TITLE: Imaging SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: The radiological presentation of bronchiolitis obliterans organizing pneumonia (BOOP) is characterized by multiple air space consolidations with a subpleural distribution or areas of ground glass lung infiltration. We report a case of BOOP presenting with a multiple nodular pattern mimicking miliary metastasis lung infiltration. CASE PRESENTATION: A 47-year-old man presented with cough. He was a current smoker for 35 years. He had COPD and DM. Vital signs were normal. Chest X-ray showed bilateral nodular opacities. Thorax computed tomography; predominantly in the upper lobe, bilateral, multiple pulmonary nodules (the largest 20 mm) with variable border features were detected, some of which were frosted glass densities (Fig.1). Mediastinal (10 mm in diameter), right suprahiler (15 mm in diameter) and both axillar lymph nodes were present. Serological tests were normal. Mycobacterium tuberculosis was negative. PET/CT: Several millimetric lymph nodes without mediastinal pathologic FDG involvement were observed. A large number of nodules were observed in both lung parenchyma, some of which were calcified, with mildly elevated FDG uptake (Early SUV max: 2,18, Late SUV max: 3,14) (Fig.1). Lung biopsies with wedge resection were perfomed under video-assisted thoracoscopy(VATS). Histopathological analysis consistented with BOOP (Fig.2). The patient underwent steroid therapy at a dose of 48 mg / day with the diagnosis of BOOP. At 3 months of treatment, control CT completely removed. The steroid treatment was stopped at 4 months because of uncontrolled diabetes mellitus. The patient was followed-up for one year, and the disease did not relapse. DISCUSSION: Heterogenic radiologic features on X-ray and on CT scan make correct diagnosis difficult, sometimes resulting in ineffective therapy and unnecessary hospitalization. Most often, CT scan shows unilateral or bilateral airspace consolidation with a predominantly peripheral distribution in lower and middle zones. Contrary to the common radiological findings in our case, there were bilateral multifocal nodules with predominantly upper lobes. In pet ct; metastatic disease can not be excluded due to increased metabolic activity in late images. Therefore, histopathological confirmation is required. We did not find any reports that bronchiolitis obliterans organized pneumonia pet ct findings. It may be said that boop pet ct findings may interfere with malignancy. CONCLUSIONS: In conclusion, our patient had an unusual radiological pattern of bilateral pulmonary nodules associated with COP that mimicked pulmonary metastases. Its radiological and nuclear properties can lead to misdiagnosis like malignancy. Reference #1: American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. Am J Respir Crit Care Med. 2002;165:277-304. DISCLOSURE: The following authors have nothing to disclose: Demet Polat, Eylem Ozgur, Sibel Atis Nayci, Tuba Kara, Feramuz Apaydin, Pelin Özcan No Product/Research Disclosure Information

Limited diagnostic value of Dual-Time-Point 18F-FDG PET/CT imaging for classifying solitary pulmonary nodules in granuloma-endemic regions both at visual and quantitative analyses

PurposeThis study is aimed to compare the diagnostic power of using quantitative analysis or visual analysis with single time point imaging (STPI) PET/CT and dual time point imaging (DTPI) PET/CT for the classification of solitary pulmonary nodules (SPN) lesions in granuloma-endemic regions. MethodsSPN patients who received early and delayed 18F-FDG PET/CT at 60min and 180min post-injection were retrospectively reviewed. Diagnoses are confirmed by pathological results or follow-ups. Three quantitative metrics, early SUVmax, delayed SUVmax and retention index(the percentage changes between the early SUVmax and delayed SUVmax), were measured for each lesion. Three 5-point scale score was given by blinded interpretations performed by physicians based on STPI PET/CT images, DTPI PET/CT images and CT images, respectively. ROC analysis was performed on three quantitative metrics and three visual interpretation scores. ResultOne-hundred-forty-nine patients were retrospectively included. The areas under curve (AUC) of the ROC curves of early SUVmax, delayed SUVmax, RI, STPI PET/CT score, DTPI PET/CT score and CT score are 0.73, 0.74, 0.61, 0.77 0.75 and 0.76, respectively. There were no significant differences between the AUCs in visual interpretation of STPI PET/CT images and DTPI PET/CT images, nor in early SUVmax and delayed SUVmax. The differences of sensitivity, specificity and accuracy between STPI PET/CT and DTPI PET/CT were not significantly different in either quantitative analysis or visual interpretation. ConclusionIn granuloma-endemic regions, DTPI PET/CT did not offer significant improvement over STPI PET/CT in differentiating malignant SPNs in both quantitative analysis and visual interpretation.

Analysis of 18F-FDG PET/CT imaging characteristics in 36 patients with autoimmune pancreatitis

Objective To investigate the imaging characteristics and the clinical value of 18F-FDG PET/CT imaging in autoimmune pancreatitis (AIP). Methods The 18F-FDG PET/CT imaging characteristics of 36 patients (33 males, 3 females; average age 60 years) with AIP proved by histopathology or clinical follow-up from August 2010 to March 2014 were retrospectively analyzed. The morphologic and metabolic abnormalities of pancreatic and extra-pancreatic lesions were analyzed. The early SUVmax and delayed SUVmax were compared by paired t test in 32 patients who underwent dual time point 18F-FDG PET/CT imaging. Results (1)18F-FDG PET/CT showed diffuse uptake of FDG by the pancreas in 17 patients (47.2%, 17/36), localized uptake in 10 patients (27.8%, 10/36), mixed uptake in 7 patients (19.4%, 7/36), and multifocal uptake in 2 patients (5.6%, 2/36). A total of 33 patients (91.7%) had intense FDG uptake in the pancreas with SUVmax of 5.32±1.83, while the others showed mild FDG uptake with SUVmax of 2.13±0.15. Delayed SUVmax was significantly different from early SUVmax (6.11±2.68 vs 5.08±2.03, t=-7.305, P<0.01) in the 32 patients undergoing delayed scan. The average retention index (RI) in those patients were (18.0±16.1)%. (2) Capsule-like rim surrounding the pancreas was found in 10 patients and abnormality of the main pancreatic duct was found in 9 patients. (3) Thirty-four (94.4%, 34/36) patients had extra-pancreatic lesions, including mediastinal and pulmonary hilar lymph nodes, salivary glands, cervical and submandibular lymph nodes, and foci with the invertedVshaped high FDG uptake in the prostate, which were found in 21 of 33 (63.6%) male patients. (4) The case-times of extra-pancreatic organs involved were 4.17±2.15 in the whole pancreas involved group (diffuse uptake + mixed uptake), and 2.64±1.63 in the partial pancreas involved group (localized uptake + multifocal uptake), which were significantly different (t=2.10, P<0.05). Conclusions Various intense uptake of FDG, which is higher on delayed scan, can be shown in the pancreas in patients with AIP. 18F-FDG PET/CT is an effective modality to detect extra-pancreatic lesions, and it could contribute to the diagnosis and evaluation of AIP. Key words: Autoimmune diseases; Pancreatitis; Tomography, emission-computed; Tomography, X-ray computed; Deoxyglucose

Analysis of 18F-FDG PET/CT imaging characteristics and metabolism features of pancreatic solid pseudopapillary tumor

Objective To summarize the imaging features and metabolic characteristics of solid pseudopapillary tumors of the pancreas (SPTP) using 18F-FDG PET/CT in order to improve the diagnostic accuracy. Methods 18F-FDG PET/CT findings and clinical data of 16 patients (3 males, 13 females, average age 38.6 years) pathologically proved SPTP from August 2010 to June 2014 in Shanghai Changhai Hospital were analyzed retrospectively. The morphology, density and metabolic characteristics of the lesions were observed, and SUVmax and tumor size were measured and recorded. The difference between early SUVmax and delayed SUVmax was evaluated with paired t test in 10 patients underwent dual-time scans, and the retention index (RI) was also calculated. Results The lesions were all single with well delineated and exogenous growth. The long diameter of the tumors was about 1.2-10.4(4.0±2.7) cm, and the short diameter was 1.0-8.6(3.3±2.2) cm. Four tumors were nearly completely solid, in which 2 lesions showed high and uniform FDG accumulation, 1 inhomogeneous high metabolic lesion, and 1 with FDG uptake similar to normal pancreas. The other 12 cases demonstrated solid and cystic mixed structures which showed uneven high metabolic components in mural nodules mixed with mild metabolic and/or uptake defect. The early SUVmax of all patients was 7.3±6.8(2.4-29.1). For the 10 patients with dual-phase scans, no statistical difference was seen between the early SUVmax (6.0±3.4) and the delayed SUVmax(6.4±3.2)(t=-1.658, P>0.05); RI was 6.9%(-4.2%, 13.6%). Among the 16 patients, 5 were found to have invasion of pancreatic duct or surrounding organs of pancreas, with early SUVmax (6.7±4.1)(3.4-13.1), SUVmax of remaining 11 patients was 4.4(2.6, 7.6). Conclusions SPTP is mostly cystic-solid or solid lesions with big volumes, calcification, well-defined borders and outward swelling. On FDG PET images, there are diverse metabolic characteristics of lesions, with high uptake on the solid part, and few changes of FDG uptake on the delayed scan. Key words: Pancreatic neoplasms; Tomography, emission-computed; Tomography, X-ray computed; Deoxyglucose

PET/CT Dual Time Point Scanning in Evaluation of Malignant Lymphoma

Purpose: The purpose of the present study is to evaluate the value of dual-time-point F-18 FDG PET/CT imaging in malignant lymphoma (ML) to differentiate between benign lesions and residual or relapsing malignant lesions. Patients and methods: This prospective study included 252 lymph nodes in 60 patients. F-18 FDG PET/CT scan was performed at 50 min (early scan) and at 100 min (delayed scan) after the injection. The maximum standardized uptake value (SUV max) of each lesion was calculated at early and delayed scans. We estimated the difference between early and delayed SUV max (D-SUV max) and the retention index (RI-SUV max) to evaluate the change of tracers handling in the lesions. Also, the early lesion/liver ratio and delayed lesion/liver ratio were calculated. Then their cut-off values were evaluated using receiver operating characteristic analysis. Correlations of these cutoff values with different clinico-pathological parameters were done. Results: The cut-off value in Early-SUV max was 4.05, Delayed-SUV max were 4.45, D-SUV max was 0.45, RISUV max was 0.155, Early lesion/liver ratio was 1.25 and in Delayed lesion/liver ratio was 1.35. The delayed-SUV max had the highest sensitivity and specificity of 85.3% and 92.6% respectively. The overall result of DTP PET/CT showed sensitivity of 95.3%, specificity of 76.4%, accuracy of 86.1%, and positive predictive value of 80.9% and negative predictive value of 94% respectively. Based on a total of true and false results in early and delayed PET/CT imaging, there was significant improvement in specificity in the delayed PET/CT imaging compared to the early PET/CT imaging. Correlation of DTP cut off value with the different clinico-pathological parameters showed that nodular sclerosis and lymphocytic predominance pathological subtypes had the highest sensitivity of 100%, while mixed cellularity showed the lowest sensitivity of 64.3%. In Hodgkin lymphoma lesions, cervical sites showed the lowest sensitivity and specificity 90.2% & 61.4% respectively.Conclusions: The dual time point FDG PET/CT scan is useful to differentiate between post-therapy changes as benign lesions and residual or relapsing malignant lesions in malignant lymphoma.

The diagnostic role of dual-phase 18F-FDG PET/CT in the characterization of solitary pulmonary nodules

Our objective was to evaluate the diagnostic role of dual-phase (18)F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) in the characterization of solitary pulmonary nodules (SPNs). A total of 48 SPNs in 48 patients were included in this retrospective study. The final diagnosis was confirmed histopathologically or by follow-up CT. Two PET/CT scans were performed: the first (early scan) was performed 1 h after injection and the second (delayed scan) was performed 2 h later. Standardized uptake values (SUVs) [early and delayed SUVmax and SUVmean adjusted to body weight, body surface area (BSA), lean body mass (LBM) and blood glucose level (Glc)], retention index and nodule-to-mediastinum (nodule activity/subcarinal region of interest activity) ratios were calculated, along with the receiver operating characteristic curve. Intraobserver and interobserver variabilities among nuclear medicine physicians were analysed for the two phases. Eighteen patients had malignant tumour, whereas 30 had benign lesions. The median (min-max) SUVmax was 1.5 (0.5-4.1) in the benign group and 3.6 (1.3-38) in the malignant group. With the threshold value of early SUVmax as 2.5 and 2.75 using the receiver operating characteristic curve, a sensitivity of 94-75%, specificity of 75-80% and an accuracy of 83-78% were calculated. With the same threshold values for delayed images, 94-100% sensitivity, 77-80% specificity and 83-88% accuracy were obtained. BSA-SUVmax, LBM-SUVmax and Glc-SUVmax did not show any advantage over other quantitative parameters in the SPN characterization. There was no variability in the results obtained between the two nuclear medicine physicians. Dual-phase PET/CT may increase the diagnostic potential of PET/CT in the characterization of SPNs. In this particular study group, a threshold value could not be determined for the retention index, but higher retention indices may show higher malignant potential in SPNs.

18F-FDG PET/CT in detection of gynecomastia in patients with hepatocellular carcinoma

ObjectiveWe retrospectively investigate the prevalence of gynecomastia as false-positive 2-[18F]fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging in patients with hepatocellular carcinoma (HCC). MethodsAmong the 127 male HCC patients who underwent 18F-FDG PET/CT scan, the 18FDG uptakes at the bilateral breasts in 9 patients with gynecomastia were recorded as standard uptake value (SUVmax) and the visual interpretation in both early and delayed images. ResultsThe mean early SUVmax was 1.58/1.57 (right/left breast) in nine gynecomastia patients. The three patients with early visual score of 3 had higher early SUVmaxs. ConclusionGynecomastia is a possible cause of false-positive uptake on 18F-FDG PET/CT images.

Shorter-time dual-phase FDG PET/CT in characterizing solid or ground-glass nodules based on surgical results

ObjectivesWe compared the accuracy of shorter-time dual-phase 18F-FDG PET/CT in evaluating 94 different lung nodules classified as solid or ground-glass nodules (GGNs). Materials and MethodsEarly and delayed maximum standardized uptake values (SUVmax) as well as the retention index (RI) of each nodule were determined in 75 solid nodules and 19 GGNs. ResultsIn solid nodules, early SUVmax, delayed SUVmax, and RI were higher in malignant than in benign lesions. In GGNs, these values were not significantly lower in the malignant than in the benign lesions. ConclusionIn the patient group with solid nodules, shorter-time dual-phase 18F-FDG PET/CT could significantly differentiate the malignant from the benign ones.