g Hyun Byun

Combination of 18F-FDG PET/CT and Diffusion-Weighted MR Imaging as a Predictor of Histologic Response to Neoadjuvant Chemotherapy: Preliminary Results in Osteosarcoma

We evaluated the potential of 18F-FDG PET/CT and diffusion-weighted imaging (DWI) to monitor the histologic response in patients with extremity osteosarcoma receiving neoadjuvant chemotherapy, using sequential PET/CT and MR imaging. Methods: We prospectively registered 28 patients with high-grade osteosarcoma treated with 2 cycles of neoadjuvant chemotherapy and surgery. All patients underwent sequential 18F-FDG PET/CT and MR imaging before (PET/MR1) and after neoadjuvant chemotherapy (PET/MR2). Maximum standardized uptake value (SUV), tumor volume based on MR imaging (MRV), and the mean apparent diffusion coefficient (ADC) values were measured on PET/MR1 (SUV1, MRV1, and ADC1) and PET/MR2 (SUV2, MRV2, and ADC2). The percentage changes in maximum SUV (ΔSUV), MRV (ΔMRV), and ADC (ΔADC) were calculated, and the correlations among these parameters were evaluated. After surgery, the effects of neoadjuvant chemotherapy were graded histopathologically: grades III and IV (necrosis of ≥ 90%) indicated a good response, and grades I and II (necrosis of < 90%) indicated a poor response. The optimum cutoff values of ΔSUV, ΔMRV, ΔADC, and their combination for predicting histologic response were assessed by single- and multi-receiver-operating-characteristic curve analysis. Results: Twenty-seven patients were enrolled in the present study after 1 patient with inadequate acquisition of MR imaging was excluded. ΔSUV and ΔADC negatively correlated with each other (ρ = −0.593, P = 0.001), and ΔMRV did not correlate with ΔSUV or ΔADC. The cutoff value, sensitivity, specificity, and accuracy for predicting good histologic response were ≤ −52%, 67%, 87%, and 78%, respectively, for ΔSUV and > 13%, 83%, 73%, and 78%, respectively, for ΔADC. However, ΔMRV did not predict histologic response. Sensitivity, specificity, and accuracy were 83%, 87%, and 85%, respectively, using the combined criterion of ΔSUV ≤ −31% and ΔADC > 13%. Conclusion: In the current preliminary study, both PET/CT and DWI are useful for predicting histologic response after neoadjuvant chemotherapy in osteosarcoma. Combining PET/CT and DWI may be an effective method to predict the histologic response of patients to neoadjuvant chemotherapy.

18F-FDG uptake and EGFR mutations in patients with non-small cell lung cancer: A single-institution retrospective analysis

This retrospective study was performed to evaluate a possible association between the presence of epidermal growth factor receptor (EGFR) mutations and the standardized uptake value (SUV) of (18)F-fluoro-2-deoxy-glucose ((18)F-FDG) uptake in patients with non-small cell lung cancer (NSCLC). We included 100 patients who were tested for EGFR mutations by direct sequencing of resected tissues and who underwent preoperative positron emission tomography/computed tomography at the time of diagnosis. The maximum SUV by the primary tumor was chosen for further analysis. EGFR mutations in exons 19 and 21 were detected in 21 NSCLC patients (21%). EGFR mutations were more frequent in never-smokers than ever-smokers (35% versus 11%; P=0.003), in adenocarcinomas than non-adenocarcinomas (34% versus 6%; P=0.001), and in females than males (41% versus 12%; P=0.001). The SUV ranged from 1.3 to 33.0 (median 10.6). Area under receiver operating characteristic curve for SUVs in respect to the presence of EGFR mutations was 0.74 (95% CI: 0.62-0.85). When a cut off value was used, patients with low SUVs were more likely to have EGFR mutations than those with high SUVs (40% versus 11%; P=0.001). On multivariate analysis, a low SUV remained a significant predictors for EGFR mutations (P=0.025). (18)F-FDG uptake was associated with the presence of EGFR mutation. These results extrapolate that (18)F-FDG uptake might be helpful to discriminate patients who harbor EGFR mutations, especially when a genetic test is not feasible.

18F-Fluoro-2-Deoxy-Glucose Uptake Predicts Clinical Outcome in Patients with Gefitinib-Treated Non–Small Cell Lung Cancer

Purpose: To evaluate response and survival according to 18F-fluoro-2-deoxy-glucose uptake at presentation in patients with gefitinib-treated non–small cell lung cancer. Experimental Design: We retrospectively analyzed 84 positron emission tomography/computed tomography findings. Patient characteristics, response rates, and survivals were evaluated according to the maximum standardized uptake value (SUV) of primary tumor. The cutoff value of SUVs was obtained from receiver operating characteristic analysis. Results: The response rate (RR) was higher for never-smokers (41%) than ever-smokers (9%; P = 0.001). Patients with adenocarcinoma showed higher RR than those with other tumor histopathology (35% versus 9%; P = 0.009). The SUV was significantly lower in patients who were never-smokers (P = 0.005), patients with adenocarcinoma (P < 0.001), and female patients (P = 0.017). Patients with a low SUV showed higher RR compared with those with a high SUV (53% versus 18%; P = 0.003). Prolonged progression-free survival was observed in patients with low SUVs compared with those with high SUVs (median, 33.1 weeks versus 8.6 weeks; P = 0.003). While controlling for performance status, smoking history, and pathology, the high SUV conferred unfavorable outcome (hazard ratio, 2.3; P = 0.012). In terms of overall survival, a low SUV was associated with favorable outcome in univariate analysis (P = 0.011). Patients with a low SUV showed prolonged survival in multivariate analysis (P = 0.043). Conclusions: These results suggest that low SUVs at presentation can predict favorable response and survival in gefitinib-treated non–small cell lung cancer patients.

Initial Metabolic Tumor Volume Measured by 18F-FDG PET/CT Can Predict the Outcome of Osteosarcoma of the Extremities

We evaluated the ability of metabolic and volumetric parameters measured by pretreatment 18F-FDG PET/CT to predict the survival of patients with osteosarcoma of the extremities. Methods: The records of 83 patients with American Joint Committee on Cancer stage II extremity osteosarcoma treated with surgery and chemotherapy were retrospectively reviewed. Imaging parameters (maximum standardized uptake value, metabolic tumor volume [MTV], total lesion glycolysis, and tumor volume based on MR images) were measured before treatment, and histologic responses to neoadjuvant chemotherapy were assessed by examination of postsurgical specimens. Receiver-operating-characteristic curve analyses and the Cox proportional hazards model were used to analyze whether imaging and clinicopathologic parameters could predict metastasis-free survival. Results: Of the imaging parameters, MTV at the fixed standardized uptake value threshold of 2.0 (MTV(2.0)) most accurately predicted metastasis by receiver-operating-characteristic curve analysis (area under the curve = 0.679, P = 0.011). By multivariate analysis, MTV(2.0) > 105 mL (relative risk, 3.93; 95% confidence interval, 1.55–9.92) and poor response to neoadjuvant chemotherapy (relative risk, 4.83; 95% confidence interval, 1.64–14.21) independently shortened metastasis-free survival (P = 0.004 for both parameters). The stratification of patients by the combined criteria of MTV(2.0) and histologic response predicted outcome in more detail. Conclusion: MTV is an independent predictor of metastasis in patients with osteosarcoma of the extremities. The combination of MTV and histologic response predicts survival more accurately than the chemotherapeutic response alone.

Prognostic Value of SUVmax Measured by Pretreatment Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Ewing Sarcoma.

Aim The aim of this retrospective study was to determine whether glucose metabolism assessed by using Fluorine-18 (F-18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) provides prognostic information independent of established prognostic factors in patients with Ewing sarcoma. Methods We retrospectively reviewed the medical records of 34 patients (men, 19; women, 15; mean age, 14.5 ± 9.7 years) with pathologically proven Ewing sarcoma. They had undergone F-18 FDG PET/CT as part of a pretreatment workup between September 2006 and April 2012. In this analysis, patients were classified by age, sex, initial location, size, and maximum standardized uptake value (SUVmax). The relationship between FDG uptake and survival was analyzed using the Kaplan-Meier method with the log-rank test and Cox’s proportional hazards regression model. Results The median survival time for all 34 subjects was 999 days and the median SUV by using PET/CT was 5.8 (range, 2–18.1). Patients with a SUVmax ≤ 5.8 survived significantly longer than those with a SUVmax > 5.8 (median survival time, 1265 vs. 656 days; p = 0.002). Survival was also found to be significantly related to age (p = 0.024), size (p = 0.03), and initial tumor location (p = 0.036). Multivariate analysis revealed that a higher SUVmax (p = 0.003; confidence interval [CI], 3.63–508.26; hazard ratio [HR], 42.98), older age (p = 0.023; CI, 1.34–54.80; HR, 8.59), and higher stage (p = 0.03; CI, 1.21–43.95; HR, 7.3) were associated with worse overall survival. Conclusions SUVmax measured by pretreatment F-18-FDG PET/CT can predict overall survival in patients with Ewing sarcoma.

Clinical significance of 18F-FDG uptake by primary sites in patients with diffuse large B cell lymphoma in the head and neck: a pilot study

ObjectiveThis pilot study was launched to explore the utility of positron emission tomography scans, at the time of diagnosis, for clinical outcomes in patients with primary extranodal non-Hodgkin’s lymphoma (PENHL) in the head and neck, retrospectively.MethodsTwenty-two patients with a diffuse large B cell lymphoma (DLBCL) among those with a PENHL were included. We retrospectively evaluated the clinical outcomes of patients according to the maximum standardized 18F-fluoro-2-deoxy-glucose (18F-FDG) uptake value of the primary lesion (SUVp). The SUVp was initially analyzed as a continuous variable. The cut-offvalue of SUVp was obtained from receiver-operating characteristic analysis to predict event-free survival. Using this value, patients were divided into those with a low and high SUV.ResultsSeventeen patients (59%) were men and the median age was 50 years. Most primary sites were in Waldeyer’s ring (73%). The SUVp ranged from 3.3 to 23.7. The international prognostic index (IPI < 2 vs. ≥ 2) was associated with the SUVp (P = 0.014). Patients with low SUVp showed favorable survival (P = 0.015). After IPI scores were stratified, the survival difference remained significant (P = 0.029).ConclusionsThe results of this pilot investigation indicate that 18F-FDG uptake of the primary lesion may be related with survival outcomes in patients with extranodal DLBCL in the head and neck. Further studies are needed to confirm and extend these results.

Lymph Node to Primary Tumor Suv Ratio by 18f-fdg Pet/ct and the Prediction of Axillary Lymph Node Metastases in Breast Cancer

Purpose The authors evaluated the usefulness of axillary lymph node (ALN) to primary breast tumor SUV ratio (determined by 18F-FDG PET/CT) for predicting the presence of ALN metastasis in breast cancer. Methods One hundred thirty-six consecutive female patients with breast cancer were enrolled in this retrospective study between January 2009 and November 2012. All patients underwent surgical resection without neoadjuvant chemotherapy, and ALN metastases were histologically confirmed by ALN dissection (n = 75) or sentinel lymph node (LN) biopsy (n = 61). The maximum SUVs of FDG-avid ALNs (SUVLN) and of primary breast tumors were measured on preoperative 18F-FDG PET/CT images, and ALN to primary breast tumor SUV ratios (LN/T ratios) were calculated. In a subgroup of patients with FDG-avid ALNs, optimal cutoff values for SUVLN and LN/T ratio were determined by receiver operating characteristic curve analysis for predicting the presence of ALN metastasis. Subsequently, the diagnostic performances of visual analysis (presence of FDG-avidity), SUVLN, and LN/T ratio for the prediction of ALN metastasis were determined. Results In a subgroup of patients with FDG-avid ALNs (n = 65), the area under the curve and the optimal criteria of SUVLN for detecting ALN metastasis were 0.655 and greater than 2.1, and those of LN/T ratio were 0.739 and greater than 0.2, respectively. For these criteria, the sensitivity, specificity, and diagnostic accuracy of detecting ALN metastasis were 71.4%, 77.3%, and 74.3%, respectively, for visual analysis; 47.1%, 93.9%, and 69.9%, respectively, for SUVLN; and 62.9%, 92.4%, and 77.2%, respectively, for LN/T ratio in all patients. The specificity of LN/T ratio was significantly higher than that of visual analysis (P = 0.0259). Although the sensitivity of LN/T ratio was higher than that of SUVLN, it did not reach a statistical significance (P = 0.0874). Conclusions The LN/T ratio better predicts the presence of ALN metastasis than visual analysis or SUVLN in breast cancer.

Head-to-head comparison of 11C-PiB and 18F-FC119S for Aβ imaging in healthy subjects, mild cognitive impairment patients, and Alzheimer's disease patients.

Abstract As a new beta amyloid (A&bgr;) positron emission tomography (PET) tracer, 18F-FC119S has shown higher cortical uptake in patients with Alzheimers disease (AD) than that in healthy control subjects without adverse effects in a previous preliminary study. The aim of this study was to compare 18F-FC119S PET and 11C-PiB PET in healthy control (HC) subjects, mild cognitive impairment (MCI) patients, and AD patients. A total of 48 subjects, including 28 HC subjects, 10 MCI patients, and 10 AD patients, underwent static 18F-FC119S PET (30 minutes after intravenous [i.v.] injection) and 11C-PiB PET (40 minutes after i.v. injection) on the same day. Both PET images were visually and quantitatively assessed. Standardized uptake value ratios (SUVRs) were calculated for each brain region using the cerebellar cortex as a reference region. None (0%) of the 28 HC subjects and 4 (40%) of 10 MCI patients had positive scans on both PET images. Of the 10 AD patients, 7 (70%) had positive scans on 11C-PiB PET while 6 (60%) had positive scans on 18F-FC119S PET. Overall, 47 (98%) of 48 participants showed identical results based on visual analysis. Cortical SUVR of 18F-FC119S was higher in AD patients (1.38 ± 0.16), followed by that in MCI patients (1.24 ± 0.10) and in HC subjects (1.14 ± 0.05). Compared with 11C-PiB PET, 18F-FC119S PET yielded a higher effect size (d = 2.02 vs. 1.67) in AD patients and a slightly lower effect size (d = 1.26 vs. 1.38) in MCI patients. In HC subjects, the nonspecific binding of 18F-FC119S to white matter (with the frontal cortex-to-white matter SUV ratio of 0.76) was slightly lower than that of 11C-PiB (ratio of 0.73). There was a significant linear correlation (slope = 0.41, r = 0.78, P < 0.001) between 11C-PiB and 18F-FC119S cortical SUVR. We could safely obtain images similar to 11C-PiB PET imaging A&bgr; in the brain using 18F-FC119S PET. Therefore, 18F-FC119S might be suitable for imaging A&bgr; deposition.

Prognostic value of SUVmax measured by pretreatment 18F-FDG PET/CT in patients with primary gastric lymphoma.

PurposeThe aim of this retrospective study was to determine whether glucose metabolism assessed by fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) provides prognostic information independent of established prognostic factors in patients with gastric lymphoma. Patients and methodsWe reviewed the medical records of 86 patients retrospectively (men, 42; women, 44; mean age 58±13 years) with pathologically proven gastric lymphoma (34 mucosa-associated lymphoid tissue and 52 aggressive non-Hodgkin’s lymphoma). They underwent 18F-FDG PET/CT as part of a pretreatment work-up from February 2004 to July 2012. For the analysis, patients were classified by age, sex, Musshoff stage, serum lactate dehydrogenase, International Prognostic Index score, extragastric spread, and visual intensity [visual assessment and maximum standardized uptake value (SUVmax), respectively]. The relationship between 18F-FDG uptake and survival was analyzed using the Kaplan–Meier method with a log-rank test and Cox’s proportional-hazard regression method. ResultsThe median survival of all 86 study participants was 1117 days and the median SUV measured by PET/CT was 6.1 (range, 1.9–32.7). Patients with an SUVmax less than or equal to 5.2 survived significantly longer than patients with an SUVmax more than 5.2 (median, 1163 vs. 1004 days; P=0.003). Survival was also found to be significantly related to age (P=0.0005), histological type (P=0.004), extragastric spread (P=0.0004), International Prognostic Index score (P<0.0001), serum lactate dehydrogenase (P=0.02), stage (P<0.0001), and visual intensity (P=0.041). A multivariate analysis showed that patients with a higher SUVmax [P=0.021; 95% confidence interval (CI), 1.52–8.14; hazard ratio (HR)=6.29], older age (P=0.001; 95% CI, 4.64–219.96; HR=18.8), more aggressive histologic type (P=0.006; 95% CI, 2.20–70.63; HR=12.76), and higher stage (P=0.0006; 95% CI, 5.81–206.43; HR=17.48) showed worse survival. ConclusionA higher SUVmax on pretreatment 18F-FDG PET/CT can predict poorer survival in patients with gastric lymphoma.

Tenosynovial Giant Cell Tumor of Diffuse Type Mimicking Bony Metastasis Detected on F-18 FDG PET/CT

Tenosynovial giant cell tumor of diffuse type (TGCT-D) is a locally aggressive neoplasm that arises in the tendon sheath, bursa, or synovium. It typically involves the appendicular skeleton and rarely involves the axial skeleton. Because there are no specific findings of TGCT-D based on imaging studies or clinical symptoms, TGCT-D can be confused with other primary or metastatic bone tumors. We report findings of TGCT-D involving the T9 vertebra incidentally detected on F-18 FDG PET/CT in a patient with papillary thyroid cancer.