Guoren Yang

Diagnostic and Prognostic Value of 18F-FDG PET/CT for Patients with Suspected Recurrence from Squamous Cell Carcinoma of the Esophagus

Patients with esophageal squamous cell carcinoma (ESCC) are commonly at high risk of recurrence within 2 y after initial treatment. The aim of this study was to evaluate the role of 18F-FDG PET/CT in patients with possibly recurrent ESCC who underwent definitive treatment. Methods: Fifty-six patients with previously treated ESCC underwent PET/CT scans. The PET/CT findings were validated by histopathology or clinical follow-up of at least 6 mo. The sensitivity, specificity, and accuracy of PET/CT for detecting recurrence were calculated. Comparison of the standardized uptake value (SUV) was performed between patients grouped according to their status at the last follow-up (relapsed or relapse-free, alive or dead). The overall survival rates were estimated by the Kaplan–Meier method. The Cox proportional hazards model was used to evaluate independent prognostic variables for both univariate and multivariate survival analysis. Results: Forty-five (80.4%) patients had recurrence in 72 (66.1%) malignant sites. On PET/CT, there were 9 false-positive and 5 false-negative results. The overall sensitivity, specificity, and accuracy of PET/CT for detecting recurrence at all sites were 93.1% (67/72), 75.7% (28/37), and 87.2% (95/109), respectively. PET/CT was highly sensitive, specific, and accurate at regional and distant sites. At local sites, sensitivity was high, but specificity was lower (50%) because of a high incidence of false-positive findings. Patients who were confirmed with recurrence or who had died at the last follow-up had higher SUVs (P = 0.027 and <0.001, respectively). In multivariate survival analysis, therapeutic modality (hazard ratio = 0.437; P = 0.044), SUV (hazard ratio = 1.071; P = 0.029), and disease status on PET/CT (hazard ratio = 2.430; P = 0.045) were independent significant prognostic predictors for overall survival. The Kaplan–Meier survival curves indicated poor prognostic outcome in subgroup patients with higher SUVs or systemic disease on PET/CT. Conclusion: 18F-FDG PET/CT is highly effective for detecting recurrent ESCC. The relatively low specificity at local sites is associated primarily with a high rate of false-positive interpretations at anastomoses. PET/CT can also provide noninvasive and independent prognostic information using SUV and recurrent disease pattern on PET/CT images for previously treated ESCC.

PET-Based Biodistribution and Radiation Dosimetry of Epidermal Growth Factor Receptor–Selective Tracer 11C-PD153035 in Humans

The present study estimated the biodistribution and radiation-absorbed dose of epidermal growth factor receptor (EGFR) radioligand 11C-PD153035 in whole-body PET examinations of healthy volunteers. Methods: Two-dimensional whole-body PET was performed on 9 subjects after injection of 11C-PD153035 at 329.3 ± 77.8 MBq (mean ± SD). A total of 12 frames were acquired for approximately 90 min in 7 segments of the body. Regions of interest were drawn on PET images of source organs. Residence time was calculated as the area under the time–activity curve. Radiation dosimetry was calculated from organ residence time by use of MIRDOSE3 software. Results: The renal and hepatobiliary systems played important roles in 11C-PD153035 excretion from the body, accounting for the excretion of approximately 23% and 19% of the injected radioactivity, respectively. Blood-pool activity was only moderate and declined over time. Tracer accumulation in the lungs, bone marrow, and muscles was slight, resulting in low background activity in the chest. The organs with the highest radiation-absorbed doses were the urinary bladder and the gallbladder; the effective doses were 6.08E−02 ± 1.85E−02 and 2.40E−02 ± 8.01E−03 mGy/MBq, respectively. The effective dose equivalent was 7.43E−03 ± 1.10E−03 mSv/MBq, and the dose-limiting organ was the urinary bladder. Conclusion: On the basis of the estimated absorbed dose, 11C-PD153035 displayed a favorable radiation dose profile in humans and therefore could be used in multiple PET examinations of the same subject per year. 11C-PD153035 is a promising ligand for the investigation of EGFR in humans, especially in chest tumors such as non–small cell lung cancer.

Comparison of 18F-Fluoroerythronitroimidazole and 18F-fluorodeoxyglucose positron emission tomography and prognostic value in locally advanced non-small-cell lung cancer.

INTRODUCTION The aim of this study was to compare glucose metabolism and hypoxia using 18F- fluorodeoxyglucose (18F-FDG) and 18F-fluoroerythronitroimidazole (18F-FETNIM) positron emission tomography (PET) and investigate their prognostic role on survival in patients with locally advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Twenty-six patients with NSCLC were imaged with 18F-FETNIM PET/computed tomography (CT), and 11 cases also with 18F-FDG PET/CT imaging among those with significant 18F-FETNIM uptake, a few days before any chemo/adiation therapy. The maximum standardized uptake value (SUVmax) was used to depict 18F-FDG uptake, and hypoxic volume (HV) and tumor:blood ratio (T/Bmax) were used to quantify hypoxia. Overall survival (OS) after treatment was selected as the endpoint of the study. RESULTS Twenty-two patients (84.6%) had significant 18F-FETNIM uptake in the primary tumor. The correlations between the overall tumor SUVmax of 18F-FDG and HV, T/Bmax ratio of 18F-FENTIM in 11 patients were small and without significant difference. In univariate analyses, log-rank tests were used to compare Kaplan-Meier survival curves. 18F-FETNIM T/Bmax ratio and HV were strong predictors for OS, and 18F-FDG uptake of the primary lesions did not have a significant relationship with survival. In multivariate survival analysis, only 18F-FETNIM T/Bmax ratio was found to be an independent prognostic factor. CONCLUSION Imaging using both 18F-FETNIM and 18F-FDG appears to be beneficial in the evaluation of solid tumors. 18F-FETNIM imaging provides us with a valuable method to detect tumor hypoxia and predict OS. These preliminary results warrant validation in larger trials.

Bone metastasis in patients with non-small cell lung cancer: The diagnostic role of F-18 FDG PET/CT

PURPOSE To evaluate the performance of F-18 FDG PET/CT in the detection of bone metastasis in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS Three hundred and sixty-two consecutive NSCLC patients who underwent F-18 FDG PET/CT scanning were retrospectively analyzed. Each image of PET/CT, combined CT, and PET was performed at 10 separate areas and interpreted blindly and separately. The sensitivity, specificity and accuracy of F-18 FDG PET/CT, combined CT and F-18 FDG PET were calculated and the results were statistically analyzed. RESULTS Bone metastasis was confirmed in 82 patients with 331 positive segments based on the image findings and clinical follow-up. On patient-based analysis, the sensitivity of F-18 FDG PET/CT (93.9%) was significantly higher than those of combined CT (74.4%) and F-18 FDG PET (84.1%), respectively (p<0.05). The overall specificity and accuracy of combined CT, F-18 FDG PET, and F-18 FDG PET/CT were 90.7%, 93.2%, 98.9% and 87.0%, 91.2%, and 97.8%, respectively (compared with PET/CT, p<0.05). On segment-based analysis, the sensitivity of the three modalities were 79.5%, 94.3%, and 98.8%, respectively (compared with PET/CT, p<0.05). The overall specificity and accuracy of the three modalities were 87.9%, 89.2%, 98.6% and 84.5%, 91.2%, 98.7%, respectively (compared with PET/CT, p<0.05). CONCLUSION F-18 FDG PET/CT is superior to F-18 FDG PET or combined CT in detecting bone metastasis of NSCLC patients because of the complementation of CT and PET. It is worth noting that the added value of F-18 FDG PET/CT may beneficially impact the clinical management of NSCLC.

Relationship between primary tumor fluorodeoxyglucose uptake and nodal or distant metastases at presentation in T1 stage non-small cell lung cancer

Many studies have shown that FDG uptake is related to prognosis of non-small cell lung cancer, and metastasis is the major cause of death due to lung cancer patients. However, the FDG uptake of primary tumor in relation to nodal or distant metastasis at presentation has not been studied directly. Newly diagnosed non-small cell lung cancer patients who accepted (18)F-FDG PET/CT staging in the nuclear medicine center of Shandong Cancer Hospital between 1 June 2004 and 1 October 2007 were retrospectively reviewed. One hundred and seven patients with clinical T1 stage and definited histologic or cytologic evidence were enrolled and analyzed. Significant differences were observed in primary tumor SUVmax for different stages (Stage Ia-IV, P=0.004), different N status (N(0)M(0) vs. N(1-3)M(0), P=0.008) and tumors absence any spread vs. presence distant metastasis (N(0)M(0) vs. M(1), P=0.000). Spearman rank analysis showed moderate correlations between SUVmax and different N or M status (r=0.369, P=0.000 for Stage Ia-IV; r=0.337, P=0.004 for N(0)M(0) vs. N(1-3)M(0); r=0.474, P=0.000 for N(0)M(0) vs. M(1); respectively). There was a statistically significant increase in the probability of metastases at presentation with each unit increase in SUVmax. (logistic regression model, OR=1.469; 95% CI, 1.175-1.836; P=0.001). These results suggest that FDG uptake is a potential indicator of metastases in small primary lesion of non-small cell lung cancer.

FDG-PET Predicts Pain Response and Local Control in Palliative Radiotherapy With or Without Systemic Treatment in Patients With Bone Metastasis From Non–small-cell Lung Cancer

UNLABELLED The purpose of the present study was to evaluate the prognostic value of the maximal standardized uptake value (SUVmax) from serial positron emission tomography scans in patients with bone metastases from non-small-cell lung cancer. The results showed that the pre-RT SUVmax predicted the initial pain severity and local control. Moreover, the change in the SUVmax after palliative radiotherapy predicted the pain response and local control rate. INTRODUCTION We sought to evaluate the value of fluorine-18 fluorodeoxyglucose positron emission tomography (PET) in predicting the pain severity, pain response, and in-field tumor control after palliative radiotherapy (RT) in patients with non-small-cell lung cancer (NSCLC) bone metastases. MATERIALS AND METHODS The present retrospective, institutional review board-approved study involved 74 patients with NSCLC and 185 bone metastatic lesions. All patients had undergone PET-computed tomography (CT) scans before and after RT. The pain scores were determined using a numerical rating scale, and the maximal standardized uptake value (SUVmax) at each location was recorded. The pain scores and responses to RT were compared using the pre-RT SUVmax and SUVmax changes after RT. Cox regression analyses were performed to identify the prognostic factors for in-field progression-free survival (PFS) and in-field event-free survival (EFS). RESULTS The pre-RT SUVmax correlated with the initial pain scores (r = 0.885, P < .001), and the decrease in the SUVmax after RT was associated with the pain response to RT (P = .001). During the follow-up period, 47.03% and 38.92% of the lesions showed in-field tumor radiographic progression and in-field events, respectively. The Cox regression analyses showed that a higher pre-RT SUVmax (≥ 8.2) was an independent prognostic factor of worse in-field PFS and worse in-field EFS (hazard ratio [HR] 1.42 and 1.46; P = .044 and P = .005, respectively) and that a greater SUVmax decrease (≥ 28.3%) after RT was an independent prognostic factor of better in-field PFS and better in-field EFS (HR 0.59 and 0.60, respectively; P < .001 for both). CONCLUSION In patients with NSCLC osseous metastasis treated with palliative RT, the pre-RT SUVmax predicted the initial pain severity and local control. Moreover, the change in the SUVmax after RT predicted the pain response and local control.