Silong Hu

Pretreatment (18)F-FDG uptake heterogeneity can predict survival in patients with locally advanced nasopharyngeal carcinoma--a retrospective study.

BackgroundIntratumoural heterogeneity has been demonstrated to be a strong indicator of malignant transformation. Our study was to investigate pretreatment 18 F-FDG parameters, including 18 F-FDG based heterogeneity for predicting survival in patients with locally advanced nasopharyngeal carcinoma (NPC).MethodsForty newly diagnosed, biopsy-proven locally advanced NPC patients who underwent 18 F-FDG PET/CT were retrospectively included. The following PET parameters were assessed: maximum and mean standardised uptake value (SUVmax and SUVmean), metabolic tumour volume (MTV), total lesion glycolysis (TLG) and intratumoral heterogeneity index (HI). The previous parameters were recorded both for the primary tumor (-T) and neck lymph nodes (-N). The following endpoints were evaluated: local control (LC), progression-free survival (PFS) and overall survival (OS). The survival analyses were performed using the Kaplan–Meier method. Univariate analysis was performed using the log-rank test.ResultsPatients with a lower HI-T, SUVmax-T, SUVmean-T and TLG-T had significantly better 2-year LC. In predicting PFS, we found that both lower HI-T and HI-N had significantly better prognosis. However, the OS was only statistically associated with HI-T.Conclusion18 F-FDG based heterogeneity appears to be an potential predicator of patient survival after treatment.

Can Fluorine-18 Fluoroestradiol Positron Emission Tomography–Computed Tomography Demonstrate the Heterogeneity of Breast Cancer In Vivo?

AIM Our study was to investigate the heterogeneity of estrogen receptor (ER) expression among tumor sites by using fluorine-18 ((18)F) fluoroestradiol (FES) positron-emission tomography-computed tomography (PET-CT) imaging. METHODS Thirty-two breast cancer patients underwent both (18)F-FES and (18)F fluorodeoxyglucose (FDG) PET-CTs from June 2010 to December 2011 in our center (mean age, 53 years; range, 27-77 years). We used the maximum standardized uptake value to quantify ER expression and a cutoff value of 1.5 to dichotomize results into ER(+) and ER(-). The difference of heterogeneity between the initial patients and patients with recurrent or metastatic disease after treatments was assessed by using the χ(2) test. Also, the (18)F-FES uptake was compared with the (18)F-FDG uptake by use of Spearman correlation coefficients. RESULTS A total number of 237 lesions in 32 patients were detected. Among them, most lesions (64.1% [152/237]) were bone metastasis. A striking 33.4-fold difference in (18)F-FES uptake was observed among different patients (maximum standardized uptake value range, 0.5 to approximately 16.7), and a 8.2-fold difference was observed among lesions within the same individual (1.0 to approximately 8.2). As for (18)F-FDG uptake, the difference was 11.6-fold (1.3 to approximately 15.1) and 9.9-fold (1.4 to approximately 13.8), respectively. In 28.1% (9/32) of the patients, both (18)F-FES(+) and (18)F-FES(-) metastases were present, which suggests partial discordant ER expression. After treatments, 37.5% (9/24) patients with recurrent or metastatic breast cancer showed heterogeneity, whereas no untreated patient was detected to exist discordant ER expression (χ(2), 4.174; P < .05). In addition, the (18)F-FES uptake showed a weak correlation with the (18)F-FDG uptake (ρ = 0.248; P < .05). CONCLUSION (18)F-FES and (18)F-FDG uptake varied greatly both within and among patients. (18)F-FES PET-CT demonstrated a conspicuous number of patients with the heterogeneity of ER expression.

Prevalence and risk of cancer of incidental uptake in prostate identified by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

OBJECTIVE The objective was to investigate the prevalence of incidental fluorine-18 fluorodeoxyglucose (FDG) uptake in positron emission tomography/computed tomography. METHODS A total of 11,239 male nonprostate disease patients were included retrospectively. RESULTS The prevalence of incidental prostate FDG uptake was approximately 1.8%. Among 198 incidental lesions, 100 patients had further examinations; 20 lesions were confirmed to be malignant, while 80 lesions were benign. After logistic regression analysis, age, site, and the maximum standard uptake value were the potent predictors for differentiation of malignant prostate lesions. CONCLUSION When focal FDG uptake in the peripheral zone of prostate is detected, especially in elderly men, further clinical evaluation is recommended.

Prevalence and risk of cancer of thyroid incidentaloma identified by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography.

OBJECTIVE To investigate the prevalence and risk of thyroid incidentaloma identified by positron emission tomography/computed tomography (PET/CT). STUDY DESIGN Historical cohort study. SETTING Fudan University Shanghai Cancer Center. METHODS A total of 15 948 non-thyroid disease patients who underwent fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT from November 2006 to September 2010 were included. They were divided into two groups: 12 080 patients for metastatic evaluation and 3868 patients for cancer screening. When thyroid incidentaloma was found, further diagnostic examination was conducted. MAIN OUTCOME MEASURES Prevalence and risk of thyroid incidentaloma. RESULTS The prevalence of incidental thyroid 18F-FDG uptake was approximately 2.5% (395 of 15 948). The prevalence of incidentaloma in healthy subjects (118 of 3868; 3.1%) was statistically higher than that in patients with suspected or known cancer (277 of 12 080; 2.3%) (p < .05). Among 395 incidentalomas, 146 patients had further examinations (53 patients with histologic confirmations, 93 patients with clinical monitoring). Finally, 43 lesions were confirmed to be malignancies. Therefore, the cancer risk was 29.5% (43 of 146), and it was higher in cancer screening patients (24 of 59; 40.7%) than in alleged cancer patients (19 of 87; 21.8%) (p < .05). As for FDG uptake pattern, the prevalence of thyroid cancer was 11.6% (5 of 43) and 36.9% (38 of 103) in the group of patients with diffuse and focal uptake, respectively (p < .05). After logistic regression analysis, age, sex, maximal standardized uptake value, and calcification were the potent predictors of differentiation. CONCLUSION The presence of focal uptake with high SUVmax and calcification detected on CT images correlates with a high likelihood of thyroid malignancy. When a focal thyroid incidentaloma is detected, further examination should be performed.

The Preliminary Study of 16α-[18F]fluoroestradiol PET/CT in Assisting the Individualized Treatment Decisions of Breast Cancer Patients

Objective To evaluate the clinical value of 16α-[18F]fluoroestradiol (18F-FES) PET/CT in assisting the individualized treatment decisions of breast cancer patients. Methods Thirty-three breast cancer patients, who underwent both 18F-FES and 18F-FDG PET/CT from July 2010 to March 2013 in our center, were enrolled in this preliminary study. All the patients used 18F-FES PET/CT as a diagnostic tool with a clinical dilemma. We used the maximum Standardized Uptake Value (SUVmax) to quantify ER expression and a cutoff value of 1.5 to dichotomize results into ER positive and negative lesions. All patients were clinically followed up at least 6 months. Results In evaluating equivocal lesions on conventional work-up group (n = 4), three lung lesions and another iliac lesion were enrolled. As for three lung lesions, 18F-FES PET/CT showed one lesion with high uptake, which suggested it was an ER positive metastasis. The other two lesions were 18F-FES negative, which meant an ER negative metastasis or secondary primary tumor. Additionally, one iliac lesion was detected by MRI. 18F-FDG uptake was high at the suspected lesion, whereas 18F-FES uptake was absent; In predicting origin of metastasis group (n = 2), two breast cancer patients had secondary primary tumors were collected. They were 18F-FES negative, which showed low possibility of metastasis from breast cancer and they were all confirmed by biopsy. In detecting ER status in metastasis group (n = 27), 18F-FES PET/CT showed increased 18F-FES uptake in all metastatic lesions in 11 patients; absent in all lesions in 13 patients; and the remaining 3 patients had both 18F-FES positive and negative lesions. Totally, on the basis of the 18F-FES PET/CT results, we found changes in the treatment plans in 16 patients (48.5%, 16/33). Conclusions 18F-FES PET/CT could assess the entire tumor volume receptor status; therefore, it may be used to assist the individualized treatment decisions of breast cancer patients.

18F-FLT PET/CT imaging is not competent for the pretreatment evaluation of metastatic gastric cancer: a comparison with 18F-FDG PET/CT imaging.

ObjectiveThe aim of this study was to evaluate the utility of 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) PET/computed tomography (CT) imaging in the pretreatment evaluation of metastatic gastric cancer in comparison with 18F-fluorodeoxyglucose (18F-FDG) PET/CT imaging. MethodsA total of 39 metastatic gastric cancer patients were enrolled in the study. Attenuation-corrected whole-body 18F-FLT and 18F-FDG PET/CT (low-dose CT) imaging was performed on two consecutive days before chemotherapy. ResultsAccumulation of focal activity was visible in primary tumors on 18F-FLT PET/CT in 36/39 patients and on 18F-FDG PET/CT in 37/39 patients, with sensitivities of 92.3 and 94.9%, respectively. Further, three of the 36 FLT-avid primary tumors were almost undetected because they were covered by a high background hepatic uptake. Because of the high physiological uptake of 18F-FLT in the liver [median maximum standardized uptake value (SUVmax) 5.5, range 4.5–8.3] and the bone marrow (median SUVmax 14.8, range 10.8–22.0), the sensitivity of 18F-FLT PET/CT versus 18F-FDG PET/CT for detecting liver metastases and bone metastases was 30.0% (6/20) versus 100% (20/20) and 1/5 (20.0%) versus 5/5 (100%), respectively (P<0.05). Metabolically positive findings of lymph node, peritoneal, and ovarian metastases were similar between the two modalities: 96.8% (30/31) versus 93.5% (29/31), 89.5% (17/19) versus 94.7% (18/19), and 90.9% (10/11) versus 90.9% (10/11) of patients for 18F-FLT versus 18F-FDG, respectively (P>0.05). Conclusion 18F-FLT PET/CT imaging is not recommended for pretreatment assessment of metastatic gastric cancer as it is not competent enough to evaluate liver and bone metastases; moreover, the high background hepatic uptake may cover the gastric primary tumors located adjacent to the liver.

Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer

Objectives:  To investigate the value of whole‐body fluorine‐18 2‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer.

99mTc-labeling and evaluation of a HYNIC modified small-molecular inhibitor of prostate-specific membrane antigen

INTRODUCTION Prostate-specific membrane antigen (PSMA) is a well-established target in the development of radiopharmaceuticals for the diagnosis and therapy of prostate cancer (PCa). In this study, we evaluated a novel 99mTc-labeled small molecular inhibitor of PSMA. METHODS This new small-molecular inhibitor of PSMA, 6-hydrazinonicotinate-Aminocaproic acid-Lysine-Urea-Glutamate (HYNIC-ALUG) was radiolabeled by 99mTc and was evaluated both in vitro and in vivo using PCa models (PC-3 and LNCaP). Radiation dosimetry was assessed in mice. RESULTS 99mTc-HYNIC-ALUG showed excellent stability in different media. A cell assay preliminarily displayed its specificity for PSMA. The inhibitor showed good pharmacokinetics making it suitable for in vivo imaging. PC-3-derived tumors showed no obvious radioactive uptake; however, the LNCaP-derived tumors showed very high radioactive uptake which was significantly decreased by the selective PSMA inhibitor 2-PMPA. Biodistribution in LNCaP xenografts showed an optimum tumor-to-blood ratio of 24.23±3.54 at 2h. Tumor uptake was also decreased in the inhibition experiment with 2-PMPA (19.45±2.14%ID/g versus 1.42±0.15%ID/g at 2h). The effective dose of the 99mTc-HYNIC-ALUG was 8.4E-04mSv/MBq. CONCLUSIONS A new 99mTc-labeled PSMA inhibitor with specific accumulation in PSMA-positive tumors and low background in other organs was synthesized. The radiopharmaceutical also showed very low radiation dosimetry. This agent may significantly improve the diagnosis, staging, and subsequent monitoring of therapeutic effects in PCa patients.

Clinical value of [18F]FDG-PET/CT in the detection of metastatic medullary thyroid cancer

PURPOSE To evaluate the value of fluorine-18 2-deoxy-2-d-glucose positron emission tomography/computed tomography ([(18)F]FDG-PET/CT) in the detection of metastatic medullary thyroid cancer. METHODS From November 2006 to November 2012, 50 medullary thyroid cancer patients (median age 48.7 years, range 18-76) who had a total thyroidectomy operation underwent whole-body [(18)F]FDG-PET/CT scans. The diagnostic accuracy of [(18)F]FDG-PET/CT was determined through both lesion-based and patient-based analyses. Further pathological tests were performed on all identified lesions or clinically followed for a minimum period of 6 months. RESULTS One hundred forty-four suspicious lesions were identified by organ-based analysis. Of these lesions, [(18)F]FDG-PET/CT detected 99 true-positive lesions, sensitivity was 73.3%, and specificity was 66.7%. On the patient-based analysis, the overall sensitivity and specificity were calculated as 65.7% and 92.3%, respectively. Using a cutoff calcitonin value of 1000 pg/ml, in patients with calcitonin lower than this value, sensitivity and specificity were 42.9% and 91.0%, respectively. In patients with calcitonin exceeding this value, they raised to 77.3% (χ(2)=4.392, P<.05) and 100% (χ(2)=0.197, P>.05), respectively. Compared with conventional imaging modality, PET/CT scans detected more lesions in 10 patients (20.4%) and correctly changed the treatment in 8 patients (16.3%). CONCLUSION [(18)F]FDG-PET/CT has excellent sensitivity and specificity, especially when the calcitonin value is higher than 1000 pg/ml for detecting metastatic medullary thyroid cancer. Compared to conventional morphologic imaging methods, it provides additional information for diagnosis.

Diagnostic value of 18F-FDG PET/CT for cutaneous extranodal natural killer/T-cell lymphoma, nasal type.

ObjectiveTo evaluate the use of fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in the diagnosis of cutaneous extranodal natural killer/T-cell lymphoma, nasal type (C-ENK/T-NT). MethodsA total of 39 patients with newly diagnosed C-ENK/T-NT were enrolled between May 2006 and November 2013. Anatomic regions (n=429; five cutaneous and six extracutaneous regions per patient) were assessed using an 18F-FDG PET/CT scan and conventional staging methods (CSMs). 18F-FDG PET/CT and CSMs were compared and evaluated for their ability to detect tumor lesions and their influence on the staging and treatment strategies. Biopsy and clinical follow-up were used as the gold standard for diagnosis. ResultsIn total, 139 lesions were detected by CSMs and 18F-FDG PET/CT, of which there were 50 cutaneous and 89 extracutaneous-positive regions. 18F-FDG PET/CT detected 48 cutaneous and 88 extracutaneous regions. CSMs, however, detected only 34 cutaneous lesions and 61 extracutaneous lesions that were positive for malignancy (cutaneous comparison of PET/CT vs. CSMs, P<0.001; extracutaneous comparison of PET/CT vs. CSMs, P<0.05). Using 18F-FDG PET/CT, 8 (42%) patients were in stage I–II and 31 patients (58%) were in stage III–IV. 18F-FDG PET/CT staging was consistent with the final stage determination in 94.9% (37/39) of patients, whereas CSMs staging was correct in final stage determination in 74.4% (29/39) of patients (P=0.025). ConclusionOur study showed that 18F-FDG PET/CT scanning is a valuable modality for the detection of cutaneous and extracutaneous lesions of C-ENK/T-NT. 18F-FDG PET/CT may therefore influence future staging and treatment strategies.