Prognostic value of pre-and post-transplantation 18F-fluorodeoxyglucose positron emission tomography results in non-Hodgkin lymphoma patients receiving autologous stem cell transplantation

Objective： High-dose chemotherapy （HDC） followed by autologous stem cell transplantation （ASCT） is the standard of care in the upfront or relapsed/refractory setting in some patients with non-Hodgkin lymphoma （NHL）. However, a proportion of patients do not respond to ASCT. lSF-fluorodeoxyglueose （FDG） positron emission tomography （PET）/computed tomography （CT） has been widely used for staging, response evaluation, and prognosis prediction. Here, we investigated the prognostic role of PET/CT in NHL patients before and after ASCT. Methods： A retrospective study was conducted at Peking University Cancer Hospital. All NHL patients who underwent ASCT between March 2010 and July 2016 were identified. Patients who had PET/CT scan before and after ASCT were included. Deauville criteria （5-point scale） were used to interpret PET scans. Univariate and multivariate survival analyses were performed using Cox regression. The predictive value of PET scanning was estimated by comparing the area under the receiver operating characteristic （ROC） curve. Results： In total, 79 patients were enrolled in this study. In univariate analysis, pre- and post-ASCT PET result was identified as prognostic factors for 3-year progression-free survival （PFS） and overall survival （OS）. Patients with negative pre-ASCT PET result demonstrated significantly better PFS （84.2% vs. 54.2%） and OS （89.2% vs. 63.6%） than patients with positive pre-ASCT PET result. PFS （91.6% vs. 25.3%） and OS （96.5% vs. 36.8%） were also significantly different between patients with negative and positive post-ASCT PET result. Multivariate analysis also showed a significant association between survival and post-ASCT PET result. ROC analysis revealed that the predictive value of post-ASCT PET result was superior to that of pre-ASCT PET result alone. Combined pre- and post-ASCT PET result is better for predicting outcomes in patients with NHL receiving transplantation. Deauville criteria score 〉3 was identified as the best cutoffvalue for post-ASCT PET. Conclusions： Post-ASCT PET result was more important than pre-ASCT PET result in predicting outcomes for NHL patients who underwent ASCT. The prognostic significance can be improved when combining pre- ASCT PET result with post-ASCT PET result. Deauville criteria can be used for interpreting PET scans in this scenario.

^(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM To compare ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ^(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P < 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

Dynamic ^(18)F-fluorodeoxyglucose positron emission tomography/CT in hibernoma: enhanced tracer uptake mimicking liposarcoma

We report on two cases of patients with fat-equivalent masses in computed tomography(CT),referred to our department for dynamic positron emission tomography/CT(dPET/CT)with18F-fluorodeoxyglucose(18FFDG)in order to investigate their dignity.Both qualitative and quantitative information,as derived from dPET/CTs,couldn’t exclude a high-grade liposarcoma:Visual evaluation,revealed a large hypermetabolic focus of intense18F-FDG uptake in each patient(average SUVs 8.3 and 11.3).Regression-based parametric imaging demonstrated an enhanced distribution volume,which correlates to perfusion,and a high phosphorylation rate that correlates to cell viability.Kinetic analysis,based on a two-tissue compartment model demonstrated an enhanced FDG transport k1and an enhanced phosphorylation rate k3.A non-compartmental approach based on fractal dimension revealed also enhanced values.However,final diagnosis was based on biopsy,which revealed hibernoma,a benign brown fat tumor.Brown adipose contains increased numbers of mitochondria and a high-rate of glucose metabolism.Therefore,they have increased FDG uptake.The evaluation of lipomatous lesions on CT,with high FDG uptake,should include the possibility of hibernoma as a differential diagnosis.

Prognostic Value of Semi-Quantitative 18F-FDG PET/CT Parameters in Hodgkin’s Lymphoma

Objective:To assess the prognostic value of maximum standardized uptake value(SUVmax),metabolic tumor volume(MTV),and total lesion glycolysis(TLG)determined by 18F-fluorodeoxyglucose positron emission tomography-computed tomography(18F-FDG PET/CT)imaging in Hodgkin’s lymphoma patients.Methods:A total of 148 Hodgkin’s lymphoma patients diagnosed with lymph node biopsy from October 2014 to October 2015 were retrospectively analyzed followed by categorizing into good(125 cases)and poor(23 cases)prognosis groups.The chi-squared test was used to analyze the clinicopathological characteristics of Hodgkin’s lymphoma patients with the semi-quantitative 18F-FDG PET/CT parameters;the Spearman method was used to analyze the correlation between the semi-quantitative parameters and clinicopathological features of Hodgkin’s lymphoma;receiver operating characteristic curve was used to analyze the predictive value of the semi-quantitative parameters for poor prognosis of Hodgkin’s lymphoma patients.Results:Mean SUVmax,MTV,and TLG of the 148 cases of Hodgkin’s lymphoma were 7.26±2.38,12.46±3.14 cm3,and 76.83±18.56 g,respectively.Significant variations in the Ann Arbor stage and clinical classification were observed with different levels of semi-quantitative parameters(P<0.05).The semi-quantitative parameters were not correlated with age and gender(P>0.05)but positively correlated with Ann Arbor stage and clinical classification(P<0.05).These parameters in the poor prognosis group were higher than those in the good prognosis group(P<0.05).The area under the curve(AUC)of SUVmax,MTV,and TLG in predicting the poor prognosis group was 0.881,0.875,and 0.838,with cut-off values of 7.264,12.898 cm3,and 74.580g,as well as specificity of 88.8%,84.0%,and 78.4%,and sensitivity of 87.0%,87.0%,and 78.3%,respectively;the AUC of the combined prediction was 0.986,with a specificity of 97.6%and sensitivity of 86.3%.Conclusion:The semi-quantitative 18F-FDG PET/CT parameters provide valuable insights for Hodgkin’s lymphoma prognosis assessment.

Multiple primary malignant tumors of upper gastrointestinal tract:A novel role of ^(18)F-FDG PET/CT

AIM: To evaluate the capacity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for detecting multiple primary cancer of upper gastrointestinal (UGI) tract. METHODS: Fifteen patients (12 without cancer histories and 3 with histories of upper GI tract cancer) were investigated due to the suspicion of primary cancer of UGI tract on X-ray barium meal and CT scan. Subsequent whole body 18F-FDG PET/CT scan was carried out for initial staging or restaging. All the patients were fi nally confi rmed by endoscopic biopsy or surgery. The detection rate of multiple primary malignant cancers was calculated based on 18F-FDG PET/CT and endoscopic examinations.RESULTS: 18F-FDG PET/CT scan was positive in 32 suspicious lesions, 30/32 were true positive primary lesions, and 2/32 were false positive. In 15 suspicious lesions with negative 18F-FDG PET/CT scan, 12/15 were true negative and 3/15 were false negative. Among the 15 patients, 12 patients had 29 primary synchronous tumors confirmed by pathology, including 8 cases of esophageal cancers accompanied with gastric cancer and 4 of hypopharynx cancers with esophageal cancer. The other 3 patients had 4 new primary metachronous tumors, which were multiple primary esophageal cancers. PET/CT imaging detected local lymph node metastases in 11 patients. Both local lymph node metastases and distant metastases were detected in 4 patients. On a per-primary lesion basis, the sensitivity, specificity, accuracy, negative predictive value and positive predictive value of 18F-FDG PET/CT for detecting multiple primary cancer of UGI tract were 90.9%, 85.7%, 89.4%, 80% and 93.7%, respectively. CONCLUSION: The whole body 18F-FDG PET/CT may play an important role in evaluating the multiple primary malignant tumors of UGI tract cancer.

Role of pre-transplant 18F-FDG PET/CT in predicting hepatocellular carcinoma recurrence after liver transplantation

The last two decades have seen a paradigm shift in the selection of patients with hepatocellular carcinoma(HCC)for liver transplantation.Microvascular invasion and differentiation have been the most significant factors affecting post-transplant recurrence;however,because of inherent disadvantages of pre-transplant biopsy,histological criteria never gained popularity.Recently,the selection criteria evolved from morphological to biological criteria,such as biomarkers and response to loco-regional therapy.With the introduction of multimodality imaging,combination of computed tomography with nuclear medicine imaging,particularly,18F-fluorodeoxyglucose positron emission tomography fulfilled an unmet need and rapidly became a critical component of HCC management.This review article will focus on the use of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the pre-transplant evaluation of HCC patients with special discussion on its ability to predict HCC recurrence after liver transplantation.

Feasibility of sentinel lymph node biopsy omission after integration of ^(18)F-FDG dedicated lymph node PET in early breast cancer: a prospective phase II trial

Objective:Sentinel lymph node biopsy(SLNB)is currently the standard of care in clinically node negative(cN0)breast cancer.The present study aimed to evaluate the negative predictive value(NPV)of 18F-FDG dedicated lymph node positron emission tomography(LymphPET)in cN0 patients.Methods:This was a prospective phase II trial divided into 2 stages(NCT04072653).In the first stage,cN0 patients underwent axillary LymphPET followed by SLNB.In the second stage,SLNB was omitted in patients with a negative preoperative axillary assessment after integration of LymphPET.Here,we report the results of the first stage.The primary outcome was the NPV of LymphPET to detect macrometastasis of lymph nodes(LN-macro).Results:A total of 189 patients with invasive breast cancer underwent LymphPET followed by surgery with definitive pathological reports.Forty patients had LN-macro,and 16 patients had only lymph node micrometastasis.Of the 131 patients with a negative LymphPET result,16 patients had LN-macro,and the NPV was 87.8%.After combined axillary imaging evaluation with ultrasound and LymphPET,100 patients were found to be both LymphPET and ultrasound negative,9 patients had LN-macro,and the NPV was 91%.Conclusions:LymphPET can be used to screen patients to potentially avoid SLNB,with an NPV>90%.The second stage of the SOAPET trial is ongoing to confirm the safety of omission of SLNB according to preoperational axillary evaluation integrating LymphPET.

Clinical value of ^(18)F-FDG PET/CT in assessing suspicious relapse after rectal cancer resection

AIM:To evaluate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT) in the restaging of resected rectal cancer.METHODS:From January 2007 to Sep 2008,21 patients who had undergone curative surgery resection for rectal carcinoma with suspicious relapse in conventional imaging or clinical findings were retrospectively enrolled in our study.The patients underwent 28 PET/CT scans(two patients had two scans,one patient had three and one had four scans).Locoregional recurrences and/or distant metastases were confirmed by histological analysis or clinical and imaging follow-up.RESULTS:Final diagnosis was confirmed by histopathological diagnosis in 12 patients(57.1) and by clinical and imaging follow-up in nine patients(42.9).Eight patients had extrapelvic metastases with no evidence of pelvic recurrence.Seven patients had both pelvic recurrence and extrapelvic metastases,and two patients had pelvic recurrence only.18F-FDG PET/CT was negative in two patients and positive in 19 patients.18F-FDG PET/CT was true positive in 17 patients and false positive in two.The accuracy of 18F-FDG PET/CT was 90.5,negative predictive value was 100,and positive predictive value was 89.5.Five patients with perirectal recurrence underwent 18F-FDG PET/CT image guided tissue core biopsy.18F-FDG PET/CT also guided surgical resection of pulmonary metastases in three patients and monitored the response to salvage chemotherapy and/or radiotherapy in four patients.CONCLUSION:18F-FDG PET/CT is useful for evaluating suspicious locoregional recurrence and distant metastases in the restaging of rectal cancer after curative resection.

Multi-site abdominal tuberculosis mimics malignancy on ^(18)F-FDG PET/CT:Report of three cases

18 F-fluorodeoxyglucose positron emission/computed tomography( 18 F-FDG PET/CT)imaging,an established procedure for evaluation of malignancy,shows an increased 18 F-FDG uptake in inflammatory conditions.We present three patients with abdominal pain and weight loss.Conventional imaging studies indicated that abdominal neoplasm and 18 F-FDG PET/CT for assessment of malignancy showed multiple lesions with intense 18 FFDG uptake in abdomen of the three cases.However,the three patients were finally diagnosed with multi-site abdominal tuberculosis(TB).Of them,two were diagnosed with TB by pathology,one was diagnosed with TB clinically.They recovered after anti-TB therapy.Few reports on accumulation of 18 F-FDG in abdominal TB are available in the literature.A high index of suspicion is necessary to achieve an early diagnosis and a better outcome of the disease.

Prognostic value of post-treatment ^(18)F-FDG PET/CT for advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy

Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcinoma （HNSCC） after combined intra-arterial chemotherapy and radiotherapy （IACR）.Methods：Thirty-six patients with HNSCC who underwent IACR were recruited.The period from the end of IACR to the last post-treatment 18F-FDG PET/CT examination was 8-12 weeks.Both patient-based and lesion-based analyses were used to evaluate the PET/CT images.For lesion-based analysis,36 regions （12 lesions of recurrences and 24 scars at primary sites） were selected.The Kaplan-Meier method was used to assess the overall survival （OS） stratified by 18F-FDG uptake or visual interpretation results.Results：Twelve patients with recurrence were identified by six months after IACR.The sensitivity and specificity in the patient-based analysis were 67％ （8/12） and 88％ （21/24）,respectively.The mean OS was estimated to be 12.1 months （95％ CI,6.3-18.0 months） for the higher maximum standardized uptake value （SUVmax） group （n=7） and 44.6 months （95％ CI,39.9-49.3 months） for the lower SUVmax group （n=29）.OS in the higher SUVmax group （cut-off point,6.1） or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group （P＜0.001 and P＜0.05,respectively）.Conclusions：The SUVmax and visual interpretation of HNSCC on post-IACR 18F-FDG PET/CT can provide prognostic survival estimates.

Optimal Threshold of Stimulated Serum Thyroglobulin Level for ^(18)F-FDG PET/CT imaging in Patients with Thyroid Cancer

This study was to explore the optimal threshold of thyroid-stimulating hormone(TSH)-stimulated serum thyroglobulin(s-Tg) for patients who were to receive18F-fluorodeoxyglucose(18F-FDG) PET/CT scan owing to clinical suspicion of differentiated thyroid cancer(DTC) recurrence but negative post-therapeutic 131I whole-body scan(131I-WBS). A total of 60 qualified patients underwent PET/CT scanning from October 2010 to July 2014. The receiver operating characteristic(ROC) curve analyses showed that s-Tg levels over 49 μg/L led to the highest diagnostic accuracy of PET/CT to detect recurrence, with a sensitivity of 89.5% and a specificity of 90.9%. Besides, bivariate correlation analysis showed positive correlation between s-Tg levels and the maximum standardized uptake values(SUVmax) of18F-FDG in patients with positive PET/CT scanning, suggesting a significant influence of TSH both on Tg release and uptake of18F-FDG. So, positive PET/CT imaging is expected when patients have negative 131I-WBS but s-Tg levels over 49 μg/L.

^11C-methionine and ^18F-fluorodeoxyglucose positron emission tomography/CT in the evaluation of patients with suspected primary and residual/recurrent gliomas

Background ^18F-fluorodeoxyglucose （FDG） is the most widely used radiotracer in tumor imaging,but its use for brain gliomas and recurrence is limited by the high ^18F-FDG uptake in normal brain tissue.^11C-methionine （MET） has low uptake in the normal brain tissue,providing potential advantages over ^18F-FDG.The aim of the study was to investigate the diagnostic value of ^11C-MET compared to ^18F-FDG positron emission tomography and computed tomography （PET/CT） in patients with suspected primary and residual/recurrent gliomas.Methods Eighty paired PET/CT scans using ^11C-MET and 18F-FDG were performed on 44 newly diagnosed patients with suspected gliomas and 36 post-operative patients with suspected residual/recurrent tumors.PET/CT results were evaluated by visual and semiquantitative analysis.The sensitivity,specificity and accuracy for detection of gliomas and residual/recurrent tumors were calculated using visual analysis.Tumor to contralateral normal gray matter （T/G） ratio was calculated for semiquantitative analysis.Results Final pathology of the 44 newly diagnosed patients included 26 gliomas （14 high-grade and 12 low-grade tumors） and 18 non-glioma benign lesions.Residual/recurrent gliomas were verified in 28 patients and excluded in 8/36 post-operative patients by subsequent histopathologic examination and/or clinical follow-up for more than six months.The sensitivity,specificity and accuracy of 11C-MET PET/CT were 88.5%,83.3% and 86.4% for gliomas and 96.4%,87.5% and 94.4% for residual/recurrent gliomas,respectively.The sensitivity,specificity and accuracy of 18F-FDG PET/CT were 50.0%,88.9% and 65.9% for gliomas and 46.4%,100.0% and 58.3% for residual/recurrent gliomas,respectively.11C-MET had a higher sensitivity than 18F-FDG （83.3% vs.33.3%,P=0.031） in low-grade gliomas,but had no significant difference in sensitivity from 18F-FDG for high-grade gliomas （92.9% vs.64.3%,P=0.219）.11C-MET T/G uptake ratios in high-grade gliomas,low-grade gliomas and benign lesions were 1.94±0.53,1.78±0.61 and 1.06±0.34,respectively.18F-FDG T/G uptake ratios in high-grade gliomas,low-grade gliomas and benign lesions were 1.05±0.37,0.66±0.14 and 0.63±0.17,respectively.Conclusions 11C-MET PET/CT is superior to 18F-FDG PET/CT in detecting and delineating gliomas and residual/recurrent tumors,especially low-grade gliomas and residual/recurrent lesions present in gray matter,but its role in non-invasive grading of the tumors is limited.

Clinical applications of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary

Background Carcinoma of unknown primary （CUP） encompasses a heterogeneous group of tumors with varying clinical features. The management of patients of CUP remains a clinical challenge. The purpose of this study was to evaluate the clinical applications of integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography （FDG PET/CT） information in patients with CUP, including detecting the occult primary tumor and effecting on disease therapy.

DNA repair capacity correlates with standardized uptake values from 18F-fluorodeoxyglucose positron emission tomography/CT in patients with advanced non-small-cell lung cancer

Objective: The DNA repair capacity (DRC) of tumor cells is an important contributor to resistance to radiation and platinum-based drugs. Because DRC may be affected by tumor cell metabolism, we measured DRC in lymphocytes from patients with non-small-cell lung cancer (NSCLC) and compared the findings with the maximum standardized uptake value (SUVmax) on 18 F-fluorodeoxyglucose positron emission tomography (FDG PET) after (chemo)radiation therapy. Methods: This study included 151 patients with stage IA-IV NSCLC who had FDG PET at a single institution and donated blood samples before chemotherapy. We assessed the correlation of DRC, measured in peripheral T lymphocytes by a host-cell reac-tivation assay with SUVmax and their associations with overall survival (OS) time by hazards ratios calculated with a Cox pro-portional hazards regression model. Results: SUVmax of the primary tumor at diagnosis was inversely associated with lymphocyte DRC (r＝－0.175, P＝0.032), particularly among patients with advanced disease (r ＝ －0.218, P ＝ 0.015). However, △SUVmax of primary tumor was not significantly associated with DRC (r＝0.005, P＝0.968). SUVmax of regional lymph nodes at diagnosis (r＝－0.307, P＝0.0008) and after (chemo)radiation treatment (r＝－0.329, P＝0.034) and SUVmax of the primary tumor after (chemo)radiation treatment (r＝－0.253, P＝0.045) were also inversely associated with OS time. Conclusion: DRC was inversely associated with primary tumor SUVmax before treatment but not with △SUVmax after (chemo)radiation.

FLT-PET/CT在监测结肠癌早期放射疗效中作用的动物研究

目的评价18F-fluorothymidine(FLT)PET/CT在监测结肠癌早期放射疗效中的作用。方法分别应用MTT、流式细胞仪检测SW480、SW620细胞接受X-线照射20Gy后细胞生长、增殖周期的变化。建立SW480、SW620荷瘤鼠模型,分别于照射前及照射后24h、72h,经尾静脉注射FLT(20±1.84MBq/0.25ml)后行动物PET/CT扫描,利用感兴趣区(ROI)计算肿瘤组织与正常组织(T/NT)的比值。结果 X-线20Gy照射细胞后,SW480较SW620生长受到明显的抑制,细胞周期发生重新分布,72h后其S期细胞分别下降83.66%、45.23%。动物PET/CT扫描显示,FLT在SW480、SW620肿瘤内T/NT比值分别为3.65±0.51,2.22±0.42。照射20Gy后24hT/NT出现下降,72h后肿瘤T/NT分别下降了45.25%、29.28%。Western blot检测发现Ki67在SW480、SW620肿瘤内均有表达,其表达在照射后发生了不同程度的降低。结论结肠癌接受照射后,FLT在肿瘤内摄取的变化可以反映肿瘤细胞的增殖状态,FLT-PET/CT可以用来判断结肠癌放射治疗的早期反应。

Monitoring early responses to irradiation with dual-tracer micro-PET in dual-tumor bearing mice

AIM: To monitor the early responses to irradiation in primary and metastatic colorectal cancer (CRC) with 18 Ffluorothymidine ( 18 F-FLT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) small-animal position emission tomography (micro-PET). METHODS: The primary and metastatic CRC cell lines, SW480 and SW620, were irradiated with 5, 10 and 20, l l l , Gy. After 24 h, the cell cycle phases were analyzed. A dual-tumor-bearing mouse model of primary and metastatic cancer was established by injecting SW480 and SW620 cells into mice. micro-PET with 18 F-FLT and 18 F-FDG was performed before and 24 h after irradiation with 5, 10 and 20 Gy. The region of interest (ROI) was drawn over the tumor and background to calculate the ratio of tumor to non-tumor (T/NT) in tissues. Immunohistochemical assay and Western blotting were used to examine the levels of integrin β3, Ki-67, vascular endothelial growth factor receptor 2 (VEGFR2) and heat shock protein 27 (HSP27). RESULTS: The proportion of SW480 and SW620 cells in the G 2 -M phase was decreased with an increasing radiation dose. The proportion of SW480 cells in the G 0 -G 1 phase was increased from 48.33% ± 4.55% to 87.09% ± 7.43% (P < 0.001) and that of SW620 cells in the S-phase was elevated from 43.57% ± 2.65% to 66.59% ± 7.37% (P = 0.021). In micro-PET study, with increasing dose of radiation, 18 F-FLT uptake was significantly reduced from 3.65 ± 0.51 to 2.87 ± 0.47 (P = 0.008) in SW480 tumors and from 2.22 ± 0.42 to 1.76 ± 0.45 (P = 0.026) in SW620 tumors. 18 F-FDG uptake in SW480 and SW620 tumors was reduced but not significantly (F = 0.582, P = 0.633 vs F = 0.273, P = 0.845). Dose of radiation was negatively correlated with 18 F-FLT uptake in both SW480 and SW620 tumors (r = -0.727, P = 0.004; and r = -0.664, P = 0.009). No significant correlation was found between 18 F-FDG uptake and radiation dose in SW480 or SW620 tumors. HSP27 and integrin β3 expression was higher in SW480 than in SW620 tumors. The T/NT ratio for 18 F-FLT uptake was positively correlated with HSP27 and integrin β3 expression (r = 0.924, P = 0.004; and r = 0.813, P = 0.025). CONCLUSION: 18 F-FLT is more suitable than 18 F-FDG in monitoring early responses to irradiation in both primary and metastatic lesions of colorectal cancer.

Enhanced myocardial fluorodeoxyglucose uptake following Adriamycin-based therapy: Evidence of early chemotherapeutic cardiotoxicity?

AIM: To analyze changes in myocardial glucose metabolism using fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients treated with adriamycin and to investigate the clinical significance of these changes.METHODS: Considering that FDG-PET scanning has the ability to show changes in glucose metabolism in the myocardium, we retrospectively analyzed the FDGPET studies of 18 lymphoma patients treated with adriamycin-based chemotherapy in both the preand posttherapy setting. Cardiac contractile parameters such as left ventricular ejection fraction were not available for correlation in all patients due to the short duration and the level of cumulative dose administered in these patients during the time of the follow-up FDG-PET study. The change in myocardial glucose utilization was estimated by change in standard uptake values (SUV) in the myocardium.RESULTS: We observed a significant change in SUVmean values in the myocardium (defined as more than change in cardiac SUVmean between pre-and post-chemotherapy PET) in 1 patients, whereas 6 patients did not show any significant cardiac FDG uptake in both preand post-therapy PET scans. Patients were divided into three groups based on the changes observed in myocardial tracer uptake on the followup 18 F-FDG-PET study. Group A (n = 8): showed an increase in cardiac 18 F-FDG uptake in the post-therapy scan compared to the baseline scan carried out prior to starting adriamycin-based chemotherapy. Group B (n = 6): showed no significant cardiac 18 F-FDG uptake in post-therapy and baseline PET scans, and group C (n = 4): showed a fall in cardiac 18 F-FDG uptake in the posttherapy scan compared to the baseline scan. Mean cumulative adriamycin dose (in mg/m 2 ) received during the time of the follow-up FDG-PET study was 256. 25, 250 and 137.5, respectively.CONCLUSION: Our study shows three different trends in the change in myocardial glucose metabolism in patients undergoing adriamycin-based chemotherapy. A further prospective study with prolonged follow-up of ventricular function is warranted to explore the significance of enhanced FDG uptake as a marker of early identification of adriamycin-induced cardiotoxicity.

Nuclear medicine and the failed joint replacement: Past, present, and future

Soon after the introduction of the modern prosthetic joint,it was recognized that radionuclide imaging provides useful information about these devices.The bone scan was used extensively to identify causes of prosthetic joint failure.It became apparent,however,that although sensitive,regardless of how the images were analyzed or how it was performed,the test was not specific and could not distinguish among the causes of prosthetic failure.Advances in anatomic imaging,notably cross sectional modalities,have facilitated the diagnosis of many,if not most,causes of prosthetic failure,with the important exception of infection.This has led to a shift in the diagnostic paradigm,in which nuclear medicine investigations increasingly have focused on diagnosing infection.The recognition that bone scintigraphy could not reliably diagnose infection led to the development of combined studies,first bone/gallium and subsequently leukocyte/bone and leukocyte/marrow imaging.Labeled leukocyte imaging,combined with bone marrow imaging is the most accurate(about90%)imaging test for diagnosing joint arthroplasty infection.Its value not withstanding,there are significant disadvantages to this test.In-vivo techniques for labeling leukocytes,using antigranulocyte antibodieshave been explored,but have their own limitations and the results have been inconsistent.Fluorodeoxyglucose(FDG)-positron emission tomography(FDG-PET)has been extensively investigated for more than a decade but its role in diagnosing the infected prosthesis has yet to be established.Antimicrobial peptides bind to bacterial cell membranes and are infection specific.Data suggest that these agents may be useful for diagnosing prosthetic joint infection,but large scale studies have yet to be undertaken.Although for many years nuclear medicine has focused on diagnosing prosthetic joint infection,the advent of hybrid imaging with singlephoton emission computed tomography(SPECT)/electronic computer X-ray tomography technique(CT)and the availability of fluorine-18 fluoride PET suggests that the diagnostic paradigm may be shifting again.By providing the anatomic information lacking in conventional radionuclide studies,there is renewed interest in bone scintigraphy,performed as a SPECT/CT procedure,for detecting joint instability,mechanical loosening and component malpositioning.Fluoride-PET may provide new insights into periprosthetic bone metabolism.The objective of this manuscript is to provide a comprehensive review of the evolution of nuclear medicine imaging of joint replacements.

FDG-PET/CT and parathyroid carcinoma:Review of literature and illustrative case series

Parathyroid cancer is an uncommon malignant cancer and is associated with a poor prognosis.The staging of parathyroid cancer represents an important issue both at initial diagnosis and after surgery and medical treatment.The role of positron emission tomography/computed tomography(PET/CT)with 18F-Fluorodeoxyglucose(18F-FDG)as an imaging tool in parathyroid cancer is not clearly reported in the literature,although its impact in other cancers is well-defined.The aim of the following illustrative clinical cases is to highlight the impact of PET/CT in the management of different phases of parathyroid cancer.We describe five patients with parathyroid malignant lesions,who underwent FDG PET/CT at initial staging,restaging and post-surgery evaluation.In each patient we report the value of PET/CT comparing its findings with other common imaging modalities(e.g.,CT,planar scintigraphy with 99mTcsestamibi,magnetic resonance imaging)thus determining the complementary benefit of FDG PET/CT in parathyroid carcinoma.We hope to provide an insight into the potential role of PET/CT in assessing the extent of disease and response to treatment which are the general principles used to correctly evaluate disease status.

Clinical relevance of fluorodeoxyglucose positron emission tomography/computed tomography and magnifying endoscopy with narrow band imaging in decision-making regarding the treatment strategy for esophageal squamous cell carcinoma

BACKGROUND Recent advances in endoscopic technology,especially magnifying endoscopy with narrow band imaging(ME-NBI)enable us to detect superficial esophageal squamous cell carcinoma(ESCC),but determining the appropriate method of resection,endoscopic resection(ER)vs surgical resection,is often challenging.Recently,several studies have reported that 18F-fluorodeoxyglucose positron emission tomography(FDG-PET)is a useful indicator for decision-making regarding treatment for superficial ESCC.Although,there are not enough reports on association between FDG-PET uptake and clinicopathological characteristics of superficial ESCC.And,there are not enough reports on evaluating the usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.This study evaluated clinical relevance of FDG-PET and ME-NBI in decision-making regarding the treatment strategy for ESCC.AIM To investigate the association between FDG uptake and the clinicopathological characteristics of superficial ESCC and its usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.METHODS A database of all patients with superficial ESCC who had undergone both MENBI and FDG-PET for pre-treatment staging at Aichi Cancer Center Hospital between January 2008 and November 2018 was retrospectively analyzed.FDG uptake was defined positive or negative whether the primary lesion was visualized or could be distinguished from the background,or not.The invasion depth of ESCC was classified according to the Japan Esophageal Society.Primary endpoint is to evaluate the association between FDG uptake and clinicopathological characteristics of superficial ESCC.Secondary endpoint is to investigate the efficacy of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.RESULTS A total of 82 lesions in 82 patients were included.FDG-PET showed positive uptake in 29(35.4%)lesions.Univariate analysis showed that uptake of FDG-PET had significant correlations with circumferential extension(P=0.014),pathological depth of tumor invasion(P<0.001),infiltrative growth pattern(P<0.001),histological grade(P=0.002),vascular invasion(P=0.001),and lymphatic invasion(P<0.001).On multivariate analysis,only depth of tumor invasion was independently correlated with FDG-PET/computed tomography visibility(P=0.018).The sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy of Type B2 in ME-NBI for the invasion depth of T1a muscularis mucosae and T1b upper submucosal layer were 68.4%/79.4%/50.0%/89.3%/76.8%,respectively,and those of Type B3 for the depth of T1b middle and deeper submucosal layers(SM2 and SM3)were 46.7%/100%/100%/89.3%/90.2%,respectively.On the other hand,those of FDGPET for SM2 and SM3 were 93.3%/77.6%/48.2%/98.1%/80.5%,respectively,whereas,if the combination of positive FDG uptake and type B2 and B3 was defined as an indicator for radical esophagectomy or definitive chemoradiotherapy,the sensitivity,specificity,PPV,NPV,and accuracy were 78.3%/91.5%/78.3%/91.5%/87.8%,respectively.CONCLUSION FDG uptake was correlated with the invasion depth of superficial ESCC.Combined use of FDG-PET and ME-NBI,especially with the microvascular findings of Type B2 and B3,is useful to determine whether ER is indicated for the lesion.