18F-FDG PET/CT in primary central nervous system lymphoma in HIV-negative patients

OBJECTIVE: To determine the value of F-FDG PET/CT in the different manifestations of primary central nervous system lymphoma (PCNSL) in HIV-negative patients. METHODS: All PCNSL and HIV-negative patients referred for PET/CT in our institution from July 2001 to June 2006 were retrospectively studied. PET/CT examinations were reviewed by two experienced readers and evaluated for each possible anatomical site of nervous system involvement: cerebral, spinal/nerve and ocular. PET/CT results were characterized as true positive or negative and false positive or negative according to the status of the disease, which was determined after the evaluation of biopsies, laboratory, clinical and imaging examinations, and follow-up. RESULTS: Forty-two PET/CT examinations were carried out in 25 PCNSL patients. For intracerebral disease, PET/CT was true positive in 13 cases, true negative in 27 and false negative in two. For disease involving spinal cord and/or nerves, PET/CT was true positive in four cases, true negative in 37 and false negative in one. For ocular disease, PET was true positive in only one case and false negative in four. The sensitivity of PET/CT in detecting active disease in the brain was 87% (13/15), in the spine/nerves 80% (4/5), and in the eyes only 20% (1/5). CONCLUSION: PET/CT seems to be sensitive for the detection of viable intracerebral as well as for spinal and peripheral nerve disease, but not for the detection of ocular involvement.     

^13N—NH3·H2O联合^18F-FDG显像鉴别诊断原发性中枢神经系统淋巴瘤和胶质瘤

目的探讨^13N-NH3·H2O联合^18F—FDGPET／CT显像在鉴别原发性中枢神经系统淋巴瘤（PCNSL）和胶质瘤中的价值。方法对2010年1月至2012年7月就诊的10例PCNSL患者[男7例,女3例,年龄43—74（59．10±12．47）岁]和15例胶质瘤患者[男8例,女7例,年龄14～72（46．73±19．61）岁]进行^13N-NH3·H2O和^18F—FDGPET／CT显像。以肿瘤与脑灰质摄取比（T／G）评价肿瘤的放射性摄取量。采用两样本t检验比较不同肿瘤对显像剂的摄取差异,通过判别函数分析两者联合的诊断效果。结果PCNSL组^18F—FDG的T／G值明显高于胶质瘤组,分别为3．27±1．21和1．57±0．39（t=5．630,P〈0．001）,而PCNSL组^13N—NH3·H2O的T／G值明显低于胶质瘤组,分别为1．43±0．26和2．12±0．69（t=-3．551,P〈0．01）。相对于^13N—NH3·H2O的T／G值,所有PCNSL病灶（14个）均表现为高的^18F-FDGT／G值,而77．8％（14／18）的胶质瘤病灶则显示相反的结果。利用判别函数分析,2种显像剂联合对肿瘤分类的整体准确性达96．9％（31／32）,仅1例胶质瘤病灶误判为PCNSL。结论^13N-NH3·H2O联合^18F-FDG有助于鉴别PCNSL和胶质瘤。     

The diagnostic role of 18F-FDG PET for primary central nervous system lymphoma

Objective

¹⁸F-FDG PET has become one of the most important methods for studying malignant lymphoma, but its diagnostic role for primary central nervous system lymphoma (PCNSL) has not been established. The aim of this study was to determine the appropriate cut-off values of FDG uptake and to investigate how corticosteroid administration influences PCNSL.

Methods

We retrospectively reviewed 82 patients with contrast-enhanced brain tumors who underwent an FDG PET scan at onset, including 19 PCNSLs. FDG uptake of the lesion was assessed by the maximum standardized uptake value (SUVmax) and the ratio of tumor to normal contralateral cortex activity (T/N ratio). Receiver operating characteristic (ROC) curves were generated from the SUVmax and T/N ratios. To investigate the influence of corticosteroid application before a FDG PET scan, we evaluated the association between the FDG uptake of the lesion and the cumulative dose of corticosteroid administration on 13 PCNSL patients who had received steroid treatment before an FDG PET examination.

Results

The mean FDG SUVmax and T/N ratio of PCNSLs were 22.6 and 2.79, respectively, and these values were significantly higher than those of the other malignant brain tumors. ROC analysis indicated that the evaluation of FDG uptake using the T/N ratio was more reliable than the SUVmax with respect to the differential diagnosis. When PCNSL patients went without steroid application before FDG PET, the accuracy of the T/N ratio with a cut-off point of 2.0 was 91.1 %, the sensitivity was 94.7 %, and the specificity was 87.3 %. Although there are no significant differences in the FDG T/N ratio for PCNSL patients with or without steroid treatment, a negative correlation was found between the T/N ratio and cumulative dose of corticosteroid before PET study (r = ?0.71, p = 0.032).

Conclusions

We concluded that the T/N ratio was superior to SUVmax for FDG uptake assessment as for distinguishing PCNSLs from other malignant brain tumors; the appropriate T/N ratio cut-off point was 2.0. In addition, FDG uptake could be influenced by cumulative doses of corticosteroid before a PET scan, and thus this fact should be taken into consideration when evaluating FDG PET for PCNSL diagnosis.     

Cosmetic-related changes on 18F-FDG PET/CT

We present 4 cases of cosmetic-related changes on 18F-FDG PET/CT. These cases represent post-treatment changes from facial juvederm injection, silicone injection in the chest wall and gluteal areas, paraffin injection in the gluteal region, and liposuction. Recognition of cosmetic-related changes and their appearance on PET and CT will help to avoid potential false-positive interpretations.     

18F-FDG PET/CT of cervical carcinoma

OBJECTIVE: This article outlines the role of FDG PET/CT in patients with cervical carcinoma for evaluating tumor extent, assessing treatment response, and detecting disease recurrence. CONCLUSION: There is increasing evidence that FDG PET/CT has a role in the primary evaluation of cervical carcinoma-in particular, for evaluating lymph node status and distant metastatic disease. PET/CT is also helpful to determine prognosis, assess treatment response, and evaluate disease recurrence.     

18F-FDG PET/CT and COVID-19

European Journal of Nuclear Medicine and Molecular Imaging -     

Use of F-18 FDG PET/CT in non-Hodgkin lymphoma with central nervous system involvement

Central nervous system (CNS) is a rare site of involvement by non-Hodgkin lymphoma (NHL). Therapeutic approach for primary and secondary CNS NHL is different and remains challenging. Therefore imaging data are essential at staging to discriminate these 2 clinical entities and during follow-up to assess therapy response. The adjunct role of positron emission tomography using F-18 fluorodeoxyglucose to morphologic imaging is still undefined. We report 2 didactic cases of primary and secondary CNS NHL assessed by F-18 fluorodeoxyglucose positron emission tomography. Metabolic imaging seems to be complementary to conventional imaging techniques for the extent-of-disease evaluation and therapy monitoring of CNS lesions.     

Complementary roles of 18F-DOPA PET/CT and 18F-FDG PET/CT in medullary thyroid cancer

Serum calcitonin and carcinoembryonic antigen (CEA) are markers of recurrent or persistent disease in medullary thyroid cancer (MTC). However, conventional imaging often fails to localize metastatic disease. Our aim was to compare fluorine-labeled dihydroxyphenylalanine ((18)F-DOPA) and (18)F-FDG PET/CT with multidetector CT (MDCT) and MRI in recurrent or persistent MTC. METHODS: Nineteen MTC patients with increased calcitonin or CEA on follow-up (mean ± SD, 93 ± 91 mo; range, 4-300 mo) after primary therapy were prospectively imaged with 4 techniques: (18)F-DOPA PET/CT, (18)F-FDG PET/CT, MDCT, and MRI. Images were analyzed for pathologic lesions, which were surgically removed when possible. The correlation between the detection rate for each method and the calcitonin and CEA concentrations and histopathologic findings was investigated. Results: On the basis of histology and follow-up, one or more imaging methods accurately localized metastatic disease in 12 (63%) of 19 patients. The corresponding figures for (18)F-DOPA PET/CT, (18)F-FDG PET/CT, MDCT, and MRI were 11 (58%) of 19, 10 (53%) of 19, 9 (47%) of 19, and 10 (59%) of 17, respectively. Calcitonin and CEA correlated with (18)F-DOPA PET/CT (P = 0.0007 and P = 0.0263, respectively) and (18)F-FDG PET/CT findings (both P < 0.0001). In patients with an unstable calcitonin doubling time (n = 8), (18)F-DOPA and (18)F-FDG PET/CT were equally sensitive. In contrast, for patients with an unstable CEA doubling time (n = 4), (18)F-FDG PET/CT was more accurate. CONCLUSION: For most MTC patients with occult disease, (18)F-DOPA PET/CT accurately detects metastases. In patients with an unstable calcitonin level, (18)F-DOPA PET/CT and (18)F-FDG PET/CT are complementary. For patients with an unstable CEA doubling time, (18)F-FDG PET/CT may be more feasible. MRI is sensitive but has the highest rate of false-positive results.     

18F-FDG PET/CT在颅内原发性中枢神经系统淋巴瘤诊断中的价值

目的 探讨18F-FDG PET/CT显像视觉和半定量分析在颅内原发性中枢神经系统淋巴瘤(PCNSL)诊断中的价值。 方法 回顾性分析2011年5月至2018年12月于郑州大学第一附属医院行18F-FDG PET/CT检查的45例颅内PCNSL患者[男性26例、女性19例,年龄（57.49±2.54）岁]的影像资料,并分别与52例脑胶质瘤和60例脑转移瘤患者进行对比,采用视觉分析3组患者的病灶分布和形态特征,半定量分析最大标准化摄取值（SUV_max）、肿瘤与对侧相应部位脑组织SUV_max的比值（T/WM）,评价18F-FDG PET/CT在颅内PCNSL诊断中的价值。2组间半定量结果的比较采用独立样本t检验和校正后t检验,2组间诊断效能的比较及鉴别诊断阈值的判断采用受试者工作特征（ROC）曲线进行分析。 结果 视觉分析结果显示,颅内PCNSL以高摄取18F-FDG的幕上、单发、结节状或团块状病灶为多见,水肿、占位效应及瘤内继发改变不明显。半定量分析结果显示,与脑胶质瘤和脑转移瘤相比,颅内PCNSL的SUV_max最高（脑胶质瘤:9.96±0.48;脑转移瘤:11.97±0.58;颅内PCNSL:26.42±1.17,t=13.02、11.07,均P=0.000）,T/WM亦最高（脑胶质瘤:2.99±0.09;脑转移瘤:2.60±0.08;颅内PCNSL:4.37±0.10,t=10.13、13.88,均P=0.000）,且差异均有统计学意义。当SUV_max=15.8时,颅内PCNSL与脑胶质瘤鉴别诊断的ROC曲线下面积（AUC）最大（0.982）,而当SUV_max=16.8时,颅内PCNSL与脑转移瘤鉴别诊断的AUC最大（0.946）;T/WM=3.395为颅内PCNSL与脑胶质瘤鉴别诊断的最佳阈值,T/WM＝3.220为颅内PCNSL与脑转移瘤鉴别诊断的最佳阈值。 结论 18F-FDG PET/CT显像可以作为传统影像学诊断颅内PCNSL的有效补充,同时在颅内PCNSL与脑胶质瘤和脑转移瘤的鉴别诊断方面具有显著优势。     

自身免疫性胰腺炎的18F-FDG PET/CT影像学特点

目的 探讨18F-FDG PET/CT在自身免疫性胰腺炎(AIP)诊断中的影像学特点及应用价值.方法 回顾性分析2005年至2012年6例AIP患者[均为男性,51～78(平均69)岁]治疗前的18 F-FDG PET/CT影像学特征(其中2例具备激素治疗前后的PET/CT影像资料).目测分析判定胰腺形态异常,并以肝脏为标准对胰腺放射性摄取进行评分(高于肝脏为3分,与肝脏近似为2分,低于肝脏为1分).半定量分析测定常规及延迟显像的胰腺SUV,并采用SPSS 17.0软件将延迟显像前后的SUV进行配对t检验.结果 6例AIP患者胰腺均表现为弥漫性增大,放射性摄取均呈弥漫斑片状分布,其中5例为3分,1例为2分,SUVmax3.2～6.0(5.2±1.1);5例延迟显像中,4例SUVmax增高,1例保持不变,延迟后SUVmax5.3～7.2,延迟显像前后SUVmax差异无统计学意义(4.8～6.0:t =-2.424,P＞0.05).5例出现胰腺外异常摄取,以颌下腺为著.2例治疗后显像者其胰腺均缩小,胰腺及胰腺外摄取灶SUV恢复正常.结论 18F-FDG PET/CT能够反映AIP胰腺和胰腺外代谢活性异常及治疗前后的病灶代谢变化,有助于AIP的诊断、鉴别诊断及疗效评价.     

18F-FDG PET/CT findings of pharyngeal tuberculosis

A 58-year-old woman with dysphagia and hoarseness underwent 18F-FDG PET/CT to detect the original lesion and disease spread. Bilateral cervical lymphadenopathy and abnormal FDG uptakes in the right tonsil and pharyngeal wall were demonstrated. CT and MRI confirmed the bilateral cervical lymphadenopathy and mucosal thickening in the pharyngeal wall. On the basis of these findings, biopsy sites were selected. Pharyngeal tuberculosis was diagnosed based on culture of the biopsy specimens. 18F-FDG PET/CT contributed to clinical management in this case by detecting tuberculous lesions and showing the extent of these lesions in one examination.     

~(18)F-FDG PET/CT在食管癌的应用进展

食管癌恶性程度高、预后差,严重威胁了人类健康,18F-FDG PET/CT集功能和解剖信息于一身,这种医学影像技术在食管癌的应用优势日益受到广大医务工作者的关注。本文综述了18F-FDG PET/CT在食管癌的诊断、分期、复发、疗效和预后评估、放射治疗计划制定等方面的研究进展。     

多发性骨髓瘤的18F-FDGPET/CT诊断

目的:多发性骨髓瘤是一种浆细胞恶性增殖性疾病,大约有80％的患者存在骨骼侵犯.本文探讨多发性骨髓瘤的18F-fluorodexoxyglucose(18F-FDG)PET/CT表现特点,提高对多发性骨髓瘤的认识.方法:26例按2001年WHO诊断标准确诊为多发性骨髓瘤的患者,均在治疗前行18F-FDG PET/CT显像.所有患者均依赖骨髓穿刺或活检取得明确病理学诊断.结果:26名患者均出现不同程度的骨质疏松.25例患者出现多发性骨质破坏,占总数的96.2％;其中11例患者出现颅骨破坏,占42.3％;25例出现脊柱骨质破坏,占96.2％;15例出现胸骨骨质破坏,占57.7％;21例出现肋骨骨质破坏,占80.8％;21例出现骨盆骨质破坏,占80.8％.部分骨破坏病灶呈18F-FDG高代谢灶.结论:多发性骨髓瘤的18F-FDG PET/CT表现具有一定特征,结合临床、影像、实验室和病理学检查能提高本病的诊断率.     

Imaging of proliferation with 18F-FLT PET/CT versus 18F-FDG PET/CT in non-small-cell lung cancer

Purpose  

To compare the diagnostic efficacies of ¹⁸F-FLT and ¹⁸F-FDG PET/CT in non-small-cell lung cancer (NSCLC), focusing on the correlation between FLT and FDG tumour uptake and tumour cell proliferation as indicated by the cyclin D1 labelling index.