Can 18F-FDG PET improve the evaluation of suspicious breast lesions on MRI?

Objective

To evaluate the impact of adding 18F-fluorine-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the evaluation of suspicious breast lesions on magnetic resonance imaging (MRI).

Methods

Sixty patients with suspicious breast lesions on MRI were selected to perform a PET–CT in prone position, dedicated to the evaluation of the breasts. The areas with increased 18F-FDG concentration relative to normal parenchyma were considered positive on PET–CT. Fusion of PET and MRI images (PET–MRI) was performed on a dedicated workstation to better locate corresponding lesions, and its findings were compared with histological results.

Results

76 lesions were evaluated, including 64 mass lesions (84.2%) and 12 non-mass lesions (15.8%). Lesions’ mean diameter on MRI was 29.6 ± 19.2 mm (range 6–94 mm). PET–CT showed increased metabolically activity on 57 lesions (75.0%), with mean maximum SUV of 5.7 ± 5.0 (range 0.8–23.1). On histopathology, there were 17 (22.4%) benign and 59 (79.7%) malignant lesions. Considering all lesions, PET–MRI fusion provided 89.8% sensitivity, 76.5% specificity and 86.8% accuracy. Considering only mass lesions higher than 10 mm, PET–MRI fusion provided 95.8% sensitivity, 83.3% specificity and 93.3% accuracy.

Conclusion

The inclusion of 18F-FDG PET on the evaluation of suspicious breast lesions on MRI helped to differentiate benign from malignant breast lesions, especially for mass lesions with a diameter higher than 10 mm.     

Role of 18F-FDG PET/CT for detection of recurrence and metastases in renal cell carcinoma—are we underusing PET/CT?

PURPOSEThe aim of this study was to compare ¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography (¹⁸F-FDG PET/CT) scan with computed tomography (CT) scan for detecting recurrence and metastasis in renal cell carcinoma patients.METHODSThis retrospective study included patients from October 2013 to April 2017. Contrast-enhanced CT and PET/CT scans were compared and correlated with histopathology or/and follow-up studies.RESULTSSeventy-six patients, 60 males, were included. Lesions included primary renal, recurrent renal fossa lesions, lymph nodes, and distant metastatic lesions. Of 176 malignant lesions, CT detected 157 lesions; of which, 154 were true positive. Twenty-two false-negative lesions showed abnormal FDG uptake. CT scan had positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity, and accuracy of 98.0%, 37.1%, 87.5%, 81.2%, and 86.9%, respectively. All 176 lesions were PET/CT-positive. PET/CT had PPV, NPV, sensitivity, specificity, and accuracy of 100% each. The specificity and NPV of PET/CT were superior (P < .05). CONCLUSIONPET/CT appears more accurate than CT scan for detecting metastasis and recurrence in renal cell carcinoma patients.

Main points

• Positron emission tomography–computed tomography (PET/CT) has a significantly higher specificity and negative predictive value than CT scan for detection of metastasis and recurrence in patients with renal cell carcinoma.
• PET/CT scan is a better imaging technique compared to CT scan for follow-up imaging.

Renal cell carcinoma (RCC) is the most common solid kidney cancer. The incidence in Asian population is 1.1-6.0/100 000. World over, the 5-year survival rate is 68.4%.¹Localized RCC patients treated surgically usually have favorable outcomes. However, about 20%-40% patients later develop distant metastases. The main aim of postoperative follow-up is early detection of local recurrence and/or distant metastases. Post-surgery follow-up imaging is commonly done with conventional imaging modalities (CIM), mainly computerized tomography (CT) scan. These have certain limitations in assessing local recurrence due to postoperative changes such as fibrosis, adjacent organs occupying the space of the renal fossa, the presence of surgical clips causing metallic artifacts, and other such changes.About one-fourth of the patients are found to be metastatic at initial presentation, with very few (<5%) having single-site metastasis.²¹⁸F-fluorodeoxyglucose positron emission tomography–computed tomography scan (¹⁸F-FDG PET/CT) provides both anatomical details and functional information. PET/CT has better specificity (83%-100%) and sensitivity (80%-100%) as compared with CT scan or PET scan alone.^2-5 PET/CT is particularly useful for detection of involvement of lymph nodes. These are often not identified on CT scan (even though they are involved), which uses the 1 cm size criteria. CT interpretation of the renal fossa (post-nephrectomy) is difficult due to post-treatment changes. However, the metabolic activity of the tumor is not affected by these factors. Therefore, PET/CT can identify renal bed recurrence earlier and better than CT scan.³During the initial staging of RCC, contrast-enhanced CT scan of the chest, abdomen, and pelvis is the modality of choice. However, PET/CT scan images the whole body (head to toe) along with a contrast-enhanced CT examination in one procedure non-invasively. Since PET/CT relies on changes in metabolic activity of tissues, early detection of pathological areas is possible even before anatomic changes are apparent.³In cases with impaired renal function, a regional abdomino pelvic magnetic resonance imaging (MRI) is the preferred imaging choice due to its high soft-tissue resolution as many lesions can be missed on a non-contrast CT scan. Now in such cases, whole-body PET/CT scan can also be performed with non-contrast CT. Current guidelines do not recommend PET/CT as the initial diagnostic imaging modality of choice in RCC. However, studies have shown PET/CT to be better than conventional imaging like CT for detecting local recurrence and distant metastases.² Detection of distant metastases and accurate restaging of RCC are important because this can lead to changes in the treatment plan.We conducted this study to compare CT scan with PET/CT for detecting recurrence and metastasis in RCC patients.     

What can 3D CT angiography add in evaluation of facial vascular lesions?

Purpose

To demonstrate the value of 3D CT angiography (CTA) in the evaluation of facial vascular lesions regarding diagnosis, characterization and full extensions compared to conventional 2D CTA.

Patients and methods

This prospective study included 16 patients with facial vascular lesions with ages that range from 1 to 45 years and mean age of 23 years, patients performed CT angiography (2D and 3D) utilizing the coronal and sagittal MPR and VR techniques. Lesions were evaluated by both 2D and 3D sequences regarding characterization and complete extension including intracranial extension. Our results were correlated with maxillofacial and plastic surgery results.

Results

Among the 16 patients, 7 had hemangiomas, 5 had AVMs and 4 had AVFs. In hemangiomas, 2D successfully evaluated (regarding diagnosis, characterization and full extensions) 5 patients (71.5%) and 2 patients were in doubt regarding diagnosis, while 3D CTA successfully evaluated all the patients (100%). In AVMs, 2D CTA successfully evaluated 4 patients (80%), one patient was in doubt regarding intracranial extension, while 3D CTA successfully evaluated all the patients (100%). In AVFs, 2D and 3D CTA successfully evaluated all the patients (100%). For all cases, diagnostic accuracy of 2D CTA was 81.3%, while diagnostic accuracy of 3D CTA was 100%.

Conclusion

CTA offered noninvasive excellent angiographic imaging modality of the facial vascular lesions. The 3D CTA in particular (with high spatial and temporal resolution) provided distinct features that enabled excellent lesion detection, characterization, visualization of feeding arteries and draining veins and complete extensions. The 3D CTA allowed accurate differentiation of hemangiomas from AVMs that is sometimes difficult using clinical examination and 2D CTA. The 3D CTA plays an important role in extension evaluation, treatment planning (through full orientation of vascular tree) and follow up, thus eliminates the need for invasive DSA.     

Can multimodality imaging using 18F-FDG/18F-FLT PET/CT benefit the diagnosis and management of patients with pulmonary lesions?

Purpose

Dual-tracer, ¹⁸F-fluorodeoxyglucose and ¹⁸F-fluorodeoxythymidine (¹⁸F-FDG/¹⁸F-FLT), dual-modality (positron emission tomography and computed tomography, PET/CT) imaging was used in a clinical trial on differentiation of pulmonary nodules. The aims of this trial were to investigate if multimodality imaging is of advantage and to what extent it could benefit the patients in real clinical settings.

Methods

Seventy-three subjects in whom it was difficult to establish the diagnosis and determine management of their pulmonary lesions were prospectively enrolled in this clinical trial. All subjects underwent ¹⁸F-FDG and ¹⁸F-FLT PET/CT imaging sequentially. The images were interpreted with different strategies as either individual or combined modalities. The pathological or clinical evidence during a follow-up period of more than 22?months served as the standard of truth. The diagnostic performance of each interpretation and their impact on clinical decision making was investigated.

Results

¹⁸F-FLT/¹⁸F-FDG PET/CT was proven to be of clinical value in improving the diagnostic confidence in 28 lung tumours, 18 tuberculoses and 27 other benign lesions. The ratio between maximum standardized uptake values of ¹⁸F-FLT and ¹⁸F-FDG was found to be of great potential in separating the three subgroups of patients. The advantage could only be obtained with the full use of the multimodality interpretation. Multimodality imaging induced substantial change in clinical management in 31.5% of the study subjects and partial change in another 12.3%.

Conclusion

Multimodality imaging using ¹⁸F-FDG/¹⁸F-FLT PET/CT provided the best diagnostic efficacy and the opportunity for better management in this group of clinically challenging patients with pulmonary lesions.     

18F-FDG PET/CT与18F-FDG PET/MRI在卵巢癌临床应用中的进展

卵巢癌是妇科恶性肿瘤中病死率最高的肿瘤。18F-FDG PET/CT在卵巢癌的诊断、分期、疗效及预后的评估上优于常规影像技术,可以指导临床采取有针对性的治疗方案,以获得更好的治疗效果。PET/MRI是最近几年继PET/CT后投入临床应用的另外一种多模态影像技术,因其多序列成像、软组织分辨率较高和辐射剂量较低,对卵巢癌的诊治具有独特的优势。笔者对18F-FDG PET/CT和18F-FDG PET/MRI在卵巢癌中的临床应用进行综述。     

核医学18F-FDG PET/CT报告书写规范

随着正电子发射计算机断层显像/计算机断层显像(positron emission tomography/computed tomography, PET/CT)临床应用的增加,氟-18标记氟代脱氧葡萄糖(flurodeoxyglucose,18F-FDG)PET/CT的诊断作用得到了临床的广泛认可.18F-FDG PE...     

胆管癌的18F-FDG PET/CT诊断价值

目的 总结胆管癌18F-FDG PET/CT显像表现,提高胆管癌的诊断准确性.方法 回顾经病理或临床综合手段证实的53例胆道疾病的18F-FDG PET/CT表现,分析PET/CT诊断胆管癌的敏感性、特异性和准确性.结果 肝内胆管癌14例、近段胆管癌18例、中远段胆总管癌15例、胆管炎性病变或伴结石6例.肝内转移9例,腹腔及腹膜后淋巴结转移15例,椎体等远处转移3例.PET/CT诊断胆管癌的敏感性为95.7％、特异性为83.3％、准确性为94.3％.结论 18F-FDG PET/CT在胆管癌的诊断与鉴别诊断、分期、检测疗效及预后等具有独特的应用价值.     

18F-FDG PET/CT探测恶性肿瘤软组织转移

笔者对11例患者16处软组织转移瘤(原发灶均经病理检查证实,软组织转移灶均经临床或病理检查证实)的PET/CT、临床资料进行回顾性分析,以提高对PET/CT在软组织转移瘤中价值的认识.     

结核病的18F-FDG PET/CT诊断辨析

结核病可以发生于全身多个脏器,且有多种多样的影像学表现,因此结核病与其他全身性疾病（尤其是肿瘤性疾病）的鉴别较为困难。18F-FDG PET/CT在全身性疾病的诊断中有一定优势,但工作中仍需结合患者的临床表现、实验室检查、病灶的CT征象及18F-FDG浓聚程度等信息进行辨析。笔者选取了临床实践中误诊的3个病例,分别为肠结核、肺结核和骨结核,分别从临床特征及18F-FDG PET/CT影像学表现等方面进行鉴别诊断,梳理诊断思路,以期为临床诊断提供帮助。     

18F-FDG PET/CT显像中的脂肪摄取

单纯PET图像难以区分脂肪或肌肉组织摄取^18F-脱氧葡萄糖（FDG）及是否为病理性摄取，CT特异性脂肪密度为其定性诊断提供了有力的佐证。现将本院在^18F-FDG PET/CT检查中的12例脂肪摄取病例报道如下。     

PET/CT evaluation of 18F-FDG uptake in pericoronary adipose tissue in patients with stable coronary artery disease: Independent predictor of atherosclerotic lesions' formation?

Journal of Nuclear Cardiology - Inflammatory infiltrations in EAT which releases inflammatory cytokines correspond anatomically to the atheromatous plaques in underlying coronary vessels. However,...     

18F-FDG PET/CT诊断多发癌的价值

目的 探讨18F-FDG PET/CT在多发癌诊断中的价值。 方法 回顾性分析5822例疑似肿瘤患者,均行18F-FDG PET/CT全身检查,经过活检或手术证实为多发癌患者32例。以病理结果作为金标准,以PET平均标准化摄取值（SUV_mean）≥2.5且CT上有形态学改变者作为PET/CT判断恶性肿瘤的标准,计算PET/CT诊断多发癌的灵敏度和准确率。 结果 本组患者中多发癌的发生率为0.55%,其中,双发癌30例、三发癌2例,共66个原发灶。32例多发癌的66个原发灶的SUV_mean的平均值为6.68±3.61。PET/CT诊断多发癌原发灶真阳性为58个,假阴性为8个。PET/CT诊断多发癌的灵敏度为87.9%,准确率为87.9%。 结论 18F-FDG PET/CT全身检查诊断多发癌具有较大价值。     

18F-FDG PET/CT在淋巴瘤诊治中的研究进展

淋巴瘤是一种可累及全身淋巴结及结外组织的恶性肿瘤。18F-FDG PET/CT在淋巴瘤的诊断、分期、再分期、疗效评估、预后判断、指导治疗等方面的价值被广泛认可。就18F-FDG PET/CT在淋巴瘤的诊治过程中的研究进展进行综述,总结其优势与不足,并从研发新型显像剂、制定精准的疗效评估标准和预后判断方法,以及治疗中期的检查时间选择的角度出发,对未来的研究进行展望。     

18F-FDG PET/CT在宫颈癌诊断中的应用

目的 探讨18F-脱氧葡萄糖(FDG) PET/CT在宫颈癌诊断及其复发、转移灶探测中的应用价值.方法 88例患者行腹部或全身18F-FDG PET/CT显像,其中初诊者30例(宫颈良性病变11例,宫颈癌19例),宫颈癌治疗后58例.病灶根据病理检查、多种影像诊断技术及临床随访确诊,随访时间均为6个月～3年.结果 30例初诊者中,PET/CT诊断宫颈癌的灵敏度、特异性和准确性分别为17/19,10/11和27/30(90.0%).58例治疗后患者中,11例存在肿瘤复发或残余,PET/CT诊断肿瘤复发、残余的灵敏度、特异性和准确性分别为10/11,47/47(100.0%)和57/58(98.3%).41例有肿瘤转移,PET/CT诊断转移灶的灵敏度、特异性和准确性分别为92.7%,88.9%和90.9%;转移灶以盆腹腔淋巴结为主,39.0%有盆腔淋巴结转移,27.3%有腹膜后淋巴结转移,所有淋巴结转移患者中PET/CT发现26.8%病灶直径＜1.0cm.28.6%(22/77)的患者PET/CT发现腹腔外远处转移灶.18例输尿管梗阻患者中,16例PET/CT发现为肿瘤侵犯压迫所致.结论 18F-FDG PET/CT显像在宫颈癌的诊断及其复发、转移灶探测中有良好的应用价值,尤其是对远处转移灶和小淋巴结转移灶的检测,可使临床分期更准确.     

18F-FDG PET/CT在黑色素瘤中的应用价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT显像在黑色素瘤诊断、临床分期及监测治疗后肿瘤复发与转移灶中的应用价值.方法 黑色素瘤患者61例,均进行18F-FDG PET/CT全身显像.所有PET、CT及PET/CT融合图像均通过融合软件进行帧对帧对比分析.肿瘤病灶根据病理学检查、多种影像学检查及临床随访结果诊断.结果 18F-FDG PET/CT显像对黑色素瘤病灶检出的灵敏度、特异性和准确性分别为90.9%(40/44)、88.2%(15/17)和90.2%(55/61).其中12例治疗前患者中,18F-FDG PET/CT显像诊断的灵敏度为83.3%(10/12).在黑色素瘤病灶局部切除、尚未进行其他治疗的9例患者中,5例残余病灶18F-FDG PET/CT显像检出3例;4例远处转移灶患者全被检出,提高了临床分期,改变了治疗方案.首先发现转移性黑色素瘤病灶并且手术切除后,寻找原发灶的7例患者中,18F-FDG PET/CT检出原发灶2例,4例其他转移灶全被检出.黑色素瘤患者根治术后监测肿瘤复发或转移患者33例,18F-FDG PET/CT显像灵敏度、特异性和准确性分别为100.0%(19/19)、85.7%(12/14)和93.9%(31/33).与同期临床其他影像学检查比较,18F-FDG PET/CT显像发现更多,33例患者中,16例(48.5%)病灶提高临床分期;7例(21.2%)排除可疑病灶,降低临床分期;10例(30.3%)检出病灶与临床一致.结论 18F-FDG PET/CT显像对于黑色素瘤的诊断,残余病灶、复发病灶及转移灶的检出,临床分期的明确具有重要价值.