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-FDOPA与18F-FDG PET/CT诊断脑肿瘤的系统评价

目的 系统评价18F-FDOPA与18F-FDG PET/CT显像在脑肿瘤诊断中的临床价值.方法 采用Meta分析与直接比较方法.使用计算机检索中国期刊全文数据库、中文科技期刊数据库、万方数据库、中国生物医学文献数据库、PubMed、Embase、The Cochrane Library,从建库至2016年10月,搜索直接比较18F-FDOPA与18F-FDG PET/CT诊断脑肿瘤的诊断性试验.用Meta-Disc 1.4软件进行分析,计算两种不同显像剂的合并敏感度(sensitivity,SEN)、合并特异度(specificity,SPE)、合并阳性似然比(positive likelihood ratio,+LR)、合并阴性似然比(negative likelihood ratio,-LR)、诊断优势比(diagnostic odds ratio,DOR),并绘制综合受试者工作特征曲线计算曲线下面积(area under curve,AUC)与Q*值.结果 最终共纳入4篇文章,Meta 分析结果显示,18F-FDOPA PET/CT对脑肿瘤诊断的合并SEN为0.97(95％ CI =0.90 ～ 1.00),SPE为0.67(95％ CI =0.45 ～0.84),+LR为2.31 (95％ CI=1.40 ～3.81),-LR为0.07 (95％ CI =0.02～ 0.24),DOR为39.72(95％ CI=8.94～176.48),AUC为0.9725,Q*为0.9239.18F-FDG PET/CT对脑肿瘤诊断的合并SEN为0.51(95％CI=0.39～0.63),SPE为0.75(95％ CI=0.53 ～0.90,+LR为l.59(95％ CI=0.70 ～ 3.61),-LR为0.63(95％ CI =0.47 ～0.86),DOR为2.55(95％ CI =0.82 ～7.92),AUC为0.5848,Q*为0.5638.结论 18F-FDOPA PET/CT显像诊断脑肿瘤的敏感性比18F-FDG高,对脑肿瘤具有良好的诊断价值,可作为脑肿瘤诊断的方法之一.     

A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma

Purpose

¹⁸F-Fluoro-l-dihydroxyphenylalanine (¹⁸F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by ⁶⁸Ga-DOTA-Tyr³-octreotide (⁶⁸Ga-DOTA-TOC) PET. Therefore, we compared ⁶⁸Ga-DOTA-TOC and ¹⁸F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard.

Methods

A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with ⁶⁸Ga-DOTA-TOC PET and ¹⁸F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUV_max) of each functional imaging modality in concordant tumour lesions was measured.

Results

Compared with anatomical imaging, ⁶⁸Ga-DOTA-TOC PET and ¹⁸F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of ⁶⁸Ga-DOTA-TOC was 100 % and that of ¹⁸F-DOPA PET was 56.0 %. Overall, ⁶⁸Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and ¹⁸F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of ⁶⁸Ga-DOTA-TOC PET was 100 % (McNemar, P?<?0.5), and that of ¹⁸F-DOPA PET was 71.1 % (McNemar, P?<?0.001). The SUV_max (mean ± SD) of all 32 concordant lesions was 67.9?±?61.5 for ⁶⁸Ga-DOTA-TOC PET and 11.8?±?7.9 for ¹⁸F-DOPA PET (Mann-Whitney U test, P?<?0.0001).

Conclusion

⁶⁸Ga-DOTA-TOC PET may be superior to ¹⁸F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically inoperable tumours and metastatic or multifocal disease.     

非18F-氟脱氧葡萄糖的脑肿瘤PET

由于大脑皮质的葡萄糖摄取相对较高，常规^18F-氟脱氧葡萄糖（^18F—FDG）PET对于脑肿瘤，特别是低度恶性脑肿瘤的显像有较大的局限性。近年来，各种特异性更高的放射性示踪剂如^11C-甲硫氨酸（^11C—MET），^11C-胆碱（^11C—choline），^18F-氟脱氧胸苷（^18F—FLT）等越来越多地应用于脑肿瘤显像。非^18F-FDG的放射性示踪剂在脑肿瘤的显像中均具有脑本底摄取低、肿瘤影像对比度好、对低级别胶质瘤敏感性较高的优点，在脑肿瘤的诊断、鉴别诊断、放疗计划的制定及疗效监测等方面比。^18F—FDG有着明显的优势。     

18F-DOPA PET/CT unravels malignant paraganglioma mimicking temporomandibular joint disorder

This report presents a 29-year-old patient with severe temporomandibular joint (TMJ) pain. Anamnesis and clinical examination led us to the diagnosis of TMJ disorder. He was also in control for a malignant paraganglioma originating from the right carotid body. After initial surgery 8.5 years ago and the removal of metastases 2 years ago he was deemed disease free. An (18)F-3,4-dihydroxyphenylalanine (DOPA) positron emission tomography (PET)/CT scan was obtained during follow-up 6 months before he was presented to our clinic. Suspicious of a connection between the actual pain and the tumour, we scrutinized these images. We found a tiny pathological tracer uptake in the right jugular foramen but no correlating finding in the matching CT. We repeated the DOPA PET/CT and found several metastases including the previously detected lesion. Further thin-slice CT and MRI showed a 5 mm paraganglioma located anteriorly to the jugular bulb within the jugular foramen. The lesion was in close relation to the Arnold's nerve, a branch of the vagus nerve which carries sensory information from the external tympanic membrane, external auditory canal and the external ear and explained the severe pain in our patient. He then underwent radiotherapy (45 Gy) during which the pain diminished considerably. In a variety of neuroendocrine tumours, including paraganglioma, DOPA PET/CT allows primary diagnosis, staging and restaging with a higher detection rate than conventional radiological imaging. Owing to low anatomical resolution however, high resolution contrast-enhanced CT and MRI are necessary to complete the investigations.     

应用18F-DOPA PET显像诊断路易小体性痴呆

目的评价测定纹状体突触前多巴胺代谢水平对路易小体性痴呆(DLB)诊断、鉴别诊断的价值.方法研究对象分为3组7例DLB患者,10例老年性痴呆(AD)患者及9例年龄相匹配的正常对照者.用18F-fluorodopa(DOPA)PET显像测定受检者纹状体突触前多巴胺的摄取(即脑内18F-DOPA放射性水平, 以流入速率常数Ki表示),然后对3组Ki值进行比较.结果①DLB组Ki值(壳核0.006 4±0.001 7,尾状核0.005 1±0.001 9)明显低于AD组(分别为0.011 9±0.002 1及0.009 2±0.001 4)及对照组(分别为0.013 1±0.002 8及0.012 2±0.003 5),差异均有显著性(P均<0.01);而AD组与对照组间的Ki值差异无显著性(P>0.05).②DLB的尾状核Ki值(正常值的42%)降低较壳核(正常值的49%)更为明显.③以Ki=0.006 2作为临界点(正常尾状核-2s),DLB与AD鉴别的灵敏度和特异性分别为86%和100%.结论用18F-DOPA PET显像检测多巴胺代谢功能有助于DLB的早期诊断和鉴别诊断.     

18F-DOPA PET/CT But Not 68Ga-DOTA-TOC PET/CT Revealed the Underlying Cause of Ectopic Cushing Syndrome

ABSTRACT: F-DOPA PET/CT but not Ga-DOTA-TOC PET/CT revealed the cause of ectopic Cushing syndrome in a 61-year-old man. The patient presented with rapid weight gain, swollen legs, and sleep disturbances. Plasma potassium level was 2.7 mM (reference range, 3.3-4.9 mM), 24-hour urinary cortisol level was 13,124 nmol (reference range, 30-144 nmol), and plasma adrenocorticotropin level was 61 ng/L (reference range, <48 g/L). CT demonstrated prominent lymph nodes in the left lung hilus and hyperplastic adrenals but no primary tumor. Ga-DOTA-TOC PET/CT, which is recommended as the first-line PET imaging, was performed, but it was not diagnostic. Imaging with F-DOPA PET/CT revealed the underlying cause.     

肺神经内分泌肿瘤的CT与 18F-FDG PET/CT显像特征的分析

目的:探讨肺神经内分泌肿瘤（PNETs）的CT与 18F-氟脱氧葡萄糖（FDG）PET/CT显像特征,比较单纯PET/CT与基于PET/CT联合增强CT及高分辨率CT多模态显像的诊断准确率。 方法:回顾性分析2010年1月至2019年5月于西南医科大学附属医院经组织病理学检查确诊的44例PNETs...     

18F-Fluciclovine (18F-FACBC) PET imaging of recurrent brain tumors

European Journal of Nuclear Medicine and Molecular Imaging - The aim of our study was to investigate the efficacy of 18F-Fluciclovine brain PET imaging in recurrent gliomas, and to compare the...     

18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT scans as diagnostic tools in focal congenital hyperinsulinism: a blinded evaluation

Purpose

Focal congenital hyperinsulinism (CHI) is curable by surgery, which is why identification of the focal lesion is crucial. We aimed to determine the use of 18F–fluoro-dihydroxyphenylalanine (18F-DOPA) PET/CT vs. 68Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic-acid-1-Nal3-octreotide (68Ga-DOTANOC) PET/CT as diagnostic tools in focal CHI.

Methods

PET/CT scans of children with CHI admitted to Odense University Hospital between August 2005 and June 2016 were retrospectively evaluated visually and by their maximal standardized uptake values (SUV_max) by two independent examiners, blinded for clinical, surgical and pathological data. Pancreatic histology was used as the gold standard. For patients without surgery, the genetic profile served as the gold standard.

Results

Fifty-five CHI patients were examined by PET/CT (18F-DOPA n = 53, 68Ga-DOTANOC n = 18). Surgery was performed in 34 patients, no surgery in 21 patients. Fifty-one patients had a classifiable outcome, either by histology (n = 33, 22 focal lesions, 11 non-focal) or by genetics (n = 18, all non-focal). The predictive performance of 18F-DOPA PET/CT to identify focal CHI was identical by visual- and cut-off-based evaluation: sensitivity (95% CI) of 1 (0.85–1); specificity of 0.96 (0.82–0.99). The optimal 18F-DOPA PET SUV_max ratio cut-off was 1.44 and the optimal 68Ga-DOTANOC PET SUV_max cut-off was 6.77 g/ml. The area under the receiver operating curve was 0.98 (0.93–1) for 18F-DOPA PET vs. 0.71 (0.43–0.95) for 68Ga-DOTANOC PET (p < 0.03). In patients subjected to surgery, localization of the focal lesion was correct in 91%, and 100%, by 18F-DOPA PET/CT and 68Ga-DOTANOC PET/CT, respectively.

Conclusion

18F-DOPA PET/CT was excellent in predicting focal CHI and superior compared to 68Ga-DOTANOC PET/CT. Further use of 68GA-DOTANOC PET/CT in predicting focal CHI is discouraged.

     

Comparison of 18F-DOPA, 18F-FDG and 68Ga-somatostatin analogue PET/CT in patients with recurrent medullary thyroid carcinoma

Purpose

To retrospectively evaluate and compare ¹⁸F-FDG, ¹⁸F-DOPA and ⁶⁸Ga-somatostatin analogues for PET/CT in patients with residual/recurrent medullary thyroid carcinoma (MTC) suspected on the basis of elevated serum calcitonin levels.

Methods

Included in the study were 18 patients with recurrent MTC in whom functional imaging with the three tracers was performed. The PET/CT results were compared on a per-patient basis and on a per-lesion-basis.

Results

At least one focus of abnormal uptake was observed on PET/CT in 13 patients with ¹⁸F-DOPA (72.2% sensitivity), in 6 patients with ⁶⁸Ga-somatostatin analogues (33.3%) and in 3 patients with ¹⁸F-FDG (16.7%) (p?18F-DOPA and ¹⁸F-FDG PET/CT (p?18F-DOPA and ⁶⁸Ga-somatostatin analogue PET/CT (p?=?0.04). Overall, 72 lesions were identified on PET/CT with the three tracers. ¹⁸F-DOPA PET/CT detected 85% of lesions (61 of 72), ⁶⁸Ga-somatostatin analogue PET/CT 20% (14 of 72) and ¹⁸F-FDG PET/CT 28% (20 of 72). There was a statistically significant difference in the number of lymph node, liver and bone lesions detected with the three tracers (p?18F-DOPA PET/CT and ¹⁸F-FDG PET/CT (p?18F-DOPA PET/CT and ⁶⁸Ga-somatostatin analogue PET/CT (p?Conclusion ¹⁸F-DOPA PET/CT seems to be the most useful imaging method for detecting recurrent MTC lesions in patients with elevated serum calcitonin levels, performing better than ¹⁸F-FDG and ⁶⁸Ga-somatostatin analogue PET/CT. ¹⁸F-FDG may complement ¹⁸F-DOPA in patients with an aggressive tumour.     

Recurrent Glioma and Crossed Cerebellar Diaschisis in a Patient Examined With 18F-DOPA and 18F-FDG PET/CT

ABSTRACT: Two years after resection of a left parietal glioma, a 46-year-old woman underwent F-FDG and F-DOPA brain PET/CT. FDG showed left parietal hypometabolism with crossed cerebellar diaschisis. No abnormally increased FDG activity was seen. F-DOPA PET/CT scan demonstrated focal left parietal uptake. Recurrent glioma was confirmed by surgical biopsy. F-DOPA may demonstrate abnormal amino acid metabolism in evaluation of recurrence of glioma.     

18F-FDOPA PET imaging of brain tumors: comparison study with 18F-FDG PET and evaluation of diagnostic accuracy.

We evaluated the amino acid and glucose metabolism of brain tumors by using PET with 3,4-dihydroxy-6-(18)F-fluoro-l-phenylalanine ((18)F-FDOPA) and (18)F-FDG. METHODS: Eighty-one patients undergoing evaluation for brain tumors were studied. Initially, 30 patients underwent PET with (18)F-FDOPA and (18)F-FDG within the same week. Tracer kinetics in normal brain and tumor tissues were estimated. PET uptake was quantified by use of standardized uptake values and the ratio of tumor uptake to normal hemispheric tissue uptake (T/N). In addition, PET uptake with (18)F-FDOPA was quantified by use of ratios of tumor uptake to striatum uptake (T/S) and of tumor uptake to white matter uptake. The accuracies of (18)F-FDOPA and (18)F-FDG PET were determined by comparing imaging data with histologic findings and findings of clinical follow-up of up to 31 mo (mean, 20 mo). To further validate the accuracy of (18)F-FDOPA PET, (18)F-FDOPA PET was performed with an additional 51 patients undergoing brain tumor evaluation. RESULTS: Tracer uptake in tumors on (18)F-FDOPA scans was rapid, peaking at approximately 15 min after intravenous injection. Tumor uptake could be distinguished from that of the striatum by the difference in peak times. Both high-grade and low-grade tumors were well visualized with (18)F-FDOPA. The sensitivity for identifying tumors was substantially higher with (18)F-FDOPA PET than with (18)F-FDG PET at comparable specificities, as determined by simple visual inspection, especially for the assessment of low-grade tumors. Using receiver-operating-characteristic curve analysis, we found the optimal threshold for (18)F-FDOPA to be a T/S of greater than 1.0 (sensitivity, 96%; specificity, 100%) or a T/N of greater than 1.3 (sensitivity, 96%; specificity, 86%). The high diagnostic accuracy of (18)F-FDOPA PET at these thresholds was confirmed with the additional 51 patients (a total of 81 patients: sensitivity, 98%; specificity, 86%; positive predictive value, 95%; negative predictive value, 95%). No significant difference in tumor uptake on (18)F-FDOPA scans was seen between low-grade and high-grade tumors (P = 0.40) or between contrast-enhancing and nonenhancing tumors (P = 0.97). Radiation necrosis was generally distinguishable from tumors on (18)F-FDOPA scans (P < 0.00001). CONCLUSION: (18)F-FDOPA PET was more accurate than (18)F-FDG PET for imaging of low-grade tumors and evaluating recurrent tumors. (18)F-FDOPA PET may prove especially useful for imaging of recurrent low-grade tumors and for distinguishing tumor recurrence from radiation necrosis.     

氟代脱氧葡萄糖与氨基酸PET在脑肿瘤中的对比研究

脑肿瘤细胞生长速率加快,能量代谢、氨基酸转运和蛋白质合成旺盛。联合18F-FDG与11C-MET的PET,比单一显像剂更有助于脑肿瘤的组织学分级、术后复发和疗效评价。11C-MET较18F-FDG能更精确地显示肿瘤扩散范围和轮廓,对制订手术和立体定向放疗计划有重要意义,是常规CT和(或)MRI的有益补充。