Role of 18F-fluoride PET/CT in the assessment of multiple myeloma: initial experience

Purpose

The aim of this study was to report our early experience with ¹⁸F-fluoride PET/CT for detecting lesions and evaluate the usefulness of this modality in the assessment of multiple myeloma (MM).

Materials and methods

¹⁸F-fluoride PET/CT and ^99mTc-MDP bone scintigraphy (BS) studies from 7 myeloma patients (4 male and 3 female, mean age 55 years) diagnosed according to standard criteria were reviewed retrospectively. Two reviewers visually and quantitatively analyzed the images and recorded their findings after reaching a consensus. Diagnostic certainty regarding the presence or absence of myeloma lesions was evaluated according to the reference standard consisting of whole-body magnetic resonance imaging and whole-body X-ray.

Results

A total of 93 affected areas were definite according to the reference standard. Of these, 83 affected areas (89 %) were identified on ¹⁸F-fluoride PET/CT, whereas 54 affected areas (58 %) were found on BS. Mean SUVmax in the affected areas was 9.8 ± 3.2 (standard deviation) ranging from 5.0 to 21.2. A total of s17 lesions with bone fracture were also detected by ¹⁸F-fluoride PET/CT and 2 lesions (12 %) were negative on BS.

Conclusion

Our result showed that ¹⁸F-fluoride PET was a possible modality to detect areas of lesions in patients with MM.     

Assessment of atherosclerosis in oncologic patients using 18F-fluoride PET/CT

Objectives

The purpose of this study was to evaluate the prevalence, distribution, and relationship of ¹⁸F-fluoride uptake and arterial calcification in oncologic patients using ¹⁸F-fluoride PET/CT.

Methods

Image data obtained from 29 oncologic patients undergoing whole-body ¹⁸F-fluoride PET/CT were evaluated retrospectively. Arterial wall ¹⁸F-fluoride uptake and calcification were analyzed both quantitatively and semiquantitatively in 8 patients with arterial ¹⁸F-fluoride uptake.

Results

Arterial ¹⁸F-fluoride uptake was observed at 35 lesions in 8 (28 %) of the 29 patients, and calcification was observed at 345 lesions in the same patients. Five of the 8 patients had prostate cancer, and the remaining patients had hepatocellular carcinoma or malignant melanoma. In these 8 patients, the prevalence of both ¹⁸F-fluoride uptake and calcification was highest in the abdominal aorta, followed by the descending thoracic aorta and the aortic arch. Colocalization of radiotracer accumulation and calcification could be observed in the 32 lesions (91 %) with arterial ¹⁸F-fluoride uptake, and only the 3 lesions (9 %) with arterial ¹⁸F-fluoride uptake were not colocalized with arterial calcification. The presence of both arterial radiotracer uptake and calcification was significantly associated with advancing age (P < 0.01).

Conclusion

Our results suggest that ¹⁸F-fluoride PET/CT might be a useful modality for detecting active mineral deposition sites of atherosclerosis in oncologic patients.     

The diabetic foot: initial experience with 18F-FDG PET/CT.

Osteomyelitis complicates up to one third of diabetic foot infections, is often due to direct contamination from a soft-tissue lesion, and represents a clinical challenge. Early diagnosis is important since antibiotic therapy can be curative and may prevent amputation. The present study assessed the role of PET/CT using 18F-FDG for the diagnosis of diabetic foot osteomyelitis. METHODS: Fourteen diabetic patients (10 men and 4 women; age range, 29-70 y) with 18 clinically suspected sites of infection underwent PET/CT after the injection of 185-370 MBq of 18F-FDG for suspected osteomyelitis complicating diabetic foot disease. PET, CT, and hybrid images were independently evaluated for the diagnosis and localization of an infectious process. Additional data provided by PET/CT for localization of infection in the bone or soft tissues were recorded. The final diagnosis was based on histopathologic findings and bacteriologic assays obtained at surgery or at clinical and imaging follow-up. RESULTS: PET detected 14 foci of increased 18F-FDG uptake suspected as infection in 10 patients. PET/CT correctly localized 8 foci in 4 patients to bone, indicating osteomyelitis. PET/CT correctly excluded osteomyelitis in 5 foci in 5 patients, with the abnormal 18F-FDG uptake limited to infected soft tissues only. One site of mildly increased focal 18F-FDG uptake was localized by PET/CT to diabetic osteoarthropathy changes demonstrated on CT. Four patients showed no abnormally increased 18F-FDG uptake and no further evidence of an infectious process on clinical and imaging follow-up. CONCLUSION: 18F-FDG PET can be used for diagnosis of diabetes-related infection. The precise anatomic localization of increased 18F-FDG uptake provided by PET/CT enables accurate differentiation between osteomyelitis and soft-tissue infection.     

Imaging infection with 18F-FDG-labeled leukocyte PET/CT: initial experience in 21 patients.

The aim of this study was to assess the feasibility and the potential role of PET/CT with (18)F-FDG-labeled autologous leukocytes in the diagnosis and localization of infectious lesions. METHODS: Twenty-one consecutive patients with suspected or documented infection were prospectively evaluated with whole-body PET/CT 3 h after injection of autologous (18)F-FDG-labeled leukocytes. Two experienced nuclear medicine physicians who were unaware of the clinical end-diagnosis reviewed all PET/CT studies. A visual score (0-3)-according to uptake intensity-was used to assess studies. The results of PET/CT with (18)F-FDG-labeled white blood cell ((18)F-FDG-WBC) assessment were compared with histologic or biologic diagnosis in 15 patients and with clinical end-diagnosis after complete clinical work-up in 6 patients. RESULTS: Nine patients had fever of unknown etiology, 6 patients had documented infection but with unknown extension of the infectious disease, 4 patients had a documented infection with unfavorable evolution, and 2 patients had a documented infection with known extension. The best trade-off between sensitivity and specificity was obtained when a visual score of >or=2 was chosen to identify increased tracer uptake as infection. With this threshold, sensitivity, specificity, and accuracy were each 86% on a patient-per-patient basis and 91%, 85%, and 90% on a lesion-per-lesion basis. In this small group of patients, the absence of areas with increased WBC uptake on WBC PET/CT had a 100% negative predictive value. CONCLUSION: Hybrid (18)F-FDG-WBC PET/CT was found to have a high sensitivity and specificity for the diagnosis of infection. It located infectious lesions with a high precision. In this small series, absence of areas with increased uptake virtually ruled out the presence of infection. (18)F-FDG-WBC PET/CT for infection detection deserves further investigation in a larger prospective series.     

18F-fluoride PET/CT for detection of axial involvement in ankylosing spondylitis: correlation with disease activity

Objectives

Aim of the current study was to evaluate the relationships between the findings of 18F-fluoride PET/CT (F-PET/CT) reflecting osteo-proliferative processes and the clinical indexes related to the disease activity. The clinical indexes are Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS).

Methods

We studied 29 AS patients aged 26–69 years with a wide range of disease activity using F-PET/CT. The number of regions of high bone turnover or osteoarthritis features at the spine and at sacroiliac joints was counted.

Results

The number of F-PET/CT positive sites was significantly higher in patients with severe functional impairment and higher disease activity and it was positively related to both BASDAI (r = 0.336; P = 0.036) and ASDAS (r = 0.408; P = 0.014) while the number of degenerative features (osteoarthritis) was related neither with functional impact nor with disease activity.

Conclusions

With a single examination, F-PET/CT accurately identifies the functional impairment and the clinical involvement of AS. The good correlation we found between the number of F-PET/CT positive sites and disease activity candidates this technique also for follow-up of AS.

     

Usefulness of 18F-fluoride PET/CT in Breast Cancer Patients with Osteosclerotic Bone Metastases

Purpose

Bone metastasis is an important factor for the treatment and prognosis of breast cancer patients. Whole-body bone scintigraphy (WBBS) can evaluate skeletal metastases, and ¹⁸F-FDG PET/CT seems to exhibit high specificity and accuracy in detecting bone metastases. However, there is a limitation of ¹⁸F-FDG PET in assessing sclerotic bone metastases because some lesions may be undetectable. Recent studies showed that ¹⁸F-fluoride PET/CT is more sensitive than WBBS in detecting bone metastases. This study aims to evaluate the usefulness of ¹⁸F-fluoride PET/CT by comparing it with WBBS and ¹⁸F-FDG PET/CT in breast cancer patients with osteosclerotic skeletal metastases.

Materials and Methods

Nine breast cancer patients with suspected bone metastases (9 females; mean age ± SD, 55.6 ± 10.0 years) underwent ^99mTc-MDP WBBS, ¹⁸F-FDG PET/CT and ¹⁸F-fluoride PET/CT. Lesion-based analysis of five regions of the skeletons (skull, vertebral column, thoracic cage, pelvic bones and long bones of extremities) and patient-based analysis were performed.

Results

¹⁸F-fluoride PET/CT, ¹⁸F-FDG PET/CT and WBBS detected 49, 20 and 25 true metastases, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of ¹⁸F-fluoride PET/CT were 94.2 %, 46.3 %, 57.7 % and 91.2 %, respectively. Most true metastatic lesions on ¹⁸F-fluoride PET/CT had osteosclerotic change (45/49, 91.8 %), and only four lesions showed osteolytic change. Most lesions on ¹⁸F-FDG PET/CT also demonstrated osteosclerotic change (17/20, 85.0 %) with three osteolytic lesions. All true metastatic lesions detected on WBBS and ¹⁸F-FDG PET/CT were identified on ¹⁸F-fluoride PET/CT.

Conclusion

¹⁸F-fluoride PET/CT is superior to WBBS or ¹⁸F-FDG PET/CT in detecting osteosclerotic metastatic lesions. ¹⁸F-fluoride PET/CT might be useful in evaluating osteosclerotic metastases in breast cancer patients.     

Direct comparison of [18F]FDG PET/CT with PET alone and with side-by-side PET and CT in patients with malignant melanoma

Purpose

The purpose of this retrospective, blinded study was to evaluate the additional value of [¹⁸F]FDG PET/CT in comparison with PET alone and with side-by-side PET and CT in patients with malignant melanoma (MM).

Methods

A total of 127 consecutive studies of patients with known MM referred for a whole-body PET/CT examination were included in this study. PET alone, side-by-side PET and CT and integrated PET/CT study were independently and separately interpreted without awareness of the clinical information. One score each was applied for certainty of lesion localisation and for certainty of lesion characterisation. Verification of the findings was subsequently performed using all available clinical, pathological (n?=?30) and follow-up information.

Results

The number of lesions with an uncertain localisation was significantly (p?p?p?=?0.057) compared versus PET alone. Respectively, PET, side-by-side PET and CT and PET/CT showed a sensitivity of 86%, 89% and 91%, a specificity of 94%, 94% and 94%, a positive predictive value of 96%, 96% and 96% and a negative predictive value of 80%, 83% and 87%.

Conclusion

Integrated PET/CT offers a significant benefit in lesion localisation and an improvement in lesion characterisation compared with PET alone or with side-by-side PET and CT. The benefit is not as great as that reported for other tumour entities, which may be due to the high avidity of MM for [¹⁸F]FDG.     

The detection of bone metastases in patients with high-risk prostate cancer: 99mTc-MDP Planar bone scintigraphy, single- and multi-field-of-view SPECT, 18F-fluoride PET, and 18F-fluoride PET/CT.

The aim of this study was to compare the detection of bone metastases by 99mTc-methylene diphosphonate (99mTc-MDP) planar bone scintigraphy (BS), SPECT, 18F-Fluoride PET, and 18F-Fluoride PET/CT in patients with high-risk prostate cancer. METHODS: In a prospective study, BS and 18F-Fluoride PET/CT were performed on the same day in 44 patients with high-risk prostate cancer. In 20 of the latter patients planar BS was followed by single field-of-view (FOV) SPECT and in 24 patients by multi-FOV SPECT of the axial skeleton. Lesions were interpreted separately on each of the 4 modalities as normal, benign, equivocal, or malignant. RESULTS: In patient-based analysis, 23 patients had skeletal metastatic spread (52%) and 21 did not. Categorizing equivocal and malignant interpretation as suggestive for malignancy, the sensitivity, specificity, positive predictive value, and negative predictive value of planar BS were 70%, 57%, 64%, and 55%, respectively, of multi-FOV SPECT were 92%, 82%, 86%, and 90%, of (18)F-Fluoride PET were 100%, 62%, 74%, and 100%, and of 18F-Fluoride PET/CT were 100% for all parameters. Using the McNemar test, 18F-Fluoride PET/CT was statistically more sensitive and more specific than planar or SPECT BS (P < 0.05) and more specific than 18F-Fluoride PET (P < 0.001). SPECT was statistically more sensitive and more specific than planar BS (P < 0.05) but was less sensitive than 18F-Fluoride PET (P < 0.05). In lesion-based analysis, 156 lesions with increased uptake of 18F-Fluoride were assessed. Based on the corresponding appearance on CT, lesions were categorized by PET/CT as benign (n = 99), osteoblastic metastasis (n = 46), or equivocal when CT was normal (n = 11). Of the 156 18F-Fluoride lesions, 81 lesions (52%), including 34 metastases, were overlooked with normal appearance on planar BS. SPECT identified 62% of the lesions overlooked by planar BS. 18F-Fluoride PET/CT was more sensitive and more specific than BS (P < 0.001) and more specific than PET alone (P < 0.001). CONCLUSION: 18F-Fluoride PET/CT is a highly sensitive and specific modality for detection of bone metastases in patients with high-risk prostate cancer. It is more specific than 18F-Fluoride PET alone and more sensitive and specific than planar and SPECT BS. Detection of bone metastases is improved by SPECT compared with planar BS and by 18F-Fluoride PET compared with SPECT. This added value of 18F-Fluoride PET/CT may beneficially impact the clinical management of patients with high-risk prostate cancer.     

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.     

18F-FDOPA PET/CT for detection of recurrence in patients with glioma: prospective comparison with 18F-FDG PET/CT

Purpose

Differentiation between recurrence and radiation necrosis in patients with glioma is crucial, since the two entities have completely different management and prognosis. The purpose of the present study was to compare the efficacies of ¹⁸F-FDG PET/CT and 3,4-dihydroxy-6-[¹⁸F]fluoro-phenylalanine (¹⁸F-FDOPA) PET/CT in detection of recurrent gliomas.

Methods

A total of 28 patients (age 38.82?±?1.25 years; 85.7 % men) with histopathologically proven glioma with clinical/imaging suspicion of recurrence were evaluated using ¹⁸F-FDG PET/CT and ¹⁸F-FDOPA PET/CT. ¹⁸F-FDG PET/CT and ¹⁸F-FDOPA PET/CT images were evaluated qualitatively and semiquantitatively. The combination of clinical follow-up, repeat imaging and/or biopsy (when available) was taken as the reference standard.

Results

Based on the reference standard, 21 patients were positive and 7 were negative for tumour recurrence. The sensitivity, specificity and accuracy of ¹⁸F-FDG PET/CT were 47.6 %, 100 % and 60.7 %, respectively, and those of ¹⁸F-FDOPA PET/CT were 100 %, 85.7 % and 96.4 %, respectively. The results of ¹⁸F-FDG PET/CT and ¹⁸F-FDOPA PET/CT were concordant in 57.1 % of patients (16 of 28) and discordant in 42.9 % (12 of 28). The difference in the findings between ¹⁸F-FDG PET/CT and ¹⁸F-FDOPA PET/CT was significant (P?=?0.0005, McNemar’s test). The difference was significant for low-grade tumours (P?=?0.0039) but not for high-grade tumours (P?=?0.250).

Conclusion

¹⁸F-FDOPA PET/CT is highly sensitive and specific for detection of recurrence in glioma patients. It is superior to ¹⁸F-FDG PET/CT for this purpose and is especially advantageous in patients with low-grade gliomas.     

Direct comparison of FDG PET and CT findings in patients with lymphoma: initial experience

PURPOSE: To retrospectively compare fluorine 18 fluorodeoxyglucose (FDG) positron emission tomographic (PET) and computed tomographic (CT) findings at the same anatomic locations in patients with lymphoma by using a combined PET/CT scanner and to analyze the lesions on metabolic and anatomic bases to evaluate causes of discrepant findings between the two modalities. MATERIALS AND METHODS: The institutional review board allowed an exempt retrospective review of cancer PET database, and informed consent was waived. The study was HIPAA compliant. Fifty-three patients with lymphoma (20 Hodgkin and 33 non-Hodgkin; mean age, 43 years; range, 12-83 years) who underwent FDG PET/CT were included. The PET and CT images were interpreted by two nuclear medicine physicians and one radiologist, respectively, blinded to the other imaging findings. Concordant PET and CT findings were regarded as positive or negative for lymphoma. The site with discordant findings was defined as positive for disease if it was accompanied by other PET- and CT-positive sites in the same patient or was confirmed clinically (histologic examination or progressive disease). Staging results were also compared by one nuclear medicine physician. RESULTS: Of a total of 1537 anatomic sites in 53 patients, 48 had discordant findings between PET and CT. Forty (83%) of the 48 sites had correct PET findings (31 positive, nine negative), five had correct CT findings, and three were unresolved. The 31 PET-positive and CT-negative sites accounted for 23% of all 134 true-positive PET sites. PET provided accurate staging in an incremental nine (17%, upstaging in four and downstaging in five) of 53 patients in whom CT staging was incorrect. CT provided correct upstaging in two patients. CONCLUSION: FDG PET/CT as a combined modality may contribute substantially to lesion characterization and staging in patients with lymphoma.     

Cardiac 82rubidium PET/CT: initial European experience

Purpose Myocardial perfusion with PET/CT has advantages over conventional SPECT. We describe our initial European experience using ⁸²Rubidium-PET/CT, as part of a clinical myocardial perfusion service. Methods We studied the first 100 patients (64 male; 36 female, mean age = 60: SD +/−12.5y, mean body mass index = 30: SD +/−6.9kg/m ² ) who underwent ⁸²Rubidium cardiac PET/CT in our institution. Thirty patients had recently undergone coronary angiography. Patients underwent imaging during adenosine infusion and at rest. Images were acquired over 5 minutes using a GE-PET/CT instrument. Image quality was described as good, adequate or inadequate. Images were reported patient-by-patient by a minimum of five nuclear medicine physicians. A segment-by-segment analysis (17-segment model) was also performed. Results Image quality was good in 77%, adequate 23% and inadequate 0%. There was no statistical difference in image quality between obese and non-obese patients (Fisher’s exact test, p = 0.2864). 59% had normal perfusion studies, 29% had inducible ischaemia, 12% had myocardial infarction (11% with super added ischaemia). There was reduced ⁸²Rubidium uptake in 132/1700 segments during stress. There was reduced ⁸²Rubidium uptake at rest in 42/1700 segments. The ⁸²Rubidium PET/CT findings were consistent with the angiographic findings in 28/30 cases. Conclusion We show that, even from initial use of ⁸²Rubidium, it is possible to perform myocardial perfusion studies quickly with good image quality, even in the obese. The PET findings correlated well in the third of the cases where angiography was available. As such, ⁸²Rubidium cardiac PET/CT is likely to be an exciting addition to the European nuclear physician/ cardiologist’s radionuclide imaging arsenal.     

Fluorocholine PET/CT in patients with prostate cancer: initial experience

Institutional review board approval and written informed consent were obtained. Patients with newly diagnosed prostate cancer and patients suspected of having recurrent prostate cancer were prospectively evaluated with fluorine 18 fluorocholine (FCH) combined in-line positron emission tomography (PET) and computed tomography (CT). In 19 patients (mean age, 67 years +/- 8; range, 57-85 years), standardized uptake values of FCH in 17 different tissues were determined by using volumes of interest. In nine patients evaluated at initial staging, histologic findings of the resected prostate were compared to FCH uptake. Only small variations of physiologic tracer accumulation were measured in all organs but the kidneys. Differentiation of benign hyperplasia from cancerous prostate lesions was not possible with FCH PET/CT. However, in patients with recurrent prostate cancer, FCH PET/CT is a promising imaging modality for detecting local recurrence and lymph node metastases.     

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.