^18F-氟化钠PET和PET-CT诊断肺癌骨转移的对比研究

目的对比研究^18F-氟化钠（^18F-NaF）PET和PET-CT对肺癌骨转移诊断的准确性。方法34例初始诊断为肺癌的患者接受^18F-NaFPET-CT检查,对PET和PET-CT图像分别进行解释,发现的病变分为恶性、良性和不确定三种。骨转移的综合评价方法包括MRI（34例）、^18F-氟脱氧葡糖糖PET-CT（4例）、组织学活检（2例）和临床随访（6例）。结果按患者水平分析时,34例患者中的11例（32％）发生骨转移,其中,^18F-NaFPET—CT准确诊断所有患者的骨转移,无假阳性和假阴性,而^18F-NaFPET诊断真阳性8例、3例不能确定,^18F-NaFPET确诊的8例骨转移患者中的4例PET没有显示全部转移病变（假阴性和不确定病变）;按病变水平分析时,118个病变获得最终诊断,其中转移病变47个、良性病变71个,其中,^18F-NaFPET诊断真阳性27个、真阴性64个、不确定病变24个、假阴性1个、假阳性2个,而^18F-NaFPET-CT诊断真阳性46个、假阴性1个、真阴性71个。按患者水平分析,将不确定病变归为恶性时,^18F-NaFPET-CT的特异性高于^18F-NaFPET（100％vs78％,χ2=10．78,P〈0．05）,二者的灵敏度均为100％;将不确定病变归为良性时,^18F-NaFPET-CT诊断骨转移的灵敏度显著高于^18F-NaFPET（100％vs73％,r=6．41,P〈0．01）,二者特异度差异无显著性（100％vs96％,χ^2=2．03,P〉0．05）;按病变水平分析时,得到与患者水平分析相似结果。结论 ^18F-NaFPET-CT诊断肺癌骨转移的准确性优于^18F-NaFPET,PET—CT中的低剂量CT可进一步提高良、恶性病变的鉴别能力。     

正电子发射计算机体层摄影-CT诊断骨转移瘤的临床价值

目的 应用^18氟-脱氧葡萄糖（^18F-FDG）正电子发射计算机体层摄影（PET）-CT全身显像，探讨PET、同机CT和PET—CT融合图像在骨转移瘤诊断中的价值。方法 共332例^18F-FDG PET—CT受检者中有35例发现骨异常病变。分别阅读和记录^18FDG PET图像、同机CT图像和PET-CT融合图像判断的良、恶性病变，比较3种方法在诊断骨转移瘤上的差异。结果 35例中共检出89个病灶，其中68个病灶最后确诊为恶性肿瘤骨转移，21个为良性病变。PET诊断骨转移病灶62个，诊断良性病变17个，诊断骨转移瘤的敏感性为91．2％（62／68个），特异性为81．0％（17／21个），准确性为88．8％（79／89个）；同机CT诊断骨转移病灶55个，良性病变16个。诊断骨转移瘤的敏感性、特异性和准确性分别为80．9％（55／68个），76．2％（16／21个）和79．8％（71／89个）；PET．CT融合图像诊断骨转移病灶64个，良性病变19个，诊断骨转移瘤的敏感性、特异性和准确性分别为94．1％（64／68个），90．5％（19／21个）和93．2％（83／89个）。结论 PET-CT融合图像在诊断骨转移瘤方面，可减少单用PET或单用CT诊断时的假阴性和假阳性，提高了鉴别骨良、恶性病变的能力。     

18F-FDG PET/CT和增强CT对胰腺病变定性诊断的价值比较

目的评价^18F-脱氧葡萄糖（FDG）PET／CT对胰腺良、恶性病变定性诊断的价值。方法对15例胰腺恶性病变，6例良性病变患者行全身^18F-FDGPET／CT和增强CT检查，根据PET、增强CT和PET／CT图像上的表现分别诊断，并将结果进行比较。结果PET和PET／CT准确诊断全部恶性病变，而增强CT准确诊断全部良性病变。PET和PET／CT在6例良性病变诊断中分别显示2例和1例假阳性，而增强CT在15例恶性病变中有2例假阴性，但在上述3种诊断方法中分别出现的假阳性或假阴性都得到了相互间的纠正。增强CT、PET和PET／CT三者在诊断胰腺恶性肿瘤上的准确性分别为90．5％，90．5％和95．2％。此外，PET／CT比增强CT检出了更多的肝脏、淋巴结和骨转移灶；两者检出病灶数量分别为35，41，9和16，24，3个。结论PET／CT在胰腺良、恶性病变定性诊断上有价值，PET／CT和增强CT联合应用有利于进一步提高对胰腺恶性肿瘤的诊断和分期准确性。     

PET与CT在肺癌诊断中的联合应用

目的:遴选CT鉴别肺部病变良恶性的征象,利用这些征象降低PET在肺癌诊断中的假阳性和假阴性。方法:42例肺部病变患者行PET和CT检查。若肺部病变放射性摄取明显增高,同时SUV≥2.5,判断为恶性病变。若肺部病变有轻度放射性摄取,但其摄取程度低于或明显低于纵隔,SUV2.5,判断为良性病变。选择CT图像上10种最常见的恶性病变征象和10种常见的良性病变征象加以对照分析。结果:PET显像高代谢恶性病变(真阳性)组11例,在CT上都观察到较多的符合征象;PET显像低代谢良性病变(真阴性)组11例,其中有10例在CT上都观察到较多符合征象,只有1例病变观察到得符合征象和质疑征象基本相等。而PET显像高代谢良性病变(假阳性)组10例,其中有9例在CT上观察到较多质疑征象,另有1例观察到较多符合征象;PET显像低代谢恶性病变(假阴性)组10例,在CT上都观察到较多质疑征象。结论:CT征像可以帮助降低PET在肺癌诊断中的假阳性和假阴性。     

18F-FDG PET与99Tcm-MDP骨扫描诊断肿瘤骨转移的比较分析

目的:探讨18F-FDG PET显像对于肿瘤骨转移的诊断价值,并与99Tcm-MDP骨显像进行对比分析。方法:97例肿瘤及疑诊为肿瘤的患者在30天内先后行18F-FDG PET-CT及99Tcm-MDP骨扫描,对比分析两者的显像结果。结果:97例中经临床和病理确诊基于病例分析,为骨转移63例,62例18F-FDG PET显像阳性,1例假阴性;99Tcm-MDP骨显像阳性49例,假阴性14例,两者敏感度分别为98.4%和77.8%,差异有显著性意义(P<0.05);34例为阴性患者,其中PET显像阴性29例、假阳性5例,骨显像阴性21例、假阳性13例,两者的特异度为85.3%和61.8%(P>0.05),符合率为93.8%和72.2%(P<0.05)。基于病灶分析,97例中共分析1261个骨骼区,骨转移存在于226个骨骼区,剔除不能定性的14个区,18F-FDG PET显像阳性222个区,假阴性4个区;而骨扫描显像阳性154个区,假阴性72个区;两者的敏感度分别为98.7%和68.1%,差异有显著性意义(P<0.05)。1021个阴性区,其中18F-FDGPET显像为阴性1010个区,假阳性11个区;骨扫描显像阴性1001个区,假阳性20个区;两者特异度分别为98.9%和98.0%,差异无统计学意义(P>0.05)。18F-FDG PET的诊断符合率为98.8%,骨显像为92.6%,两者差异有显著性意义(P<0.05)。以CT表现分组,溶骨性病灶和CT上无明显异常改变病灶的FDG PET和骨扫描的检出率分别为99.4%和72.6%及81.5%和40.7%,差异有显著性意义(P<0.05)。结论:18F-FDG PET诊断敏感度及准确性均高于骨扫描对溶骨病灶和CT上无明显改变病灶的检出优于骨扫描。     

~(18)F-FDG PET-CT对椎管内病变的诊断价值

目的 :探讨~(18)F-FDG PET-CT对椎管内良恶性病变的诊断价值。方法 :回顾性分析PET-CT提示椎管疾病患者41例。测量病变标准摄取最大值(SUV_(max)),并与术后病理或随访结果做对比。绘制ROC曲线获得椎管良恶性病变的SUV_(max)最佳诊断阈值。采用SPSS 20.0软件分析,计算~(18)F-FDG PET-CT在SUV_(max)2.5诊断标准时的敏感度、特异度、阳性预测值、阴性预测值。结果:术后病理及随访得出良性15例,恶性26例,在SUV_(max)2.5标准时,~(18)F-FDG PET-CT诊断良性7例,恶性34例,诊断敏感度100.00%、特异度46.67%、阳性预测值76.47%、阴性预测值100.00%。利用ROC曲线确定SUV_(max)的诊断阈值以2.95最佳,敏感度100.00%、特异度60.00%、阳性预测值81.25%、阴性预测值100.00%。结论 :SUV_(max)2.95较SUV_(max)2.5可能更适合作为判断椎管内病变良恶性的标准。     

18F-FDG PET/CT显像诊断心包恶性病变的价值

目的 评价18F-脱氧葡萄糖（FDG）PET/CT对心包恶性病变的诊断价值.方法 对23例心包积液患者进行18F-FDG PET/CT显像,并采用两独立样本非参数检验分析良恶性病灶最大标准摄取值（SUVmax）差异有无统计学意义.结果 经病理检查证实恶性心包积液14例,良性心包积液9例.1例PET/CT假阴性,2例PET/CT假阳性.18F-FDG PET/CT鉴别诊断良恶性心包积液的灵敏度、特异性、准确性、阳性预测值、阴性预测值分别为92.9%（13/14）、7/9、87.0%（20/23）、86.7%（13/15）和7/8.良、恶性病变的SUVmax中位值分别为2.2和6.0,两者间比较差异有统计学意义（z=-3.279,P=0.001）.结论 18F-FDG PET/CT是评价心包恶性病变较好的无创性手段,对良恶性心包积液的诊断与鉴别诊断有一定临床价值.     

肺癌脊椎骨转移（18）F-FDG PET/CT与MRI的对比分析

目的：比较分析18 F-FDG PET/CT与MRI在肺癌脊椎骨转移诊断方面的敏感性、特异性。方法：28例肺癌PET/CT疑脊椎转移患者行MRI检查,比较两种方法对脊椎转移的显示征象。统计学方法采用配对四格表资料2检验,P〈0.05被认为差异有显著性。结果：经病理或随访确诊脊椎骨转移22例。以受累椎体病灶个数为统计单位,脊椎范围内共700个椎体,153个为真阳性,574个为真阴性。PET/CT诊断正确143个病灶,假阴性10个,假阳性24个,其敏感性93.4%,特异性95.6%。MRI诊断正确145个病灶,假阴性8个,无假阳性,其敏感性94.7%,特异性100%。结论：在显示脊椎骨转移方面,MRI较PET/CT具有更高的敏感性、特异性。     

^11C-胆碱PET显像的临床初步应用

目的: 初步探讨11C-胆碱PET显像诊断体内占位病变的良恶性价值.材料和方法: 对3例脑内、14例肺内占位病变患者同时行N-甲基-11C胆碱(11C-胆碱)和18F-FDG PET显像,ROI方法测定最大标准摄取值(SUVmax).结果: 13处恶性占位病灶11C-胆碱PET显像均为阳性;但病灶大小与SUVmax间无明显相关性.8处良性占位病灶,18F-FDG均为假阳性,11C-胆碱PET显像仅有1例为假阳性.11C -胆碱显像漏检1处肺癌肾上腺转移病灶.结论: 11C-胆碱PET显像可能成为肿瘤良恶性鉴别的可靠方法.     

^18F-FDG PET-CT对妇科肿瘤定性诊断的准确性

目的通过与传统的影像学、血清学和组织学检查比较,评估18F-FDG PET-CT在妇科肿瘤诊断中的准确性。方法 63例妇科肿瘤中,卵巢肿瘤29例,宫颈肿瘤17例,子宫内膜肿瘤12例,阴道肿瘤5例。全部患者进行全身18F-FDGPET-CT扫描,51例进行了放射学检测（CT/MRI/超声）,15例进行了血清学分析,40例进行了组织学或细胞学诊断。采用PET-CT扫描仪,经肘静脉注射5.5 MBq/kg 18 F-FDG后45～50 min,采集、重组图像。结果 18 F-FDG PET-CT诊断准确率为84.2%,其中58.8%为真阳性,25.4%为真阴性。18 F-FDG PET-CT对肿瘤原发灶（卵巢、宫颈、子宫内膜、阴道）的诊断准确率分别为82.8%、82.3%、91.7%和80%;而18F-FDG PET-CT仅显示了15.8%的错误结果,包括6.3%的假阳性和9.5%的假阴性。而且假阳性结果与18F-FDG摄取区周围有炎性细胞的存在有关;假阴性结果与肿瘤的分级低（2例）、正在化疗（2例）和技术问题（1例）有关;还有1例假阴性结果仅与血清学指标的轻度升高有关,但没有细胞学和组织学支持。放射学检测的51例中,21例18F-FDG PET-CT发现转移灶,而放射学检测却没有提示。18F-FDG PET-CT的阳性预测值为84.6%（22/26）,阴性预测值为76.9%（10/13）。结论 18F-FDG PET-CT能早期准确诊断妇科肿瘤的复发或肿瘤活性组织的残留;但在化疗中的肿瘤和恶性程度低的肿瘤中,会出现假阴性结果;想得到有意义的结论还需要更多数据的支持。     

Assessment of malignant skeletal disease: initial experience with 18F-fluoride PET/CT and comparison between 18F-fluoride PET and 18F-fluoride PET/CT.

18F-fluoride PET/CT was performed on 44 oncologic patients to evaluate its diagnostic accuracy in assessing malignant osseous involvement and in differentiating malignant from benign bone lesions. METHODS: (18)F-fluoride PET and (18)F-fluoride PET/CT were interpreted separately. Lesions showing increased (18)F-fluoride uptake were categorized as malignant, benign, or inconclusive. The final diagnosis of lesions was based on histopathology, correlation with contemporaneous diagnostic CT or MRI, or clinical follow-up of at least 6 mo (mean, 10 +/- 3 mo). RESULTS: Increased (18)F-fluoride uptake was detected at 212 sites, including 111 malignant lesions, 89 benign lesions, and 12 lesions for which the final diagnosis could not be determined. In a lesion-based analysis, the sensitivity of PET alone in differentiating benign from malignant bone lesions was 72% when inconclusive lesions were considered false negative and 90% when inconclusive lesions were considered true positive. On PET/CT, 94 of 111 (85%) metastases presented as sites of increased uptake with corresponding lytic or sclerotic changes, and 16 of the 17 remaining metastases showed normal-appearing bone on CT, for an overall sensitivity of 99% for tumor detection. For only 1 metastasis was PET/CT misleading, suggesting the false diagnosis of a benign lesion. The specificity of PET/CT was significantly higher than that of PET alone (97% vs. 72%, P < 0.001). PET/CT identified benign abnormalities at the location exactly corresponding to the scintigraphic increased uptake for 85 of 89 (96%) benign lesions. In a patient-based analysis, the sensitivity of PET and PET/CT was 88% and 100%, respectively (P < 0.05) and the specificity was 56% and 88%, respectively (not statistically significant). Among the 12 patients referred for (18)F-fluoride assessment because of bone pain despite negative findings on (99m)Tc-methylene diphosphonate bone scintigraphy, (18)F-fluoride PET/CT suggested malignant bone involvement in all 4 patients with proven skeletal metastases, a potential benign cause in 4 of 7 patients who had no evidence of metastatic disease, and a soft-tissue tumor mass invading a sacral foramen in 1 patient. CONCLUSION: The results indicate that (18)F-fluoride PET/CT is both sensitive and specific for the detection of lytic and sclerotic malignant lesions. It accurately differentiated malignant from benign bone lesions and possibly assisted in identifying a potential cause for bone pain in oncologic patients. For most lesions, the anatomic data provided by the low-dose CT of the PET/CT study obviates the performance of full-dose diagnostic CT for correlation purposes.     

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.     

Prospective comparison of <Superscript>68</Superscript>Ga-PSMA PET/CT, <Superscript>18</Superscript>F-sodium fluoride PET/CT and diffusion weighted-MRI at for the detection of bone metastases in biochemically recurrent prostate cancer

Purpose

To prospectively compare diagnostic accuracies for detection of bone metastases by ⁶⁸Ga-PSMA PET/CT, ¹⁸F-NaF PET/CT and diffusion-weighted MRI (DW₆₀₀-MRI) in prostate cancer (PCa) patients with biochemical recurrence (BCR).

Methods

Sixty-eight PCa patients with BCR participated in this prospective study. The patients underwent ⁶⁸Ga-PSMA PET/CT, a ¹⁸F-NaF PET/CT and a DW₆₀₀-MRI (performed in accordance with European Society of Urogenital Radiology guidelines, with b values of 0 and 600 s/mm²). Bone lesions were categorized using a three-point scale (benign, malignant or equivocal for metastases) and a dichotomous scale (benign or metastatic) for each imaging modality by at least two experienced observers. A best valuable comparator was defined for each patient based on study-specific imaging, at least 12 months of clinical follow-up and any imaging prior to the study and during follow-up. Diagnostic performance was assessed using a sensitivity analysis where equivocal lesions were handled as non-metastatic and then as metastatic.

Results

Ten of the 68 patients were diagnosed with bone metastases. On a patient level, sensitivity, specificity and the area under the curve (AUC) by receiver operating characteristic analysis were, respectively, 0.80, 0.98–1.00 and 0.89–0.90 for ⁶⁸Ga-PSMA PET/CT (n?=?68 patients); 0.90, 0.90–0.98 and 0.90–0.94 for ¹⁸NaF PET/CT (n?=?67 patients); and 0.25–0.38, 0.87–0.92 and 0.59–0.62 for DW₆₀₀-MRI (n?=?60 patients). The diagnostic performance of DW₆₀₀-MRI was significantly lower than that of ⁶⁸Ga-PSMA PET/CT and ¹⁸NaF PET/CT for diagnosing bone metastases (p?<?0.01), and no significant difference in the AUC was seen between ⁶⁸Ga-PSMA PET/CT and ¹⁸NaF PET/CT (p?=?0.65).

Conclusion

⁶⁸Ga-PSMA PET/CT and ¹⁸F-NaF PET/CT showed comparable and high diagnostic accuracies for detecting bone metastases in PCa patients with BCR. Both methods performed significantly better than DW₆₀₀-MRI, which was inadequate for diagnosing bone metastases when conducted in accordance with European Society of Urogenital Radiology guidelines.

     

Comparison of [<Superscript>68</Superscript>Ga]Ga-PSMA-11 PET/CT with [<Superscript>18</Superscript>F]NaF PET/CT in the evaluation of bone metastases in metastatic prostate cancer patients prior to radionuclide therapy

Aim

The purpose of this study was to investigate the diagnostic performance of ⁶⁸Ga-PSMA-11 PET/CT in the evaluation of bone metastases in metastatic prostate cancer (PC) patients scheduled for radionuclide therapy in comparison to [¹⁸F]sodium fluoride (¹⁸F-NaF) PET/CT.

Methods

Sixteen metastatic PC patients with known skeletal metastases, who underwent both ⁶⁸Ga-PSMA-11 PET/CT and ¹⁸F-NaF PET/CT for assessment of metastatic burden prior to radionuclide therapy, were analysed retrospectively. The performance of both tracers was calculated on a lesion-based comparison. Intensity of tracer accumulation of pathologic bone lesions on ¹⁸F-NaF PET and ⁶⁸Ga-PSMA-11 PET was measured with maximum standardized uptake values (SUV_max) and compared to background activity of normal bone. In addition, SUV_max values of PET-positive bone lesions were analysed with respect to morphologic characteristics on CT. Bone metastases were either confirmed by CT or follow-up PET scan.

Results

In contrast to 468 PET-positive lesions suggestive of bone metastases on ¹⁸F-NaF PET, only 351 of the lesions were also judged positive on ⁶⁸Ga-PSMA-11 PET (75.0%). Intensity of tracer accumulation of pathologic skeletal lesions was significantly higher on ¹⁸F-NaF PET compared to ⁶⁸Ga-PSMA-11 PET, showing a median SUV_max of 27.0 and 6.0, respectively (p?<?0.001). Background activity of normal bone was lower on ⁶⁸Ga-PSMA-11 PET, with a median SUV_max of 1.0 in comparison to 2.7 on ¹⁸F-NaF PET; however, tumour to background ratio was significantly higher on ¹⁸F-NaF PET (9.8 versus 5.9 on ⁶⁸Ga-PSMA-11 PET; p?=?0.042). Based on morphologic lesion characterisation on CT, ¹⁸F-NaF PET revealed median SUV_max values of 23.6 for osteosclerotic, 35.0 for osteolytic, and 19.0 for lesions not visible on CT, whereas on ⁶⁸Ga-PSMA-11 PET median SUV_max values of 5.0 in osteosclerotic, 29.5 in osteolytic, and 7.5 in lesions not seen on CT were measured. Intensity of tracer accumulation between¹⁸F-NaF PET and ⁶⁸Ga-PSMA-11 PET was significantly higher in osteosclerotic (p?<?0.001) and lesions not visible on CT (p?=?0.012).

Conclusion

In comparison to ⁶⁸Ga-PSMA-11 PET/CT, ¹⁸F-NaF PET/CT detects a higher number of pathologic bone lesions in advanced stage PC patients scheduled for radionuclide therapy. Our data suggest that ⁶⁸Ga-PSMA-11 PET should be combined with ¹⁸F-NaF PET in PC patients with skeletal metastases for restaging prior to initiation or modification of therapy.

     

Screening for bone metastases: whole-body MRI using a 32-channel system versus dual-modality PET-CT

The diagnostic accuracy of screening for bone metastases was evaluated using whole-body magnetic resonance imaging (WB-MRI) compared with combined fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) (FDG-PET-CT). In a prospective, blinded study, 30 consecutive patients (18 female, 12 male; 24–76 years) with different oncological diseases and suspected skeletal metastases underwent FDG-PET-CT as well as WB-MRI with the use of parallel imaging (PAT). With a 32-channel scanner, coronal imaging of the entire body and sagittal imaging of the complete spine was performed using T1-weighted and short tau inversion recovery (STIR) sequences in combination. PET-CT was conducted using a low-dose CT for attenuation correction, a PET-emission scan and diagnostic contrast-enhanced CT scan covering the thorax, abdomen and pelvis. Two radiologists read the MRI scans, another radiologist in combination with a nuclear medicine physician read the PET-CT scans, each in consensus. The standard of reference was constituted by radiological follow-up within at least 6 months. In 28 patients, 102 malignant and 25 benign bone lesions were detected and confirmed. WB-MRI showed a sensitivity of 94% (96/102), PET-CT exams achieved 78% (79/102; P<0.001). Specificities were 76% (19/25) for WB-MRI and 80% (20/25) for PET-CT (P>0.05). Diagnostic accuracy was 91% (115/127) and 78% (99/127; P<0.001), respectively. Cut-off size for the detection of malignant bone lesions was 2 mm for WB-MRI and 5 mm for PET-CT. WB-MRI revealed ten additional bone metastases due to the larger field of view. In conclusion, WB-MRI and FDG-PET-CT are robust imaging modalities for a systemic screening for metastatic bone disease. PAT allows WB-MRI bone marrow screening at high spatial resolution and with a diagnostic accuracy superior to PET-CT.     

High predictive value of F-18 FDG PET patterns of the spine for metastases or benign lesions with good agreement between readers

Two nuclear medicine physicians retrospectively evaluated fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) spine abnormalities in patients with cancer with the purpose of identifying straightforward criteria for benign versus malignant spine abnormalities. Four hundred seventy-five consecutive patients with colon, breast, and lung cancer were evaluated with FDG. Thirty-two patients (32) had spine abnormalities, 30 of 32 patients had adequate follow up for a final diagnosis, and 29 of 30 patients' studies were available to both PET readers for this retrospective review. The readers categorized the FDG PET abnormalities as benign, metastatic, or equivocal using a straightforward set of criteria. A final diagnosis was made using magnetic resonance imaging (MRI), computed tomography (CT), plain films, bone scans, previous studies, and clinical follow up. A single spinal focus of increased FDG activity had a relatively high probability of being a spinal metastasis (71%); and the more foci, the higher the probability. Segmental decreased activity of the spine after radiation therapy indicated benignity. The only discrepancies were with 3 abnormalities, each called metastasis by 1 reader and equivocal by the other, with a final diagnosis of metastasis in each case. Equivocal patterns required CT or MR correlation, because these could be either malignant or benign. However, abnormal patterns fulfilling either the benign or metastatic criteria described here resulted in the correct diagnoses of benign spinal changes or spinal metastases, respectively, in 100% of cases with low interobserver variation. No study was interpreted as benign by 1 reader and metastasis by the other. The 2 nuclear medicine readers agreed in their interpretations in 90% of cases.     

Comparisons between glucose analogue 2-deoxy-2-(18F)fluoro-D-glucose and 18F-sodium fluoride positron emission tomography/computed tomography in breast cancer patients with bone lesions

AIM: To compare 2-deoxy-2-(¹⁸F)fluoro-D-glucose(¹⁸F-FDG) and ¹⁸F-sodium (¹⁸F-NaF) positron emission tomography/computed tomography (PET/CT) accuracy in breast cancer patients with clinically/radiologically suspected or known bone metastases.METHODS: A total of 45 consecutive patients with breast cancer and the presence or clinical/biochemical or radiological suspicion of bone metastatic disease underwent ¹⁸F-FDG and ¹⁸F-fluoride PET/CT. Imaging results were compared with histopathology when available, or clinical and radiological follow-up of at least 1 year. For each technique we calculated: Sensitivity (Se), specificity (Sp), overall accuracy, positive and negative predictive values, error rate, and Youden’s index. McNemar’s χ² test was used to test the difference in sensitivity and specificity between the two diagnostic methods. All analyses were computed on a patient basis, and then on a lesion basis, with consideration ofthe density of independent lesions on the co-registered CT (sclerotic, lytic, mixed, no-lesions) and the divergent site of disease (skull, spine, ribs, extremities, pelvis). The impact of adding ¹⁸F-NaF PET/CT to the work-up of patients was also measured in terms of change in their management due to ¹⁸F-NaF PET/CT findings.RESULTS: The two imaging methods of ¹⁸F-FDG and ¹⁸F-fluoride PET/CT were significantly different at the patient-based analysis: Accuracy was 86.7% and 84.4%, respectively (McNemar’s χ² = 6.23, df = 1, P = 0.01). Overall, 244 bone lesions were detected in our analysis. The overall accuracy of the two methods was significantly different at lesion-based analysis (McNemar’s χ² = 93.4, df = 1, P < 0.0001). In the lesion density-based and site-based analysis, ¹⁸F-FDG PET/CT provided more accurate results in the detection of CT-negative metastasis (P < 0.002) and vertebral localizations (P < 0.002); ¹⁸F-NaF PET/CT was more accurate in detecting sclerotic (P < 0.005) and rib lesions (P < 0.04). ¹⁸F-NaF PET/CT led to a change of management in 3 of the 45 patients (6.6%) by revealing findings that were not detected at ¹⁸F-FDG PET/CT.CONCLUSION: ¹⁸F-FDG PET/CT is a reliable imaging tool in the detection of bone metastasis in most cases, with a diagnostic accuracy that is slightly, but significantly, superior to that of ¹⁸F-NaF PET/CT in the general population of breast cancer patients. However, the extremely high sensitivity of ¹⁸F-fluoride PET/CT can exploit its diagnostic potential in specific clinical settings (i.e., small CT-evident sclerotic lesions, high clinical suspicious of relapse, and negative ¹⁸F-FDG PET and conventional imaging).     

18F-Fluoride PET/CT is highly effective for excluding bone metastases even in patients with equivocal bone scintigraphy

Purpose

Bone scintigraphy (BS) has been used extensively for many years for the diagnosis of bone metastases despite its low specificity and significant rate of equivocal lesions. ¹⁸F-Fluoride PET/CT has been proven to have a high sensitivity and specificity in the detection of malignant bone lesions, but its effectiveness in patients with inconclusive lesions on BS is not well documented. This study evaluated the ability of ¹⁸F-fluoride PET/CT to exclude bone metastases in patients with various malignant primary tumours and nonspecific findings on BS.

Methods

We prospectively studied 42 patients (34–88?years of age, 26 women) with different types of tumour. All patients had BS performed for staging or restaging purposes but with inconclusive findings. All patients underwent ¹⁸F-fluoride PET/CT. All abnormalities identified on BS images were visually compared with their appearance on the PET/CT images.

Results

All the 96 inconclusive lesions found on BS images of the 42 patients were identified on PET/CT images. ¹⁸F-Fluoride PET/CT correctly excluded bone metastases in 23 patients (68 lesions). Of 19 patients (28 lesions) classified by PET/CT as having metastases, 3 (5 lesions) were finally classified as free of bone metastases on follow-up. The sensitivity, specificity, and positive and negative predictive values of ¹⁸F-fluoride PET/CT were, respectively, 100?%, 88?%, 84?% and 100?% for the identification of patients with metastases (patient analysis) and 100?%, 82?% and 100?% for the identification of metastatic lesions (lesion analysis).

Conclusion

The factors that make BS inconclusive do not affect ¹⁸F-fluoride PET/CT which shows a high sensitivity and negative predictive value for excluding bone metastases even in patients with inconclusive conventional BS.