基于PET代谢参数构建孤立性肺良恶性病变预测模型

目的 基于PET代谢参数构建预测模型，探讨其鉴别诊断孤立性肺良恶性病变的价值。方法 回顾性分析接受¹⁸F-FDG PET/CT检查的135例孤立性肺病变患者，测量病灶代谢参数，包括肿瘤代谢体积（MTV）、最大标准化摄取值（SUV_max）、标准化摄取值峰值（SUV_peak）、平均标准化摄取值（SUV_mean）和标准化糖酵解总量（SUV_tlg），以及瘦体质量SUV（SUL），包括SUL_max、SUL_peak、SUL_mean和SUL_tlg。利用支持向量机（SVM）对PET代谢参数构建模型，以赤池信息准则筛选最优化模型。绘制ROC曲线，评价模型对肺良恶性病变的诊断价值，以置换检验进行内部验证。结果 最终获得2个最优化模型（AIC值均为－232.92），分别称为Mgroup A（纳入参数为MTV、SUV_peak和SUV_tlg）和Mgroup B（纳入参数为MTV、SUV_peak和SUL_tlg）。Mgroup A模型诊断肺良恶性病变的AUC为0.865（P=0.021），灵敏度82.72%，特异度83.33%，准确率82.96%；Mgroup B模型的AUC为0.863（P=0.030），灵敏度82.72%，特异度83.33%，准确率82.96%；2个模型间AUC差异无统计学意义（P=0.294）。置换检验提示模型均稳定可靠。结论 基于PET代谢参数构建SVM模型对肺孤立性良恶性病变具有较好的鉴别诊断效能，但脂肪校正不能提高代谢参数的诊断效能。     

Targeting Prostate-Specific Membrane Antigen (PSMA) with F-18-Labeled Compounds: the Influence of Prosthetic Groups on Tumor Uptake and Clearance Profile

Purpose

Prostate-specific membrane antigen (PSMA) is an important biomarker expressed in the majority of prostate cancers. The favorable positron emission tomography (PET) imaging profile of the PSMA imaging agent 2-(3-(1-carboxy-5-[(6-[¹⁸F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentane-dioic acid [¹⁸F]DCFPyL in preclinical prostate cancer models and in prostate cancer patients stimulated the development and validation of other fluorine-containing PSMA inhibitors to further enhance pharmacokinetics and simplify production methods. Here, we describe the synthesis and radiopharmacological evaluation of various F-18-labeled PSMA inhibitors which were prepared through different prosthetic group chemistry strategies.

Procedures

Prosthetic groups N-succinimidyl-4-[¹⁸F]fluorobenzoate ([¹⁸F]SFB), 4-[¹⁸F]fluorobenzaldehyde, and 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG) were used for bioconjugation reactions to PSMA-binding lysine-urea-glutamate scaffold via acylation and oxime formation. All fluorine-containing PSMA inhibitors were tested for their PSMA inhibitory potency in an in vitro competitive binding assay in comparison to an established reference compound [¹²⁵I]TAAG-PSMA. Tumor uptake and clearance profiles of three F-18-labeled PSMA inhibitors ([¹⁸F]4, [¹⁸F]7, and [¹⁸F]8) were studied with dynamic PET imaging using LNCaP tumor-bearing mice.

Results

F-18-labeled PSMA inhibitors were synthesized in 32–69 % radiochemical yields using (1) acylation reaction at the primary amino group of the lysine residue with [¹⁸F]SFB and (2) oxime formation with 4-[¹⁸F]fluorobenzaldehyde and [¹⁸F]FDG using the respective aminooxy-functionalized lysine residue. Compound 7 displayed an IC₅₀ value of 6 nM reflecting very high affinity for PSMA. Compounds 4 and 8 showed IC₅₀ values of 13 and 62 nM, respectively. The IC₅₀ value of reference compound DCFPyL was 13 nM. Dynamic PET imaging revealed the following SUV_60min for radiotracer uptake in PSMA(+) LNCaP tumors: 0.98 ([¹⁸F]DCFPyL), 2.11 ([¹⁸F]7), 0.40 ([¹⁸F]4), and 0.19 ([¹⁸F]8).

Conclusion

The observed tumor uptake and clearance profiles demonstrate the importance of the selected prosthetic group on the pharmacokinetic profile of analyzed PSMA-targeting radiotracers. Radiotracer [¹⁸F]7 displayed the highest uptake and retention in LNCaP tumors, which exceeded uptake values of reference compound [¹⁸F]DCFPyL by more than 100 %. Despite the higher kidney and liver uptake and retention of compound [¹⁸F]7, the simple radiosynthesis and the exceptionally high tumor uptake (SUV_60min 2.11) and retention make radiotracer [¹⁸F]7 an interesting alternative to radiotracer [¹⁸F]DCFPyL for PET imaging of PSMA in prostate cancer.

     

Uptake of Radium-223 Dichloride and Early [<Superscript>18</Superscript>F]NaF PET Response Are Driven by Baseline [<Superscript>18</Superscript>F]NaF Parameters: a Pilot Study in Castration-Resistant Prostate Cancer Patients

Purpose

The purpose of this study is to identify predictive factors on baseline [¹⁸F]NaF positron emission tomography (PET)/computed tomography (CT) of early response to radium-223 dichloride after 3 cycles of treatment in metastatic castration-resistant prostate cancer patients.

Procedures

Analysis of 152 metastases was performed in six consecutive patients who underwent [¹⁸F]NaF PET/CT at baseline and for early monitoring after 3 cycles of radium-223 dichloride. All metastases depicted on whole-body [¹⁸F]NaF PET/CT were contoured and CT (density in Hounsfield units, sclerotic, mixed, or lytic appearance) as well as [¹⁸F]NaF [maximum standardized uptake value (SUV_max), SUV_mean, and lesion volume (V_18F-NaF)] patterns were recorded. Tumor response was defined as percentage change in SUV_max and SUV_mean between baseline and post-treatment PET. Bone lesions were defined as stable, responsive, or progressive, according to thresholds derived from a recent multicentre test-retest study in [¹⁸F]NaF PET/CT. Total [¹⁸F]NaF uptake in metastases, defined as MATV × SUV_mean, was correlated to uptake of radium-223 on biodistribution scintigraphy performed 7 days after the first cycle of treatment.

Results

Among metastases, 116 involved the axial skeleton and 36 the appendicular skeleton. Lesions were sclerotic in 126 cases and mixed in 26 cases. No lytic lesion was depicted. ROC analysis showed that SUV_max and SUV_mean were better predictors of lesion response than V_18F-NaF and density on CT (P < 0.0001 and P = 0.001, respectively). SUV_max and SUV_mean were predictors of individual tumor response in separate multivariate models (P = 0.01 and P = 0.02, respectively). CT pattern (mixed versus sclerotic) and lesion density were independent predictors only when assessing response with delta SUV_max (P = 0.002 and 0.007, respectively). A good correlation between total [¹⁸F]NaF uptake within metastases and their relative radium-223 uptake assessed by two observers 7 days after treatment (r = 0.72 and 0.77, P < 0.0001) was found.

Conclusions

SUV_max and SUV_mean on baseline [¹⁸F]NaF PET/CT are independent predictors of bone lesions’ response to 3 cycles of radium-223 dichloride, supporting the use of NaF to select patients more likely to respond to treatment.

     

结直肠癌18F-FDG的摄取与Glut-1表达的相关性

目的 探讨结直肠癌18F-FDG摄取与肿瘤组织葡萄糖转运蛋白-1(Glut-1)表达的相关性.方法 对20例结直肠癌患者术前进行18F-FDG PET/CT检查,测定肿瘤平均标准摄取值(SUVmean);对手术切除标本进行病理检查,并应用免疫组织化学法检测肿瘤组织Glut-1的表达.分析SUVmean值与组织病理关系及与Glut-1表达的相关性.结果 20例结直肠癌均为高摄取,SUVmean值为5.42±1.67.大体分型中,浸润型结直肠癌的SUVmean值(6.55±1.63)高于肿块型(4.20±1.29)和溃疡型(5.83±1.60),但差异无统计学意义(P＞0.05).M分期中,远处转移者的SUVmean值(7.14±1.07)高于无转移者(4.84士1.41,P=0.04).SUVmean值与Glut-1的表达呈正相关(r=0.53,P=0.02).结论 结直肠癌18F-FDG摄取(SUVmean值)与Glut-1表达呈现正相关.     

一体化18F-FDG PET/MR评估缺血性脑血管病

目的 探讨一体化¹⁸F-FDG PET/MR显像对于慢性缺血性脑血管病的应用价值。方法 对10名成年健康志愿者及17例慢性单侧颈内动脉（ICA）或大脑中动脉（MCA）闭塞患者行一体化¹⁸F-FDG PET/MR检查。由2名医师分析图像，定量分析和比较健康志愿者左侧与右侧不同脑区、慢性缺血性脑血管病患者脑梗死患侧与对侧相应区域及脑梗死周围区与对侧相应区域间平均ADC值（ADC_mean）、平均标准化摄取值（SUV_mean）及最大标准化摄取值（SUV_max）的差异。结果 10名健康志愿者MRI均未见异常，¹⁸F-FDG脑代谢图像清晰，各脑区代谢分布对称；左侧与右侧额叶、顶叶、颞叶、枕叶ADC_mean、SUV_mean、SUV_max差异均无统计学意义（P均>0.05）。17例慢性缺血性脑血管病MRI均可见脑梗死灶，¹⁸F-FDG脑代谢图显示患侧均较对侧相应区域ADC_mean、SUV_mean、SUV_max明显减低（P均<0.01）；脑梗死周围区与对侧相应区域比较ADC_mean、SUV_mean、SUV_max亦明显减低（P均<0.01）。结论 利用一体化¹⁸F-FDG PET/MR检查可同时获得脑结构和脑代谢综合信息，全面评价慢性缺血性脑血管病。     

骨髓、脾脏FDG摄取水平与非小细胞肺癌临床病理特征

目的 观察¹⁸F-FDG PET/CT所示骨髓及脾脏FDG摄取水平与非小细胞肺癌(NSCLC)患者临床病理特征的关系。方法 纳入82例术前接受¹⁸F-FDG PET/CT检查的NSCLC患者(NSCLC组)及41例非肿瘤患者(对照组),比较2组骨髓、脾脏FDG摄取水平差异，观察其与临床病理特征之间的关系。结果 NSCLC组骨髓平均标准摄取值(SUV_mean)、骨髓SUV_mean与肝脏SUV_mean比值(BLR),以及脾脏SUV_mean与肝脏SUV_mean比值(SLR)均高于对照组(P均<0.05)。男性患者、鳞癌、高TNM分期、肿瘤>3 cm及伴局部淋巴结转移者NSCLC原发灶的最大标准摄取值(SUV_max)更高(P均<0.05);高TNM分期、肿瘤>3 cm及伴局部淋巴结转移患者骨髓SUV_mean及BLR更高(P均<0.05);高TNM分期及肿瘤>3 c...     

[18F]-JK-PSMA-7 PET/CT Under Androgen Deprivation Therapy in Advanced Prostate Cancer

Purpose

PSMA imaging is frequently used for monitoring of androgen deprivation therapy (ADT) in prostate cancer. In a previous study, [¹⁸F]-JK-PSMA-7 exhibited favorable properties for tumor localization after biochemical recurrence. In this retrospective study, we evaluated the performance of [¹⁸F]-JK-PSMA-7 under ADT.

Procedures

We examined the performance of [¹⁸F]-JK-PSMA-7 in 70 patients (first cohort) with increasing or detectable PSA values under ADT (PSA < 2 ng/ml for 21/70 patients). We further analyzed 58 independent patients with PSA levels < 2 ng/ml under ADT, who were imaged with [⁶⁸Ga]PSMA-11 or [¹⁸F]DCFPyL (second cohort). Finally, we compared detection rates between [¹⁸F]-JK-PSMA-7, [⁶⁸Ga]PSMA-11, and [¹⁸F]DCFPyL.

Results

In the first cohort, we detected [¹⁸F]-JK-PSMA-7-positive lesions in 63/70 patients. In patients with PSA levels ≥ 2 ng/ml, the detection rate was 100 % (49/49). In patients with PSA < 2 ng/ml, the detection rate was significantly lower (66.7 %, 14/21, p = 9.7 × 10^?5) and dropped from 85.7 % (12/14, PSA levels between 0.3 and 2.0 ng/ml) to 28.6 % (2/7) for PSA levels < 0.3 ng/ml (p = 1.73 × 10^?2). In the second cohort (PSA < 2 ng/ml), the detection rate was 79.3 % (46/58) for [⁶⁸Ga]PSMA-11 or [¹⁸F]DCFPyL. Again, the detection rate was significantly higher (p = 1.1 × 10^?2) for patients with PSA levels between 0.3 and 2.0 ng/ml (87.0 %, 40/46) relative to those with PSA levels < 0.3 ng/ml (50 %, 6/12). No significant difference was found between [¹⁸F]-JK-PSMA-7 and [⁶⁸Ga]PSMA-11 or [¹⁸F]DCFPyL in patients with PSA levels < 2 ng/ml (p = 0.4295).

Conclusion

[¹⁸F]-JK-PSMA-7 PET showed a high detection rate in patients with PSA levels ≥ 0.3 ng/ml under ADT. The lower PSA threshold of 0.3 ng/ml for high detection rates was consistent across the three PSMA ligands. Thus, PSMA imaging is suitable for clinical follow-up of patients with increasing PSA levels under ADT.

     

18F-FDG PET/CT代谢参数与食管癌临床病理特征的相关性

目的 观察食管癌原发灶的PET/CT代谢参数与其临床病理特征的相关性。方法 回顾性分析54例食管癌患者术前¹⁸F-FDG PET/CT的影像学表现及临床资料,检测原发灶最大标准摄取值（SUV_max）、平均标准摄取值（SUV_mean）、代谢体积（MTV）,并计算病灶糖酵解总量（TLG）,分析上述参数与临床病理特征的相关性。结果 54例食管癌原发灶的SUV_max、SUV_mean、MTV及TLG分别为9.92±5.10、6.04±3.23、（12.34±9.20） cm³和63.75（17.75,110.03） g。SUV_max、SUV_mean、MTV与原发灶最大径呈中等正相关,TLG与原发灶最大径呈较高度正相关（P均<0.05）。SUV_max、SUV_mean、MTV、TLG与肿瘤原发灶T分期均呈中等正相关（r=0.360、0.347、0.477、0.556,P均<0.05）;MTV、TLG与肿瘤原发灶N分期均呈中等正相关（r=0.328、0.357,P均<0.05）;SUV_max、SUV_mean、MTV及TLG与肿瘤M分期线性相关差异均无统计学意义（P均>0.05）。SUV_max、SUV_mean与肿瘤临床分期线性相关差异均无统计学意义（P均>0.05）,MTV和TLG与肿瘤的临床分期均呈中等正相关（r=0.462、0.435,P均<0.05）。TLG与原发灶的病理分化程度呈中等正相关（P=0.036）,SUV_max、SUV_mean、MTV与原发灶病理分化程度线性相关差异均无统计学意义（P均>0.05）。结论 食管癌原发灶代谢参数与临床病理特征具有较好相关性,可在一定程度上反映肿瘤的部分病理特征。     

原发系统性间变性大细胞淋巴瘤18F-FDG PET/CT表现

目的 观察原发系统性间变性大细胞淋巴瘤(ALCL)¹⁸F-FDG PET/CT表现。方法 纳入21例原发系统性ALCL,观察病灶PET/CT表现。结果 21例中,15例ALK⁺、6例ALK^-ALCL;19例累及多部位淋巴结,主要包括颈部(13例)、纵隔(12例)及腹膜后(12例)淋巴结,2例仅累及单一部位淋巴结。12例累及结外器官/部位,其中6例累及软组织如皮肤、肌肉等,4例累及骨骼,14例累及脏器,包括肺部(4例)、肝脏(3例)、胰腺(2例)、肾脏(2例)、胃肠道(2例)及甲状腺(1例)。21例中,19例淋巴结形态欠规则并融合成团,17例密度均匀,3例可见坏死,1例可见钙化。21例病灶均表现为高代谢,受累淋巴结最大标准摄取值(SUV_max)、平均标准摄取值(SUV_mean)分别为17.04±9.94、9.96±6.15,全部病灶肿瘤代谢体积(MTV)、病灶糖酵解总量(TLG)分别为92.54(67.61,249.21)cm³、723.46(419.78,...     

18F-FDOPA PET/CT评估放射化学治疗用于高级别脑胶质瘤效果

目的 观察以¹⁸F-L-6-氟-3,4-二羟基苯丙氨酸(¹⁸F-FDOPA)PET/CT评估放射及化学治疗(放疗及化疗)用于高级别脑胶质瘤效果的价值。方法 回顾性分析84例接受精准放疗及同步化疗的高级别脑胶质瘤患者资料,根据疗效将其分为有效组(完全缓解+部分缓解+疾病稳定,n=60)及无效组(疾病进展,n=24)。比较组间及组内治疗前后肿瘤¹⁸F-FDOPA PET/CT代谢参数,包括肿瘤代谢体积(MTV)、最大标准摄取值(SUV_max)及平均标准摄取值(SUV_mean);以Spearman相关性分析观察代谢参数与放化疗效果的相关性。结果 治疗后有效组MTV、SUV_max及SUV_mean均低于无效组(P均<0.05)。有效组治疗前、后代谢参数差异有统计学意义(P均<0.05)。高级别脑胶质瘤MTV、SUV_max、SUV_mean与放化疗效果呈负相关(r=-0.63、-0.52、-0...     

原发胃癌18F-FDG PET/CT代谢参数与临床病理特征的相关性

目的 探讨原发胃癌¹⁸F-FDG PET/CT代谢参数与临床病理特征的相关性。方法 回顾性分析我院经手术病理证实的44例胃癌患者的¹⁸F-FDG PET/CT显像特征和临床资料,记录胃癌原发灶的最大标准摄取值（SUV_max）、平均标准摄取值（SUV_mean）及代谢体积（MTV）,并计算病灶糖酵解总量（TLG）。分别比较不同肿瘤T分期、N分期、病理分期及细胞组织分化程度组间上述代谢参数的差异,并分析上述代谢参数与临床病理特征的相关性。结果 44例原发胃癌的SUV_max、SUV_mean、MTV及TLG分别为5.81（3.45,7.77）、3.42（1.87,4.37）、14.80（9.02,25.19）cm³及42.03（18.89,107.87）g。不同T分期胃癌原发灶的SUV_max、SUV_mean、MTV、TLG差异均无统计学意义（P均>0.05）;不同N分期及病理分期胃癌原发灶的MTV、TLG差异均有统计学意义（P均<0.05）,而SUV_max、SUV_mean差异均无统计学意义（P均>0.05）;不同细胞组织分化程度胃癌原发灶SUV_max、SUV_mean差异有统计学意义（P均<0.05）,而MTV、TLG差异无统计学意义（P均>0.05）。SUV_max、SUV_mean与肿瘤T分期及细胞组织分化程度呈中度正相关（P均<0.05）,与肿瘤N分期及病理分期均无显著相关性（P均>0.05）;MTV及TLG与肿瘤T分期、N分期及病理分期均呈中度正相关（P均<0.05）;MTV及TLG与肿瘤细胞组织分化程度均无显著相关（P均>0.05）。结论 胃癌原发灶的¹⁸F-FDG PET/CT代谢参数可反映肿瘤的部分临床病理特征,有助于临床制定个体化治疗方案。     

结直肠腺癌18F-FDG PET/CT代谢参数与临床病理因素的关系

目的 探讨原发结直肠腺癌¹⁸F-FDG PET/CT代谢参数与临床病理因素的关系。方法 回顾性分析经手术病理证实的52例结直肠腺癌患者的¹⁸F-FDG PET/CT显像特征和临床资料,记录肿瘤原发灶最大径、最大标准摄取值（SUV_max）、平均标准摄取值（SUV_mean）及代谢体积（MTV）,并计算病灶糖酵解总量（TLG）。按肿瘤原发灶最大径、T分期、N分期及细胞组织分化程度分别进行分组,比较组间上述参数的差异,分析其与临床病理特征的相关性。结果 52例结直肠腺癌原发灶的SUV_max、SUV_mean、MTV及TLG分别为13.38±7.34、7.75±3.94、（15.83±11.18）cm³及103.15（45.28,140.23）g。不同原发灶最大径组间各代谢参数差异均有统计学意义（P均<0.05）;不同T分期组间肿瘤原发灶SUV_max、SUV_mean差异均无统计学意义（P均>0.05）,MTV、TLG差异有统计学意义（P均<0.05）;不同N分期、细胞组织分化程度组间肿瘤原发灶各代谢参数差异均无统计学意义（P均>0.05）。SUV_max、SUV_mean与原发灶最大径呈正相关（P均<0.05）,与T分期、N分期、细胞组织分化程度均无明显相关（P均>0.05）;MTV、TLG与原发灶最大径、T分期呈正相关（P均<0.05）,与N分期和组织分化程度无明显相关（P均>0.05）。结论 结直肠腺癌的体积参数MTV、TLG可在一定程度上反映病理因素,较SUV_max、SUV_mean的评价价值更高。     

Initial Experience with the Radiotracer Anti-1-amino-3-[18F]Fluorocyclobutane-1-Carboxylic Acid (Anti-[18F]FACBC) with PET in Renal Carcinoma

Purpose

Assessment of renal masses with conventional imaging may be challenging. Anti-1-amino-3-[¹⁸F]fluorocyclobutane-1-carboxylic acid (anti-[18F]FACBC) is a synthetic l-leucine analog with relatively little renal excretion. The present study examines anti-[¹⁸F]FACBC positron emission tomography uptake in patients with renal masses.

Procedures

Six patients with seven renal lesions were imaged dynamically for 2 h after injection of 10–10.9 mCi (370–403 MBq) anti-[¹⁸F]FACBC. Lesions were evaluated qualitatively and quantitatively and correlated with histology.

Results

Four clear cell and one Rosai–Dorfman lesion were hypo/isointense to normal cortex; two papillary lesions in the same patient were hyperintense. Mean SUV_max?±?SD at 30 min was 2.8?±?0.24 for clear cell carcinomas and 4.5?±?1.7 for papillary cell lesions. Mean SUV_max/SUV_mean ratios?±?SD of lesion to normal cortex at 30 min was 1.15?±?0.19 for the clear cell carcinomas and 2.3?±?0.84 for papillary cell.

Conclusions

In this small patient sample, relative amino acid transport compared with renal cortex is elevated in renal papillary cell carcinoma but not in clear cell carcinoma.     

18FDG-PET/MR观察宫颈鳞状细胞癌ADC值与SUV的相关性

目的 应用¹⁸FDG-PET/MR一体机观察宫颈鳞状细胞癌ADC值与FDG-PET标准化摄取值（SUV）的相关性。方法 对30例宫颈鳞状细胞癌患者行盆腔PET/MR检查。采用随机自带软件,利用轴位像对PET图像、ADC图及T2WI进行自动配准,并在同一层面勾画ROI,测量感兴趣体积（VOI）内肿瘤最大SUV（SUV_max）和平均SUV（SUV_mean）、最小ADC值（ADC_min）和平均ADC值（ADC_mean）。结果 30例宫颈鳞状细胞癌的ADC_min与SUV_max、ADC_min与SUV_mean、ADC_mean与SUV_max、ADC_mean与SUV_mean均无明显相关性;中-高分化和低分化宫颈鳞状细胞癌的上述ADC和SUV指标间亦无明显相关性。中-高分化与低分化宫颈鳞状细胞癌ADC_min差异有统计学意义（t=-2.06,P=0.049）。结论 ADC和SUV是诊断宫颈鳞状细胞癌的相互独立的指标。恶性程度分级评价中,ADC可能较SUV敏感。     

Response Monitoring with [<Superscript>18</Superscript>F]FLT PET and Diffusion-Weighted MRI After Cytotoxic 5-FU Treatment in an Experimental Rat Model for Colorectal Liver Metastases

Purpose

The aim of the study was to investigate the potential of diffusion-weighted magnetic resonance imaging (DW-MRI) and 3′-dexoy-3′-[¹⁸F]fluorothymidine ([¹⁸F]FLT) positron emission tomography (PET) as early biomarkers of treatment response of 5-fluorouracil (5-FU) in a syngeneic rat model of colorectal cancer liver metastases.

Procedures

Wag/Rij rats with intrahepatic syngeneic CC531 tumors were treated with 5-FU (15, 30, or 60 mg/kg in weekly intervals). Before treatment and at days 1, 3, 7, and 14 after treatment rats underwent DW-MRI and [¹⁸F]FLT PET. Tumors were analyzed immunohistochemically for Ki67, TK1, and ENT1 expression.

Results

5-FU inhibited the growth of CC531 tumors in a dose-dependent manner. Immunohistochemical analysis did not show significant changes in Ki67, TK1, and ENT1 expression. However, [¹⁸F]FLT SUV_mean and SUV_max were significantly increased at days 4 and 7 after treatment with 5-FU (60 mg/kg) and returned to baseline at day 14 (SUV_max at days ?1, 4, 7, and 14 was 1.1 ± 0.1, 2.3 ± 0.5, 2.3 ± 0.6, and 1.5 ± 0.4, respectively). No changes in [¹⁸F]FLT uptake were observed in the nontreated animals. Furthermore, the apparent diffusion coefficient (ADC_mean) did not change in 5-FU-treated rats compared to untreated rats.

Conclusion

This study suggests that 5-FU treatment induces a flare in [¹⁸F]FLT uptake of responsive CC531 tumors in the liver, while the ADC_mean did not change significantly. Future studies in larger groups are warranted to further investigate whether [¹⁸F]FLT PET can discriminate between disease progression and treatment response.

     

Standardized Uptake Value Atlas: Characterization of Physiological 2-Deoxy-2-[<Superscript>18</Superscript>F]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Uptake in Normal Tissues

Purpose The purpose of this study was to map the distribution of 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) uptake in organs of patients with no known abnormalities in those tissues. Procedures We measured maximum and mean standardized uptake values (SUV) from FDG-positron emission tomography (PET)/computed tomography (CT) obtained from 98 patients (48 males and 50 females). Results Significant uptake (mean SUV_mean > 2.5) was visualized in the cerebellum (8.0 ± 2.2), soft palate (2.92 ± 0.86), palatine tonsils (3.45 ± 1.4), lingual tonsils (3.08 ± 1.05), sublingual glands (3.3 ± 1.5), and testes (2.57 ± 0.56). Negative correlation for FDG uptake versus age was observed for the palatine tonsils, sublingual glands, and lungs (P < 0.001). Conclusion Better understanding of physiological uptake throughout the body is valuable for improved interpretive accuracy and should be useful for future semi-automated comparisons to a normal SUV database.     

国人脊柱与骨盆99mTc-MDP定量SPECT/CT标准化摄取值的正常分布特点

目的：探讨骨显像单光子发射计算机体层成像/计算机体层成像（SPECT/CT）骨定量分析国人脊柱及骨盆的标准化摄取值（SUV）的正常分布。方法：回顾性分析500例入组肿瘤骨转移患者的锝[^99mTc]-亚甲基二磷酸盐（^99mTc-MDP）骨定量SPECT/CT显像数据。在正常颈、胸、腰、骶椎及骨盆骨骼处勾画感兴趣区,测量最大（maximum）和平均（mean）SUV（SUV_max和SUV_mean）,统计分析SUV值在正常骨骼的分布及其与年龄、身高、体质量和CT值的相关性。结果：SUV_max和SUV_mean在第6颈椎最大,分别为7.4±2.5和6.0±2.2,在第3骶椎最小,分别为4.4±2.0和2.2±1.1。脊柱及骨盆SUV_max和SUV_mean的变异系数（CV）大小相近,分别在31.6%~45.6%和34.1%~52.7%,骨盆组成骨SUV_max（CV_骨盆=42.4%、CV_脊柱=35.0%）和SUV_mean（CV_骨盆=52.7%、CV_脊柱=38.3%）个体间差异略大于脊柱。骨骼SUV值在不同性别间无统计学差异。脊柱及骨盆的SUV_max和SUV_mean与身高均无显著相关性,与年龄负相关,与体质量及CT值正相关。结论：骨定量SPECT/CT可获得^99mTc-MDP在正常骨骼中的SUV值,可用于骨转移诊断及评估的参考;不同部位骨骼SUV值存在一定差异,应用SUV值诊断和评估肿瘤骨转移时需具体部位具体分析。     

99Tcm-MDP骨显像腰椎标准摄取值与骨密度的相关性

目的 观察不同骨密度（BMD）患者⁹⁹Tc^m-亚甲基二磷酸盐（⁹⁹Tc^m-MDP）骨显像腰椎标准摄取值（SUV）的差异，并分析其与BMD的相关性。方法 回顾性分析62例接受⁹⁹Tc^m-MDP全身骨显像、腰椎SPECT/CT断层显像及双能X线腰椎BMD检测患者，根据BMD结果将其分为骨量正常组（n=18）、骨量减低组（n=24）和骨质疏松组（n=20），比较3组腰椎平均SUV（SUV_mean）、最大SUV（SUV_max）及BMD等的差异，分析其与腰椎平均CT值、患者年龄、体质量及身高的相关性。结果 腰椎SUV_max和SUV_mean分别为7.39±1.84和4.90±1.27，均与BMD呈正相关（r=0.64、0.63，P均<0.01）。腰椎SUV_max、SUV_mean和BMD均与年龄呈负相关（r=-0.33、-0.44、-0.43，P均<0.05），与体质量（r=0.42、0.30、0.35）及平均CT值（r=0.56、0.59、0.73）呈正相关（P均<0.05），与身高无明显相关（P均>0.05）。3组间腰椎SUV_max、SUV_mean、BMD和平均CT值差异均有统计学意义（F=24.09、30.50、94.85、30.24，P均<0.01）。骨量减低组腰椎SUV_max、SUV_mean、BMD和平均CT值明显低于正常组（P均<0.01）；骨质疏松组明显低于骨量正常组和骨量减低组（P均<0.01）。结论 ⁹⁹Tc^m-MDP骨显像腰椎SUV可用于评价骨质疏松及评估疗效。腰椎SUV_max及SUV_mean均与BMD呈正相关。骨质疏松患者腰椎SUV_max和SUV_mean明显降低。     

Effects of a Ketogenic Diet on [18F]FDG-PET Imaging in a Mouse Model of Lung Cancer

Purpose

Myocardial uptake can hamper visualization of lung tumors, atherosclerotic plaques, and inflammatory diseases in 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) studies because it leads to spillover in adjacent structures. Several preparatory pre-imaging protocols (including dietary restrictions and drugs) have been proposed to decrease physiological [¹⁸F]FDG uptake by the heart, although their effect on tumor glucose metabolism remains largely unknown. The objective of this study was to assess the effects of a ketogenic diet (as an alternative protocol to fasting) on tumor glucose metabolism assessed by [¹⁸F]FDG positron emission tomography (PET) in a mouse model of lung cancer.

Procedures

PET scans were performed 60 min after injection of 18.5 MBq of [¹⁸F]FDG. PET data were collected for 45 min, and an x-ray computed tomograph (CT) image was acquired after the PET scan. A PET/CT study was obtained for each mouse after fasting and after the ketogenic diet. Quantitative data were obtained from regions of interest in the left ventricular myocardium and lung tumor.

Results

Three days on a ketogenic diet decreased mean standard uptake value (SUVmean) in the myocardium (SUVmean 0.95?±?0.36) more than one night of fasting (SUVmean 1.64?±?0.93). Tumor uptake did not change under either dietary condition.

Conclusions

These results show that 3 days on high-fat diets prior to [¹⁸F]FDG-PET imaging does not change tumor glucose metabolism compared with one night of fasting, although high-fat diets suppress myocardial [¹⁸F]FDG uptake better than fasting.

     

99TcmO4- SPECT/CT评估131I治疗格雷夫斯病效果

目的 观察⁹⁹Tc^mO₄^- SPECT/CT评估¹³¹I治疗格雷夫斯病（GD）效果的价值。方法 根据随访结果将44例接受¹³¹I治疗的GD患者分为治愈组（n=20）、未愈组（n=9）和甲减组（n=15）,观察各组治疗前、后⁹⁹Tc^mO₄^- SPECT/CT定量参数的差异,包括甲状腺体积、平均标准摄取值（SUV_mean）、最大标准摄取值（SUV_max）、锝摄取率及功能甲状腺质量（FTM）,及其与总三碘甲腺原氨酸（TT₃）、总甲状腺素（TT₄）、游离三碘甲腺原氨酸（FT₃）、游离甲状腺素（FT₄）及促甲状腺素（TSH）水平的关系,并观察各参数评估¹³¹I疗效的效能。结果 治疗前,3组甲状腺体积及SUV_mean差异均有统计学意义（P均<0.05）,而SUV_max、锝摄取率及FTM间差异无统计学意义（P均>0.05）。治疗后,3组甲状腺体积、SUV_mean、SUV_max、锝摄取率及FTM差异均有统计学意义（P均<0.05）;且所有患者治疗后甲状腺体积、SUV_mean、SUV_max、锝摄取率及FTM均较治疗前明显减小（P均<0.001）。其中,治愈组和甲减组治疗后甲状腺体积、SUV_mean、SUV_max、锝摄取率和FTM均较治疗前明显减小（P均<0.001）,而未愈组则无明显变化（P均>0.05）。治疗前、后甲状腺24 h摄碘率差值与SUV_mean差值及SUV_max差值均呈极强正相关（r=0.86、0.84,P均<0.05）,与FTM差值呈中度正相关（r=0.46,P<0.05）,而与锝摄取率差值呈弱正相关（r=0.38,P<0.05）。治疗前、后甲状腺体积差值与TT₃差值呈弱正相关（r=0.37,P<0.05）,而与FT₃差值呈中度正相关（r=0.43,P<0.05）。治疗前SUV_mean、SUV_max和锝摄取率判断¹³¹I治疗有效的曲线下面积（AUC）分别为0.84、0.74和0.85;治疗后,甲状腺体积、SUV_mean、SUV_max、锝摄取率及FTM较治疗前变化百分比的AUC分别为0.76、0.92、0.94、0.95及0.96,最佳截断值分别为34.50%、18.50%、24.50%、55.00%和53.00%。结论 ⁹⁹Tc^mO₄^- SPECT/CT定量参数甲状腺体积、SUV_mean、SUV_max、锝摄取率和FTM评估¹³¹I治疗GD效果具有一定价值。