Significance of incidental focal fluorine-18 fluorodeoxyglucose uptake in colon/rectum,thyroid,and prostate:With a brief literature review

BACKGROUND Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography(F-18 FDG PET/CT),a functional imaging method,is usually performed on the entire torso,and regions of unexpected suspicious focal hypermetabolism are not infrequently observed.Among the regions,colon,thyroid,and prostate were found to be the common organs in a recent umbrella review.Some studies reported that a high rate of malignancy was shown in incidentally identified focal hypermetabolic regions and suggested that further examinations should not be ignored.AIM To investigate the malignancy rate of incidental focal FDG uptake,useful PET parameters and their cutoffs in discrimination between malignant and benign lesions.METHODS Retrospectively,the final reports of 16510 F-18 FDG PET/CT scans performed at our hospital between January 2016 and March 2022 were reviewed to identify incidentally observed FDG uptake in the colon/rectum,thyroid,and prostate.The scans of patients with current or prior malignancies at each corresponding location,without the final reports of histopathology or colonoscopy(for colon and rectum)for the corresponding hypermetabolic regions,or with diffuse(not focal)hypermetabolism were excluded.Finally,88 regions of focal colorectal hypermetabolism in 85 patients(48 men and 37 women with mean age 67.0±13.4 years and 63.4±15.8 years,respectively),48 focal thyroid uptakes in 48 patients(12 men and 36 women with mean age 62.2±13.1 years and 60.8±12.4 years,respectively),and 39 focal prostate uptakes in 39 patients(mean age 71.8±7.5 years)were eligible for this study.For those unexpected focal hypermetabolic regions,rates of malignancy were calculated,PET parameters,such as standardized uptake value(SUV),capable of distinguishing between malignant and benign lesions were investigated,and the cutoffs of those PET parameters were determined by plotting receiver operating characteristic curves.RESULTS In the colon and rectum,29.5%(26/88)were malignant and 33.0%(29/88)were premalignant lesions.Both SUVmax and SUVpeak differentiated malignant/premalignant from benign lesions,however,no parameters could distinguish malignant from premalignant lesions.Higher area under the curve was shown with SUVmax(0.752,95%CI:0.649-0.856,P<0.001)and the cutoff was 7.6.In the thyroid,60.4%(29/48)were malignant.The majority were well-differentiated thyroid cancers(89.7%,26/29).The results of BRAF mutation tests were available for 20 of the 26 welldifferentiated thyroid cancers and all 20 had the mutation.Solely SUVmax differentiated malignant from benign lesions and the cutoff was 6.9.In the prostate,56.4%(22/39)were malignant.Only SUVmax differentiated malignant from benign lesions and the cutoff was 3.8.Overall,among the 175 focal hypermetabolic regions,60.6%(106/175)were proven to be malignant and premalignant(in colon and rectum)lesions.CONCLUSION Approximately 60%of the incidentally observed focal F-18 FDG uptake in the colon/rectum,thyroid,and prostate were found to be malignant.Of the several PET parameters,SUVmax was superior to others in distinguishing between malignant/premalignant and benign lesions.Based on these findings,incidental focal hypermetabolism should not be ignored and lead physicians to conduct further investigations with greater confidence.

Assessment of incidental focal colorectal uptake by analysis of fluorine-18 fluorodeoxyglucose positron emission tomography parameters

BACKGROUND Colon and rectal cancers are among the top five cancers worldwide in terms of their incidence and mortality rates.As the treatment options for cure include surgery even in specific advanced-stage cases,the early detection of lesions is important for applying active treatment methods.Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)is an established imaging study for many types of cancers;however,physiologic uptake in the gastrointestinal tract is a frequent finding and may interfere with lesion identification.Nevertheless,as unexpectedly observed focal colorectal F-18 FDG uptake may harbor malignant lesions,further examination must not be avoided.AIM To assess the clinical implications of unexpected focal colorectal F-18 FDG uptake by analyzing FDG PET parameters.METHODS A total of 15143 F-18 FDG PET/CT scans performed at our hospital between January 2016 and September 2021 were retrospectively reviewed to identify incidentally observed focal colorectal FDG uptake.Finally,83 regions showing focal colorectal FDG uptake with final histopathological reports from 80 patients(45 men and 35 women with mean ages of 66.9±10.7 years and 63.7±15.3 years,respectively)were eligible for inclusion in the present study.Each focal hypermetabolic colorectal region was classified as malignant,premalignant,or benign according to the histopathological report.PET parameters such as maximum and peak standardized uptake value(SUVmax and SUVpeak),metabolic tumor volume(MTV),mean SUV of the metabolic tumor volume(mSUVmtv),and total lesion glycolysis(TLG)were measured or calculated for the corresponding hypermetabolic regions.Parametric and nonparametric statistical comparisons of these parameters were performed among the three groups.Receiver operating characteristic curves were plotted to identify cut-off values.RESULTS The detection rate of incidental focal colorectal uptake was 0.53%(80/15,143).Of the 83 regions with unexpected focal colorectal hypermetabolism,28.9%(24/83)were malignant,32.5%(27/83)were premalignant,and 38.6%(32/83)were benign.Overall,61.4% of the regions had malignant or premalignant lesions.SUVmax,SUVpeak,and mSUVmtv differentiated malignant and/or premalignant lesions from benign lesions with statistical significance(P<0.05).mSUVmtv3.5 differentiated malignant from benign lesions,with the largest area under the curve(AUC)of 0.792 and a cut-off of 4.9.SUVmax showed the largest AUC of 0.758 with a cut-off value of 7.5 for distinguishing between premalignant and benign lesions.Overall,SUVmax with a cut-off value of 7.6(AUC:0.770,95% confidence interval(CI):0.668-0.872;sensitivity,0.686;specificity,0.688)was a superior parameter for distinguishing between malignant/premalignant and benign lesions or physiologic uptake.No parameters differentiated malignant from premalignant lesions.Moderate or weak positive correlations were observed between the long diameter of the malignant lesions and PET parameters such as SUVpeak and some mSUVmtv.CONCLUSION Approximately two-thirds(61.4%)of incidental focal hypermetabolic colorectal regions were malignant/premalignant lesions,for which SUVmax was an independent diagnostic parameter.Unexpected suspicious focal colorectal FDG uptake should not be avoided and consideration for further evaluation is strongly recommended not to miss the two-thirds.

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography for Osteochondromas Utilizing a Triple-Time Point Protocol

Purpose: The purpose of this study was to assess solitary osteochondroma and hereditary multiple osteochondral exostoses (HMOCE) utilizing FDG PET and a triple time point protocol. Methods: Seven patients were consented and recruited for PET evaluation of presumed benign osteochondroma. Following injection of 15 mCi of FDG, the lesion(s) of interest was imaged with PET-CT at 45 minutes post injection, whole body at 50 minutes post, and lesion of interest at 95 minutes post injection. A maximum standardized uptake value (SUVmax) was obtained for the lesion(s) of interest at each time point, and an SUVΔ was calculated for each lesion of interest from the first time point to the third time point. Results: 16 lesions from 7 patients were included in the study. Mean SUVmax for all 3 time points was 1.04 with a standard deviation of 0.50 (range 0.3 - 2.2). The mean SUV was 0.096 with a range of 0 - 0.4. Among the 3 patients with histologically confirmed osteochondromas, mean SUVmax was 0.67, with standard deviation of 0.23 and range of 0.3 to 1.0. The mean SUVΔ13 was 0.081 (range 0 - 0.4), mean SUVΔ12 was 0.10 (0 - 0.3), and mean SUVΔ23 was 0.11 (range 0 - 0.4) (p = 0.74). Conclusion: Benign lesions were found to not have progressively increasing uptake on multiple time point FDG PET. Until chondrosarcomas are evaluated using triple time point 18FDG PET, its applicability in the evaluation of osteochondroma versus malignant change remains uncertain.

Imaging of atherosclerotic aorta of rabbit model by detection of plaque inflammation with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

Abstract：Background Atherosclerotic plaque rupture is the primary mechanism of thrombosis which plays a key role in the onset of acute coronary syndromes. Detection of these plaques prone to rupture （vulnerable plaque） could be clinically significant for prevention of cardiac events. It has been shown that high metabolism cells have a high uptake of fluorine-18 fluorodeoxyglucose （18F-FDG）. The objective of this study was to investigate the correlation of FDG uptake and the immuno-histochemistry parameters of plaques, and the effect of atorvastatin on vulnerable atherosclerotic plaque in a rabbit model.Methods Ten male New Zealand White rabbits were divided into three groups as follows： （1） normal control group （n=2,C group）： the animals were fed a standard diet at 120 g/d and were given water ad labium; （2） atherosclerosis group （n=4,As group）： animals were fed with high fat diet for 5 months after aortic endothelia damage; （3） treatment group （atherosclerosis ＋ atorvastatin, n=4, Statin group）： animals were fed with high fat diet for 5 months and then changed into normal chow plus atorvastatin （2.5 mg·d-1·kg-1） treatment for another 4 months. Then these four rabbits were imaged with fluorine-18 fluorodexyglucose positron emission tomography/computed tomography （PET/CT） and sacrificed for pathohistologic studies. FDG uptake by the aorta was expressed as target-to-background ratio （TBR）. Maximal standardized uptake value （SUV） was measured over the thoracic and abdominal aortas. The aortic smooth muscle cell （SMC） number, CD-14 antibody positive cell （macrophage） number and the ratio of the thickness of fibrous cap to the thickness of lipid core （cap-to-core ratio） in atherosclerotic plaques were analyzed.Results As group showed significantly higher uptake of FDG than C group （SUVs： 0.746±0.172 vs. 0.286±0.073, P 〈0.001）. After 4 months of atorvastatin treatment and the modification of diet, SUVs decreased significantly （Statin group：0.550±0.134, compared to As group, P 〈0.001）. However, no marked difference was found in TBR, the number of macrophages, the number of SMC and the cap-to-core ratio in the aortic segments between Statin group and As group.The correlation of aortic FDG uptake with SMC assessed by histopathology was negatively significant （r=0.57, P〈0.001）. When aortic FDG uptake was expressed as TBR, it correlated significantly （r=0.69, P 〈0.001） with the macrophage number, and also correlated significantly （r=0.78, P 〈0.001） with the cap-to-core ratio.Conclusion 18F-FDG PET/CT might serve as a useful non-invasive imaging technique for detection of atherosclerotic plaque and potentially permit monitoring of relative changes in inflammation within the atherosclerotic lesion.

Appearance of aseptic vascular grafts after endovascular aortic repair on[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography

BACKGROUND Diagnosis of prosthetic vascular graft infection with[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)allows for early detection of functional changes associated with infection,based on increased glucose utilization by activated macrophages and granulocytes.Aseptic vascular grafts,like all foreign bodies,can stimulate an inflammatory response,which can present as increased activity on 18F-FDG PET/CT.Consequently,distinguishing aseptic inflammation from graft infection,though important,can be difficult.In the case of endovascular aneurysm repair(EVAR),a minimally invasive procedure involving the transfemoral insertion of an endoprosthetic stent graft,the normal postoperative appearance of these grafts on 18F-FDG PET/CT can vary over time,potentially confounding study interpretation.AIM To investigate the visual,semiquantitative,and temporal characteristics of aseptic vascular grafts in patients status post EVAR.METHODS In this observational retrospective cohort study,patients with history of EVAR who underwent 18F-FDG PET/CT for indications other than infection were identified retrospectively.All patients were asymptomatic for graft infection-no abdominal pain,fever of unknown origin,sepsis,or leukocytosis-at the time of imaging and for≥2 mo after each PET/CT.Imaging studies such as CT for each patient were also reviewed,and any patients with suspected or confirmed vascular graft infection were excluded.One hundred two scans performed on 43 patients(34 males;9 females;age=77±8 years at the time of the final PET/CT)were retrospectively reviewed.All 43 patients had an abdominal aortic(AA)vascular graft,40 patients had a right iliac(RI)limb graft,and 41 patients had a left iliac(LI)limb graft.Twentytwo patients had 1 PET/CT and 21 patients had from 2 to 9 PET/CTs.Grafts were imaged between 2 mo to 168 mo(about 14 years)post placement.Eight grafts were imaged within 6 mo of placement,including three that were imaged within three months of placement.The mean interval between graft placement and PET/CT for all 102 scans was 51±39 mo.PET/CT data was reconstructed with region-of-interest analysis of proximal,mid and distal portions of the grafts and background ascending aorta.Maximum standardized uptake value(SUVmax)was recorded for each region.SUVmax-to-background uptake ratios(URs)were calculated.Visual assessment was performed using a 2-pattern grading scale:Diffuse(homogeneous uptake less than liver uptake)and focal(one or more areas of focal uptake in any part of the graft).Statistical analysis was performed.RESULTS In total,there were 306 AA grafts,285 LI grafts,282 RI grafts,and 306 ascending aorta background SUVmax measurements.For all 102 scans,mean SUVmax values for AA grafts were 2.8-3.0 along proximal,mid,and distal segments.Mean SUVmax values for LI grafts and RI grafts were 2.7-2.8.Mean SUVmax values for background were 2.5±0.5.Mean URs were 1.1-1.2.Visual analysis of the scans reflected results of quantitative analysis.On visual inspection,98%revealed diffuse,homogeneous 18F-FDG uptake less than liver.Graft URs and visual pattern categories were significantly associated for AA graft URs(F-ratio=21.5,P<0.001),LI graft URs(F-ratio=20.4,P<0.001),and RI graft URs(F-ratio=30.4,P<0.001).Thus,visual patterns of 18F-FDG uptake corresponded statistically significantly to semiquantitative URs.The age of grafts showing focal patterns was greater than grafts showing diffuse patterns,87±89 vs 50±37 mo,respectively(P=0.02).URs were significantly associated with graft age for AA grafts(r=0.19,P=0.001).URs were also significantly associated with graft age for LI grafts(r=0.25,P<0.0001),and RI grafts(r=0.31,P<0.001).Quartiles of similar numbers of graft(n=25-27)grouped by graft age indicated that URs were significantly higher for 4th quartile vs 2nd quartile URs(F-ratio=19.5,P<0.001).When evaluating URs,graft SUVmax values within 10%-20%of the ascending aorta SUVmax is evident in aseptic grafts,except for grafts in the oldest quartiles.In this study,grafts in the oldest quartiles(>7 years post EVAR)showed SUVmax up to 30%higher than the ascending aorta SUVmax.CONCLUSION Characteristics of an aseptic vascular stent graft in the aorta and iliac vessels on 18F-FDG PET/CT include graft SUVmax values within 10%-20%of the ascending aorta background SUVmax.The SUVmax of older aseptic grafts can be as much as 30%above background.The visual uptake pattern of diffuse,homogeneous uptake less than liver was seen in 98%of aseptic vascular grafts,making this pattern particularly reassuring for clinicians.

Cost-effectiveness of Fluorine-18-Fluorodeoxyglucose positron emission tomography in tumours other than lung cancer: A systematic review

AIM: To systematically review published data on the cost-effectiveness of Fluorine-18-Fluorodeoxyglucose positron emission tomography(FDG-PET) or PET/computed tomography(PET/CT) in tumours other than lung cancer. METHODS: A comprehensive literature search of studies published in PubMed/MEDLINE, Scopus and Embase databases through the 10th of October in 2013 was carried out. A search algorithm based on a combination of the terms:(1) "PET" or " PET/computed tomography(PET/CT)" or "positron emission tomography"; and(2) "cost-effectiveness" or "cost-utility" or "cost-efficacy" or "technology assessment" or "health technology assessment" was used. Only cost-effectiveness or cost-utility analyses in English language were included. Exclusion criteria were:(1) articles not within the field of interest of this review;(2) review articles, editorials or letters, conference proceedings; and(3) outcome evaluation studies, cost studies or health technology assessment reports. For each included study, information was col-lected concerning basic study, type of tumours evaluated, perspective/type of study, results, unit and comparison alternatives. RESULTS: Sixteen studies were included. Head and neck tumours were evaluated in 4 articles, lymphoma in 4, colon-rectum tumours in 3 and breast tumours in 2. Only one article was retrieved for melanoma, oesophagus and ovary tumours. Cost-effectiveness results of FDG-PET or PET/CT ranged from dominated to dominant. CONCLUSION: Literature evidence about the costeffectiveness of FDG-PET or PET/CT in tumours other than lung cancer is still limited. Nevertheless, FDGPET or PET/CT seems to be cost-effective in selective indications in oncology(staging and restaging of head and neck tumours, staging and treatment evaluation in lymphoma).

^(18)F-FDG PET/CT征象及Ki-67表达与肺腺癌EGFR突变相关性研究

目的探讨^(18)F-FDG PET/CT征象及Ki-67表达与肺腺癌表皮生长因子受体(epidermal growth factor receptor,EGFR)突变的相关性。方法回顾分析95例经病理证实肺腺癌患者的^(18)F-FDG PET/CT征象、EGFR突变检测结果、Ki-67表达及一般临床资料。分析PET/CT征象(包括毛刺征、分叶征、胸膜牵拉征、血管集束征、空泡征、支气管截断征、SUVmax)、Ki-67表达、性别、年龄、吸烟史与EGFR突变状态的相关性。采用受试者工作特征(receiver operating characteristic,ROC)曲线计算最大标准摄取值(SUVmax)的截断值,Logistic回归分析影响EGFR突变的预测因素。结果EGFR突变患者的SUVmax值明显低于野生型患者(t=2.813,P=0.006),21号外显子突变患者的SUVmax低于野生型患者(t=3.274,P=0.002),野生型患者与19号外显子突变患者的SUV m a x差异无统计学意义(t=1.323,P=0.193),两种不同类型突变型SUVmax差异无统计学意义(t=-1.579,P=0.124)。ROC曲线分析显示,SUVmax预测EGFR突变的截断值为6.36。EGFR突变患者的Ki-67与野生型相比更易发生低表达(χ^(2)=4.867,P=0.027),21号外显子突变型患者Ki-67表达与野生型差异有统计学意义(χ^(2)=5.576,P=0.018),19号外显子突变型与野生型Ki-67表达差异无统计学意义(χ^(2)=0.328,P=0.567),两种不同类型突变型Ki-67表达差异无统计学意义(χ^(2)=1.791,P=0.181)。单因素分析结果显示,性别、吸烟、分叶征、血管集束征及SUVmax与EGFR突变有关(P<0.05),而年龄、毛刺征、胸膜牵拉征、空泡及支气管截断征与EGFR突变无关(P>0.05)。根据Logistic多因素分析的结果,性别、血管集束征和SUVmax是预测EGFR突变的独立因素(P<0.05)。结论SUVmax是预测肺腺癌EGFR突变的独立因素,在预测EGFR突变中具有一定的参考价值。

骨髓坏死^(18)F-FDG PET/CT与MRI对照分析

目的探索骨髓坏死氟-18-脱氧葡萄糖(^(18)F-fluorodeoxyglucose,^(18)F-FDG)正电子发射断层显像/计算机断层显像(positron emission tomography/computed tomography,PET/CT)表现,提高对该病的认识。方法回顾性分析9例磁共振成像(magnetic resonance imaging,MRI)诊断为骨髓坏死患者的PET/CT及临床资料,对照MRI影像,总结病变分布,选择最大病变,分析^(18)F-FDG代谢特点及CT征象。结果患者男6例,女3例,中位年龄28.0岁,均患淋巴瘤。MRI检查髋部6例、胸腰椎2例、膝部1例。6例髂骨病变,内部均为T1加权像(T1-weighted image,T1WI)高信号,T2脂肪抑制像(T2-fat suppressed image,T2FSI)低信号,伴T1WI边缘环状低信号,其中5例内部代谢减低,边缘代谢增高伴骨质硬化;1例密度及代谢未见异常,MRI显示病变狭长。2例脊柱病变T1WI呈等、低信号,T2FSI高信号,其中1例为等代谢,密度稍高;1例代谢减低,密度未见异常。1例股骨病变T1WI高信号,T2FSI低信号,代谢及密度增高。8例PET/CT发现MRI检查范围之外更多病变。8例更早期的PET/CT发现部分病变呈低代谢、等密度。结论^(18)F-FDG代谢减低,后期可伴有边缘线状代谢及密度增高,是骨髓坏死的常见PET/CT影像特点。PET/CT有助于检出骨髓坏死,发现多骨病变。

^(18)F-FDG PET/CT显像在特发性炎性肌病中的多重价值

目的:探讨^(18)F-FDG PET/CT显像在特发性炎性肌病(IIM)中的多重价值。方法:通过回顾性分析2014年8月至2022年4月在我院行PET/CT检查的特发性炎症性肌病患者21例,搜集患者的临床资料、肌酶等相关实验室指标及PET/CT影像资料。同时选取年龄及性别相匹配的PET/CT健康体检者21例(排除风湿性疾病及恶性肿瘤病史),并进行分析。结果:IIM患者肌肉SUVmax为(2.51±0.87)g/mL,对照组肌肉SUVmax为(1.24±0.26)g/mL。IIM患者肌肉的FDG摄取量显著高于对照组,差异具有统计学意义(t=23.6,P<0.005)。ROC曲线结果分析显示,^(18)F-FDG PET/CT显像诊断IIM的最佳诊断截点为SUVmax=1.705g/mL,此时曲线下面积(Area Under Curve,AUC)为0.99,诊断灵敏度为90.5%,特异性为98.7%。21例IIM患者中,经PET/CT检查发现并最终确诊为恶性肿瘤的患者5例,包括鼻咽癌、食管癌、乳腺癌、乙状结肠癌及肺弥漫性大B细胞淋巴瘤。恶性肿瘤病灶的SUVmax为(4.68±1.77)g/mL。合并间质性肺病ILD患者14例,肺部病灶SUVmax为(2.44±1.36)g/mL。Pearson相关性分析显示,IIM患者四肢FDG摄取与血清肌酸激酶(CK)(r=0.742,P<0.05)、肌酸激酶同工酶(CK-MB)(r=0.863,P<0.05)及乳酸脱氢酶(LDH)(r=0.897,P<0.05)水平升高均呈正相关性。结论:对于IIM患者,^(18)F-FDG PET/CT在评估肌病状态、诊断恶性肿瘤及间质性肺疾病等方面具有多重价值。因此,PET/CT可作为一种有效的影像诊断手段,通过一次成像进行多器官探查,用于IIM及相关并发症的诊断及病情评估。

Emerging role of ^(18)F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of major causes of cancer mortality worldwide. For decades, ^(18)F-fluorodeoxyglucose(FDG) positron emission tomography(PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.

新发每日持续性头痛^(18)F-FDG PET脑代谢特点

目的初步探讨氟-18-脱氧葡萄糖(^(18)F-fluorodeoxyglucose,^(18)F-FDG)正电子发射型计算机断层扫描显像(positron emission tomography,PET)在新发每日持续性头痛(new daily persistent headache,NDPH)患者各脑区的代谢特点。方法以2021年5月至2023年7月在首都医科大学附属北京天坛医院核医学科行^(18)F-FDG PET检查的临床诊断为NDPH的患者为研究对象,应用Cortex ID(GE Healthcare)对PET图像进行分析,得到NDPH患者26个大脑区域的Z评分(Z-score)分布。应用Z评分分布来评估NDPH患者脑区的代谢特点。结果NDPH患者在左、右前额内侧(P=0.004、P=0.009)、右侧扣带回后侧(P=0.003)、右侧楔前叶(P=0.003)、左侧运动整合区(P=0.036)、右侧扣带回前区(P=0.040)、左侧扣带回前区(P=0.037)、左侧扣带回后区(P=0.037)、右侧顶上小叶(P=0.002)、左侧顶上小叶(P=0.019)、左侧额叶前外侧((P<0.001)、左、右侧顶下小叶(P<0.001)、左、右颞叶中线区(P<0.001)和右侧颞叶外侧(P<0.001)、脑桥(P<0.001)等多个脑区表现出代谢降低。结论^(18)F-FDG PET可以显示出NDPH患者不同脑区的代谢特点,为NDPH及其并发症的病理机制提供一定的代谢信息。

肺腺癌组织中METTL3蛋白表达水平及其与18 F-FDG最大标准摄取值的相关性

目的探讨肺腺癌(LUAD)组织中甲基转移酶3(METTL3)蛋白表达水平及其与18 F-氟脱氧葡萄糖(18 F-FDG)最大标准摄取值(SUVmax)的相关性。方法回顾性分析2017年1月至2018年12月在该院进行肺部手术前接受18 F-FDG PET/CT扫描的所有LUAD患者资料,共收集89例LUAD患者的肿瘤组织标本及其相匹配的30例癌旁组织标本。采用免疫组织化学染色法检测LUAD组织中METTL3蛋白表达水平。对所有患者随访1年,并进行生存分析。采用Spearman相关对METTL3蛋白表达评分与PET/CT参数的相关性进行分析。结果TCGA数据库癌症基因组图谱数据显示,483例LUAD组织中METTL3 mRNA表达水平明显高于59例正常肺组织,差异有统计学意义(P<0.05)。89例LUAD组织中METTL3蛋白阳性表达率为52.81%(47/89),与相匹配的30例癌旁组织比较,LUAD组织中METTL3蛋白阳性表达率(56.67%)明显高于癌旁组织(16.67%),差异有统计学意义(P<0.05)。不同肿瘤最大径、肿瘤分化程度和淋巴结转移LUAD患者肿瘤组织METTL3蛋白表达情况比较,差异均有统计学意义(P<0.05)。与METTL3阴性组比较,METTL3阳性组SUVmax明显升高,差异有统计学意义(P<0.05)。Spearman相关分析结果显示,LUAD患者METTL3蛋白表达评分与SUVmax呈明显正相关(r=0.667,P<0.001)。SUVmax预测METTL3阳性表达的受试者工作特征曲线下面积为0.851(95%CI:0.773~0.928),对应的最佳截断值为10.55,灵敏度和特异度分别为83.0%和73.8%。随访期间,METTL3蛋白阳性组较阴性组中位总生存期更短,且总生存率更低,差异有统计学意义(χ^(2)=9.726,P=0.002)。结论LUAD组织中METTL3有望成为新的病理诊断和预后标志物。LUAD组织中METTL3蛋白表达评分与18 F-FDG SUVmax呈正相关,18 F-FDG SUVmax可能是反映METTL3蛋白表达评分的无创检测工具。

Prognostic value and clinical correlations of18-fluorodeoxyglucose metabolism quantifiers in gastriccancer

AIM： To investigate the correlations of pre-treatmentpositron emission tomography-computer tomography（PET-CT） metabolic quantifiers with clinical data ofunstratified gastric cancer （GC） patients.METHODS： Forty PET-CT scans utilising 18-fluorodeoxyglucosein patients who received no prior treatmentwere analysed. Analysis involved measurements ofmaximum and mean standardised uptake volumes（SUV）, coefficient of variation （COV）, metabolictumour volumes and total lesion glycolysis of differentthresholds above which the tumor volumes wereidentified. The threshold values were： SUV absolutevalue of 2.5, 30% of SUVmax, 40% of SUVmax,and liver uptake-based （marked 2.5, 30, 40 and liv,respectively）. Clinical variables such as age, sex,clinical stage, performance index, weight loss, tumorhistological type and grade, and CEA and CA19.9 levelswere included in survival analysis. Patients receivedvarious treatment modalities appropriate to theirdisease stage and the outcome was defined by time tometastasis （TTM） and overall survival （OS）. Clinical andmetabolic parameters were evaluated by analysis of variance, receiver operating characteristics, univariateKaplan-Meier, and multivariate Cox models. P 〈 0.05was considered statistically significant.RESULTS： Significant differences were observedbetween initially disseminated and non-disseminatedpatients in mean SUV （6.05 vs 4.13, P = 0.008）, TLG2.5（802 cm3 vs 226 cm3; P = 0.031）, and TLG30 （436 cm3vs 247 cm3, P = 0.018）. Higher COV was associatedwith poor tumour differentiation （0.47 for G3 vs0.28 for G1 and G2; P = 0.03）. MTV2.5 was positivelycorrelated to patient weight loss （〈 5%, 5%-10%and 〉 10%： 40.4 cm3 vs 123.6 cm3 vs 181.8 cm3,respectively, P = 0.003）. In multivariate Cox analysis,TLG30 was prognostic for OS （HR = 1.001, 95%CI：1.0009-1.0017; P = 0.047） for the whole group ofpatients. In the same model yet only including patientswithout initial disease dissemination TLG30 （HR = 1.009,95%CI： 1.003-1.014; P = 0.004） and MTV2.5 （HR = 1.02,95%CI： 1.002-1.036; P = 0.025） were prognostic forOS; for TTM TLG30 was the only significant prognosticvariable （HR = 1.006, 95%CI： 1.001-1.012; P = 0.02）.CONCLUSION： PET-CT in GC may represent a valuablediagnostic and prognostic tool that requires furtherevaluation in highly standardised environments such asrandomised clinical trials.

Clinical significance of prostate 18F-labelled fluorodeoxyglucose uptake on positron emission tomography/computed tomography:A five-year review

AIM To determine the significance and need for investigation of incidental prostatic uptake in men undergoing ^(18)F-labelled fluorodeoxyglucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT) for other indications.METHODS Hospital databases were searched over a 5-year period for patients undergoing both PET/CT and prostate magnetic resonance imaging(MRI). For the initial analysis, the prostate was divided into six sectors and suspicious or malignant sectors were identified using MRI and histopathology reports respectively. Maximum and mean ^(18)F-FDG standardised uptake values were measured in each sector by an investigator blinded to the MRI and histopathology findings. Two agematched controls were selected per case. Results were analysed using a paired t-test and one-way ANOVA. For the second analysis, PET/CT reports were searched for prostatic uptake reported incidentally and these patients were followed up. RESULTS Over a 5-year period, 15 patients underwent both PET/CT and MRI and had biopsy-proven prostate cancer.Malignant prostatic sectors had a trend to higher ^(18)F-FDG uptake than benign sectors, however this was neither clinically nor statistically significant(3.13 ±0.58 vs 2.86 ± 0.68, P > 0.05). ^(18)F-FDG uptake showed no correlation with the presence or histopathological grade of tumour. ^(18)F-FDG uptake in cases with prostate cancer was comparable to that from age-matched controls. Forty-six(1.6%) of 2846 PET/CTs over a 5-year period reported incidental prostatic uptake. Of these, 18(0.6%) were investigated by PSA, 9(0.3%)were referred to urology, with 3(0.1%) undergoing MRI and/or biopsy. No cases of prostate cancer were diagnosed in patients with incidental ^(18)F-FDG uptake in our institute over a 5-year period.CONCLUSION ^(18)F-FDG uptake overlaps significantly between malignant and benign prostatic conditions. Subsequent patient management was not affected by the reporting of incidental focal prostatic uptake in this cohort.

^(18)F-FDG和^(18)F-FAPI PET/CT在腹盆腔恶性肿瘤治疗后可疑复发的诊断价值比较研究

目的:比较^(18)F-氟代脱氧葡萄糖(flurodeoxyglucose,FDG)正电子发射体层成像(positron emission tomography,PET)/计算机体层成像(computed tomography,CT)和^(18)F-成纤维细胞活化蛋白抑制剂(fibroblast activation protein inhibitor,FAPI)PET/CT对腹盆腔恶性肿瘤治疗后临床怀疑复发/转移的诊断价值。方法:回顾并分析2021年9月—2024年2月就诊于中山大学肿瘤防治中心的腹盆腔恶性肿瘤治疗后临床怀疑肿瘤复发/转移患者的临床随访结果、病理学资料及^(18)F-FDG PET/CT、^(18)F-FAPI PET/CT显像结果,分别测量患者病灶最大标准摄取值(maximum standard uptake value,SUVmax)并计算肿瘤背景比值(tumor-to-background ratio,TBR),利用小提琴图及配对t检验统计分析两种显像剂的SUVmax及TBR,并计算各自的诊断效能。结果:64例(男性33例,女性31例)腹盆腔恶性肿瘤治疗后临床怀疑肿瘤复发/转移患者中52例被临床或病理学检查证实为转移。两种显像所示SUVmax差异无统计学意义(P>0.05),小提琴图中,^(18)F-FAPI PET/CT的SUVmax中位数高于^(18)F-FDG PET/CT显像,并且分布较为集中;TBR差异有统计学意义(P<0.0001),^(18)F-FAPI PET/CT TBR高于^(18)F-FDG PET/CT。^(18)F-FDG PET/CT和^(18)F-FAPI PET/CT诊断转移的灵敏度分别为55.8%(29/52)和88.5%(46/52),特异度为83.3%(10/12)和58.3%(7/12),准确度为60.9%(39/64)和82.8%(53/64)。结论:对于腹盆腔恶性肿瘤治疗后临床怀疑复发/转移的患者,^(18)F-FAPI PET/CT是优于^(18)F-FDG PET/CT的成像方式,特别是腹膜转移,^(18)F-FAPI PET/CT可作为^(18)F-FDG-PET/CT显像阴性时的补充方法,为临床医师提供更多信息。

基于^(18)F-FDG PET/CT影像组学在食管癌诊疗中的应用进展

食管癌是消化道常见的恶性肿瘤之一,我国食管癌的治疗模式逐步向精准医学理念指导下的个体化多学科综合治疗模式演化。^(18)F-氟代脱氧葡萄糖(^(18)F-FDG)正电子发射体层成像(PET)/CT在食管癌的诊断及精准分期中起重要作用。但传统PET/CT图像仍存在一定局限性。近年来,影像组学发展迅猛,采用PET/CT影像组学方法提取食管癌相应区域的图像特征获得了海量数据特征,并将其与患者的病灶信息、疗效、预后、生存期等临床参数结合后建立定量关系,最终将其应用于食管癌早期诊断、疗效评估及预测预后等方面。未来还需深入研究^(18)F-FDG PET/CT影像组学在食管癌诊疗中的应用。

^(18)F-FDG PET/CT代谢参数联合临床病理特征对晚期结直肠癌患者KRAS基因突变的评估价值

目的探讨^(18)F-氟代脱氧葡萄糖(^(18)F-FDG)PET/CT代谢参数联合临床病理特征对晚期结直肠癌患者鼠类肉瘤病毒癌基因(KRAS)基因突变的评估价值。方法回顾性分析64例晚期结直肠癌患者的临床资料。所有患者在治疗前均接受^(18)F-FDG PET/CT检查。分析最大标准化摄取值(SUV_(max))、不同阈值下的代谢肿瘤体积(MTV)和病变总糖酵解(TLG)、临床病理特征与患者KRAS基因突变状态之间的关系。通过多因素Logistic回归模型分析与患者KRAS基因突变相关的因素。采用受试者工作特征曲线分析^(18)F-FDG PET/CT代谢参数、临床病理特征及二者联合评估患者KRAS基因突变的效能。基于^(18)F-FDG PET/CT代谢参数和临床病理特征构建列线图模型。结果单因素和多因素Logistic回归分析结果显示,SUV_(max)≥19.55、MTV50%≥7.95、肿瘤组织中/高分化与患者KRAS基因突变有关。SUV_(max)、MTV50%和肿瘤组织分化程度评估患者KRAS基因突变的曲线下面积(AUC)分别为0.653、0.625和0.621,三者联合评估的AUC为0.800,均高于单个指标的AUC(P<0.05)。基于SUV_(max)、MTV50%和肿瘤组织分化程度构建的列线图模型的一致性指数为0.800,校准曲线与参考线基本拟合。结论^(18)F-FDG PET/CT的代谢参数SUV_(max)、MTV50%与晚期结直肠癌患者KRAS基因突变密切相关,联合肿瘤组织分化程度所构建的列线图模型对患者KRAS基因突变具有较高的评估价值。

^(18)F-FDG PET/CT显像中标准化摄取值测量技术、影响因素及临床应用的研究进展

^(18)F-氟代脱氧葡萄糖(^(18)F-FDG)正电子发射计算机断层/电子计算机断层扫描(PET/CT)显像在临床应用中较为广泛,标准化摄取值(SUV)是重要的半定量指标,对于疾病的早期诊断和鉴别诊断、预测肿瘤治疗的早期响应和疗效监测具有重要意义。该文就^(18)F-FDG PET/CT显像中SUV测量技术、影响因素及临床应用的研究进展作一综述。

Tumor characteristics of ductal carcinoma in situ of breast visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography: Results from a retrospective study

AIM To clarify clinicopathological features of ductal carcinoma in situ(DCIS) visualized on [F-18] fluorodeoxyglucosepositron emission tomography/computed tomography(FDG-PET/CT).METHODS This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDGPET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value(SUVmax) was compared with clinicopathological characteristics.RESULTS[F-18] FDG uptake was visualized in 28 lesions(53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation(P = 0.012 and 0.002, respectively), palpability(P = 0.030 and 0.024, respectively), use of core-needle biopsy(CNB)(P = 0.023 and 0.012, respectively), ultrasound-guided biopsy(P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging(MRI)(P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology(P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status(estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation(P = 0.019 and 0.001, respectively), use of CNB(P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI(P = 0.001 and 0.049, respectively) on multivariate analysis.CONCLUSION Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors(≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT.

F-18 fluorodeoxyglucose positron emission tomography/computed tomography image of gastric mucormycosis mimicking advanced gastric cancer: A case report

BACKGROUND Mucormycosis is a very rare fungal infection,and its prognosis is poor.Most common sites of infection are the sinuses,lung,or skin,and gastric involvement is uncommon.The standard antifungal therapy is the treatment of choice for gastric mucormycosis.However,the symptoms of gastric mucormycosis are varied and the early diagnosis is not easy.CASE SUMMARY I report a 53-year-old alcoholic man,who was admitted due to epigastric pain.The upper gastrointestinal endoscopy revealed a huge ulcer lesion in the stomach,which was suspected to be gastric cancer.F-18 fluorodeoxyglucose positron emission tomography/computed tomography(F-18 FDG PET/CT)showed diffusely intense FDG uptake at the ulcer lesion of the stomach,and several enlarged hypermetabolic lymph nodes were noted at the left gastric chain.Although,endoscopy and F-18 FDG PET/CT findings suggested advanced gastric cancer with regional lymph node metastases,there was no cancer cells in the biopsy results and multiple fungal hyphae were noted in the periodic acid-Schiff stained image.CONCLUSION He was diagnosed with gastric mucormycosis and successfully underwent amphotericin B and posaconazole treatment.