Dual-Time-Point FDG-PET/CT for the Detection of Hepatic Metastases

Purpose  To prove the sensitivity of dual-time-point imaging with 18F-flourodeoxyglucose-positron emission tomography (18F-FDG-PET) of the liver to evaluate possible changes in the tumor-to-background ratio considering an improved detection rate of liver lesions. Procedures  Image acquisition for the first whole-body scan started at a mean time point of 69 min (55–110 min). The mean time interval between the injection of 18F-FDG and the second delayed scan was 100 min (85–166 min). Results  Of 90 proven liver metastases in 34 patients, the first scan detected 53 (59%) liver lesions correctly, whereas in the second, delayed scan 81 (90%) lesions were diagnosed correctly (p<0.001). The mean Standardized uptake values in the first and second delayed scan were 6.59 g/ml versus 8.09 g/ml, respectively (p<0.001). Tumor-to-background ratio of the first and second delayed scan were 2.0 and 2.7, respectively (p = 0.04). Conclusions  Dual-time-point-imaging of the liver showed a significant increase of tumor-to-background ratio and hypermetabolic lesion diameter. Although, 30% of all verified liver lesions could only be detected in the second delayed scan 10% of all malignant liver lesions were missed with FDG-PET.     

Metabolic Imaging Phenotype Using Radiomics of [18F]FDG PET/CT Associated with Genetic Alterations of Colorectal Cancer

Molecular Imaging and Biology - To understand the association between genetic mutations and radiomics of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET)/x-ray computed...     

结肠癌肝转移的螺旋CT特征及临床价值

目的 评价螺旋CT对于结肠癌肝转移术前检出与可切除性评估价值。方法 螺旋CT扫描对100例肝转移病例进行术前分期，层厚5mm，重建间隔5mm；以2．0～3．0ml／s速率静脉注入100ml含碘造影剂后60～70s后开始扫描。螺旋CT征象与手术及病理所见按病灶逐一对照。结果 触诊与病理学检查揭示了184个肝转移灶，螺旋CT扫描正确预测了其中的156个，总体检出率84．8％，阳性预测值96．0％，假阳性率3．8％(7／184)。在72例患者的76例次手术中，71例次为可治愈切除，可切除率为93．4％(71／76)。病例五年生存率为54．2％。结论 螺旋CT扫描应被看作是结肠癌肝转移的标准或最佳术前检出方法.     

Prospective Evaluation of 99mTc MDP Scintigraphy, 18F NaF PET/CT, and 18F FDG PET/CT for Detection of Skeletal Metastases

Introduction  

Technetium (Tc) methylene diphosphonate (MDP) has been the standard method for bone scintigraphy for three decades. ¹⁸F sodium fluoride (¹⁸F NaF) positron emission tomography (PET)/computed tomography (CT) has better resolution and is considered superior. The role of 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F FDG) PET/CT is proven in a variety of cancers, for which it has changed the practice of oncology. There are few prospective studies comparing these three methods of detection of skeletal metastases. Thus, we were prompted to initiate this prospective pilot trial.     

Pharmacodynamic Evaluation of Irinotecan Therapy by FDG and FLT PET/CT Imaging in a Colorectal Cancer Xenograft Model

Purpose

Longitudinal changes of 3??-[¹⁸?F]fluoro-3??-deoxythymidine (FLT) and 2-deoxy-2-[¹⁸?F]fluoro-d-glucose (FDG) in response to irinotecan therapy in an animal model of colorectal cancer were compared.

Procedures

SCID/CB-17 mice with HCT116 tumors were treated with 50?mg/kg irinotecan by intraperitoneal injection weekly for 3?weeks. FLT and FDG-positron emission tomography (PET) were performed at baseline, the day after each treatment, and 5?days after the first treatment. Proliferation and apoptosis were evaluated by immunohistochemistry (IHC) after day 15 of imaging.

Results

Irinotecan treatment resulted in a suppression of tumor growth. Tumor FLT uptake was decreased the day after each treatment but to a lesser extent 5?days after the first treatment. FDG uptake increased the day after each treatment with a continuous increase throughout the experiment. IHC analysis of phospho-H3 and Ki67 confirmed FLT-PET results, indicating a decrease in proliferation the day after the final irinotecan treatment. Increased apoptosis monitored by caspase-3 was observed after day 15 with irinotecan treatment.

Conclusions

FLT-PET may be a better method than FDG-PET for assessing treatment response to irinotecan. Changes in imaging occur before changes in tumor volume.     

CT 相对于18F-FDG PET 对脊椎转移瘤的诊断评价

目的评价比较ＣＴ与ＰＥＴ对脊椎转移瘤的诊断价值。方法３４例病人,男２８例,女６例,年龄２４－７４岁。３４例原发灶明确。分别对其ＣＴ与ＰＥＴ检查结果进行比较。结果３４例中共侵犯椎骨５９个,包括颈椎１个,胸椎２４个,腰骶椎３４个,ＣＴ与ＰＥＴ结果完全符合２５例,占７３．５％（２５／３４）;部分符合７例,占２０．６％（７／３４）;完全不符合２例,占５．９０％（２／３４）。５９个椎骨中完全符合４５个椎骨,     

MR三维全肝灌注成像在结直肠癌肝转移定量分析中的可行性研究

目的:探讨MR三维全肝灌注成像对结直肠癌肝转移定量分析的可行性.方法:对27例结直肠癌肝转移患者行MR三维全肝灌注成像扫描,采用三维容积屏气内插检查序列,对比剂按0.1 mmol/kg体质量计算,注射速度5 mL/s.由2名放射科医师采用Tissue 4D软件分析灌注参数:容量转移常数(Ktrans)、血管外细胞外间隙容积比(Ve)、速率常数(Kep).采用计算一致性相关系数和Bland-Altman分析2位医师各参数结果间的一致性.结果:2位医师评价27例结直肠癌肝转移灌注参数的Ktrans、Ve和Kep的观察者间一致性经Bland-Altman分析,其平均差异分别为(0.0069±0.0135)min-1、(-0.0084±0.0371)min、(0.0385±0.0685)min-1;95％一致性界限分别为-0.0196～0.0333、-0.0812～0.0644、-0.0958～0.1728.而Ktrans、Ve和Kep的一致性相关系数分别为0.95、0.94和0.99.结论:采用MR三维全肝灌注成像技术进行结直肠癌肝转移定量分析具有良好的可靠性和可行性.     

F-18 FDG PET/CT在继发性噬血细胞综合征中的临床价值研究

本研究旨在探讨F-18 FDG PET/CT在噬血细胞综合征（HPS）的诊断和预后判断中的作用。回顾性分析了11例行F-18 FDG PET/CT检查的HPS患者,评估了F-18 FDG PET/CT对HPS相关的恶性肿瘤的诊断价值,计算了骨髓和脾脏的最大标准摄取值（SUVmax）,对骨髓和脾脏的SUVmax与HPS的多个实验室参数以及临床转归的关系进行了分析。结果表明：11患者中4例伴恶性肿瘤;通过F-18 FDG PET/CT检测判断HLH患者是否伴有恶性肿瘤的敏感性、特异性和准确性分别为100.0%、66.7%和75.0%;骨髓和脾脏的SUVmax与实验室参数无显著的相关性;预测患者预后的脾脏SUVmax值和骨髓SUVmax值的最佳截断点分别为3.10和3.47;单因素分析提示,骨髓和脾脏中F-18 FDG高摄取患者的存活时间较短。结论：F-18 FDG PET/CT在继发性HPS的病因诊断和预后判断中具有重要作用。     

Hepatic Transit Time Analysis Using Contrast-Enhanced Ultrasound with BR1: A Prospective Study Comparing Patients with Liver Metastases from Colorectal Cancer with Healthy Volunteers

We prospectively compared hepatic transit time (HTT) measurements in subjects with liver metastases from colorectal cancer (group a) and healthy volunteers (group b) using contrast-enhanced ultrasound with BR1. The purpose of this study was to verify our hypothesis that the hemodynamic changes of the liver, which occur during metastasis seeding, would shorten the HTT, and we expect that such changes could be used for the detection of occult liver metastases from colorectal cancer in the future. The study had institutional review board approval and all subjects gave informed written consent. Group a and group b consisted of 22 subjects each. Baseline and post contrast images were acquired starting 10 s before and ending 40 s after administration of BR1, using nonlinear imaging at a frame rate of 5/s. The baseline images were used to determine the signal intensity without contrast enhancement as the reference signal. Arrival times (AT) of the contrast agent for the hepatic artery, the portal vein and one hepatic vein were determined using (i) quantitative analysis and (ii) subjective analysis by two blinded readers. HTT was calculated based on arrival time measurements. Quantitative and subjective analysis showed significantly shorter arterial to venous and portal to venous HTT in group a compared with group b (p < 0.001). Arterial to venous HTT (quantitative analysis) was ≤9 s in 19 of 22 subjects of group a and >9 s in 18 of 22 subjects of group b (sensitivity 86%, specificity 82%, positive predictive value 83%, negative predictive value 86%, area under the curve [AUC] 0.87). Portal to venous HTT (quantitative analysis) was < 7 s in 21 of 22 subjects of group a and > 7s in 15 of 22 subjects of group b (sensitivity 95%, specificity 68%, PPV 75%, NPV 94%, AUC 0.85). There was an inverse relation with number of liver segments involved for arterial to venous and portal to venous HTT in group a (p < 0.05), but no correlation between HTT and overall volume of metastases (group a) or subject age (group b). From the results of our study, we conclude that HTT measurements using contrast-enhanced ultrasound with BR1 can detect hemodynamic changes caused by metastatic liver disease from colorectal cancer. However, comparison with the literature suggests that the use of other contrast agents might provide better results. Comparison of different contrast agents for the purpose of transit time analysis would therefore be useful before embarking on a prospective trial looking at the detection of occult liver metastases in patients with colorectal cancer. (E-mail: jhohmann@uhbs.ch)     

高强度聚焦超声治疗结直肠癌肝转移的临床观察

目的探讨高强度聚焦超声(HIFU)治疗结直肠癌肝转移的有效性及安全性。方法21例结直肠癌术后肝转移患者37个病灶行HIFU治疗,观察患者的生命体征、主要脏器功能、CT或MRI检查结果、不良反应和肿瘤转归情况。结果21例患者生命体征均平稳,肝肾功能正常。随访观察37个病灶中,22个病灶肿瘤体积缩小,11个病灶肿瘤体积保持稳定,1例4个病灶放弃。平均随访17(5~36)个月,生存12例,中位生存时间为17个月,6、12、24、36个月的生存率分别为94.74%、87.45%、61.84%、32.98%。8例患者皮肤出现条索状灼痕。结论HIFU治疗是一种安全、有效的治疗结直肠癌肝转移的方法。     

肺癌骨转移SPECT/CT融合图像的影像学特点分析

目的:探讨99 Tcm-亚甲基二膦酸盐(methylene diphosphonate,MDP)单光子发射计算机断层/CT(single photon emission computed tomography/spiral computed tomography,SPECT/CT)所显示的肺癌骨转移病灶的图像特点及SPECT/CT显像对肺癌骨转移的诊断价值。方法:回顾分析113例病理证实为肺癌、初次全身骨显像及SPECT/CT显像诊断为肺癌骨转移的患者的骨转移病灶的SPECT/CT图像特点,经病理诊断或再次全身骨显像及SPECT/CT显像随访确认,分析SPECT/CT显像所示肺癌骨转移病灶的部位、数量、放射性分布及CT表现的特点。结果:113例患者共482处病灶纳入本研究,肺癌骨转移病灶429处。肺癌骨转移病灶中位于脊柱者占50.6%(217/429),胸廓者占29.1%(125/429),骨盆者占17.0%(73/429),四肢者占2.1%(9/429),颅骨者占1.2%(5/429)。肺癌骨转移病灶SPECT/CT图像表现为放射性异常浓聚者占90.7%(389/429),无放射性分布异常者占9.3%(40/429);CT图像表现为成骨性转移者占41.0%(176/429),溶骨性转移者占50.3%(216/429),混合性(兼有溶骨和成骨)转移者占4.0%(17/429),骨质形态学正常者占4.7%(20/429)。113例患者中有23例患者同时伴有良性病灶,共53处。结论:肺癌骨转移的部位以脊柱居首,胸廓次之;肺腺癌患者容易发生骨转移,以成骨性转移多见。SPECT/CT诊断肺癌骨转移病灶的敏感度和特异性均较高。     

结直肠癌确诊时合并肝转移危险因素分析

目的：分析结直肠癌确诊时合并肝转移的临床和病理危险因素,为结直肠癌肝转移的早期诊断和进一步治疗提供参考。方法：对2006年1月—2008年6月宁波市第一医院普外科收治的247例结直肠癌手术患者临床和病理资料进行回顾分析,根据术前检查和术中探查,分为合并肝转移组与无肝转移组,用单因素和多因素回归分析方法分析两组的年龄、性别、有无肝炎病史、肝功能指标、肿瘤指标、肿瘤部位、浸润深度、淋巴结有无转移、肿瘤标本巨检和分化程度、是否合并急性肠梗阻等与肝转移的相关性,从而得出肝转移的相关危险因素。结果：247例患者中有22例合并肝转移,占8.9%。单因素分析提示,结直肠癌确诊时合并肝转移的危险因素有：女性患者、有急性肠梗阻、盆腔腹膜或大网膜有转移结节、低或未分化肿瘤、肿瘤大小和浸润程度及术前血清CEA水平。多因素Logistic回归分析表明,肿瘤浸润深度、区域淋巴结转移、术前血CEA水平、肿瘤标本巨检、腹膜和大网膜转移结节与肝转移密切相关。术前血清CEA大于27.75ng·mL^-1结直肠发生肝转移的发生率明显增高。结论：结直肠癌确诊时合并肝转移与肿瘤浸润深度、区域淋巴结有无转移、术前血CEA、肿瘤标本巨检、腹膜及大网膜转移结节相关。     

Prospective Comparison of FDG and FET PET/CT in Patients with Head and Neck Squamous Cell Carcinoma

Aim  The clinical usefulness of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in head and neck squamous cell carcinoma (HNSCC) is now well-documented. However, its sensitivity is greater than its specificity due to false-positive results in inflammatory or infectious lesions, which are frequent in this area, in particular after treatment by surgery and/or radiotherapy. O-2-fluoro-(18F)-ethyl-L-thyrosine (FET) has been reported not to be taken up by such lesions, and a preliminary study indicated that this may be clinically useful in HNSCC. We performed a prospective study to compare the diagnostic performances of FDG and FET PET/CT in the different settings of HNSCC. Materials and Methods  Twenty-seven patients (20 men and seven women, aged 48–76, among 30 patients included) and 69 suspected cancer sites are now evaluable on basis of postsurgical histology and/or follow-up greater than 6 months; 15 patients were referred for initial staging and 12 during posttherapy follow-up, a recurrence being suspected in eight of them. FDG and FET PET/CT were performed on two different days, the patient fasting for 6 h, 1 h after injection of 5 MBq/kg of body mass of each radiopharmaceutical. Both PET/CT examinations were blind read more than 6 months after the end of inclusions in a random order for each tracer and with a time interval greater than 1 month between FDG and FET PET/CT blind readings. Results  Overall diagnostic performances, derived from blind reading: FDG PET/CT on a per patient basis: sensitivity 100%, specificity 71%, accuracy 93%; FDG PET/CT on a per site basis: sensitivity 95%, specificity 63%, accuracy 83%; FET PET/CT on a per patient basis: sensitivity 70%, specificity 100%, accuracy 78%; FET PET/CT on a per site basis: sensitivity 64%, specificity 100%, accuracy 78%. At site level, sensitivity was significantly greater with FDG (p < 0.02) and specificity with FET (p < 0.01). The statistical level of significance was not reached at patient level. Conclusion  Although its good specificity was confirmed, FET did not appear to be suited as a first-line PET tracer in HNSCC imaging and cannot replace FDG for staging due to insufficient sensitivity. However, it was useful in a few selected cases to favor a wait and see attitude when a FDG+ FET− focus was discovered in patients referred for systematic FDG PET during follow-up. In contrast, second primary cancers should not be ruled out if FDG was clearly positive in the lungs or the digestive tract.     

F-18 FDG-PET and PET/CT Imaging of Cancer Patients

¹⁸F-FDG PET imaging diagnoses, stages, and restages many cancers with accuracies ranging form 80% to 90%. Because of the high accuracy of FDG-PET as a molecular imaging technique of disease biology, the U.S. Food and Drug Administration (FDA) has approved PET-FDG for all cancers. Fusion of both PET and CT images enhances the inherent clinical potential of both techniques and provides synergistic knowledge that is greater than the sum of information provided by each modality alone. Since the concept of PET/CT imaging only 6 years ago, state-of-the-art CT imaging technology has been combined with high-end PET systems. Acceptance and clinical use of these hybrid systems have been widespread. This nonsystematic review describes basic aspects of FDG-PET and PET/CT in cancer imaging, patient preparation and factors affecting imaging protocol.     

18F-FDG PET/CT在泌尿系统肿瘤转移灶寻找中的应用

目的:探讨18F-FDG显像在泌尿系统恶性肿瘤转移病灶方面诊断的价值.方法:58例原发泌尿系统恶性肿瘤患者,其中肾脏透明细胞癌33例、肾脏肉瘤1例、膀胱移行细胞癌20例、输尿管移行细胞癌4例,进行常规18F-FDG PET/CT检查.所有病例均行独立的PET、CT评价,比较PET与CT在泌尿道肿瘤转移灶方面的诊断价值.所有病例均经过1年以上随访观察.结果:58例患者共发现68处病灶,最后证实为转移病灶共61处(45例患者).PET敏感性为98.3%,特异性85.7%,阳性预测值98.36%,阴性预测值98.36%,准确性94%.CT敏感性为88.52%,特异性71.43%,阳性预测值96.43%,阴性预测值41.67%,准确性86.5%.PET/CT的敏感性为95%,特异性100%,阳性预测值100%,阴性预测值70%,准确性96.5%.结论:18F-FDG PET/CT融合显像对泌尿道肿瘤转移病灶的定性、定位诊断有更大的临床意义.     

FDG PET/CT in the liver: lesions mimicking malignancies

Purpose

18F-fluorodeoxyglucose (FDG) PET/CT is invaluable in managing liver lesions, in particular in the evaluation of suspected liver metastases. It is both sensitive and specific in detecting liver metastases from a wide range of primary cancers, and may change clinical management, most commonly by detecting additional lesions and decreasing the number of futile surgeries. However, some benign lesions may also show increased metabolic activity which can lead to false positive PET findings. We describe some of these lesions and their imaging characteristics that may help in differentiating them from malignant metastases.

Methods

We reviewed all whole body FDG PET/CT studies performed over a 5-year period in our institution, and identified those with focal liver lesions showing increased FDG uptake for which histological results were available.

Results

A majority of lesions showing increased metabolic activity were due to malignant disease, such as metastases or primary liver tumours. However, we also found increased FDG uptake in non-neoplastic lesions such as Cryptococcosis, abscesses, and secondary inflammation from cholecystitis. Increased metabolic activity was also seen in some benign neoplasms such as hepatic adenomas and hemangioendotheliomas.

Conclusion

FDG PET/CT is currently the most sensitive non-invasive imaging modality for the detection of hepatic metastases, particularly from the gastrointestinal tract. False positive results are rare, and have been described mainly in abscesses. However, other lesions can also show increased metabolic activity, and failure to differentiate these from metastases may result in inappropriate treatment.     

Pretreatment with Diphenoxylate Hydrochloride/Atropine Sulfate (Lomotil) does not Decrease Physiologic Bowel FDG Activity on PET/CT Scans of the Abdomen and Pelvis

Purpose  Physiologic uptake of 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) by bowel can confound positron emission tomography/computed tomography (PET/CT) assessment for abdominal pathology, particularly within the bowel itself. We wished to determine if oral administration of the antimotility agent, Lomotil (5 mg diphenoxylate hydrochloride/0.05 mg atropine sulfate; G.D. Searle and Company, a division of Pfizer), prior to PET/CT scanning would reduce physiologic uptake of FDG by the small bowel and colon (lower gastrointestinal [GI] tract). Procedures  Patients undergoing PET/CT scans for lymphoma were enrolled in a prospective, randomized, double-blinded study and received either 10 mL water (control group) or 10 mL Lomotil (experimental group) orally 30–60 min prior to scanning. Scans were reviewed independently by two blinded experienced readers and scored for the degree of FDG activity in the lower GI tract relative to liver activity. Results  The administration of Lomotil prior to PET/CT scanning did not reduce physiologic FDG activity in the small bowel and colon. In contrast, increased radiotracer uptake by the lower GI tract was observed in the Lomotil group compared to the control group. Conclusions  Pretreatment with Lomotil prior to PET/CT scanning confers no benefit toward the reduction of physiologic FDG uptake by the small bowel and colon.     

肝癌经动脉栓塞化疗后FDG PET显像的临床价值 ——附10例FDG PET和CT结果对照

目的：探讨核医学影像诊断技术－FDG PET在中晚期肝癌栓塞化疗后随诊中的临床价值,并着重比较FDG PET与CT在判断介入治疗后局部肿瘤坏死及残留状况方面的互补作用。方法：10例临床确诊的肝癌患者,术前CT或MRI示肿瘤短轴均大于4cm,经栓塞化疗后6－10个月同期行FDG PET和CT检查,并采用双盲法将FDG PET与CT结果进行比较。结果：10例CT扫描结果显示,4例肿瘤内碘油分布密集,3例肿瘤内碘油分布稀疏,3例肿瘤内碘油短期内排空;PET显示其中6例肿瘤内碘油分布稀疏或碘油短期内排空者局部肿瘤内及周边区域均有FDG明显浓聚的病变,4例肿瘤内碘油分布密集者,FDG PET均显示肿瘤边缘部位可见到不规则的放射性分布浓聚现象。结论：中晚期肝癌栓塞化疗后病灶边缘部分多有肿瘤存活或残留,但CT检查不能准确判断这一现象,而FDG PET在准确定位肿瘤残留病灶方面正好弥补了CT扫描的不足。     

Colorectal cancer staging: comparison of whole-body PET/CT and PET/MR

Purpose

Correct staging is imperative for colorectal cancer (CRC) since it influences both prognosis and management. Several imaging methods are used for this purpose, with variable performance. Positron emission tomography–magnetic resonance (PET/MR) is an innovative imaging technique recently employed for clinical application. The present study was undertaken to compare the staging accuracy of whole-body positron emission tomography–computed tomography (PET/CT) with whole-body PET/MR in patients with both newly diagnosed and treated colorectal cancer.

Methods

Twenty-six patients, who underwent same day whole-body (WB) PET/CT and WB-PET/MR, were evaluated. PET/CT and PET/MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Correct staging was compared between methods using McNemar’s Chi square test.

Results

The two methods were in agreement and correct for 18/26 (69%) patients, and in agreement and incorrect for one patient (3.8%). PET/MR and PET/CT stages for the remaining 7/26 patients (27%) were discordant, with PET/MR staging being correct in all seven cases. PET/MR significantly outperformed PET/CT overall for accurate staging (P = 0.02).

Conclusion

PET/MR outperformed PET/CT in CRC staging. PET/MR might allow accurate local and distant staging of CRC patients during both at the time of diagnosis and during follow-up.