18F-FDG PET/CT与PET/MRI在结直肠癌肝转移诊断中的比较分析

目的:比较 18F-氟脱氧葡萄糖（FDG） PET/CT与PET/MRI显像对结直肠癌肝转移的诊断价值。 方法:回顾性分析2018年9月至2019年9月于宁波明州医院行全身 18F-FDG PET/CT显像及上腹部 18F-FDG PET/MRI显像,并疑似有结直肠癌肝转移...     

Impact of 18F-FDG PET/CT on therapeutic decisions in patients with colorectal cancer and liver metastases

ObjectivesSurgical resection and radio-frequency ablation (RFA) are standard therapeutic procedures for colorectal metastases confined to the liver. The presence of extrahepatic disease has a significant effect on the management of these patients. The goal of this study is to assess the value of positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET/CT) in the decision making whether to perform RFA or surgical resection of liver metastases in patients with metastatic colorectal cancer.Material and methodsThirty-five consecutive patients (23 men, 12 women; age range: 46–78 years) with colorectal carcinoma and liver metastases were prospectively enrolled. Nineteen of them were considered candidates for surgical resection and 16 for RFA. All underwent 18F-FDG PET/CT, helical computed tomography of the chest and abdomen and, some of them, magnetic resonance imaging of the abdomen. The 18F-FDG PET/CT studies were performed within 4 weeks from conventional imaging, and additional findings were later confirmed or not, either by histology or follow up.ResultsIn the surgical candidate group, 18F-FDG PET/CT detected extrahepatic disease, missed by conventional imaging, in 9/19 patients (47.3%). These findings directly altered the management in 7 patients (36.8%). In the group of RFA candidates, 18F-FDG PET/CT detected additional extrahepatic disease in 4/16 patients (25%) and directly altered management in all of them. Overall, in 11/35 patients (31.4%), 18F-FDG PET/CT detected extrahepatic metastatic disease.ConclusionIn patients with colorectal cancer and liver metastases, 18F-FDG PET/CT provides relevant additional information that has significant impact on management.     

Sensitivity of PET/MR images in liver metastases from colorectal carcinoma

Our aim was to evaluate the sensitivity of positron emission tomography/magnetic resonance image (PET/MRI) in the detection of liver metastases in patients from colorectal cancer as compared with computed tomography (CT), magnetic resonance imaging (MRI), PET and PET/CT images. From April 2008 to April 2010, twenty-four patients (mean age 56.5±10.5 years) with liver metastases from colorectal cancer diagnosed by pathology were retrospectively studied as above. All image data were respectively collected and fused. PET/CT and PET/MRI fusion images were successfully performed with a PET-MR-CT robot transmission-fusion imaging system. Pathologic findings and clinical follows-up were performed as referenced standards. Images were reviewed independently by at least three experts. We found a total number of 121 metastatic lesions and 35 of them, with a maximum diameter less than 1cm. According to a per-lesion analysis, the sensitivity on liver metastases was 64.5%, 80.2% and 54.5% on CT, MRI and PET, respectively. Based on reconstruction imaging analysis, PET/CT and PET/MRI showed sensitivities of 84.2% and 98.3%. Sensitivity comparison of PET/MRI had superior sensitivity of 98.08%. Paired data analysis (McNemar) resulted a type I error which equated to 0.05. There was a statistically significant difference between CT and MRI or PET for the detection of patients with liver metastatic lesions (P<0.05). However, PET/MRI can efficiently detect more metastatic lesions than PET/CT (P<0.05) among those with diameter <1cm. In conclusion, PET/MRI was a quite efficient diagnostic modality compared to conventional imaging modalities and should be considered the procedure of choice in the detection of liver metastatic lesions from colorectal cancer.     

Reproducibility of functional volume and activity concentration in 18F-FDG PET/CT of liver metastases in colorectal cancer

Purpose

Several studies showed potential for monitoring response to systemic therapy in metastatic colorectal cancer patients with ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Before ¹⁸F-FDG PET can be implemented for response evaluation the repeatability should be known. This study was performed to assess the magnitude of the changes in standardized uptake value (SUV), volume and total lesion glycolysis (TLG) in colorectal liver metastases and validate the biological basis of ¹⁸F-FDG PET in colorectal liver metastases.

Methods

Twenty patients scheduled for liver metastasectomy underwent two ¹⁸F-FDG PET scans within 1?week. Bland-Altman analysis was performed to assess repeatability of SUV_max, SUV_mean, volume and TLG. Tumours were delineated using an adaptive threshold method (PET_SBR) and a semiautomatic fuzzy locally adaptive Bayesian (FLAB) delineation method.

Results

Coefficient of repeatability of SUV_max and SUV_mean were ～39 and ～31?%, respectively, independent of the delineation method used and image reconstruction parameters. However, repeatability was worse in recently treated patients. The FLAB delineation method improved the repeatability of the volume and TLG measurements compared to PET_SBR, from coefficients of repeatability of over 85?% to 45?% and 57?% for volume and TLG, respectively. Glucose transporter 1 (GLUT1) expression correlated to the SUV_mean. Vascularity (CD34 expression) and tumour hypoxia (carbonic anhydrase IX expression) did not correlate with ¹⁸F-FDG PET parameters.

Conclusion

In conclusion, repeatability of SUV_mean and SUV_max was mainly affected by preceding systemic therapy. The repeatability of tumour volume and TLG could be improved using more advanced and robust delineation approaches such as FLAB, which is recommended when ¹⁸F-FDG PET is utilized for volume or TLG measurements. Improvement of repeatability of PET measurements, for instance by dynamic PET scanning protocols, is probably necessary to effectively use PET for early response monitoring.     

Response assessment of colorectal liver metastases with contrast enhanced CT/18F-FDG PET

Purpose

Evaluate the diagnostic performance of contrast enhanced CT/PET (ceCT/PET) in the response assessment of patients with colorectal cancer liver metastases.

Methods

33 ce CT/PET studies of 19 patients with colorectal liver metastases were prospectively evaluated. All of them, 13 (68.4%) were males and 6 (31.6%) females. Mean age and range were 63 [42–78]. All patients were treated with neoadjuvant chemotherapy. In all cases post-therapy diagnostic confirmation of liver lesions was obtained. A ce CT PET/was obtained 1 h after the injection of 370 MBq of 18F-FDG.Metabolic and morphologic studies were evaluated by two blinded nuclear physicians and radiologists respectively to assess the location, size and suspected diagnosis of lesions (benign or malignant). A combined assessment of both techniques was performed.The final diagnosis was established by histopathology or clinical/radiological follow-up greater than 6 months.

Results

A total of 120 liver lesions were identified, 115 were malignant and 5 benign.From the malignant lesions, 105 were identified with the ceCT, 44 with the PET and 109 with ceCT/PET. All of the benign lesions were correctly classified with any of the three imaging techniques.The sensitivity of PET, ceCT and ceCT/PET were of 38%, 91% and 95% respectively and the specificity was 100% in all three of the diagnostic studies.

Conclusion

Administration of intravenous contrast in the PET/CT is mandatory to evaluate treatment response rate of liver metastases due to the limitations of isolated metabolic images in these cases.     

Spinal cord metastases from lung cancer: detection with F-18 FDG PET/CT

Preoperative F-18 FDG PET/CT study in this 57-year-old woman showed an FDG avid lesion in the left upper lung without evidence of lymphadenopathy or distant metastasis. She underwent a left upper lobectomy in June 2005 revealing moderately poorly differentiated adenocarcinoma (pT3N0M0) and subsequent chemotherapy completed December 2005. Nine months later, a left parietal lobe metastatic lesion was surgically resected. A true whole body FDG PET/CT study in November 2006 for restaging demonstrated new FDG avid spinal cord foci, which were highly suspicious for spinal cord metastases; these lesions were confirmed by MRI. Clinically, the patient recently developed back pain without evidence of neurologic deficits.     

18F-FDG PET and PET/CT for detection of pulmonary metastases from musculoskeletal sarcomas

OBJECTIVE: Sarcomas represent a significant therapeutic challenge and their potential for distant pulmonary metastases is well known. [(18)F]Fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) has a role in differentiating sarcomas from benign tumours and assessing the response to therapy in advanced sarcomas. However, PET appears to be less accurate in detection of pulmonary metastases. We were therefore prompted to review our experience with PET and PET/computed tomography (CT) in osseous and soft tissue sarcomas (OSTSs). METHODS: This is a retrospective study (January 1995 to December 2004) of 106 patients with histological diagnosis of OSTS, who had PET and PET/CT at our institution. The group included 52 men and 54 women, aged 12-92 years (average, 45+/-20 years). RESULTS: For all the patients in the analysis, the sensitivity and specificity were 68.3% (95% CI: 53-80.4) and 98.4% (95% CI: 91.8-99.7) for PET, with 95.1% sensitivity (95% CI: 83.8-98.6) and 92.3% specificity (95% CI: 83.2-96.7) for CT. Pulmonary metastases were seen in 40 patients. CT identified 17 lesions larger than 1.0 cm, while PET identified 13 of them (76.5%). CONCLUSIONS: Chest CT is more sensitive than PET in detecting pulmonary metastases from OSTS. A significant portion of known pulmonary metastases greater than 1.0 cm on CT, are PET negative. Sub-centimetre CT lesions should not be considered false positive if inactive on PET. A negative PET scan in the presence of suspicious CT findings in the chest cannot reliably exclude pulmonary metastases from OSTS.     

Multiple muscle metastases from lung cancer detected by FDG PET/CT

A 71-year-old man with right lung mass, who was recently diagnosed histopathologically with pulmonary adenocarcinoma, was referred for staging of the primary tumor. Whole-body F-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) demonstrated multiple hypermetabolic foci in various skeletal muscle localizations, suggesting extensive metastatic muscle involvements in addition to increased FDG uptake in the primary tumor. Subsequent biopsy and histopathological study confirmed muscle metastasis from lung adenocarcinoma. Skeletal muscle metastasis from lung cancer is rare, but multiple muscle metastases are even more unusual. FDG PET/CT is able to detect unexpected metastatic involvements such as multiple muscle metastases in lung cancer patients.     

Contribution of PET in the detection of liver metastases from pancreatic tumours

AIM: Although uptake of 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) in the liver is basically high, metastatic liver tumours are known to be positive on positron emission tomography (PET). The purpose of this study is to evaluate the diagnostic accuracy of FDG-PET in detecting hepatic metastases from pancreatic cancer. METHODS: Thirty-four patients with histologically proven malignant tumours of the pancreas underwent FDG-PET, computed tomography (CT) and transabdominal ultrasound (US). The findings of PET, CT and US were compared with the histopathologic findings at surgery or with clinical follow-up and the diagnostic accuracy of PET was evaluated. RESULTS: PET showed 28 regions of high FDG uptake (SUV = 3.3-9.1) in 13 patients. Twenty-six foci were metastatic lesions confirmed by surgery (n = 11), clinical follow-up (n = 10) or autopsy (n = 5). FDG-PET accurately differentiated seven metastatic lesions from cysts when the diagnosis by US or CT was unreliable because of the small size of the lesion. In two patients who had areas of high uptake in the liver, no metastases were detected by surgery. FDG-PET showed no areas of increased uptake in 21 patients. Surgery revealed no metastatic lesions in the liver in 20 of 21 patients, but a liver metastasis was found at surgery in one patient. The diagnostic accuracy of FDG-PET was 90%, which was comparable with that of US or CT. CONCLUSION: Our data suggest that PET is reliable in detecting liver, metastases from pancreatic cancer.     

^18F-FDG PET／CT在诊断转移性肝肿瘤中的应用

目的：探讨^18F-FDG PEF／CT在诊断转移性肝肿瘤中的应用。方法：回顾性分析49例转移性肝肿瘤患者的PET／CT影像资料,探讨^18F-FDG PET／CT诊断转移性肝肿瘤的影像表现及应用价值。结果：49例转移性肝肿瘤患者中45例^18F-FDG PET／CT表现为病灶^18F-FDG摄取明显高于周围正常肝组织;其中25例进行了延迟显像,22例表现为SUVmax及T／N值明显升高;发现肝转移同时伴有肝外转移患者38例。结论：^18F-FDG PET／CT诊断转移性肝肿瘤灵敏度高,准确,并可以同时对全身情况加以评价,对肿瘤患者肝转移的评价及治疗具有重要指导作用。     

Role of FDG PET/CT for detection of primary tumor in patients with extracervical metastases from carcinoma of unknown primary

AimTo explore the diagnostic performance of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to detect the primary tumor site in patients with extracervical metastases from carcinoma of unknown primary (CUP). We evaluated patient outcomes as overall survival (OS).Materials and methodsIn a single-center, retrospective study (2005–2019), patients with extracervical metastases from CUP underwent FDG PET/CT to detect primary tumor sites. The final diagnosis was based on histopathology/or clinical follow-up of at least 12 months.ResultsA total of 83 patients [Male 41 (49%), mean age 59 ± 14 years, range: 32–83 years] fulfilled the inclusion/exclusion criteria and were enrolled for analysis. The primary tumor was detected in 36 out of 83 (43%) patients based on histopathology/or clinical follow-up. PET/CT suggested the primary tumor site in 39 (47%) patients with diagnostic accuracy of 87%, sensitivity 89%, specificity 85%, PPV 82%, NPV 91% and detection rate 39%. Patients with oligometastases (<3) (2.16 years, 1.04–2.54) and primary unidentified (1 year, 0.34–2.14) had longer median survival time compared to the patients with multiple metastases (0.67 years, 0.17–1.58, p = 0.009) and primary identified (0.67 years,0.16–1.33, p = 0.002). The SUVmax of the primary or metastatic lesions with maximum uptake was not significantly related to survival.ConclusionsPET/CT could reveal the primary tumor site in 39% of the patients. It demonstrated the metastatic disease burden and distribution in patients with ‘primary obscured’, which directs management. Patients with multiple metastases and primary identified had a poorer prognosis. In patients with primary unidentified after PET/CT, a further search was futile.     

Usefulness of FDG-PET/CT in the detection of pancreatic metastases from lung cancer

Objective  The objective of this study was to assess the ability to detect pancreatic metastasis of lung cancer and to clarify the degree of fluorodeoxyglucose (FDG) accumulation and computed tomography (CT) characteristics of pancreatic metastasis from lung cancer. Methods  A total of 573 patients (415 men and 158 women) with lung cancer were retrospectively evaluated. All patients underwent FDG-positron emission tomography (PET)/CT with contrast-enhanced CT for first=stage (313 patients; initial study group) or follow-up study (260 patients; follow-up study group). A lesion was regarded as positive for metastasis on the basis of visual judgment of the degree of increased metabolism by two experienced and independent interpreters, supported by semiquantitative evaluation on the basis of calculation of the maximum standardized uptake value (SUV_max). Results  Abnormal accumulations in the pancreas were detected in 5 of 313 patients (1.60%) in the initial study group, and 6 of 260 patients (2.31%) in the follow-up study group. Seven of these patients had adenocarcinoma, three had small cell carcinoma, and the rest had large cell endocrine carcinoma. Tumor sizes (longitudinal diameter), measured by CT, of these 11 patients ranged from 6 mm to 52 mm (mean ± SD 8.3 mm ± 11.9 mm), and SUV_max for 1 h ranged from 3.37 to 11.1 (mean ± SD 6.12 ± 2.43). Three of these pancreatic lesions were difficult to determine by routine transaxial images, and detection was obvious only by thin-slice images or multiplanar reconstruction images. Contrast-enhanced CT showed gradual fill-in from the peripheral portion to the center. In addition, 10 of 11 cases did not show main pancreatic duct dilatation even if the tumor size was large. Conclusions  Metastases to the pancreas in lung cancer patients are not so rare and radiologists first have an important role to detect the pancreatic mass and then suggest to metastasis as the likely diagnosis. For this purpose, FDG-PET/CT has an advantage in depicting unsuspected pancreatic metastasis from lung cancer, particularly that which is not detected by CT alone.