Comparison of (11)C-choline PET/CT and enhanced CT in the evaluation of patients with pulmonary abnormalities and locoregional lymph node involvement in lung cancer

BackgroundThis study compares the diagnostic abilities of integrated ¹¹C-choline PET/CT imaging and contrast-enhanced helical CT imaging in pulmonary lesions and locoregional lymph node metastases in patients with lung cancer.Patients and MethodsOne hundred eight patients with proven or suspected lung cancer underwent integrated ¹¹C-choline PET/CT and contrast-enhanced CT, followed by surgical resection and nodal staging.ResultsThe ¹¹C-choline PET/CT and CT diagnoses of pulmonary lesions and locoregional lymph node metastases were compared with pathologic findings, which revealed benign lesions in 26 patients (tuberculoma [8 patients], inflammatory pseudotumor [7 patients], hamartoma [6 patients], sclerosing hemangioma [4 patients], and pulmonary sequestration [1 patient]) and lung cancers in 82 patients (adenocarcinoma [39 patients], squamous cell carcinoma [23 patients], carcinoid [7 patients], small-cell lung cancer [5 patients], adenosquamous carcinoma [5 patients], and large-cell lung cancer [3 patients]). The accuracy, sensitivity, and specificity of ¹¹C-choline PET/CT for diagnosing lung cancer were 82.4%, 85.4%, and 73.1%, respectively, compared with 73.1%, 76.8%, and 61.5%, respectively, for CT. Differences between ¹¹C-choline PET/CT and CT in diagnosing lung cancer were not statistically significant (p = .503, .118, and .375, respectively). We used receiver operating characteristic (ROC) curve for analysis, finding the ROC of standard uptake value (SUV_max) for diagnosing lung cancer. The cutoff value of SUV_max was 3.54. Preoperative nodal staging was compared with postoperative histopathologic staging. ¹¹C-choline PET/CT correctly staged 80.5% of patients, 12.2% were overstaged, and 7.3% were understaged; for CT these values were 58.5%, 24.4%, and 17.1%, respectively. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ¹¹C-choline PET/CT for lymph nodes were 83.8%, 82.4%, 84.1%, 50.3%, and 96.1%, respectively, compared with 69.3%, 63.7%, 71.2%, 30.2%, 91.0%, respectively, for CT.ConclusionDifferences in the accuracy, sensitivity, specificity, PPV, and NPV between ¹¹C-choline PET/CT and CT are thus statistically significant for nodal staging (p = .003, .007, .000, .000, and .004, respectively). Although ¹¹C-choline PET/CT is not significantly better at diagnosing pulmonary lesions than is enhanced CT, ¹¹C-choline PET/CT has improved sensitivity, specificity, accuracy, PPV, and NPV relative to enhanced CT in the evaluation of locoregional lymph nodes.     

The value of lymph node ultrasound and whole body 18F-FDG PET/CT in stage IIB/C melanoma patients prior to SLNB

BackgroundStage IIB/IIC (8th AJCC) melanoma patients are known to have high-risk primary tumors, however they follow the same routine to sentinel lymph node biopsy (SLNB) as more low risk tumors. Guidelines are not conclusive regarding the use of preoperative imaging for these patients. The aim of this pilot study was to assess the value of ultrasound (US) and ¹⁸F-FDG PET/CT prior to lymphoscintigraphy (LSG) and SLNB for stage IIB/C melanoma patients.MethodsFrom 2019-04 till 2020–01, all stage IIB/C melanoma patients underwent US of the regional lymph nodes and whole body ¹⁸F-FDG PET/CT before their planned LSG and SLNB. Suspected metastases were confirmed with fine needle aspiration (FNA), prior to surgery.ResultsIn total 23 patients were screened: six had metastases detected by imaging, two by US, one by ¹⁸F-FDG PET/CT and three were detected by both imaging modalities. All metastases were nodal and therefore treatment was altered to lymph node dissection and all but one also received adjuvant therapy. Eight (47%) of the 17 patients without macroscopic disease, still had a positive SN. Sensitivity, specificity and false negative rate for US and ¹⁸F-FDG PET/CT were 36%, 89%, 64% and 29%, 100% and 71%, respectively.ConclusionPreoperative negative imaging does not exclude the presence of SN metastases, therefore SLNB cannot be foregone. However, US detected metastases in 22% of patients, altering their treatment, which suggests it is effective in the work-up of stage IIB/C melanoma. Staging with ¹⁸F-FDG PET/CT is not of added value prior to LSG and SLNB and should therefore not be used.     

The role of F-FDG PET/CT for evaluation of metastatic mediastinal lymph nodes in patients with lung squamous-cell carcinoma or adenocarcinoma

Objectives

To evaluate the efficacy of ¹⁸F-FDG PET/CT in depicting metastatic mediastinal lymph nodes in patients with lung squamous-cell carcinoma (LSCC) or lung adenocarcinoma (LAC) in a tuberculosis-endemic country.

Methods

This study retrospectively reviewed patients with LSCC or LAC, who underwent preoperative ¹⁸F-FDG PET/CT to assess mediastinal lymph node metastasis. Patients with the short-axis of mediastinal lymph node ≤ 15 mm were included. PET/CT interpretation was analyzed in two ways. Firstly, with CT for anatomical localization, lymph nodes showing greater ¹⁸F-FDG uptake than vessel pool on PET were regarded malignant. Secondly, lymph nodes with positive uptake on PET were considered malignant, only when nodes had neither calcification nor higher attenuation than vessel pool on CT.

Results

One hundred and sixteen LSCCs and 234 LACs were evaluated. With CT for anatomical localization, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of PET were 78.6%, 45.5%, 53.4%, 31.4% and 87.0% in LSCC group, and 61.8%, 66.3%, 65.0%, 42.9% and 80.9% in LAC group. PET showed higher specificity and accuracy in LAC group compared with LSCC group (p = 0.001 and p = 0.038, respectively). Considering calcification or high attenuation on CT, the sensitivity, specificity, accuracy, PPV and NPV of PET/CT were 71.4%, 67.0%, 68.1%, 40.8% and 88.1% in LSCC group, and 54.4%, 86.1%, 76.9%, 61.7% and 82.2% in LAC group. Compared with PET, PET/CT possessed higher specificity and accuracy in LSCC group (p = 0.000 and p = 0.000, respectively), and higher specificity, accuracy and PPV in LAC group (p = 0.000, p = 0.000 and p = 0.022, respectively).

Conclusions

¹⁸F-FDG PET displays limited efficacy in assessing mediastinal lymph node metastasis with the short-axis diameter <15 mm in LSCC and LAC groups and higher false-positivity in LSCC group. The specificity and accuracy in LSCC and LAC groups are enhanced by interpreting attenuation characteristic on CT.     

Diagnostic accuracy of CT in assessing extra-regional lymphadenopathy in pancreatic and peri-ampullary cancer: A systematic review and meta-analysis

ObjectivesComputed tomography (CT) is the most widely used method to assess resectability of pancreatic and peri-ampullary cancer. One of the contra-indications for curative resection is the presence of extra-regional lymph node metastases. This meta-analysis investigates the accuracy of CT in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer.MethodsWe systematically reviewed the literature according to the PRISMA guidelines. Studies reporting on CT assessment of extra-regional lymph nodes in patients undergoing pancreatoduodenectomy were included. Data on baseline characteristics, CT-investigations and histopathological outcomes were extracted. Diagnostic accuracy, positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity were calculated for individual studies and pooled data.ResultsAfter screening, 4 cohort studies reporting on CT-findings and histopathological outcome in 157 patients with pancreatic or peri-ampullary cancer were included. Overall, diagnostic accuracy, specificity and NPV varied from 63 to 81, 80–100% and 67–90% respectively. However, PPV and sensitivity ranged from 0 to 100% and 0–38%. Pooled sensitivity, specificity, PPV and NPV were 25%, 86%, 28% and 84% respectively.ConclusionsCT has a low diagnostic accuracy in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer. Therefore, suspicion of extra-regional lymph node metastases on CT alone should not be considered a contra-indication for exploration.     

18F-FDG PET/CT显像在鼻咽癌分期与疗效监测中的临床应用价值

背景与目的:18F-脱氧葡萄糖(fluorine-18 fluorodeoxyglucose,18F-FDG)PET/CT显像可明显提高肺癌、食管癌等多种肿瘤的诊断、分期与疗效监测的准确性,有助于更准确地制定治疗方案.本研究探讨全身18F-FDG PET/CT显像在鼻咽癌首次分期、再分期及疗效监测中的临床应用价值.方法:回顾性分析澳大利亚Peter MacCallum肿瘤中心2002年2月至2005年12月43例鼻咽癌患者的18F-FDG PET/CT全身扫描报告,根据临床资料、病理结果及临床随访结果,计算18F-FDG PET/CT与传统影像学检查CT、MRI的准确性、特异性、灵敏度、阳性预测值与阴性预测值,并对结果进行比较和分析.结果:18F-FDGPET/CT诊断鼻咽癌总的准确率、敏感性、特异性、阳性预测值与阴性预测值分别为95.3%、100.0%、85.7%、93.8%、100.0%,传统影像学检查CT、MRI分别为65.5%、79.4%、64.7%、81.8%、57.9%. 18F-FDG PET/CT诊断结果使2例首次分期、7例再分期患者治疗方案得到改变,并影响1例首次分期和3例再分期患者治疗方案的制定;在疗效监测组中,指导医生修改治疗方案共11例(其中5例为原则性的修改).18F-FDG PET/CT检测到2例第二原发肿瘤,1例是甲状腺癌,1例是低度恶性胃癌.结论:18F-FDG PET/CT全身显像对鼻咽癌N、M分期与疗效监测的临床作用可能优于CT、MR检查.     

18F-Fludeoxyglucose PET/CT in SCLC: Analysis of the CONVERT Randomized Controlled Trial

IntroductionWe used phase-3 CONVERT trial data to investigate the impact of fludeoxyglucose F 18 (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) in SCLC.MethodsCONVERT randomized patients with limited-stage SCLC to twice-daily (45 Gy in 30 fractions) or once-daily (66 Gy in 33 fractions) chemoradiotherapy. Patients were divided into two groups in this unplanned analysis: those staged with conventional imaging (contrast-enhanced thorax and abdomen CT and brain imaging with or without bone scintigraphy) and those staged with ¹⁸F-FDG PET/CT in addition.ResultsData on a total of 540 patients were analyzed. Compared with patients who underwent conventional imaging (n = 231), patients also staged with ¹⁸F-FDG PET/CT (n = 309) had a smaller gross tumor volume (p = 0.003), were less likely to have an increased pretreatment serum lactate dehydrogenase level (p = 0.035), and received more chemotherapy (p = 0.026). There were no significant differences in overall (hazard ratio = 0.87, 95% confidence interval: 0.70–1.08, p = 0.192) and progression-free survival (hazard ratio = 0.87, 95% confidence interval: 0.71–1.07], p = 0.198) between patients staged with or without ¹⁸F-FDG PET/CT. In the conventional imaging group, we found no survival difference between patients staged with or without bone scintigraphy. Although there were no differences in delivered radiotherapy dose, ¹⁸F-FDG PET/CT–staged patients received lower normal tissue (lung, heart, and esophagus) radiation doses. Apart from a higher incidence of late esophagitis in patients staged with conventional imaging (for grade ≥1, 19% versus 11%; [p = 0.012]), the incidence of acute and late radiotherapy-related toxicities was not different between the two groups.ConclusionIn CONVERT, survival outcomes were not significantly different in patients staged with or without ¹⁸F-FDG PET/CT. However, this analysis cannot support the use or omission of ¹⁸F-FDG PET/CT owing to study limitations.     

The Comparative Study of Ultrasonography,Contrast-Enhanced MRI,and 18F-FDG PET/CT for Detecting Axillary Lymph Node Metastasis in T1 Breast Cancer

Purpose

A more noninvasive evaluation of axillary lymph node in breast cancer is one of the principal challenges of breast cancer treatment. To detect axillary lymph node metastasis (ALNM) in T1 breast cancer, we have compared the axillary ultrasonography (AUS), contrast-enhanced magnetic resonance imaging (cMRI), and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) to determine the most adequate test or a combination of tests.

Methods

Retrospectively, 349 T1 breast cancer patients who were preoperatively examined using AUS, cMRI, and PET/CT between 2008 and 2011 and whom underwent pathological evaluations of axillary lymph nodes were reviewed and analyzed.

Results

In total, 26.4% (92/349) of patients exhibited ALNM. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of AUS for determining ALNM were 44.6%, 88.7%, 58.6%, 81.7%, and 77.1%, respectively. cMRI was similar to AUS. The sensitivity, specificity, PPV, NPV, and accuracy of PET/CT were 44.5%, 94.2%, 73.2%, 82.6%, and 81.1%, respectively. The combination including cMRI and PET/CT was the most accurate with sensitivity, specificity, PPV, NPV, and accuracy values of 39.1%, 98.8%, 92.3%, 81.9%, and 83.1%, respectively. The mean number (3.5±4.2) of ALNMs in the patients who were positive based on cMRI and PET/CT and also pathologically proven to exhibit ALNM was significantly larger than the number (2.16±2.26) in other patients who exhibited ALNM (p=0.035).

Conclusion

There are no definitive modalities for detecting ALNM in T1 breast cancers to replace sentinel lymph node biopsy (SLNB). If ALNM is suspected based on cMRI and PET/CT, the axillary dissection without SLNB might be a better option because it is related to high possibilities of ALNM and large axillary metastatic volumes.     

Diagnostic Value of 18F-FDG PET/CT in Comparison to Bone Scintigraphy,CT and 18F-FDG PET for the Detection of Bone Metastasis

Purpose: To evaluate the diagnostic value of 18F-FDG PET/CT for detection of bone metastasis in comparisonwith the efficacies of 18F-FDG PET/CT, CT, 18F-FDG PET and conventional planar bone scintigraphy in a seriesof cancer patients. Methods: Five hundred and thirty patients who underwent both 18F-FDG PET/CT and bonescintigraphy within 1 month were retrospectively analyzed. The skeletal system was classified into 10 anatomicsegments and interpreted blindly and separately. For each modality, the sensitivity, specificity, accuracy, PPVand NPV were calculated and the results were statistically analyzed. Results: Bone metastases were confirmedin 117 patients with 459 positive segments. On patient-based analysis, the sensitivity, specificity, accuracy, PPVand NPV of 18F-FDG PET/CT were significantly higher than bone scintigraphy, CT and 18F-FDG PET (P<0.05).On segment-based analysis, the sensitivity of CT, bone scintigraphy, 18F-FDG PET and 18F-FDG PET/CT were70.4%, 89.5%, 89.1% and 97.8%, respectively (P<0.05, compared with 18F-FDG PET/CT). The overall specificityand accuracy of the four modalities were 89.1%, 91.8%, 90.3%, 98.2% and 90.3%, 90.9%, 89.8%, 98.0%,respectively (P<0.05, compared with 18F-FDG PET/CT). The PPV and NPV were 89.8%, 87.6%, 85.6%, 97.2%and 85.6%, 93.2%, 92.8%, 98.6%, respectively. Three hundred and twelve lesions or segments were presentedas lytic or sclerotic changes on CT images at the corresponding sites of increased 18F-FDG uptake. In lytic ormixed lesions, the sensitivity of 18F-FDG PET/CT and 18F-FDG PET were better than bone scintigraphy, whilein osteoblastic lesions bone scintigraphy had a similar performance with 18F-FDG PET/CT but better than18F-FDG PET alone. Conclusion: Our data allow the conclusion that 18F-FDG PET/CT is superior to planar bonescintigraphy, CT or 18F-FDG PET in detecting bone metastasis. 18F-FDG PET/CT may enhance our diagnosis oftumor bone metastasis and provide more information for cancer treatment.     

Clinical value of F-FDG PET/CT in assessing suspicious relapse after rectal cancer resection

AIM: To evaluate the value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the restaging of resected rectal cancer.METHODS: From January 2007 to Sep 2008, 21 patients who had undergone curative surgery resection for rectal carcinoma with suspicious relapse in conventional imaging or clinical findings were retrospectively enrolled in our study. The patients underwent 28 PET/CT scans (two patients had two scans, one patient had three and one had four scans). Locoregional recurrences and/or distant metastases were confirmed by histological analysis or clinical and imaging follow-up.RESULTS: Final diagnosis was confirmed by histopathological diagnosis in 12 patients (57.1%) and by clinical and imaging follow-up in nine patients (42.9%). Eight patients had extrapelvic metastases with no evidence of pelvic recurrence. Seven patients had both pelvic recurrence and extrapelvic metastases, and two patients had pelvic recurrence only. ¹⁸F-FDG PET/CT was negative in two patients and positive in 19 patients. ¹⁸F-FDG PET/CT was true positive in 17 patients and false positive in two. The accuracy of ¹⁸F-FDG PET/CT was 90.5%, negative predictive value was 100%, and positive predictive value was 89.5%. Five patients with perirectal recurrence underwent ¹⁸F-FDG PET/CT image guided tissue core biopsy. ¹⁸F-FDG PET/CT also guided surgical resection of pulmonary metastases in three patients and monitored the response to salvage chemotherapy and/or radiotherapy in four patients.CONCLUSION: ¹⁸F-FDG PET/CT is useful for evaluating suspicious locoregional recurrence and distant metastases in the restaging of rectal cancer after curative resection.     

Is 18F-FDG PET accurate to predict neoadjuvant therapy response in breast cancer? A meta-analysis

Clinical evidence regarding the value of ¹⁸F-FDG PET for therapy responses assessment in breast cancer is increasing. The objective of this study is to evaluate the accuracy of ¹⁸F-FDG PET in predicting responses to neoadjuvant therapies with meta-analysis and explore its optimal regimen for clinical use. Articles in English language relating to the accuracy of ¹⁸F-FDG PET for this utility were retrieved. Methodological quality was assessed by QUADAS tool. Pooled estimation and subgroup analysis data were obtained by statistical analysis. Nineteen studies met the inclusion criteria and involved 920 pathologically confirmed patients in total (mean age 49.8 years, all female). Methodological quality was relatively high. To predict histopathological response in primary breast lesions by PET, the pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratio were 84% (95% CI, 78–88%), 66% (95% CI, 62–70%), 50% (95% CI, 44–55%), 91% (95% CI, 87–94%), and 11.90 (95% CI, 6.33–22.36), respectively. In regional lymph nodes, sensitivity and NPV of PET were 92% (95% CI, 83–97%) and 88% (95% CI, 76–95%), respectively. Subgroup analysis showed that performing a post-therapy ¹⁸F-FDG PET early (after the 1st or 2nd cycle of chemotherapy) was significantly better than later (accuracy 76% vs. 65%, P = 0.001). Furthermore, the best correlation with pathology was yielded by employing a reduction rate (RR) cutoff value of standardized uptake value between 55 and 65%. ¹⁸F-FDG PET is useful to predict neoadjuvant therapy response in breast cancer. However, the relatively low specificity and PPV still call for caution. It is suggested to perform PET in an earlier course of therapy and use RR cutoff value between 55 and 65%, which might potentially identify non-responders early. However, further prospective studies are warranted to assess this regimen and adequately position PET in treatment management.     

Selective Axillary Surgery in Breast Cancer Patients Based on Positron Emission Tomography with 18F-Fluoro-2-Deoxy-D-Glucose: not Yet!

We prospectively evaluated 31 patients with invasive breast cancer. Preoperative positron emission tomography (PET) with ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) for detection of axillary lymph node metastases was compared with the histopathologic status of the sentinel lymph node (SLN). Sensitivity of PET imaging was 43%, specificity and negative predictive value were 94 and 67%, respectively. The smallest metastasis detected by PET measured 3mm in diameter. The results of this study suggest that detection of small axillary lymph node metastases is limited by the currently achievable spatial resolution of PET imaging. Selective axillary surgery in breast cancer patients based on ¹⁸F-FDG PET is yet not possible.     

18F-FDG PET-CT CT 在诊断乳腺癌腋窝淋巴结转移状态的对比研究*

目的:通过与CT对比,探讨18F-FDG PET-CT 在诊断乳腺癌患者腋窝淋巴结转移中的价值。方法:回顾性分析22例行乳腺癌改良根治术患者的术前18F-FDG PET-CT 、CT图像。在CT图像上分别以淋巴结最短径>0.5cm（A 标准）、最短径≥1.0cm（B 标准）及最长径≥1.0cm（C 标准）为判定淋巴结转移的标准;在PET-CT 图像上,分别以目测腋窝淋巴结出现18F-FDG 异常放射性浓聚为判定淋巴结阳性的标准（D 标准）及半定量分析法异常放射性浓聚灶最大标准化摄取值（maximum standard uptake value ,SUV max）≥1.0 为判定淋巴结转移标准（E 标准）。 以术后病理为金标准,比较不同影像方法诊断腋窝淋巴结转移状态的价值。结果:乳腺癌患者腋窝阳性与阴性淋巴结在大小及SUV max 方面的差异均具有统计学意义。不同诊断标准中,以PET-CT 的总体诊断准确率及与病理吻合度Kappa 值最高,其中A 标准灵敏度最高（59.3%）而特异度最低（83.5%）;B 标准特异度和阳性预测值最高（分别为98.2% 、72.7%）,而灵敏度和阴性预测值最低（27.1% 、88.4%）;C 标准各项诊断指标相对较差,无突出项;PET-CT 图像目测与半定量诊断结果相同,其诊断准确性（90.1%）、阴性预测值（92.5%）均优于单独CT诊断,且与病理诊断吻合度较好（Kappa 值为0.57）,在诊断灵敏度（55.9%）、特异度（96.1%）及阳性预测值（71.7%）方面与单独CT比较也具较高诊断价值,阳性组SUV max 较阴性组明显为高,二者差异有统计学意义（P=0.000）。 不同影像方法在诊断腋窝淋巴结转移时差异有统计学意义（P<0.05）。 结论:18F-FDG PET-CT 是一种直观有效的评价乳腺癌腋窝淋巴结转移状态的方法。      

The role of diffusion-weighted MRI and 18F-FDG PET/CT in the prediction of pathologic complete response after radiochemotherapy for rectal cancer: A systematic review

After neoadjuvant radiochemotherapy (RCT) for locally advanced rectal cancer, 15–27% of the patients experience a pathological complete response (pCR). This observation raises the question as to whether invasive surgery could be avoided in a selected cohort of patients who obtain a clinical complete response after preoperative RCT. In this respect, there has been growing interest in functional imaging techniques to improve clinical response assessment. This systematic review focuses on the role of diffusion-weighted imaging (DWI) and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the prediction of pCR after RCT for rectal cancer.A total of 14 publications on DWI and 25 on ¹⁸F-FDG PET/CT were retrieved. Pooled analysis of individual patient data shows both imaging modalities have a low positive predictive value in the prediction of pCR (mean PPV of 54% and 39% for DWI- and ¹⁸F-FDG PET/CT-based parameters respectively). Especially pre-RCT imaging is unable to predict pCR with overall accuracies of 68–72% for DWI and 44% for ¹⁸F-FDG PET/CT. Qualitative DWI assessment 5–10 weeks after the end of RCT may outperform apparent diffusion coefficient (ADC)-based DWI-parameters (overall accuracy of 87% vs. 74–78%). Although few data are available, early changes in FDG-uptake seem promising in the prediction of pCR and the role of ¹⁸F-FDG PET/CT during RCT should be further investigated. Quantitative and qualitative ¹⁸F-FDG PET/CT measurements are equally effective in the assessment of pCR after RCT.The major strength of DWI and ¹⁸F-FDG PET/CT lies in the identification of non-responders who are not candidates for organ preservation. Up to now, DWI and ¹⁸F-FDG PET/CT are not accurate enough to safely select patients for organ-sparing strategies. Future research must focus on the integration of functional imaging with clinical data and molecular biomarkers.     

Preoperative lymph node staging of early-stage cervical carcinoma by [18F]-fluoro-2-deoxy-D-glucose-positron emission tomography

BACKGROUND: Increasing evidence has documented the value of positron emission tomography (PET) in oncology, but only limited data are available comparing PET findings with the pathologic status of regional lymph nodes in patients with cervical carcinoma. The objective of this study was to determine the sensitivity and specificity of PET in detecting lymph node metastasis in women with early-stage cervical carcinoma. METHODS: The authors performed a retrospective review of all patients with Stage IA-IIA cervical carcinoma who underwent PET before surgery from 1999 to 2004. The status of the regional lymph nodes was correlated with lymph node pathology. RESULTS: Fifty-nine patients were identified. Pelvic lymph node metastases were present in 32% of the patients and were detected by PET with a sensitivity of 53%, a specificity of 90%, a positive predictive value (PPV) of 71%, and a negative predictive value (NPV) of 80%. Paraaortic lymph node disease was present in 9% of patients and was detected by PET with a sensitivity of 25%, a specificity 98%, a PPV of 50%, and an NPV of 93%. The mean size of the tumor deposits was larger in the PET-positive pelvic nodes (15.2 mm; range, 2-35 mm) than in the PET-negative lymph nodes (7.3 mm; range, 0.3-20 mm; P = 0.002). Computed tomography (CT) scans were obtained before surgery in 42 patients. The combined sensitivity of PET and CT in these patients was 75%. PET alone detected 9 (36%) of the positive lymph node groups, whereas CT alone detected 3 (12%) of the positive lymph node groups. Neither PET nor CT detected the positive lymph node groups in 8 patients (32%). CONCLUSIONS: Pathologic validation of PET imaging demonstrated a low sensitivity and a high specificity for PET in patients with early-stage cervical carcinoma.     

Additional value of F-18 FDG PET/CT for initial staging in breast cancer with clinically negative axillary nodes

The aim of this study was to evaluate the clinical impact of the preoperative ¹⁸F-FDG PET/CT in the initial workup of breast cancer with clinically negative axillary nodes. Whether the status of the clinical axillary nodal involvement can be considered a parameter for making a decision to omit the preoperative ¹⁸F-FDG PET/CT in the situation reported herein was also determined. A total of 178 patients who had newly diagnosed breast cancer and for whom the conventional diagnostic modalities showed no sign of axillary node metastasis were retrospectively enrolled in this study. All the patients underwent preoperative ¹⁸F-FDG PET/CT. The images and histologic results that were obtained were analyzed. ¹⁸F-FDG PET/CT detected primary lesions in 156 of the 178 patients, with an overall sensitivity of 87.6 %, and false negative results were obtained for 22 patients (12.4 %). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ¹⁸F-FDG PET/CT in the detection of axillary nodes were 20.8, 86.9, 37.0, 74.8, and 69.1 %, respectively. Extra-axillary node metastasis was identified in two patients (1.1 %) who had internal mammary nodes. There was no distant metastasis, but coexisting primary tumor was detected in five patients (2.8 %). In total, the therapeutic plan was changed based on ¹⁸F-FDG PET/CT in seven (3.9 %) of the 178 patients, but considering only the cases confined to breast cancer, the change occurred in only two patients (1.1 %). ¹⁸F-FDG PET/CT almost did not affect the initial staging and treatment plan in breast cancer with clinically negative axillary node. If the axillary node is clinically negative in the preoperative workup of breast cancer, then ¹⁸F-FDG PET/CT can be omitted.     

Diagnostic accuracy of <Superscript>18</Superscript>F–FDG PET/CT and MR imaging in patients with adenoid cystic carcinoma

Background

The aim of this study was to evaluate the value of 18F–FDG PET/CT (PET/CT) and MRI for local and/or whole-body restaging of adenoid cystic carcinoma of the head and neck (ACC).

Methods

Thirty-six patients with ACC underwent conventional MRI of the head and neck and a whole-body PET/CT and were analysed with regards to detection of a local tumor recurrence, lymph node or distant metastases. A consensus interpretation of all available imaging data was used as reference standard. Sensitivity, specificity, diagnostic accuracy, positive and negative predictive values were calculated for MRI and PET/CT.

Results

The sensitivity of PET/CT and MRI was 96% (89%), specificity 89% (89%), PPV 96% (96%), NPV 89% (73%) and accuracy 94% (89%) for detection of local tumors. Additionally, PET/CT revealed lymph node metastases in one patient and distant metastases in 9/36 patients. In three patients secondary primaries were found.

Conclusions

Whole-body PET/CT in addition to MRI of the head and neck improves detection of local tumour and metastastic spread in ACC.

     

COVID-19 vaccine related hypermetabolic lymph nodes on PET/CT: Implications of inflammatory findings in cancer imaging

We observed several patients presenting 2-[¹⁸F]FDG uptake in the reactive axillary lymph node at PET/CT imaging, ipsilateral to the site of the COVID-19 vaccine injection. Analog finding was documented at [¹⁸F]Choline PET/CT. The aim of our study was to describe this source of false positive cases. All patients examined by PET/CT were included in the study. Data concerning patient anamnesis, laterality, and time interval from recent COVID-19 vaccination were recorded. SUVmax was measured in all lymph nodes expressing tracer uptake after vaccination. Among 712 PET/CT scans with 2-[¹⁸F]FDG, 104 were submitted to vaccination; 89/104 patients (85%) presented axillary and/or deltoid tracer uptake, related to recent COVID-19 vaccine administration (median from injection: 11 days). The mean SUVmax of these findings was 2.1 (range 1.6–3.3). Among 89 patients with false positive axillary uptake, 36 subjects had received chemotherapy due to lymph node metastases from somatic cancer or lymphomas, prior to the scan: 6/36 patients with lymph node metastases showed no response to therapy or progression disease. The mean SUVmax value of lymph nodal localizations of somatic cancers/lymphomas after chemotherapy was 7.8. Only 1/31 prostate cancer patients examined by [¹⁸F]Choline PET/CT showed post-vaccine axillary lymph node uptake. These findings were not recorded at PET/CT scans with [¹⁸F]-6-FDOPA, [⁶⁸Ga]Ga-DOTATOC, and [¹⁸F]-fluoride. Following COVID-19 mass vaccination, a significant percentage of patients examined by 2-[¹⁸F]FDG PET/CT presents axillary, reactive lymph node uptake. Anamnesis, low-dose CT, and ultrasonography facilitated correct diagnosis. Semi-quantitative assessment supported the visual analysis of PET/CT data; SUVmax values of metastatic lymph nodes were considerably higher than post-vaccine lymph nodes. [¹⁸F]Choline uptake in reactive lymph node after vaccination was confirmed. After the COVID-19 pandemic, nuclear physicians need to take these potential false positive cases into account in daily clinical practice.     

18F-FDG PET对睾丸生殖细胞肿瘤化疗后肿瘤残留的准确性判断

  目的  探讨睾丸生殖细胞肿瘤化疗后18F-FDG PET对腹膜后残留病灶的准确性判断。  方法  回顾性分析2014年2月至2016年12月北京大学肿瘤医院泌尿外科16例睾丸生殖肿瘤伴腹膜后淋巴结转移患者的资料,4~6个疗程的博来霉素+顺铂+依托泊苷（BEP）化疗后行腹部CT检查,所有患者的腹膜后肿块直径＞2 cm。18F-FDG PET检查后行腹膜后淋巴结清扫术,并进行术后病理与术前18F-FDG PET结果比较。  结果  16例患者中10例18F-FDG PET结果阳性,其中5例术后病理存在肿瘤残留、5例无肿瘤残留组织;6例18F-FDG PET结果为阴性,2例术后病理肿瘤残留患者均为成熟畸胎瘤、4例无肿瘤组织残留。18F-FDG PET的准确率为56.25%（9/16）,灵敏度为71.42%（5/7）,特异度为44.44%（4/9）,阳性预测率为50.00%（5/10）,阴性预测率为66.67%（4/6）。  结论  18F-FDG PET灵敏度较高,但多种因素会影响18F-FDG PET结果的准确性,成熟畸胎瘤易造成18F-FDG PET的假阴性,大量炎性组织易造成18F-FDG PET假阳性,需结合多种检查提高结果准确性。      

Positron emission tomography of esophageal carcinoma using (11)C-choline and (18)F-fluorodeoxyglucose: a novel method of preoperative lymph node staging.

BACKGROUND: Accurate preoperative staging is an important but difficult problem in determining therapy for patients with esophageal carcinoma. Positron emission tomography (PET) is used with [methyl-(11)C]choline ((11)C-choline) and 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) to detect a variety of malignancies. The authors used PET with both of these agents to detect lymph node metastases in patients with esophageal carcinoma. METHODS: Lymph node metastases in 33 patients with biopsy-proven esophageal carcinoma (16 patients with tumors classified as T1 and 17 patients with tumors classified as T2-4) was examined by PET using (11)C-choline and (18)F-FDG, and the accuracy of the results was correlated with pathology findings after surgery. RESULTS: (11)C-choline PET was more effective than (18)F-FDG PET and computed tomography (CT) in detecting very small metastases localized in the mediastinum. It was ineffective, however, in detecting metastases localized in the upper abdomen, because of the normal uptake of (11)C-choline in the liver. (18)F-FDG PET was superior to CT in detecting metastases in the mediastinum and the upper abdomen, whereas (11)C-choline PET was superior to (18)F-FDG PET in detecting metastases in the mediastinum. When (11)C-choline PET and (18)F-FDG PET were used in combination, they were very effective in evaluating the lymph node status in both the mediastinum and the upper abdomen, and detected 85% of the metastatic lymph nodes (n = 46). CONCLUSIONS: In this study, the combination of (11)C-choline PET and (18)F-FDG PET was very effective in evaluating the lymph node status of patients with esophageal carcinoma preoperatively.     

18F-FDG PET-CT在非小细胞肺癌术前区域淋巴结分期中的价值

目的 探讨18F-FDG PET-CT在非小细胞肺癌(NSCLC)患者术前区域淋巴结(N)分期方面的价值,以及CT密度和双时相扫描在淋巴结性质判定方面的作用.方法 43例手术病理证实的NSCLC患者均于术前行18F-FDG PET-CT扫描,对常规扫描图像采用PET法(单纯根据18F-FDG摄取水平判断淋巴结性质)和PET+CT密度法(结合CT密度和摄取水平判断淋巴结性质)分析.摄取水平通过目测法和半定量分析法结合判定.双时相扫描的储留指数(RI)>10%为摄取升高.以病理检查作为金标准对所得结果进行分析.结果 以区域淋巴结组为单位,PET法的诊断敏感度、特异度、准确度、阳性预测值和阴性预测值分别为88.0%、88.4%、88.3%、59.5%和97.4%,PET+CT密度法的相应值分别为84.0%、94.6%、92.9%、75.0%和96.8%,其中2种方法的特异度和准确度之间差异有统计学意义(P<0.05).28组淋巴结行双时相扫描,良恶性组摄取变化值(△SUVmax)之间和砒之间差异无统计学意义(P>0.05);在23组延迟相摄取升高的淋巴结中,11组为转移;在5组无摄取升高的淋巴结中,1组为转移.结论 18F-FDG PET-CT在肺癌患者术前N分期方面有较高的诊断价值,结合淋巴结CT密度和18F-FDG摄取水平可进一步提高诊断的特异度和准确度.对于常规相摄取增高的淋巴结,延迟相摄取升高对判断淋巴结性质的价值有限,但无摄取升高则更支持良性诊断.