Integrated positron emission tomography/computed tomography in patients with non-small cell lung cancer: normal variants and pitfalls

The purpose of this pictorial essay is to illustrate a spectrum of normal variants and potential pitfalls in integrated positron emission tomography (PET)/computed tomography (CT) imaging in the evaluation of patients with non-small cell lung cancer. Knowledge of the normal variants and potential pitfalls in PET/CT imaging as well as patients' clinical histories, together with the use of CT to localize foci of increased tracer uptake accurately, is useful in preventing misinterpretation.     

The value of positron emission tomography in patients with non-small cell lung cancer

Background

Pre-operative assessment of non-small cell lung cancer (NSCLC) is a major application of positron emission tomography (FDG-PET). Despite substantial evidence of diagnostic accuracy, relatively little attention has been paid to its effects on patient outcomes. This paper addresses this by extending an existing decision model to include patient-elicited utilities.

Patients and methods

A decision-tree model of the effect of FDG-PET on pre-operative staging was converted to a Markov model. Utilities for futile and appropriate thoracotomy were elicited from 75 patients undergoing staging investigation for NSCLC. The decision model was then used to estimate the expected value of perfect information (EVPI) associated with three sources of uncertainty—the accuracy of PET, the accuracy of CT and the patient related utility of a futile thoracotomy.

Results

The model confirmed the apparent cost-effectiveness of FDG-PET and indicated that the EVPI associated with the utility of futile thoracotomy considerably exceeds that associated with measures of accuracy.

Conclusion

The study highlights the importance of patient related utilities in assessing the cost-effectiveness of diagnostic technologies. In the specific case of PET for pre-operative staging of NSCLC, future research effort should focus on such elicitation, rather than further refinement of accuracy estimates.     

Positron emission tomography/computed tomography for staging and restaging of head and neck cancer: comparison with positron emission tomography read together with contrast-enhanced computed tomography

This retrospective study aimed to describe the differences between image readings done with combined positron emission tomography/computed tomography (PET/CT) and PET read together with contrast-enhanced CT (ceCT) in patients with squamous cell carcinoma of the head and neck. In 46 patients, no differences were found between the two readings for assessing infiltration of adjacent structures (P=.63), transgression of the midline (P=.67), lymph node involvement (P=.32), and T- and N stage. PET/CT and PET read together with ceCT have comparable diagnostic yield.     

Depiction of celiac ganglia on positron emission tomography and computed tomography in patients with lung cancer

ObjectiveTo differentiate imaging characteristics of celiac ganglia from metastatic lesion on positron emission tomography–computed tomography (PET-CT) in patients with lung cancer and correlate these findings to postmortem multidetector row computed tomography (MDCT).MethodsOne hundred twenty-nine patients were included. Imaging characteristics and fluorodeoxyglucose (FDG) avidity of the celiac ganglia were recorded. Postmortem MDCT of 20 subjects were reviewed.ResultsCeliac ganglia were identified unilaterally in 127 and bilaterally in 108 patients without abnormal FDG uptake. Postmortem images showed celiac ganglia in all cases with no significant difference compared to our patients.ConclusionsFamiliarity with CT characteristics and FDG-avidity of celiac ganglia enable us to distinguish them from metastatic lesions in their vicinity.     

Dynamic contrast-enhanced MRI of primary rectal cancer: quantitative correlation with positron emission tomography/computed tomography

Purpose

To assess the correlations between parameters measured on dynamic contrast‐enhanced magnetic resonance imaging and 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) in rectal cancer.

Materials and Methods

To assess the correlations between parameters measured on dynamic contrast‐enhanced MRI and FDG‐PET in rectal cancer.

Results

Significant correlations were only demonstrated between k_ep and SUVmax (r = 0.587, P = 0.001), and k_ep and SUVmean (r = 0.562, P = 0.002). No significant differences were found in imaging parameters between well, moderately and poorly differentiated adenocarcinoma groups. However, there was a trend that higher imaging values were found in poorly differentiated adenocarcinomas.

Conclusion

Positive correlations were found between k_ep and SUV values in primary rectal adenocarcinomas suggesting an association between angiogenesis and metabolic activity and further reflecting that angiogenic activity in washout phase is better associated with tumor metabolism than the uptake phase. J. Magn. Reson. Imaging 2011;33:340–347. © 2011 Wiley‐Liss, Inc.     

18F-FLT与18F-FDG PET/CT对非小细胞肺癌淋巴结分期的比较

目的 比较3′-脱氧-3′-18F-FLT与18F-FDG PET/CT对NSCLC淋巴结分期的诊断价值,探讨肿瘤FLT和FDG摄取与细胞周期蛋白Cyclin D1表达的相关性.方法 选择手术治疗的NSCLC患者31例,男22例,女9例,年龄38～84岁.术前2周内行18F-FLT和18F-FDG PET/CT检查,术后行病理和转移淋巴结的免疫组织化学Cyclin D1检测.以病理诊断为“金标准”,评价18F-FLT和18F-FDG PET/CT显像对NSCLC的诊断价值.应用SPSS 12.0软件,计数资料行,检验,组间SUV.差异行方差分析,SUV.与Cyclin D1的表达行直线相关分析.结果 FLT和FDG PET/CT对NSCLC原发灶诊断的灵敏度分别为74.2％(23/31)和93.5％ (29/31),二者差异有统计学意义(x2=4.29,P =0.038).FLT PET/CT对NSCLC区域淋巴结诊断的灵敏度、特异性、准确性和阳性预测值分别为65％(39/60)、98％ (291/296)、93％(330/356)和85％(39/46),FDG PET/CT则分别为85％(51/60)、84％(249/296)、84％(300/356)和52％(51/98),二者差异有统计学意义(x2值分别为6.40、32.89、12.40、14.32和2.98,P均＜0.05).对于N分期,FLT PET/CT能使77.4％(24/31)的NSCLC患者分期正确,6.5％(2/31)的患者分期过高(假阳性),16.1％(5/31)的患者分期过低(假阴性);而FDG PET/CT相应数据则分别为77.4％(24/31)、16.1％(5/31)和6.5％(2/31).原发灶18F-FLT SUVmax与肿瘤组织Cyclin D1表达呈正相关(r=0.644,P＜0.01),FDG SUVmax则无相关性(r=0.293,P＞0.05).临床分期越晚,FLT SUVmax越高(F=12.2,P＜0.05),但FDG SUVmax则无此趋势(F=3.1,P＞0.05);二者在不同病理类型、分化程度之间差异无统计学意义(F=1.1、0.6、0.8和1.1,P均＞0.05).结论 与FDG PET/CT相比,FLT PET/CT对NSCLC淋巴结分期过低的患者多,而分期过高的患者少;对区域淋巴结诊断灵敏度降低,但有更高的特异性、准确性和阳性预测值.肿瘤FLT摄取与细胞周期蛋白Cyclin D1的表达有相关性.     

Whole-body diffusion-weighted magnetic resonance imaging in the staging of oncological patients: comparison with positron emission tomography computed tomography (PET-CT) in a pilot study

Purpose

The aim of this pilot study was to compare positron emission tomography computed tomography (PET-CT) and whole-body DWIBS in staging oncological patients to determine the staging accuracy of whole-body DWIBS.

Materials and methods

We initiated a prospective, blinded investigation on 29 patients affected by oncological diseases (n=14) or lymphoma (n=15), who underwent fluorodeoxyglucose (FDG)-based PET-CT and whole-body DWIBS for restaging purposes. Magnetic resonance (MR) imaging was conducted with a multistack (n=4) DWIBS pulse sequence. Images were read independently by two experienced radiologists and one nuclear physician. Statistical analysis assessed interobserver agreement and diagnostic accuracy.

Results

Whole-body DWIBS had a room occupation time of 20 min. Mean postprocessing time was 15 min (range 10–17 min). Mean reading time was 20 min for reader 1 (range 15–25 min) and 18 min for reader 2 (range 13–22 min). Interobserver agreement was almost perfect (=0.93). Reader 1 had a sensitivity of 89.07%, a specificity of 98.5%, and an accuracy of 97.65%, with a positive predictive value (PPV) of 85.48% and a negative predictive value (NPV) of 98.91%. Reader 2 had a sensitivity of 87.39%, a specificity of 98.39% and a diagnostic accuracy of 97.8%, with a PPV of 88.13% and a NPV of 98.75%.

Conclusions

The whole-body DWIBS protocol provided a fast whole-body examination with high specificity and NPV. One major bias of the study was the inclusion of patients with diffuse disease and advanced disease stage and the heterogeneity of the neoplastic diseases included.     

Fluorine-18 deoxyglucose positron emission tomography for the detection of bone metastases in patients with non-small cell lung cancer

Despite advances in morphological imaging, some patients with lung cancer are found to have non resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using bone scintigraphy, which has a high sensitivity but a poor specificity. We have attempted to evaluate the utility of the fluorine-18 deoxyglucose positron emission tomography (FDG PET) for the detection of bone metastasis. One hundred and ten consecutive patients with histological diagnosis of non-small cell lung cancer (NSCLC) who underwent both FDG PET and bone scintigraphy were selected for this review. In this group, there were 43 patients with metastatic disease (stage IV). Among these, 21 (19% of total group) had one or several bone metastases confirmed by biopsy (n = 8) or radiographic techniques (n = 13). Radionuclide bone scanning correctly identified 54 out of 89 cases without osseous involvement and 19 out of 21 osseous involvements. On the other hand, FDG PET correctly identified the absence of osseous involvement in 87 out of 89 patients and the presence of bone metastasis in 19 out of 21 patients. Thus using PET there were two false-negative and two false-positive cases. PET and bone scanning had, respectively, an accuracy of 96% and 66% in the evaluation of osseous involvement in patients with NSCLC. In conclusion, our data suggest that whole-body FDG PET may be useful in detecting bone metastases in patients with known NSCLC. Received 10 March and in revised form 7 May 1998     

A positron emission tomography/computed tomography (PET/CT) acquisition protocol for CT radiation dose optimization

BACKGROUND: In current combined positron emission tomography/computed tomography (PET/CT) systems, high-quality CT images not only increase diagnostic value by providing anatomic delineation of hyper- and hypometabolic tissues, but also shorten the acquisition time for attenuation correction compared with standard PET imaging. However, this technique potentially introduces more radiation burden to patients as a result of the higher radiation exposure from CT. METHODS: In this study, the radiation doses delivered from typical germanium-based and CT-based transmission scans were measured and compared using an anthropomorphic Rando Alderson phantom with insertions of thermoluminescent dosimeters. Image geometric distortion and quantified uptake values in PET images with different manipulating CT acquisition protocols for attenuation correction were also evaluated. RESULTS: It was found that radiation doses during germanium-based transmission scans were almost negligible, while doses from CT-based transmission scans were significantly higher. Using a lower radiation dose, the CT acquisition protocol did not significantly affect attenuation correction and anatomic delineation in PET. CONCLUSIONS: This study revealed the relation between image information and dose. The current PET/CT imaging acquisition protocol was improved by decreasing the radiation risks without sacrificing the diagnostic values.     

The usefulness of FDG positron emission tomography for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer: a comparative study with X-ray computed tomography

We evaluated the usefulness of fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer and then compared the findings with the results of X-ray CT by region based on the histological diagnoses. We examined 29 patients with non-small cell lung cancer. One hundred and thirty-two mediastinal lymph nodes were surgically removed and the histological diagnoses were confirmed. FDG PET images, including 146 mediastinal regions, were visually analysed and the mediastinal lymph nodes were scored as positive when the FDG uptake was higher than that in the other mediastinal structures. On the X-ray CT scans, any mediastinal lymph nodes with a diameter of 10 mm or larger were scored as positive. All three examinations were successfully performed on 71 regions. For FDG PET, we found a sensitivity of 76%, a specificity of 98% and an accuracy of 93%. On the other hand, for X-ray CT a sensitivity of 65%, a specificity of 87% and an accuracy of 82% were observed. A significant difference was observed in respect of both specificity and accuracy (P<0.05). Based on the above findings, FDG PET is suggested to be superior to X-ray CT when used for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer.     

F-18]fluorodeoxyglucose positron emission tomography and positron emission tomography: computed tomography in recurrent and metastatic cholangiocarcinoma

OBJECTIVES: We retrospectively assessed the diagnostic utility of dedicated positron emission tomography (PET) and hybrid PET-computed tomography (CT) scans with [F-18]fluorodeoxyglucose (FDG) in the imaging evaluation of patients with known or suspected recurrent and metastatic cholangiocarcinoma. METHODS: The study group included 24 patients (13 males and 11 females; age range, 34-75 years) with known or suspected recurrent and metastatic cholangiocarcinoma. We performed 8 dedicated PET scans (Siemens 953/A, Knoxville, Tenn) in 8 patients and 24 hybrid PET-CT scans (Siemens Biograph, Knoxville, Tenn) in 16 patients. Four patients underwent both pretreatment and posttreatment scans. Nonenhanced CT transmission scans were obtained for attenuation correction after administration of oral contrast material. PET images were obtained 60 minutes after the intravenous administration of 15 mCi (555 MBq) FDG. Prior treatments included surgery alone in 12 patients, surgery and chemotherapy in 6 patients, and surgery and combined chemoradiation therapy in 6 patients. Diagnostic validation was conducted through clinical and radiologic follow-up (2 months to 8 years). RESULTS: PET and CT were concordant in 18 patients. PET-CT correctly localized a hypermetabolic metastatic lesion in the anterior subdiaphragmatic fat instead of within the liver and was falsely negative in intrahepatic infiltrating type cholangiocarcinoma. PET was discordant with CT in 6 patients. PET was negative in an enlarged right cardiophrenic lymph node on CT, which remained stable for 1 year. In 1 patient, PET-CT scan showed hypermetabolic peritoneal disease in the right paracolic gutter without definite corresponding structural abnormalities, which was subsequently confirmed on a follow-up PET-CT scan performed 6 months after the initial study, at which time peritoneal nodular thickening was evident on concurrent CT. PET-CT documented the progression of locally recurrent and metastatic disease in another patient based on interval appearance of several new hypermetabolic lesions and significant increase in the standardized uptake values of the known lesions despite little interval change in the size and morphologic character of lesions on concurrent CT. It was also helpful in excluding metabolically active disease in patients with contrast enhancement at either surgical margin of hepatic resection site or focally within hepatic parenchyma and in an osseous lesion. Overall, based on the clinically relevant patient basis for detection of recurrent and metastatic cholangiocarcinoma, the sensitivity and specificity of PET (alone and combined with CT) were 94% and 100% and, for CT alone, were 82% and 43%, respectively. CONCLUSIONS: FDG PET and PET-CT are useful in the imaging evaluation of patients with cholangiocarcinoma (except for infiltrating type) for detection of recurrent and metastatic disease and for assessment of treatment response. In particular, the combined structural and metabolic information of PET-CT enhances the diagnostic confidence in lesion characterization.     

The role of positron emission tomography/computed tomography in radiation therapy planning for patients with lung cancer

Positron emission tomography (PET)/computed tomography (CT) has rapidly assumed a critical role in the management of patients with locoregionally advanced lung cancers who are candidates for definitive radiation therapy (RT). Definitive RT is given with curative intent, but can only be successful in patients without distant metastasis and if all gross tumor is contained within the treated volume. An increasing body of evidence supports the use of PET-based imaging for selection of patients for both surgery and definitive RT. Similarly, the use of PET/CT images for accurate target volume definition in lung cancer is a dynamic area of research. Most available evidence on PET staging of lung cancer relates to non-small cell lung cancer (NSCLC). In general clinical use, (18)F-fluorodeoxyglucose (FDG) is the primary radiopharmaceutical useful in NSCLC. Other tracers, including proliferation markers and hypoxia tracers, may have significant roles in future. Much of the FDG-PET literature describing the impact of PET on actual patient management has concerned candidates for surgical resection. In the few prospective studies where PET was used for staging and patient selection in NSCLC candidates for definitive RT, 25%-30% of patients were denied definitive RT, generally because PET detected unsuspected advanced locoregional or distant metastatic disease. PET/CT and CT findings are often discordant in NSCLC but studies with clinical-pathological correlation always show that PET-assisted staging is more accurate than conventional assessment. In all studies in which "PET-defined" and "non-PET-defined" RT target volumes were compared, there were major differences between PET and non-PET volumes. Therefore, in cases where PET-assisted and non-PET staging are different and biopsy confirmation is unavailable, it is rational to use the most accurate modality (namely PET/CT) to define the target volume. The use of PET/CT in patient selection and target volume definition is likely to lead to improvements in outcome for patients with NSCLC.     

非小细胞肺癌动态CT增强值与正电子发射计算机体层摄影脱氧葡萄糖标准摄取值的相关性探讨

目的探讨非小细胞肺癌动态CT增强值与正电子发射计算机体层摄影(PET)中18氟-脱氧葡萄糖(18F-FDG)标准摄取值(SUV)的相关性。方法搜集行PET-CT和动态增强CT检查的28例非小细胞肺癌和13例良性肺结节病例,测量结节增强前后各时相的平均CT值、18F-FDG标准摄取值的最大值和平均值,计算结节增强峰值,用Pearson相关分析方法评价良恶性结节动态CT增强峰值和18F-FDG SUV的相关性。结果非小细胞肺癌和良性结节CT增强峰值[(35·09±11·41)、(26·92±19·98)HU]的差异无统计学意义(t=1·374,P=0·189),SUV最大值(7·23±4·38、2·97±2·80)差异有统计学意义(t=-3·972,P<0·001),SUV平均值差异有统计学意义(t=-4·061,P<0·001)。非小细胞肺癌CT增强峰值[(35·09±11·41)HU]和18F-FDG SUV的平均值(4·93±3·53)及最大值(7·23±4·38)之间均无相关关系(r=-0·040,P=0·839及r=0·056,P=0·778)。结论非小细胞肺癌动态CT增强值与FDG SUV之间无相关关系,FDG SUV可能不适用于非小细胞肺癌抗肿瘤血管生成治疗的疗效评价。     

Regional nodal staging with 18F-FDG PET-CT in non-small cell lung cancer: Additional diagnostic value of CT attenuation and dual-time-point imaging

Background

[Fluorine-18]-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET–CT) is widely performed in the regional nodal staging of non-small cell lung cancer (NSCLC). However, the uptake of ¹⁸F-FDG by tubercular granulomatous tissues may lead to false-positive diagnosis. This is of special concern in China, where tubercular granulomatous disease is epidemic. Herein, we evaluated the efficacy of an additional CT attenuation and a dual-time-point scan in determining the status of lymph nodes.

Methods

Eighty NSCLC patients underwent curative surgical resection after ¹⁸F-FDG PET–CT and separate breath-hold CT examinations. The initial images were analyzed by two methods. In method 1, nodal status was determined by ¹⁸F-FDG uptake only. In Method 2, nodal status was determined by ¹⁸F-FDG uptake associated with CT attenuation. For dual-time-point imaging, the retention index (RI) of benign and malignant nodal groups with positive uptake in the initial scan was examined.

Results

A total of 265 nodal groups were documented. On a per-nodal-group basis, the diagnostic sensitivity, specificity, and accuracy of Method 1 were 66.7%, 89.7%, and 85.3%, respectively, whereas those of Method 2 were 64.7%, 96.7%, and 90.6%, respectively. The improvement in diagnostic specificity and accuracy associated with the addition of CT attenuation in Method 2 as compared to Method 1 was statistically significant (p < 0.01). Thirty-nine nodal groups with positive uptake in the initial scan underwent dual-time-point imaging and the difference in the RI between benign and malignant groups showed no statistical significance (p > 0.05).

Conclusion

¹⁸F-FDG PET–CT has high diagnostic value for preoperative lymph-node (N) staging of NSCLC patients. We show that ¹⁸F-FDG uptake combined with CT attenuation improves the diagnostic specificity and accuracy of nodal diagnosis in NSCLC. For the lymph nodes with positive uptake in the initial scan, dual-time-point imaging has limited effect in differentiation.     

New CT criteria for nodal staging in non-small cell lung cancer

ObjectiveThe purpose of our study was to develop a simple noninvasive technique for nodal staging using routine preoperative computed tomography (CT).Materials and methodsThe institutional review board approved this retrospective study, and written informed consent to perform the initial and follow-up CT studies was obtained from all patients. Preoperative CT findings (n= 218 patients with resectable non-small cell lung cancer) and pathological diagnoses after surgical resection were evaluated. Using CT images, lymph node section area, circumference, and lesion attenuation values (LAVs) were drawn freehand, and the short axis (SA) and long axis (LA) were measured using caliper software. Receiver operating characteristic (ROC) curves were then used to analyze the section area, circumference, and LAVs.ResultsBased on ROC curves, two cut-off values, lymph node section area > 30 mm² and circumference > 25 mm, showed greater sensitivity for nodal staging than the conventional criterion of lymph node SA ≥ 10 mm or the LA, SA/LA ratio or LAVs. Using lymph node section area > 30 mm² for diagnosis, the sensitivity, specificity, and accuracy of nodal staging were 90.5%, 56.3%, and 58.3%, respectively. Using lymph node circumference > 25 mm, the values were 76.2%, 70.4%, and 70.8%, respectively.ConclusionLymph node section area > 30 mm² and circumference > 25 mm can serve as supportive criteria used by radiologists and surgeons to determine nodal staging. If these CT criteria are met, use of a more sensitive procedure such as positron emission tomography or mediastinoscopy is recommended.Concise abstractCT is used routinely during preoperative management of lung cancer. Based on ROC analyses, the cut-off values for surface area, circumference, the SA/LA ratio, and LAVs for diagnosis of lymph node metastasis were 30 mm², 25 mm, 0.65, and 50 Hounsfield units, respectively. Our findings indicate that lymph node surface area > 30 mm² and circumference > 25 mm are supportive criteria that can be used by radiologists and thoracic surgeons to determine nodal staging and surgical indications.     

Indeterminate pleural metastasis on contrast-enhanced chest CT in non-small cell lung cancer: improved differential diagnosis with 18F-FDG PET/CT

Purpose

To evaluate the diagnostic performance of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT (PET/CT) for determining the presence of pleural metastasis in patients with indeterminate findings on a contrast-enhanced chest CT (CECT) for non-small cell lung cancer (NSCLC).

Materials and methods

This is a retrospective study. NSCLC patients (n?=?63) who underwent thoracentesis and/or pleural biopsy were enrolled. CECT and PET/CT reports of pleural metastasis were analyzed based on comparison with cytological or histological confirmation. Negative cytologic results were re-confirmed with follow-up study prior to cancer-related therapy. CECT results were classified into 3 categories: negative, indeterminate, and positive for pleural metastasis. PET/CT results were classified into 2 categories (negative and positive for pleural metastasis) based on FDG uptake visual grading. The level of max SUV of pleura was also analyzed. ROC analysis was done for establishing the max SUV cut-off value.

Result

PET/CT could differentiate pleural metastasis with 70.8% diagnostic accuracy when the CECT finding was indeterminate (n?=?24). Optimal cut-off value to predict pleural metastasis was 2.8 for max SUV. Diagnosis by max SUV 2.8 had lower sensitivity (86.3 vs. 92.2%), but higher specificity (66.7 vs. 58.3%) than PET/CT by FDG visual grading criteria.

Conclusion

PET/CT showed better diagnostic performance than CECT for detecting pleural metastasis in NSCLC patients. When the finding of CECT is controversial, PET/CT can differentiate the metastatic pleural lesion. Both FDG uptake visual grading and max SUG cut-off value can be used as diagnostic criteria for pleural metastasis.     

Preoperative staging of non-small cell lung cancer: prospective comparison of PET/MR and PET/CT

Objectives

To prospectively compare the accuracies of PET/MR and PET/CT in the preoperative staging of non-small cell lung cancer (NSCLC).

Methods

Institutional review board approval and patients’ informed consents were obtained. 45 patients with proven or radiologically suspected lung cancer which appeared to be resectable on CT were enrolled. PET/MR was performed for the preoperative staging of NSCLC followed by PET/CT without contrast enhancement on the same day. Dedicated MR images including diffusion weighted images were obtained. Readers assessed PET/MR and PET/CT with contrast-enhanced CT. Accuracies of PET/MR and PET/CT for NSCLC staging were compared.

Results

Primary tumour stages (n?=?40) were correctly diagnosed in 32 patients (80.0 %) on PET/MR and in 32 patients (80.0 %) on PET/CT (P?=?1.0). Node stages (n?=?42) were correctly determined in 24 patients (57.1 %) on PET/MR and in 22 patients (52.4 %) on PET/CT (P?=?0.683). Metastatic lesions in the brain, bone, liver, and pleura were detected in 6 patients (13.3 %). PET/MR missed one patient with pleural metastasis while PET/CT missed one patient with solitary brain metastasis and two patients with pleural metastases (P?=?0.480).

Conclusions

This study demonstrated that PET/MR in combination with contrast-enhanced CT was comparable to PET/CT in the preoperative staging of NSCLC while reducing radiation exposure.

Key points

? PET/MR can be comparable to PET/CT for preoperative NSCLC staging.? PET/MR and PET/CT show excellent correlation in measuring SUVmax of primary lesions.? Using PET/MR, estimated radiation dose can decrease by 31.1?% compared with PET/CT.

     

Non-small cell lung cancer: FDG PET for nodal staging in patients with stage I disease

PURPOSE: To determine the accuracy of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the evaluation of regional lymph nodes in patients with stage I non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Imaging and clinical findings obtained during 5 years in 84 patients (mean age, 66 years) were reviewed. Patients had thoracic computed tomographic findings of stage I NSCLC, an FDG PET study, and histopathologic proof of lung cancer. At the time of diagnosis, disease stage was assigned on the basis of FDG PET results and was compared with the histopathologic stage to determine the accuracy of PET. RESULTS: When PET stage was compared with histopathologic stage, the disease in 72 (86%) patients was accurately staged with PET, understaged in two (2%), and overstaged in 10 (12%). The overall sensitivity, specificity, and positive and negative predictive values for PET of regional lymph nodal metastases were 82%, 86%, 47%, and 97%, respectively. CONCLUSION: FDG PET enables accurate staging of regional lymph node disease in patients with stage I NSCLC. A negative PET scan in these patients suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy.