An initial experience with FDG-PET in the imaging of residual disease after induction therapy for lung cancer

BACKGROUND: The 2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) imaging is an advance over computed tomography alone in the staging of untreated nonsmall cell lung cancer (NSCLC). Aside from one 9-patient study, there are no data comparing FDG-PET imaging with surgical staging of NSCLC after induction therapy. METHODS: We reviewed our institutional experience with FDG-PET imaging followed by surgical staging of nonsmall cell lung cancer after induction therapy. A nuclear physician blinded to surgical findings reviewed the FDG-PET scans and assigned a clinical TNM stage. A thoracic surgeon assigned a pathologic TNM stage. Then the clinical TNM stage and the pathologic TNM stage were compared. RESULTS: Fifty-six patients (30 males and 26 females; median, age 60) with nonsmall cell lung cancer underwent chemotherapy (40 patients), chemoradiation (11 patients), or radiation alone (5 patients) followed by PET and operations. PET had a positive predictive value of 98% for detecting residual viable disease in the primary tumor. PET over-staged nodal status in 33% of patients, under staged nodal status in 15%, and was correct in 52%. PET correctly classified all patients with M1 disease. CONCLUSIONS: Positron emission tomography after induction therapy accurately detects residual viable primary tumor, but not the involvement of mediastinal lymph nodes.     

Integrated FDG-PET/CT does not make invasive staging of the intrathoracic lymph nodes in non-small cell lung cancer redundant: a prospective study

BACKGROUND: Staging of non-small cell lung cancer (NSCLC) is important for determining choice of treatment and prognosis. The accuracy of FDG-PET scans for staging of lymph nodes is too low to replace invasive nodal staging. It is unknown whether the accuracy of integrated FDG-PET/CT scanning makes invasive staging redundant. METHODS: In a prospective study, the mediastinal and/or hilar lymph nodes in patients with proven NSCLC were investigated with integrated FDG-PET/CT scanning. Pathological confirmation of all suspect lymph nodes was obtained to calculate the accuracy of the fusion images. In addition, the use of the standardised uptake value (SUV) in the staging of intrathoracic lymph nodes was analysed. RESULTS: 105 intrathoracic lymph node stations from 52 patients with NSCLC were characterised. The prevalence of malignancy in the lymph nodes was 36%. The sensitivity of the integrated FDG-PET/CT scan to detect malignant lymph nodes was 84% and its specificity was 85% (positive likelihood ratio 5.64, negative likelihood ratio 0.19). SUV(max), SUV(mean) and the SUV(max)/SUV(liver) ratio were all significantly higher in malignant than in benign lymph nodes. The area under the receiver operating curve did not differ between these three quantitative variables, but the highest accuracy was found with the SUV(max)/SUV(liver) ratio. At a cut-off value of 1.5 for the SUV(max)/SUV(liver )ratio, the sensitivity and specificity to detect malignant lymph node invasion were 82% and 93%, respectively. CONCLUSION: The accuracy of integrated FDG-PET/CT scanning is too low to replace invasive intrathoracic lymph node staging in patients with NSCLC. The visual interpretation of the fusion images of the integrated FDG-PET/CT scan can be replaced by the quantitative variable SUV(max)/SUV(liver) without loss of accuracy for intrathoracic lymph node staging.     

Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer

OBJECTIVE: To determine the sensitivity, specificity, and accuracy of positron emission tomography with 2-fluorine-18-fluorodeoxyglucose (PET-FDG) in the preoperative staging (N and M staging) of patients with lung cancer. The authors wanted to compare the efficacy of PET scanning with currently used computed tomography (CT) scanning. MATERIALS AND METHODS: Results of whole-body PET-FDG imaging and CT scans were compared with histologic findings for the presence or absence of lymph node disease or metastatic sites. Sampling of mediastinal lymph nodes was performed using mediastinoscopy or thoracotomy. RESULTS: PET-FDG imaging was significantly more sensitive, specific, and accurate for detecting N disease than CT. PET changed N staging in 35% and M staging in 11% of patients. CT scans helped in accurate anatomic localization of 6/57 PET lymph node abnormalities. CONCLUSION: PET-FDG is a reliable method for preoperative staging of patients with lung cancer and would help to optimize management of these patients. Accurate lymph node staging of lung cancer may be ideally performed by simultaneous review of PET and CT scans.     

Comparison of Integrated Positron Emission Tomography/Computed Tomography and Mediastinoscopy in Mediastinal Staging of Non-Small Cell Lung Cancer: Analysis of 212 Patients

Background : Mediastinal staging is crucial to determine the prognosis and treatment options for patients with non-small cell lung cancer (NSCLC). In this study, we compared the results of integrated positron emission tomography-computerised tomography (PET/CT) with those of mediastinoscopy in mediastinal staging of NSCLC patients. Methods : PET/CT and mediastinoscopy was performed on 250 consecutive patients diagnosed with NSCLC between September 2005 and March 2008. Thirty-eight patients were excluded from the study. Standard cervical mediastinoscopy was performed in all patients, and simultaneous extended cervical mediastinoscopy was performed in 52 patients with left sided lesions. Patients with negative mediastinoscopy underwent resection. The pathological results were correlated with PET/CT findings.

Results : A total of 212 patients (199 male, 13 female; mean age: 58.3 years) were evaluated. In PET/CT analysis 60 true-positive, 45 false-positive, 103 true-negative and 4 false-negative patients were found. The rate of PET/CT positivity of mediastinal lymph nodes was 49.5%. The sensitivity, specificity, positive and negative predictive values and accuracy for PET/CT were 93.8%, 69.6%, 57.1%, 96.3% and 76.9% respectively. The incidence of N2 disease in NSCLC patients with negative mediastinal lymph node uptake on PET/CT was 3.7% (4 of 107). In univariate analysis, right upper lobe tumours were significantly (p < 0.05) more associated with occult N2 disease.

Conclusions : In patients with positive mediastinal lymph node uptake on PET/CT invasive mediastinal staging appears necessary for exact staging. Mediastinoscopy can be omitted in NSCLC patients with negative mediastinal uptake on PET/CT in regions where the rate of PET/CT positivity of mediastinal lymph nodes is high.     

The size of mediastinal lymph nodes and its relation with metastatic involvement: a meta-analysis.

Positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) seems to be superior to computed tomography (CT) in staging the mediastinum in patients with non-small-cell lung cancer (NSCLC). However, recent results suggest that FDG-PET performance characteristics are conditional for nodal size as shown by CT: FDG-PET is more sensitive but less specific with lymph node enlargement on CT. The association between size and the probability of malignancy needs to be known to predict the post-test probabilities after PET, and finally, stratify patients for mediastinoscopy or thoracotomy depending on the PET and CT results. Therefore, we performed a meta-analysis of available studies reporting on the prevalence of metastatic involvement for different size categories of enlarged lymph nodes in patients with NSCLC and were able to include 14 studies. The prevalence of metastatic involvement and conditional test performance of CT and FDG-PET were calculated for lymph nodes measuring 10-15 mm, 16-20 mm and >20 mm. We found a post-test probability for N2 disease of 5% for lymph nodes measuring 10-15 mm on CT in patients with a negative FDG-PET result, suggesting that these patients should be planned for thoracotomy because the yield of mediastinoscopy will be extremely low. For patients with lymph nodes measuring > or =16 mm on CT and a negative FDG-PET result a post-test probability for N2 disease of 21% was found, suggesting that these patients should be planned for mediastinoscopy prior to possible thoracotomy to prevent too many unnecessary thoracotomies in this subset.     

^18FDG—PET在肺癌诊断中的价值

目的研究氟脱氯葡萄糖F18-正电子发射计算机电子扫描(18FDG-PET)在鉴别肺部肿块性质和肺癌术前纵隔淋巴结转移分期中的应用价值.方法对34例肺部肿块患者进行18FDG-PET和CT检查,PET资料分别采用目测法和计算标准化摄取值(SUV)的半定量法进行分析,并同病理结果对照.结果目测法18FDG-PET诊断肺部肿块性质的敏感度、准确度分别是93%、85%;CT分别为63%、53%,2种方法差异有显著性意义(P＜0.05);半定量法准确度为74%,与CT相比,差异也有显著性意义(P＜0.05).肺部恶性肿块的SUV是4.4±1.9,良性为2.2±1.7,2者差异有显著性意义(P＜0.05).18FDG-PET和CT2种检查方法术前对纵隔淋巴结转移的分期与病理结果符合率分别为100%和78%,2者差异有显著性意义(P＜0.05).结论同CT相比,18FDG-PET能更准确地鉴别肺部肿块性质及确定纵隔淋巴结转移分期,是一种较好的无创性肺癌诊断技术.     

Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography

Objective: To evaluate the accuracy of integrated positron emission tomography with ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) and computed tomography (PET/CT) in preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer (NSCLC) and to ascertain the role of invasive staging in verifying positron emission tomography (PET)/computed tomography (CT) results. Methods: Retrospective, single institution study of consecutive patients with suspected or pathologically proven, potentially resectable NSCLC undergoing integrated PET/CT scanning in the same PET centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station bases. Results: A total of 1001 nodal stations (723 mediastinal, 148 hilar and 130 intrapulmonary) were evaluated in 159 patients. Nodes were positive for malignancy in 48 (30.2%) out of 159 patients (N1 = 17; N2 = 30; N3 = 1) and 71 (7.1%) out of 1001 nodal stations (N1 = 24; N2 = 46; N3 = 1). At univariate analysis, lymph node involvement was significantly associated (p < 0.05) with the following primary tumour characteristics: increasing diameter, maximum standardised uptake value >9, central location and presence of vascular invasion. PET/CT staged the disease correctly in 128 out of 159 patients (80.5%), overstaging occurred in nine patients (5.7%) and understaging in 22 patients (13.8%). The overall sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting metastatic lymph nodes were 54.2%, 91.9%, 74.3%, 82.3% and 80.5% on a per-patient basis, and 57.7%, 98.5%, 74.5%, 96.8% and 95.6% on per-nodal-station basis. With regard to N2/N3 disease, PET/CT accuracy was 84.9% and 95.3% on a per-patient basis and on per-nodal-station basis, respectively. Referring to nodal size, PET/CT sensitivity to detect malignant involvement was 32.4% (12/37) in nodes <10 mm, and 85.3% (29/34) in nodes ≥10 mm. Conclusion: Our data show that integrated PET/CT provides high specificity but low sensitivity and accuracy in intrathoracic nodal staging of NSCLC patients and underscore the continued need for surgical staging.     

Pattern and predictors of occult mediastinal lymph node involvement in non-small cell lung cancer patients with negative mediastinal uptake on positron emission tomography.

OBJECTIVE: We sought to assess the incidence, pattern and predictors of occult mediastinal lymph node involvement (N2) in non-small cell lung cancer patients with negative mediastinal uptake of 2-deoxy-2-[(18)F]-fluoro-d-glucose ((18)FDG) on integrated positron emission tomography-computerised tomography (PET-CT). METHODS: All patients who underwent surgical resection in our unit over a 30-month period were reviewed (n=215). All patients had preoperative PET-CT prior to lung resection as an adjunct to a dedicated chest CT. Diabetic patients, patients who received neoadjuvant chemotherapy and those with positive mediastinal nodes on PET-CT (N2/N3) were excluded from this study. The population of interest was 153 non-small cell cancer patients (NSCLC), all of which had no FDG uptake in the mediastinum. No preoperative mediastinoscopy was carried out in this group and all underwent curative intent surgical resection. The pathological results were retrospectively reviewed and correlated with CT and integrated PET-CT findings. RESULTS: The incidence of occult N2 disease in NSCLC patients with negative mediastinal uptake of (18)FDG on PET-CT was 16% (25 of 153). The highest incidence of occult N2 involvement was in American thoracic society (ATS) 7 (16 of 25 patients, 64%) followed by ATS 4 (seven patients of 25, 28%). In univariate analysis, the following were significant predictors of occult N2 disease: centrally located tumours (P=0.049), right upper lobe tumours (P=0.04), enlarged lymph nodes (>1cm) on CT (P=0.048) and PET positive uptake in N1 nodes (P=0.006). In multivariate analysis, the following were independent predictors of occult N2 disease: centrally located tumours, right upper lobe tumours and PET positive uptake in N1 nodes (P<0.05). CONCLUSIONS: In NSCLC patients who are clinically staged as N2/N3 negative in the mediastinum by integrated PET-CT, 16% will have occult N2 disease following resection. Patients with the following: centrally located tumours, right upper lobe tumours and positive N1 nodes on PET should have preoperative cervical mediastinoscopy to rule out N2 nodal involvement, especially in ATS stations 7 and 4 as the incidence of occult nodal metastasis in these nodes is high. This study has potential implications in decision-making and planning best treatment approach.     

The role of FDG-PET scan in staging patients with nonsmall cell carcinoma

BACKGROUND: To assess the role of flourodeoxyglucose-positron-emission tomography (FDG-PET) scan in staging patients with nonsmall cell lung cancer (NSCLC). METHODS: We prospectively studied 400 patients with NSCLC. Each patient underwent a computed tomography (CT) scan of the chest and upper abdomen, other conventional staging studies and had a FDG-PET scan within 1 month before surgery. All suspicious N2 lymph nodes by either chest CT or by FDG-PET scan were biopsied. Patients that were N2 and M1 negative underwent pulmonary resection and complete thoracic lymphadenectomy. RESULTS: The FDG-PET had a higher sensitivity (71% vs 43%, p < 0.001), positive predictive value (44% vs 31%, p < 0.001), negative predictive value (91% vs 84%, p = 0.006), and accuracy (76% vs 68%, p = 0.037) than CT scan for N2 lymph nodes. Similarly, FDG-PET had a higher sensitivity (67% vs 41%, p < 0.001), but lower specificity (78% vs 88%, p = 0.009) than CT scan for N1 lymph nodes. FDG-PET led to unnecessary mediastinoscopy in 38 patients. FDG-PET was most commonly falsely negative in the subcarinal (#7) station and the aortopulmonary window lymph node (#5, #6) stations. It accurately upstaged 28 patients (7%) with unsuspected metastasis and it accurately downstaged 23 patients (6%). CONCLUSIONS:The FDG-PET scan allows for improved patient selection. It more accurately stages the mediastinum, however there are many false positives lymph nodes and it may be more likely to miss N2 disease in the #5, #6, and #7 stations. A positive FDG-PET scan means a tissue biopsy is indicated in that location.     

New Endoscopic Ultrasound (EUS) Applications in Lung Cancer: Evaluation of Patients With Negative Mediastinal CT and Re-Staging After Neoadjuvant Treatment

The main purpose of staging in non-small cell lung cancer (NSCLC) is to assess mediastinal lymph node involvement, with thoracic CT being the main non-invasive test for this. However, given that up to 15% of patients who show no mediastinal lymph node involvement in the CT has lymph node metastasis during surgery, other examinations are required. Endoscopic ultrasonography guided fine-needle aspiration (EUS-FNA) was shown to be able to detect advanced disease (metastatic mediastinal lymph nodes, adrenal metastasis, mediastinal invasion by the tumor) in approximately 25% of patients with a CT that suggested a non-advanced disease.Another situation in which CT has a very limited value is in the evaluation of the response to induction therapy, with its most limiting factor being its intrinsic inability to distinguish between a tumor and necrosis. In this context, EUS-FNA was shown to have a good performance, with a sensitivity, negative predictive value and precision of 75%, 67%, and 83%, respectively.In conclusion, EUS-FNA may be considered a good alternative in the pre-operative staging of patients with NSCLC, with and without diseased mediastinal lymph nodes in CT, and could play an important role in the mediastinal re-staging of these patients by identifying a patient sub-group who might benefit from additional surgical treatment.     

Endoscopic ultrasound in lung cancer patients with a normal mediastinum on computed tomography

BACKGROUND: Computed tomography (CT) is the most common method of staging lung cancer. We have previously shown endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) to be highly accurate in staging patients with nonsmall cell lung cancer (NSCLC) who have enlarged mediastinal lymph nodes on CT scan. In this study we report the accuracy and yield of EUS-FNA in staging patients without enlarged mediastinal lymph nodes by CT. METHODS: Patients with NSCLC and CT scan showing no enlarged mediastinal lymph nodes (> 1 cm for all nodes except > 1.2 cm for subcarinal) in the mediastinum underwent EUS. Fine needle aspiration was performed on at least one lymph node, if present, in the upper mediastinum, aortopulmonary window, subcarinal, and periesophagus regions. Each specimen was evaluated with on-site cytopathology and confirmed with complete cytopathologic examination. RESULTS: Sixty-nine patients without enlarged mediastinal lymph nodes were evaluated. Endoscopic ultrasound detected malignant mediastinal lymph nodes in 14 of 69 patients as well as other advanced (American Joint Committee on Cancer [AJCC] stage III/IV) in 3 others (1 left adrenal, and 2 with mediastinal invasion of tumor) for a total of 17 of 69 (25%, 95% confidence interval: 16% to 34%) patients. Eleven additional patients were found to have advanced disease by bronchoscopy (2), mediastinoscopy (2), and thoracotomy with mediastinal lymph node dissection (7). The sensitivity of EUS for advanced mediastinal disease was 61% (49% to 75%), and the specificity was 98% (95% to 100%). CONCLUSIONS: Endoscopic ultrasound guided fine needle aspiration can detect advanced mediastinal disease and avoid unnecessary surgical exploration in almost one of four patients who have no evidence of mediastinal disease on CT scan. In addition to previously reported results in patients with enlarged lymph nodes on CT, these data suggest that all potentially operable patients with nonmetastatic NSCLC may benefit from EUS staging.     

Bronchogenic carcinoma: incidence of metastases to normal sized lymph nodes.

BACKGROUND--The incidence of metastases to mediastinal lymph nodes was evaluated in patients with normal sized mediastinal nodes on the computed tomographic (CT) scan who underwent thoracotomy. The use of hilar lymph nodes in predicting mediastinal lymph node metastases was also assessed. METHODS--Ninety patients with non-small cell lung cancer who later underwent thoracotomy wer prospectively examined by CT scanning. Lymph nodes with a short axis diameter of 10 mm or more were considered abnormal. RESULTS--Mediastinal lymph node metastases were present at thoracotomy in 19 patients (21%). In 14 these lymph node metastases were misdiagnosed because the nodes were normal in size on the CT scan. In only one of the 19 patients with N2 nodes was an N1 lymph node enlarged, and four of the 19 patients with N2 nodes had metastases to these mediastinal nodes without N1 disease ("skipping metastases"). CONCLUSIONS--Metastases in normal sized nodes seen on the CT scan are a major problem in staging. Hilar lymph nodes did not help to predict reliably the presence or absence of metastases to the mediastinal lymph nodes.     

~(18)FDG-PET在肺癌诊断中的价值

目的　研究氟脱氯葡萄糖F18 正电子发射计算机电子扫描 (1 8FDG PET)在鉴别肺部肿块性质和肺癌术前纵隔淋巴结转移分期中的应用价值。　方法　对 34例肺部肿块患者进行1 8FDG PET和CT检查 ,PET资料分别采用目测法和计算标准化摄取值 (SUV)的半定量法进行分析 ,并同病理结果对照。　结果　目测法1 8FDG PET诊断肺部肿块性质的敏感度、准确度分别是 93%、85 % ;CT分别为 6 3%、5 3% ,2种方法差异有显著性意义 (P <0 0 5 ) ;半定量法准确度为 74% ,与CT相比 ,差异也有显著性意义 (P <0 0 5 )。肺部恶性肿块的SUV是 4 4± 1 9,良性为 2 2± 1 7,2者差异有显著性意义 (P <0 0 5 )。1 8FDG PET和CT 2种检查方法术前对纵隔淋巴结转移的分期与病理结果符合率分别为10 0 %和 78% ,2者差异有显著性意义 (P <0 0 5 )。　结论　同CT相比 ,1 8FDG PET能更准确地鉴别肺部肿块性质及确定纵隔淋巴结转移分期 ,是一种较好的无创性肺癌诊断技术。     

Advantages of positron emission tomography over computed tomography in mediastinal staging of non-small cell lung cancer

BACKGROUND: New treatment algorithms in early stage non-small cell lung cancer (NSCLC) involving preoperative chemotherapy require accurate clinical staging of the mediastinum. This study compares the accuracy of 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) scanning with that of computed tomography (CT) scanning in the clinical staging of non-small cell lung cancer. MATERIALS AND METHODS: A retrospective review was performed on 52 patients with NSCLC who were evaluated with both CT and PET scans. All patients had their mediastinal lymph nodes sampled by mediastinoscopy or at the time of thoracotomy for pulmonary resection. Each imaging study was evaluated separately and correlated with histopathologic results. RESULTS: For detecting mediastinal metastases the sensitivities of PET and CT scans were 67 and 50%, respectively; specificities were 91 and 65%, respectively; accuracies were 88 and 63%, respectively; positive predictive values were 50 and 16%, respectively; negative predictive values were 95 and 88%, respectively. PET scans were significantly better than CT scans at detecting mediastinal metastases (PET, 4/8; CT, 3/19) (P = 0.01). CONCLUSIONS: PET scanning is superior to CT scanning for clinical staging of the mediastinum in NSCLC. A more confident decision regarding stratification of patients into current treatment algorithms can be made when the decision is based on PET scanning rather than the current "gold standard" of CT scanning.     

FDG-PET imaging for lymph node staging and pathologic tumor response after neoadjuvant treatment of non-small cell lung cancer.

PURPOSE: A number of studies have demonstrated that 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is effective for staging of lung cancer. However, the efficacy of FDG-PET for staging lung cancer after neoadjuvant treatment is still controversial. This study compared FDG-PET and computed tomography (CT) for lung cancer staging, and evaluated the ability of the two methods to predict the pathologic response of the primary tumor to neoadjuvant treatment. PATIENTS AND METHODS: Twenty-two patients who underwent neoadjuvant treatment followed by surgery were investigated. Eighteen patients received chemoradiotherapy and four patients received chemotherapy only. One hundred and three lymph node stations in the 22 patients were evaluated by FDG-PET and CT. The pathologic responses of the tumors were compared by FDG-uptake and tumor size on CT for the 15 patients who underwent FDG-PET and CT both before and after neoadjuvant treatment. RESULTS: There was no significant difference in the ability of FDG-PET or CT to predict residual viable tumor. Although positive predictive value by FDG-PET (0.29) was lower than that by CT (0.64) (p=0.04) in the mediastinal lymph nodes, there were no statistically significant differences in the other results of lymph nodes by FDG-PET and CT. Both decrease in FDG-uptake and decrease in tumor size by CT after neoadjuvant treatment correlated significantly with pathologic response in the 15 patients (p=0.003 and 0.009, respectively). CONCLUSION: FDG-PET did not appear to offer any advantages over CT for lymph node staging or for predicting the pathologic response after neoadjuvant treatment of non-small cell lung cancer.     

Diagnosis of esophageal cancer using positron emission tomography

Fluorodeoxyglucose positron emission tomography (FDG-PET) is more accurate than computed tomography (CT) for evaluating lymph node metastases and for N staging, but less accurate than combined CT and endoscopic ultrasonography (EUS). Lymph nodes located adjacent to the primary lesion tend to be false negatives. We consider that combined FDG-PET and EUS is the most accurate for the detection of lymph node metastasis in esophageal cancer. FDG-PET is also more accurate than CT for detecting distant metastases and improves the detection of stage IV disease compared with the conventional staging modalities. For the diagnosis of recurrence except for perianastomotic recurrence, FDG-PET provides additional information and is more sensitive than conventional work-ups. FDGPET is a valuable tool for the noninvasive assessment of tumor response after neoadjuvant therapy. 11C-methionine (MET) is another tracer for PET that can be used to assess the metabolism of amino acids, since MET accumulates in esophageal malignant tumors. Choline-PET is more accurate than FDG-PET for the detection of mediastinal lymph node metastases.     

Histopathologic validation of lymph node staging with FDG-PET scan in cancer of the esophagus and gastroesophageal junction: A prospective study based on primary surgery with extensive lymphadenectomy

OBJECTIVE: To assess the value of positron emission tomography with 18fluorodeoxyglucose (FDG-PET) for preoperative lymph node staging of patients with primary cancer of the esophagus and gastroesophageal junction. SUMMARY BACKGROUND DATA: FDG-PET appears to be a promising tool in the preoperative staging of cancer of the esophagus and gastroesophageal junction. Recent reports indicate a higher sensitivity and specificity for detection of stage IV disease and a higher specificity for diagnosis of lymph node involvement compared with the standard use of computed tomography and endoscopic ultrasound. METHODS: Forty-two patients entered the prospective study. All underwent attenuation-corrected FDG-PET imaging of the neck, thorax, and upper abdomen, a spiral computed tomography scan, and an endoscopic ultrasound. The gold standard consisted exclusively of the histology of sampled nodes obtained by extensive two-field or three-field lymphadenectomies (n = 39) or from guided biopsies of suspicious distant nodes indicated by imaging (n = 3). RESULTS: The FDG-PET scan had lower accuracy for the diagnosis of locoregional nodes (N1-2) than combined computed tomography and endoscopic ultrasound (48% vs. 69%) because of a significant lack of sensitivity (22% vs. 83%). The accuracy for distant nodal metastasis (M+Ly), however, was significantly higher for FDG-PET than the combined use of computed tomography and endoscopic ultrasound (86% vs. 62%). Sensitivity was not significantly different, but specificity was greater (90% vs. 69%). The FDG-PET scan correctly upstaged five patients (12%) from N1-2 stage to M+Ly stage. One patient was falsely downstaged by FDG-PET scanning. CONCLUSIONS: FDG-PET scanning improves the clinical staging of lymph node involvement based on the increased detection of distant nodal metastases and on the superior specificity compared with conventional imaging modalities.     

Use of positron emission tomography in initial staging of nonsmall cell lung carcinoma: a regional teaching hospital experience

The ability to accurately diagnose mediastinal lymph node involvement is significantly important in patients with nonsmall cell lung cancer (NSCLC). Positron emission tomography (PET) imaging has become a standard technique to assess lymph node involvement in patients with NSCLC. The purpose of this study is to evaluate the accuracy of PET scan imaging as a mediastinal staging tool in patients with NSCLC at our regional teaching institution. We performed a single-institution, retrospective review of patients diagnosed with NSCLC from January 1, 2006, through December 31, 2007. We included only those patients who underwent computed tomography (CT), PET, and pathologic assessment of mediastinal lymph nodes. Using pathologic assessment as the criterion standard, the overall accuracy, sensitivity, specificity, and positive and negative predictive values of CT and PET were calculated. One hundred seventeen patients were identified for inclusion in the study. The overall accuracy was 81.2 per cent for CT and 91.5 per cent for PET. Sensitivity was 42.1 per cent for CT and 52.6 per cent for PET. Specificity was 88.8 per cent for CT and 99.0 per cent for PET. Positive predictive values were 42.1 per cent for CT and 90.9 per cent for PET; negative predictive values were 88.8 per cent for CT and 91.5 per cent for PET. False-negative result rates were 9.4 per cent for CT and 7.7 per cent for PET; false-positive result rates were 9.4 per cent for CT and 0.9 per cent for PET. Our analysis confirms the use of PET scan imaging in the staging of patients with NSCLC at a regional teaching institution.     

FDG/PET and spiral CT image fusion for medistinal lymph node assessment of non-small cell lung cancer patients

BACKGROUND: To assess the potential usefulness of 18F-FDG/PET and spiral-CT images concurrent assessment and coregistration in staging mediastinal lymph node involvement in patients with non small cell lung cancer. METHODS: 28 patients waiting to undergo surgical treatment underwent spiral-CT and PET examinations on the same day. The results of the two studies were interpreted separately, together (CT&PET) and following their fusion in a single image (CT+PET). Results of spiral-CT, PET, CT&PET and CT+PET were assessed with respect to the histological diagnosis. RESULTS: A correct assessment of mediastinal lymph nodes was achieved by spiral-CT in 21 of the 28 patients, in 22 of the 28 patients by PET, in 24 patients by CT&PET and in 25 patients by CT+PET. CONCLUSIONS: CT+PET is more accurate than spiral-CT and PET alone in staging mediastinal lymph node involvement in lung cancer patients, with possible implications for their prognosis and therapy.     

FDG-PET/CT for the Preoperative Lymph Node Staging of Invasive Bladder Cancer

Background

Locoregional lymph node metastasis is an important prognostic factor in patients with bladder cancer. Multimodal treatment, depending on preoperative stage, may improve survival. The standard imaging modalities for staging (computed tomography [CT] or magnetic resonance imaging [MRI]) have an accuracy range of 70–90% for lymph node staging. A more accurate preoperative diagnostic test could improve survival rates even more.

Objective

To determine whether the use of 2-deoxy-2 [F] fluoro-D-glucose (FDG) positron emission tomography (PET) in combination with CT (FDG-PET/CT) can increase the reliability of preoperative lymph node staging in patients with nonmetastatic invasive bladder cancer (T2 or higher, M0) or recurrent high-risk superficial disease (T1G3 with or without Tis, M0).

Design, setting, and participants

Fifty-one patients underwent a preoperative FDG-PET/CT between April 2004 and December 2007. Independent of the result for lymph node status, all patients underwent a radical cystectomy and an extended lymphadenectomy. The FDG-PET/CT and CT results were compared with the definitive pathologic results.

Measurements

Among the 51 patients, 13 patients had metastatically involved locoregional lymph nodes, diagnosed on histopathology. In six patients, these nodes demonstrated increased FDG uptake on PET. In seven patients, PET/CT did not diagnose the positive lymph nodes. PET/CT was false positive in one patient.

Results and limitations

For the diagnosis of node-positive disease, the accuracy, the sensitivity, and the specificity of FDG-PET/CT were 84%, 46%, and 97%, respectively. When analysing the results of CT alone, there was accuracy of 80%, sensitivity of 46%, and specificity of 92%. The use of FDG-PET/CT is hampered by technical limitations.

Conclusions

We found no advantage for combined FDG-PET/CT over CT alone for lymph node staging of invasive bladder cancer or recurrent high-risk superficial disease.