Fluorodeoxyglucose positron emission tomography improves preoperative staging of resectable lung metastasis

OBJECTIVE: F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is now a procedure of proven clinical value in the staging of primary lung cancer. This study evaluated the role of PET in the preoperative assessment of resectable lung metastases. METHODS: Eighty-six patients with previously treated malignancy and proven or suspected lung metastases, deemed resectable at computed tomography scan, were investigated with 89 preoperative PET procedures. Primary tumor sites were: gastrointestinal in 32 cases, sarcoma in 13, urologic in 14, breast in 8, head and neck in 7, gynecologic in 5, thymus in 5, other in 5. Seventy lung resections were performed in 68 patients of whom only 54 proved to be lung metastasis, 7 were primary lung tumors, and 9 were benign lesions. RESULTS: In 19 cases (21%) lung surgery was excluded on the basis of PET scan results due to extrapulmonary metastases (11 cases), primary site recurrence (2), mediastinal adenopathy (2), or benign disease (4). All mediastinal node metastases (7 cases) were detected by PET with a sensitivity, accuracy, and negative predictive value for mediastinal staging of 100%, 96%, and 100%, respectively, versus 71%, 92%, and 95% of the computed tomography scan. In the group of patients who underwent lung resection, PET sensitivity for detection of lung metastasis was 87%. CONCLUSIONS: PET scan proved to be a valuable staging procedure in patients with clinically resectable lung metastasis and changed the therapeutic management in a high proportion of cases.     

Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET)

BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease.     

Factors associated with false-positive staging of lung cancer by positron emission tomography

BACKGROUND: Positron emission tomography imaging is gaining popularity as a noninvasive staging tool in non-small cell lung cancer. Nonmalignant processes can also affect radio-tracer uptake. This study seeks to identify factors associated with false-positive staging of mediastinal metastases. METHODS: A retrospective review was performed of 100 patients with early stage non-small cell lung cancer referred for positron emission tomography scan evaluation. All had pathologic confirmation of their disease. Positron emission tomography scans, radiology records, operative reports, and pathology results were reviewed. Patients with positron emission tomography scans interpreted as positive for mediastinal involvement and negative pathology at operation were selected. RESULTS: Seven patients were found to have a false-positive positron emission tomography evaluation for mediastinal metastases. All but 1 patient had a concurrent inflammatory process or an anatomic factor associated with the false positive. The sensitivity and specificity in detecting involved mediastinal nodes was 87.5% and 90.7%, respectively. The negative predictive value was 95.8%. CONCLUSIONS: Although positron emission tomography has been established as an accurate modality to stage non-small cell lung cancer, false-positive evaluation of mediastinal metastases can occur in the setting of concurrent inflammatory lung diseases or for centrally located tumors. Pathologic evaluation of mediastinal disease should be pursued whenever suggested by a positive positron emission tomography scan especially in the face of those factors described.     

The impact of fluorodeoxyglucose F 18 positron-emission tomography on the surgical staging of non-small cell lung cancer

OBJECTIVES: Staging data on patients with non-small cell lung cancer were prospectively collected to evaluate the accuracy and anatomic information provided by fluorodeoxyglucose F 18 positron-emission tomography and its impact on improving the accuracy of surgical staging. METHODS: A total of 142 patients with potentially resectable non-small cell lung cancer were imaged with positron-emission tomography (neck to pelvis). Positron-emission tomographic scans were read prospectively with thoracic computed tomographic comparison. Patients without distant metastases at positron-emission tomography underwent staging with bronchoscopy and mediastinoscopy, with or without mediastinotomy or thoracoscopy. Patients with metastases, pleural implants, or N2 or N3 disease did not undergo primary resection. RESULTS: Positron-emission tomography revealed unsuspected distant metastases in 24 of 142 patients (16.9%) and unsuspected pleural implants in 6 others. Nodal stage was surgically established in 118 cases. Positron-emission tomography showed that 5 patients had nodal disease not accessible by mediastinoscopy. In 35 (24.6%) of these 142 cases, positron-emission tomography directed the evaluation away from routine bronchoscopy and mediastinoscopy staging that would have resulted in inappropriate treatment selection. Positron-emission tomography correctly differentiated resectable stages IA through IIIA (N1) from stages IIIA (N2) through IV in 88.7% of cases. In identifying N2 or N3 disease, positron-emission tomography had an accuracy of 90.7%, a sensitivity of 80.9%, a specificity of 96%, and positive and negative predictive values of 91.9% and 90.1%, respectively. Of the 8 cases in which positron-emission tomography missed N2 disease, 7 had the disease discovered by mediastinoscopy and 1 had it discovered at thoracotomy. CONCLUSIONS: The diagnostic accuracy of positron-emission tomography-enhanced clinical staging is high. Positron-emission tomography has previously been used primarily to screen for lymph node spread and distant metastases, but it also provides localizing information that allows directed and more sensitive surgical staging and refinement of patient selection for curative resection. Positron-emission tomography and surgical staging play complementary roles in the journey toward more accurate overall staging.     

Intraoperative radioisotope sentinel lymph node mapping in non-small cell lung cancer

BACKGROUND: Lymph node metastases are the most significant prognostic factor in localized non-small cell lung cancer (NSCLC). Nodal micrometastases may not be detected. Identification of the first nodal drainage site (sentinel node) may improve detection of metastatic nodes. We performed intraoperative Technetium 99m sentinel lymph node (SN) mapping in patients with resectable NSCLC. METHODS: Fifty-two patients (31 men, 21 women) with resectable suspected NSCLC were enrolled. At thoracotomy, the primary tumor was injected with 2 mCi Tc-99. After dissection, scintographic readings of both the primary tumor and lymph nodes were obtained with a handheld gamma counter. Resection with mediastinal node dissection was performed and findings were correlated with histologic examination. RESULTS: Seven of the 52 patients did not have NSCLC (5 benign lesions, and 2 metastatic tumors) and were excluded. Forty-five patients had NSCLC completely resected. Mean time from injection of the radionucleide to identification of sentinel nodes was 63 minutes (range 23 to 170). Thirty-seven patients (82%) had a SN identified; 12 (32%) had metastatic disease. 35 of the 37 SNs (94%) were classified as true positive with no metastases found in other intrathoracic lymph nodes without concurrent SN involvement. Two inaccurately identified SNs were encountered (5%). SNs were mediastinal (N2) in 8 patients (22%). CONCLUSIONS: Intraoperative SN mapping with Tc-99 is an accurate way to identify the first site of potential nodal metastases of NSCLC. This method may improve the precision of pathologic staging and limit the need for mediastinal node dissection in selected patients.     

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.     

Selective preoperative evaluation for possible N2 disease in carcinoma of the lung

The efficacy of computed tomography and surgical mediastinal exploration in determining tumor resectability were retrospectively evaluated in 92 consecutive patients with non-small cell lung carcinoma. Status of mediastinal nodes was ultimately determined by surgical mediastinal exploration or thoracotomy. Patients were divided into three groups on the basis of chest roentgenography: Group I comprised 30 patients with peripheral T1 or T2 lesions with normal hilar and mediastinal shadows. Only one patient was found to have an involved node. Chest roentgenography had an accuracy rate of 96% and computed tomography, 93%. Thoracotomy is recommended without either computed tomography or surgical mediastinal exploration in this group. Group II comprised 47 patients with T1 or T2 lesions with an abnormal hilus, an abnormal mediastinal shadow, or either the hilus or mediastinum obscured by overlying parenchymal disease. Computed tomography revealed mediastinal nodes 1 cm or greater in size (abnormal node group) in 21 patients (45%) and smaller than 1 cm (normal node group) in 26 patients (55%). Surgical mediastinal exploration was performed in the abnormal node group and involved nodes were found in 17 of 21 patients (81%). In the normal node group, thoracotomy only was performed and no involved nodes were found. Computed tomography is recommended in all patients in Group II. Patients in the normal node group may be subjected to thoracotomy only and those in the abnormal node group should undergo surgical mediastinal exploration as the next diagnostic step before thoracotomy. Group III comprised 15 patients with grossly abnormal mediastinal shadows. Findings from computed tomography were abnormal in all 10 patients in whom it was done. Surgical mediastinal exploration was done in all 15 and yielded abnormal results in 14. It is recommended in this group that computed tomography is unnecessary and surgical mediastinal exploration should be the only diagnostic procedure. Thus, in potentially resectable non-small cell lung carcinoma, the use of computed tomography and surgical mediastinal exploration should be selective and should be determined by appropriate initial interpretation of the chest roentgenogram.     

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.     

The practice of cardiothoracic surgeons in the perioperative staging of non-small cell lung cancer.

BACKGROUND: The treatment and prognosis of non-small cell lung cancer, and assessment of the results of treatment, depend on accurate perioperative staging. The extent to which this is carried out in the United Kingdom is unknown. METHODS: A postal questionnaire survey was undertaken in 1990 to determine the perioperative staging practices of cardiothoracic surgeons in the United Kingdom. RESULTS: Replies from 77 surgeons, who between them performed about 4833 pulmonary resections a year for lung cancer, were analysed. Forty four per cent of surgeons, operating on 43% of the patients, do not perform computed tomography of the thorax or mediastinal exploration before surgery. They may therefore embark on a thoracotomy for stage III disease. At thoracotomy 45% of surgeons, operating on 40% of patients, do not sample macroscopically normal lymph nodes. They may therefore understage cases as N0/N1 when there is at least microscopic disease in mediastinal lymph nodes. CONCLUSIONS: The staging of lung cancer in the United Kingdom in 1990 appears in many instances to be inadequate. There should be a more organised approach to perioperative staging so that prognosis may be assessed and comparisons between groups of patients can be made.     

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.     

Computed tomography for the evaluation of intrathoracic invasion by lung cancer

We conducted computed tomographic examinations of the chest in 171 patients with lung cancer whose disease was subsequently surgically staged; routine mediastinal exploration was undertaken in all patients undergoing thoracotomy (151), and in 20 patients only anterior mediastinotomy or mediastinoscopy was performed. We have considered three groups of patients: In Group I (including all 171 patients) mediastinal lymph nodes were evaluated for metastatic involvement; nodes were considered diseased when greater than 1 cm. Sensitivity, specificity, and accuracy were 95%, 83%, and 89%. Among these 171 patients, 34 (Group II) had a central tumor otherwise considered operable, which was shown on plain roentgenograms to be in contact with the mediastinum; infiltration of hilar and mediastinal vessels and of mediastinal tissues was investigated preoperatively with computed tomography and then ascertained at thoracotomy. Sensitivity, specificity, and accuracy were 68%, 72% and 70%. Twenty-seven patients (Group III) had a peripheral tumor abutting the pleural surface and suspected to invade the parietal pleura and chest wall; patients with evident bone infiltration were excluded. Sensitivity, specificity, and accuracy of computed tomography were 50%, 90%, and 65%.     

Positron emission tomography defines metastatic disease but not locoregional disease in patients with malignant pleural mesothelioma

BACKGROUND: Computed tomography and magnetic resonance imaging often fail to predict resectability in patients with malignant pleural mesothelioma. Small studies suggest that fluorodeoxyglucose-positron emission tomography may improve staging. We analyzed our experience to determine more definitively the potential utility of fluorodeoxyglucose-positron emission tomography. METHODS: Patients with malignant pleural mesothelioma who underwent fluorodeoxyglucose-positron emission tomography scanning were identified from an institutional database. All patients fasted and received a minimum of 10 mCi of F-18-fluorodeoxyglucose. Whole-body emission studies were acquired, followed by whole-body transmission studies, allowing iterative reconstruction. Blinded review of positron emission tomography scans was performed for clinical staging, which was then correlated with surgical and pathologic findings. Sensitivity and specificity were determined for tumor and nodal status. RESULTS: From 1998 to 2002, 63 patients underwent positron emission tomography scans, 60 preoperatively and 3 to assess disease recurrence after surgery. Increased fluorodeoxyglucose uptake was seen in all but 1 tumor, which was very early stage (IA). Positron emission tomography findings yielded sensitivities of only 19% and 11% for tumor and nodal status, respectively. However, a high standard uptake value in the primary tumor correlated with the presence of N2 disease. Positron emission tomography correctly identified supraclavicular N3 or M1 disease in 6 patients. CONCLUSIONS: Positron emission tomography does not identify the local extent of tumor or mediastinal nodal metastases reliably but detects extrathoracic metastases, thereby obviating inappropriate thoracotomy. Further studies of the association between tumor standard uptake value and the presence of N2 disease are warranted.     

The size of metastatic foci and lymph nodes yielding false-negative and false-positive lymph node staging with positron emission tomography in patients with lung cancer

BACKGROUND: We examined the sizes of lymph nodes and metastatic foci within the lymph nodes that affect false-positive and false-negative lymph node staging by positron emission tomography in lung cancer. METHODS: Preoperative positron emission tomography and computed tomography scans were performed for 564 lymph node stations in 80 patients with peripheral-type lung cancer. The sizes of both the lymph nodes and the metastatic foci within the lymph nodes were measured, and these measurements were compared with those obtained with positron emission tomography scanning. To establish general sizes of metastatic foci within the lymph nodes, 277 metastatic lymph nodes in operative specimens previously resected from another 111 patients with lung cancer were examined as a control. RESULTS: The sensitivity was significantly higher for positron emission tomography than for computed tomographic scanning (P =.026). The sizes of metastatic foci within lymph nodes that showed false-negative (n = 8) and true-positive (n = 28) with positron emission tomography ranged from 0.5 to 9 mm (3 +/- 1 mm) and from 4 to 18 mm (10 +/- 3 mm), respectively (P <.001). None of the metastatic foci smaller than 4 mm could be detected with positron emission tomography scanning. The review of the 277 previously resected metastatic lymph nodes showed that 89 (32%) had metastatic foci smaller than 4 mm. The sizes of true-positive (n = 28) and false-positive (n = 10) lymph nodes ranged from 6 to 15 mm (10 +/- 2 mm) and from 9 to 16 mm (12 +/- 2 mm), respectively (P <.01). None of the false-positive lymph nodes was smaller than 9 mm. CONCLUSIONS: Although positron emission tomography was superior to computed tomography scanning in lymph node staging in lung cancer, positron emission tomography was unable to distinguish metastatic foci smaller than 4 mm, which were not unusual sizes for lymph node metastases in lung cancer. Positive lymph nodes with positron emission tomography smaller than 9 mm are likely to be true-positive rather than false-positive.     

Improved pre-operative mediastinal staging in non-small-cell lung cancer by serial sectioning and immunohistochemical staining of lymph-node biopsies.

OBJECTIVE: Mediastinal staging of non-small-cell lung carcinoma (NSCLC) by mediastinoscopy suffers from a low sensitivity, leading to a number of patients with unforeseen N2 disease at thoracotomy. This study was undertaken to assess whether pre-operative staging could be improved by serial sectioning and immunohistochemical staining of mediastinoscopy biopsies. METHODS: In 183 consecutive patients with NSCLC, a thoracotomy was performed after a thorough mediastinal staging by computed tomography scan and cervical mediastinoscopy. In 158 patients (88%), a mediastinal node dissection was performed, revealing unforeseen N2 disease in 24 cases (15%). The preserved mediastinoscopy biopsies of these patients were retrospectively serially sectioned and stained with MNF 116. RESULTS: Metastases could be identified in seven cases (30%), reducing unforeseen N2 disease from 15 to 10%. The number of patients who could theoretically benefit from neo-adjuvant therapy would have been increased by at least 10%. CONCLUSIONS: Pre-operative mediastinal staging can be improved considerably by serial sectioning and immunohistochemical staining of mediastinoscopic biopsy specimens.     

Oesophageal endoscopic ultrasound with fine needle aspiration improves and simplifies the staging of lung cancer

BACKGROUND: Positron emission tomography (PET) is accurate for mediastinal staging of lung cancer but has a moderate positive predictive value, necessitating pathological verification. Endoscopic ultrasonography with fine needle aspiration (EUS-FNA) is a technique for tissue verification of mediastinal and upper retroperitoneal abnormalities. The use of EUS-FNA may decrease the number of surgical procedures and thereby staging costs. METHODS: EUS-FNA was used prospectively for the cytological assessment of mediastinal and/or upper retroperitoneal PET hot spots in patients with suspected lung cancer. Only if EUS-FNA was positive for malignancy was subsequent mediastinoscopy or exploratory thoracotomy cancelled. The cost effectiveness of EUS-FNA was determined. RESULTS: Of 488 consecutive patients with suspected lung cancer, 81 were enrolled with mediastinal and/or upper retroperitoneal PET hot spots. EUS-FNA was positive in 50 (62%) patients, negative in six, and inconclusive in 25. Of the 31 negative or inconclusive patients, 26 underwent surgical staging (resulting in 14 patients with and 12 without mediastinal malignancy), while five patients had mediastinal metastases during follow up. No EUS-FNA related morbidity or mortality was encountered. The accuracy of the decision to proceed to surgery (or not) on the basis of EUS-FNA was 77% (95% CI 68 to 86). EUS-FNA detected more mediastinal abnormalities than PET except for the upper mediastinal region. Addition of EUS-FNA to conventional lung cancer staging reduced staging costs by 40% per patient, mainly due to a decrease in surgical staging procedures. CONCLUSION: EUS-FNA can replace more than half of the surgical staging procedures in lung cancer patients with mediastinal and/or upper retroperitoneal PET hot spots, thereby saving 40% of staging costs.     

Role of fiberscopic transbronchial needle aspiration in the staging of N2 disease due to non-small cell lung cancer

BACKGROUND: Transbronchoscopic needle aspiration (TBNA) can offer a unique opportunity to identify surgically unresectable lung cancer and to avoid surgical mediastinal exploration in many patients with mediastinal lymph node extension of the tumor. The aim of this study was to assess the yield of TBNA performed with either histology or cytology needles in mediastinal staging of N2 disease due to non-small cell lung cancer (NSCLC). METHODS: Retrospective chart review was carried out on 194 TBNA procedures performed between January 1997 and September 2000 at a single institution. Inclusion criteria were pathologic evidence of NSCLC; contrast enhancement computed tomography scan of the chest suggesting N2 disease; and negative bronchoscopic examination for possible neoplastic lesions at the site of RESULTS: Overall sensitivity and diagnostic accuracy were 71% and 73%, respectively, with no significant differences between 19-gauge and 22-gauge cytology needles. Procedures performed for right paratracheal and subcarinal lymph node stations had a significantly higher yield than those for the left paratracheal station. CONCLUSIONS: TBNA mediastinal staging, performed during the initial diagnostic evaluation of NSCLC, can spare costs and risks of more invasive procedures in patients with inoperable tumors, in patients who are not candidates for operation because of coexistent significant comorbidities, and in patients with N2 disease.     

ESTS guidelines for preoperative lymph node staging for non-small cell lung cancer.

Accurate preoperative staging and restaging of mediastinal lymph nodes in patients with non-small cell lung cancer (NSCLC) is of paramount importance. It will guide choices of treatment and determine prognosis and outcome. Over the last years, different techniques have become available. They vary in accuracy and procedure-related morbidity. The Council of the ESTS initiated a workshop on preoperative mediastinal lymph node staging. This resulted in guidelines for primary staging and restaging. For primary staging, mediastinoscopy remains the gold standard for the superior mediastinal lymph nodes. Invasive procedures can be omitted in patients with peripheral tumors and negative mediastinal positron emission tomography (PET) images. However, in case of central tumors, PET hilar N1 disease, low fluorodeoxyglucose uptake of the primary tumor and LNs > or = 16 mm on CT scan, invasive staging remains indicated. PET positive mediastinal findings should always be cyto-histologically confirmed. Transbronchial needle aspiration (TBNA), ultrasound-guided bronchoscopy with fine needle aspiration (EBUS-FNA) and endoscopic esophageal ultrasound-guided fine needle aspiration (EUS-FNA) are new techniques that provide cyto-histological diagnosis and are minimally invasive. Their specificity is high but the negative predictive value is low. Because of this, if they yield negative results, an invasive surgical technique is indicated. However, if fine needle aspiration is positive, this result may be valid as proof for N2 or N3 disease. For restaging, invasive techniques providing cyto-histological information are advisable despite the encouraging results supported with the use of PET/CT imaging. Both endoscopic techniques and surgical procedures are available. If they yield a positive result, non-surgical treatment is indicated in most patients.     

Anti-CEA immunoscintigraphy and computed tomographic scanning in the preoperative evaluation of mediastinal lymph nodes in lung cancer.

BACKGROUND: Thoracic computed tomography (CT) provides most of the staging information needed before operation for lung cancer and can reduce the number of exploratory thoracotomies. In recent years a new immunoscintigraphic technique with anti-carcinoembryonic antigen (CEA) monoclonal antibodies has been shown to be effective in lung cancer staging. This study compares the yields of CT scans and immunoscintigraphy in the preoperative evaluation of the medistinal lymph nodes of patients with non-small cell lung cancer. METHODS: One hundred and thirty one patients believed on clinical grounds to have a operable non-small cell lung cancer were photoscanned with the indium-111 labelled F(ab')2 fragments of the antibody FO23C5. Both planar and single photoemission computed tomography (SPECT) thoracic views were recorded. CT scan of the thorax, abdomen, and brain were obtained in all patients. Seventy of the patients eventually underwent surgery, an additional seven underwent mediastinoscopy or mediastinotomy, and a further 10 had both cervical exploration and thoracotomy. Pathological evaluation of the mediastinal nodes was available in all 87 patients, but in only 80 of them was the diagnosis of lung cancer eventually confirmed. RESULTS: The diagnostic accuracy of planar immunoscintigraphy, SPECT immunoscintigraphy, and CT scanning for N2 disease was 76%, 74%, and 71%, respectively. The corresponding sensitivity and specificity rates were 45%, 77%, 64% and 88%, 72%, and 74%. These were not significantly different. CONCLUSIONS: This study shows that anti-CEA immunoscintigraphy has no advantage over conventional CT scanning in assessing mediastinal lymphoadenopathy in patients with lung cancer. CT scanning remains the gold standard test in these patients.     

Computed tomography. An effective technique for mediastinal staging in lung cancer

Computed tomographic scans of the chest were utilized to stage mediastinal disease in 148 instances of bronchogenic carcinoma considered for resection in 146 patients. Nodes greater than or equal to 1.5 cm in diameter were interpreted as abnormal. All nodes positive by computed tomography were evaluated by mediastinoscopy, anterior mediastinotomy, or thoracotomy. All patients with negative computed tomographic findings underwent thoracotomy without prior surgical staging. Patients undergoing thoracotomy were divided into two groups. In Group I (first 51 instances) routine mediastinal exploration was not carried out; in Group II (last 97 instances) the mediastinum was explored in every patient and nodes were submitted for histopathological study. The computed tomographic and pathological findings on the mediastinal lymph nodes were compared. The sensitivity, specificity, and accuracy of computed tomography in Group I were 88%, 94%, and 92%, respectively, in Group II 75%, 89%, and 86%, and in the combined group, 80%, 91%, and 88%. The positive predictive index in Group I, Group II, and in the combined group was 88%, 69%, and 77%, respectively. It was lower for central than peripheral lesions (74% versus 88%) and was lowest for lesions in the right upper and left lower lobes. The negative predictive index was greater than 90% for all groups and all tumor sites except the left upper lobe, where it was 89%. Ten patients had false-positive scans, three with old mediastinitis and seven with postobstructive pneumonia; nine of the 10 had central lesions, and seven of these lesions were located in the right upper lobe. Eight patients had false-negative scans; six had para-aortic, subaortic, or postsubcarinal nodes. These nodes would not have been accessible to mediastinoscopy. In only one patient with false-negative nodes would routine mediastinoscopy have prevented thoracotomy and resection. Computed tomographic staging of mediastinal disease is indicated for all patients with lung cancer in whom operation is contemplated. Computed tomography directs the most appropriate staging procedure for patients with positive findings and obviates invasive staging for patients with negative findings.     

PET-FDG scan enhances but does not replace preoperative surgical staging in non-small cell lung carcinoma.

OBJECTIVE: To assess the effectiveness of positron emission tomography with radiolabeled [18F]-2-fluoro-deoxy-D-glucose (PET-FDG) imaging in mediastinal lymph node (LN) staging for non-small cell lung carcinoma (NSCLC) and to compare it to conventional clinical and surgical staging. METHODS: From June 1998 to February 2000, we enrolled 64 potentially resectable NSCLC patients in a prospective study of PET-FDG imaging of the mediastinum to assess LN involvement. Results of this technique were compared to conventional clinical and surgical staging. Diagnostic efficacy was determined by calculating sensitivity, specificity, overall accuracy, and positive and negative predictive values for each method. RESULTS: PET-FDG imaging correctly identified nodal stage (N0-N1 vs. N2) in 50 out of 61 patients (82%), overstaging occurred in eight patients (13%), and understaging in three patients (4.9%). The sensitivity, specificity, accuracy, and positive and negative predictive values for PET-FDG scan imaging were 67, 85, 82, 43, and 93.6%, respectively. Conventional staging correctly identified nodal stage (N0-N1 vs. N2) in 51 out of 62 patients (82%), overstaging occurred in five patients (8.1%), and understaging in six patients (9.7%). The sensitivity, specificity, accuracy, and positive and negative predictive values for conventional staging were 33, 90.6, 82, 37, and 89%, respectively. With regard to N2 disease, conventional staging showed a poor sensitivity (33%). Indeed, six out of 64 patients were understaged for mediastinal LN involvement. Even though the improvement was not statistically significant (McNemar P=0.08), the combined use of PET-FDG scan and computerized tomography (CT) scan allowed a two-fold increase in the sensitivity of our clinical preoperative staging. Moreover, relying on the PET-scan high negative predictive value might have contributed to a three-fold decrease in the number of required surgical staging procedures. CONCLUSIONS: Our study shows that the PET-FDG imaging strength lies in its very high negative predictive value and increased sensitivity. In this study, the overall accuracy of PET-FDG scan (82%) was lower than previously reported. Combined with chest CT-scan preoperatively, it may alleviate the need for surgical staging when PET-FDG studies of the mediastinum are negative. However, with a positive PET-FDG scan result, further diagnostic procedures should be pursued in order to avoid overstaging and allow better surgical patient selection.