***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Several authors proposed the stage at diagnosis and some histopathological features as prognostic factors of bronchial carcinoids . However , since large tumour diameters or nodal metastases are frequently associated to aggressive histology , their prognostic role is unclear . To investigate the relationships between the clinicopathological parameters at diagnosis and outcome , 21 patients were analysed . Overall 26 % of the radically resected patients recurred . Recurrences and disease-specific mortality were related to atypical histology and , only in cases with typical histology , to the presence of hilar or mediastinal lymph node metastases . These prognostic factors were valuable independently of the size of the primary tumour , that was remarkably homogeneous , always less than 3 cm , thus not predictive of recurrence . Moreover we evaluated the role of  somatostatin receptor scintigraphy  , a diagnostic tool only preliminary studied in this field . Scintigraphy with 111In-octreotide revealed the primary tumours at diagnosis ( 8/8 ) , the increase in tumour size in two unresected patients , and all the cases of recurrent or metastatic disease ( 5/11 ) , sometimes before the appearance of symptoms . These results suggest the usefulness of histology and nodal status as prognostic factors in clinical practice . Somatostatin receptor scintigraphy turns out to be a powerful diagnostic tool , for an accurate staging and an early diagnosis of recurrence in bronchial carcinoids Background : [18F]Fluoro-2-deoxy-D-glucose ( FDG ) positron emission tomography ( PET ) scan is widely used for the staging evaluation of nonsmall cell lung cancer , however , its use in small cell lung cancer ( SCLC ) remains investigational . Patient and Methods : We design ed a prospect i ve study to evaluate the role of PET in SCLC . Patients with SCLC underwent PET scanning as well as conventional imaging before and after treatment . Results : A total of 39 PET scan examinations were performed in 21 patients with SCLC ; 18 studies were performed before first-line chemotherapy and 21 studies were done during or after treatment .  PET findings were compared with findings on CT scans of the chest or abdomen and bone scan . Discordant findings were detected in 14 out of 383 comparisons ( 4 % ) for 10 anatomic sites . In the thorax and the abdomen , PET agreed with  CT scan in 92 % to 100 % of examinations assessing potential disease sites , including the contralateral chest , liver , and adrenals . PET agreed with bone scan in detecting bony lesions in 27 out of 32 imaging studies ( 84 % ) : in 4 out of 5 discordant cases , PET findings were true and in 1 case indeterminate . Staging at baseline ( limited , n = 6 ; extensive , n = 12 ) was identical when PET and sum of other staging procedures were compared . Response assessment was concordant between PET and CT scans in 8 of 9 patients who had evaluation before and after first-line chemotherapy . Conclusions : PET is potentially useful for the initial staging and monitoring of patients with SCLC and it may be superior to bone scan in detecting bone metastasis . The cost effectiveness of PET scan in SCLC remains to be determined PURPOSE Positron emission tomography ( PET ) is a costly new technology with potential to improve preoperative evaluation for patients with non-small-cell lung cancer ( NSCLC ) . There is increasing pressure for PET to be included in st and ard diagnostic work-up before decisions about surgical management of NSCLC . The re source implication s of its widespread use in staging NSCLC are significant . METHODS A r and omized controlled trial was conducted to investigate the impact of PET on clinical management and surgical outcomes for patients with stage I-II NSCLC . The primary hypothesis was that PET would reduce the proportion of patients with stage I-II NSCLC who underwent thoracotomy by at least 10 % through identification of patients with inoperable disease . RESULTS One hundred eighty-four patients with stage I-II NSCLC were recruited and r and omly assigned ; 92 % had stage I disease . Following exclusion of one ineligible patient , 92 patients were assigned to no PET and 91 to PET . Compared with conventional staging , PET upstaged 22 patients , confirmed staging in 61 and staged two patients as benign . Stage IV disease was rarely detected ( two patients ) . PET led to further investigation or a change in clinical management in 13 % of patients and provided information that could have affected management in a further 13 % of patients . There was no significant difference between the trial arms in the number of thoracotomies avoided ( P = .2 ) . CONCLUSION For patients who are carefully and appropriately staged as having stage I-II disease , PET provides potential for more appropriate stage-specific therapy but may not lead to a significant reduction in the number of thoracotomies avoided UNLABELLED The goal of this study was to assess the value of hybrid imaging using a combined PET/CT device with 18F-FDG in the diagnosis and clinical management of suspected recurrent lung cancer . METHODS Forty-two patients with non-small cell lung cancer ( NSCLC ) with suspected recurrence due to new clinical , biochemical , and radiologic findings were prospect ively evaluated .  PET/CT results were compared with PET interpreted with side-by-side CT data . A final diagnosis of recurrence was confirmed by histologic tissue sampling during surgery or biopsy or by further clinical and radiologic work-up . The impact of PET/CT on patient management was assessed . RESULTS Twenty-four of 27 positive PET/CT studies ( 89 % ) were proven to have recurrent disease . Fourteen of 15 negative PET/CT studies ( 93 % ) had no evidence of disease . The sensitivity , specificity , and positive and negative predictive values of  PET/CT for diagnosis of recurrence were 96 % , 82 % , 89 % , and 93 % compared with 96 % , 53 % , 75 % , and 90 % , respectively , for PET . PET/CT changed the PET lesion classification in 22 patients ( 52 % ) , by determining the precise localization of sites of increased 18F-FDG uptake . PET/CT changed the management of 12 patients ( 29 % ) by eliminating previously planned diagnostic procedures ( 5 patients ) , by initiating a previously unplanned treatment option ( 4 patients ) , or by inducing a change in the planned therapeutic approach ( 3 patients ) . CONCLUSION In patients with a suspected recurrence of NSCLC , PET/CT provides a better anatomic localization of suspicious lesions compared with PET interpreted with side-by-side CT data . This improved diagnostic performance of PET/CT has a further impact on the clinical management and treatment planning of the patients Purpose The purpose of this study was to evaluate the impact of [18F]fluorodeoxy-d-glucose positron emission tomography ( FDG-PET ) on the primary staging of patients with small-cell lung cancer ( SCLC ) . Methods FDG-PET was performed in 120 consecutive patients with SCLC during primary staging . In addition , brain examinations with both FDG-PET and cranial magnetic resonance imaging ( MRI ) or computed tomography ( CT ) were performed in 91 patients . Results of FDG-PET were compared with those of conventional staging procedures . FDG-PET detected markedly increased FDG uptake in the primary tumours of all 120 patients ( sensitivity 100 % ) . Results Complete agreement between FDG-PET results and other staging procedures was observed in 75 patients . Differences occurred in 45 patients at 65 sites . In 47 sites the FDG-PET results were proven to be correct , and in ten , incorrect . In the remaining eight sites , the discrepancies could not be clarified . In 14/120 patients , FDG-PET caused a stage migration , correctly upstaging ten patients to extensive disease and downstaging three patients by not confirming metastases of the adrenal gl and s suspected on the basis of CT . Only 1/120 patients was incorrectly staged by FDG-PET , owing to failure to detect brain metastases . In all cases the stage migration led to a significant change in the treatment protocol . Sensitivity of FDG-PET  was significantly superior to that of CT in the detection of extrathoracic lymph node involvement ( 100 % vs 70 % , specificity 98 % vs 94 % ) and distant metastases except to the brain ( 98 % vs 83 % , specificity 92 % vs 79 % ) . However , FDG-PET was significantly less sensitive than cranial MRI/CT  in the detection of brain metastases ( 46 % vs 100 % , specificity 97 % vs 100 % ) . Conclusion The introduction of FDG-PET in the diagnostic evaluation of SCLC will improve the staging results and affect patient management , and may reduce the number of tests and invasive procedures BACKGROUND Small-cell lung cancer ( SCLC ) accounts for 15%-20 % of all lung cancer cases . Accurate and fast staging is m and atory when choosing treatment , but current staging procedures are time consuming and lack sensitivity . PATIENTS AND METHODS A prospect i ve study was design ed to examine the role of combined positron emission tomography/computed tomography ( PET/CT ) compared with st and ard staging ( CT , bone scintigraphy and immunocytochemical assessment of bone marrow biopsy ) of patients with SCLC . Thirty-four consecutive patients were included . Twenty-nine patients received initial PET/CT .  RESULTS PET/CT caused change of stage in 5/29 ( 17 % ) . Excluding patients with unconfirmed findings or pleural effusion , the sensitivity for accurate staging of patients with extensive disease was the following : for st and ard staging 79 % , PET 93 % and PET/CT 93 % . Specificity was 100 % , 83 % and 100 % , respectively . CONCLUSION The results from this first study on PET/CT in SCLC indicates that PET/CT can simplify and perhaps even improve the accuracy of the current staging procedure in SCLC . A larger clinical trial , preferably with consequent histological confirmation in case of discordance , however , is warranted BACKGROUND We compared the diagnostic accuracy of integrated positron-emission tomography ( PET ) and computed tomography ( CT ) with that of CT alone , that of PET alone , and that of conventional visual correlation of PET and CT in determining the stage of disease in non-small-cell lung cancer . METHODS In a prospect i ve study , integrated PET-CT was performed in 50 patients with proven or suspected non-small-cell lung cancer .  CT and PET alone , visually correlated PET and CT , and integrated PET-CT were evaluated separately , and a tumor-node-metastasis ( TNM ) stage was assigned on the basis of image analysis . Nodal stations were identified according to the mapping system of the American Thoracic Society . The st and ard of reference was histopathological assessment of tumor stage and node stage . Extrathoracic metastases were confirmed histopathologically or by at least one other imaging method . A paired sign test was used to compare integrated PET-CT with the other imaging methods . RESULTS Integrated PET-CT provided additional information in 20 of 49 patients ( 41 percent ) , beyond that provided by conventional visual correlation of PET and CT . Integrated PET-CT had better diagnostic accuracy than the other imaging methods . Tumor staging was significantly more accurate with integrated PET-CT than with CT alone ( P=0.001 ) , PET alone ( P<0.001 ) , or visual correlation of PET and CT ( P=0.013 ) ; node staging was also significantly more accurate with integrated PET-CT than with PET alone ( P=0.013 ) . In metastasis staging , integrated PET-CT increased the diagnostic certainty in two of eight patients . CONCLUSIONS Integrated PET-CT improves the diagnostic accuracy of the staging of non-small-cell lung cancer UNLABELLED We proposed to train a back-propagation artificial neural network ( aNN ) on a cohort of surgically proven non-small cell lung cancers ( NSCLCs ) and compare its accuracy with that of a trained (18)F-FDG PET reader . We plan to show that an aNN trained on (18)F-FDG PET- and CT-derived data is more accurate in predicting the true surgicopathologic nodal stage than a human reader . METHODS One hundred thirty-three NSCLC patients with surgically proven N status treated at the University of Washington Medical Center or the Veterans Affairs Puget Sound Health Care System between February 1998 and September 2002 were used as inputs for the creation of an aNN . From CT of the thorax and (18)F-FDG PET ( neck to pelvis ) performed before surgery , we extracted the primary tumor size and uptake ( maximum pixel SUV [ maxSUV ] ) , normal lung and mediastinal uptake , and nodal uptake ( maxSUV ) . Using the same 133 cases , the same output ( surgical N status , N(0 ) to N(3 ) ) , and the same software configuration setting s , scenarios were created to assess which input parameters were most influential in creating an optimal aNN . To compute this optimal aNN , cases were split r and omly 100 times into a training subset of 103 cases and a testing subset of 30 cases having the same proportion of N(0 ) , N(1 ) , N(2 ) , and N(3 ) cases . N status predicted by the aNN was compared with the proven surgical N status to calculate the aNN accuracy . The N status readings from (18)F-FDG PET were also compared with the surgical N status for the same cases to determine (18)F-FDG 
    Output:
    
RESULTS FDG-PET ( PET/CT ) allows the differentiation of indeterminate lung lesions with high accuracy .
FDG-PET ( PET/CT ) is the most accurate non-invasive procedure to assess the mediastinal nodal stage , for non-small cell as well as for small cell lung cancer .
Unexpected extrathoracic metastases detected by FDG-PET imply important changes in therapeutic management .
The upcoming S3 guideline on lung cancer will recommend FDG-PET in several indications due to its clinical efficacy well proven by data from literature ( high level of evidence ) .