Results of the American College of Surgeons Oncology Group Z0050 trial: the utility of positron emission tomography in staging potentially operable non-small cell lung cancer

OBJECTIVES: The American College of Surgeons Oncology Group undertook a trial to ascertain whether positron emission tomography with 18F-fluorodeoxyglucose could detect lesions that would preclude pulmonary resection in a group of patients with documented or suspected non-small cell lung cancer found to be surgical candidates by routine staging procedures. METHODS: A total of 303 eligible patients registered from 22 institutions underwent positron emission tomography after routine staging (computed tomography of chest and upper abdomen, bone scintigraphy, and brain imaging) had deemed their tumors resectable. Positive findings required confirmatory procedures. RESULTS: Positron emission tomography was significantly better than computed tomography for the detection of N1 and N2/N3 disease (42% vs 13%, P =.0177, and 58% vs 32%, P =.0041, respectively). The negative predictive value of positron emission tomography for mediastinal node disease was 87%. Unsuspected metastatic disease or second primary malignancy was identified in 18 of 287 patients (6.3%). Distant metastatic disease indicated in 19 of 287 patients (6.6%) was subsequently shown to be benign. By correctly identifying advanced disease (stages IIIA, IIIB, and IV) or benign lesions, positron emission tomography potentially avoided unnecessary thoracotomy in 1 of 5 patients. CONCLUSIONS: In patients with suspected or proven non-small cell lung cancer considered resectable by standard staging procedures, positron emission tomography can prevent nontherapeutic thoracotomy in a significant number of cases. Use of positron emission tomography for mediastinal staging should not be relied on as a sole staging modality, and positive findings should be confirmed by mediastinoscopy. Metastatic disease, especially a single site, identified by positron emission tomography requires further confirmatory evaluation.     

Comparison of clinical and surgical-pathologic staging of the patients with non-small cell lung carcinoma

Objective: Clinical staging of non-small cell lung cancer helps to determine the extent of disease and separate patients with potentially resectable disease from those that are unresectable. Since, clinical staging is based on radiologic and bronchoscopic findings, overstaging or understaging may occur comparing to the final surgical-pathologic evaluation. We aimed to analyze preoperative and postoperative stagings in order to evaluate stage migrations and our surgical strategy for marginally resectable patients. Methods: We did a retrospective analysis of 180 patients with non-small cell lung cancer who underwent resectional surgery between 1994 and 2000. In all patients, a thoracic computerized tomography and bronchoscopy were performed to define clinical staging (cTNM). Results: In 86 patients (47.7%) clinical and surgical-pathologic staging concurred. When comparing T subsets alone, correct staging, overstaging and understaging occurred in 133 (73.9%), 28 (15.5%), 47 (26.1%) patients, respectively. Only 13 of 21 patients (61.9%) who were thought to have T4 tumor preoperatively were found to have pT4. Also six patients with cT2 and five patients with cT3 were subsequently found to have T4 disease according to pathology. Clinical staging overestimated the nodal staging in 35 patients (19.4%), while underestimated the lymph node involvement in 45 patients (25%). Conclusion: Construction of cTNM stage remains a crude evaluation, preoperative mediastinoscopy in every patient must be performed. Preoperative limited T4 disease is not to deny surgery to patients since a considerable number of patients with cT4 are to be understaged following surgery.     

Use of Positron Emission Tomography in Assessing Hidden Extrathoracic Metastasis in Non Small Cell Lung Cancer

IntroductionPositron emission tomography combined with computed axial tomography (PET/CT) is used for staging non small cell lung cancer (NSCLC). This study aims to describe PET/CT findings of unsuspected extrathoracic metastasis when used in mediastinal evaluation of patients with apparently resectable NSCLC.Patients and methodProspective and concurrent study including all NSCLC patients between June 2004 and November 2006 who underwent PET/CT after considering them as candidates for surgery, with resectable disease after bronchoscopy, thorax and abdominal CT, brain CT and bone gammagraphy evaluation, if metastasis at these locations were suspected. Metastasis were confirmed histopathologically or assumed when they had a compatible evolution.ResultsA total of 91 patients with NSCLC underwent PET/CT. In 24 of them (26%) at least one suspicious extrathoracic uptake was seen. In 7 patients (7.7%) those uptakes were NSCLC extrathoracic metastasis hidden from conventional staging. In 3 of these cases (13.1%) extrathoracic uptakes corresponded to metacrhonous tumours or pre-malignant conditions. Benign lesions were found in 12 patients (13.1%), and in 2 cases (2.2%) the uptake origins were undetermined.ConclusionsPET/CT is a complementary diagnosis method for assessing hidden metastases which could modify the therapeutical approach in patients otherwise suitable for surgery.     

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.     

Limitations of computerized tomography in staging invasive bladder cancer before radical cystectomy

PURPOSE: Computerized tomography (CT) of the abdomen and pelvis is often routine in the preoperative staging assessment of invasive transitional cell carcinoma of the bladder. We determine the accuracy of staging CT findings, usefulness before planned extirpative surgery and impact on surgical management of this disease. MATERIALS AND METHODS: We retrospectively reviewed the medical records, including radiographic, operative and pathological reports, of 82 consecutive cases. All patients presented with muscle invasive bladder tumors, were considered candidates for radical cystectomy and underwent preoperative staging CT of the abdomen and pelvis between July 1994 and June 1998. The ability of CT to provide additional staging information in terms of depth of tumor invasion, local extent of tumor, pelvic lymph node involvement and distant metastases was examined. We determined whether CT findings altered surgical management for individual patients. RESULTS: CT was able to discriminate depth of invasion in only 1 patient (1.2%) and correctly identified extravesical tumor spread in 4 (4.9%). Lymph node and distant metastases were accurately determined in 4 (4.9%) and 2 (2.4%) cases, respectively. The overall accuracy of CT was 54. 9%, with an under staging and over staging rate of 39.0% and 6.1%, respectively. CT provided accurate, additional staging information in only 8 cases (9.8%). Surgical management was altered in 3 cases (3.7%) and only 1 (1.2%) avoided an unnecessary operation as a result of CT findings. CONCLUSIONS: Staging CT of the abdomen and pelvis in patients with invasive bladder carcinoma has limited accuracy, mainly because of its inability to detect microscopic or small volume extravesical tumor extension and lymph node metastases. CT tends to under stage advanced disease and failed to alter surgical management in nearly all of our cases.     

Results of preoperative mediastinoscopy for small cell lung cancer

BACKGROUND: The significance of mediastinoscopy for small cell lung cancer is unclear owing to the small number of surgical cases. METHODS: To determine the N component of the TNM staging system, computed tomographic findings and the results of mediastinoscopy were compared with the pathologic examination of surgical specimens. RESULTS: Four cases among 37 patients (10.8%) were determined as inoperable by mediastinoscopy because of mediastinal lymph node metastasis. A thoracotomy was performed in 33 patients. Six patients (18.2%) who had been judged to have no metastasis by mediastinoscopy were found to have N2 disease after examination of the surgical specimens. In the identification of all mediastinal metastases, mediastinoscopy was 40.0% sensitive, 100% specific, and 83.8% accurate. When the superior mediastinal, paratracheal, pretracheal, tracheobronchial, and subcarinal lymph nodes were defined as approachable nodes, mediastinoscopy was 66.7% sensitive, 100% specific, and 94.6% accurate in the evaluation of these restricted nodes. Four cases among 8 patients with cN1 lesions resulted in a designation as pN2. CONCLUSIONS: Mediastinoscopy is useful for the diagnosis of an approachable mediastinal lymph node in small cell lung cancer cases. This exploration is necessary for patients with small cell lung cancer who are diagnosed as cN1 before thoracotomy.     

Restaging the Mediastinum in Non-Small Cell Lung Cancer after Induction Therapy: Non-Invasive Versus Invasive Procedures

Objective : Nodal status after induction therapy in patients with stage III non-small cell lung cancer (NSCLC) is an independent prognostic factor for survival. Prognosis is poor in patients with persisting mediastinal lymph node involvement.

Methods : From February 2000 to September 2007, restaging for NSCLC was performed in 25 patients (23 men, 2 women) by computed tomography (CT), positron emission tomography (PET) as well as repeat mediastinoscopy. Initial proof of N2 or N3 disease was obtained by mediastinoscopy.

Results : The non-invasive restaging modalities CT and PET had a rather low accuracy of 64% and 72%, respectively. Repeat mediastinoscopy performed better with an accuracy of 84%.

Conclusion : Histological proof of mediastinal involvement after induction therapy in NSCLC is necessary to select those patients who will benefit from surgical resection. When a first mediastinoscopy has been performed to obtain pathological proof of N2 or N3 disease, repeat mediastinoscopy proves to be more accurate than CT or PET scanning for mediastinal restaging.     

Evaluation of fluorine-18-fluorodeoxyglucose whole body positron emission tomography imaging in the staging of lung cancer

BACKGROUND: Surgical resection of lung cancer remains the treatment of choice in appropriately staged disease, but conventional imaging techniques have limitations. Positron emission tomography (PET) may improve staging accuracy. METHODS: We studied whole body and localized thoracic PET in staging lung cancer. Standardized uptake value was calculated for the primary lesion. Ninety-seven patients under consideration for surgical resection were included. PET, computed tomography, and clinical staging were compared to stage at operation, biopsy, or final outcome. Mean follow up was 17.5 months. RESULTS: PET detected all primary lung cancers with two false-positive primary sites. Sensitivity and specificity for N2 and N3 mediastinal disease was 20% and 89.9% for computed tomography and 70.6% and 97% for PET. PET correctly altered stage in 26.8%, nodal stage in 13.4%, and detected distant metastases in 16.5%. PET missed 7 of 10 cerebral metastases. PET altered management in 37% of patients. PET staging (p<0.0001) and standardized uptake value (p<0.001) were the best predictors of time to death apart from operative staging. CONCLUSIONS: PET provides significant staging and prognostic information in lung cancer patients considered operable by standard criteria. Routine use of PET will prevent unnecessary operation and may be cost effective.     

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.     

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.     

Staging of non-small cell lung cancer: clinical value of positron emission tomography and mediastinoscopy

We report about a MEDLINE research from 2000 to 2005 with the key words 'positron emission tomography AND/OR mediastinoscopy'. The search identified 448 potential studies. Out of the published data sensitivity, specificity, positive and negative predictive value, and accuracy for mediastinal lymph node staging by FDG-PET ranged from 58%-94%, 76%-96%, 43%-95%, 56%-98% to 74%-91%, respectively. With corresponding values of 80%-96%, 100%, 100%, 92%-97%, and 94%, respectively, for mediastinoscopy. FDG-PET improved the rate of detection of local and distant metastases in 12% to 62% and changed the management of treatment in 8% to 60% of patients with NSCLC. Our study shows that in the diagnostic strategy of patients with NSCLC, additional FDG-PET can prevent non-therapeutic thoracotomy in a significant number of cases. If FDG-PET imaging and CT scan is negative for mediastinal lymph node involvement routinely mediastinoscopy can be omitted and thoracotomy can immediately be performed. In patients with negative FDG-PET scan, but positive CT scan, histologic verification by invasive methods can individually be considered. Patients with positive FDG-PET scan mediastinoscopy still remain a reliable standard for exact lymph node staging. By incorporating FDG-PET in clinical staging unnecessary exploratory thoracotomies, and mediastinoscopy, can be omitted.     

Fluorodeoxyglucose positron emission tomography integrated with computed tomography to determine resectability of primary lung cancer

PURPOSE: Fluorodeoxyglucose positron emission tomography integrated with computed tomography (FDGPET/CT) was evaluated as a routine staging technique for primary lung cancer. MATERIALS AND METHODS: We prospectively compared FDG-PET/CT in determining clinical stage and surgical indication with conventional staging not including positron emission tomography (PET). A total of 50 consecutive patients diagnosed with primary lung cancer by cytological or histological examination were studied; 20 of them underwent surgery. RESULTS: Discrepancies between the two staging methods were observed in 14 patients (28%). The stage assigned by PET increased in 12 cases (24%) and decreased in 2 (4%). PET staging was accurate in eight cases with otherwise undetected distant metastases (M1) but was incorrect in six cases, including five where it overdiagnosed nodal metastases (N). Two clinical N3 patients (4%) would have missed a chance of surgery if the surgical indication had been determined by PET staging alone. According to our criteria for surgery, other patients were assigned correctly to surgery by PET staging. The maximum standard uptake value (maxSUV) of all primary lesions ranged from 0 to 23.0 (mean +/- SD, 8.0 +/- 4.4). The mean maxSUV among surgical cases (5.8 +/- 3.6) was significantly smaller than among nonsurgical cases (9.5 +/- 4.2) (P < 0.05). CONCLUSION: Staging examination including FDG-PET/CT and brain magnetic resonance imaging ordinarily can determine the clinical stage and resectability of primary lung cancer. False-positive findings in regional lymph nodes, possibly reflecting past infectious disease, are the most important remaining problem.     

Preoperative staging of lung cancer: accuracy of computed tomography versus mediastinoscopy.

Forty-four patients coming to surgery for carcinoma of the bronchus underwent preoperative staging of the mediastinum by computed tomography (CT scanning) and surgical exploration of the mediastinum by cervical mediastinoscopy or left anterior mediastinotomy or both. Where mediastinal nodes were affected the sensitivity and specificity of computed tomography was inferior to that of mediastinoscopy (57% and 85% versus 71% and 100%). The sensitivity of computed tomography in predicting mediastinal invasion was superior to that of mediastinoscopy (77% v 46%), especially in the case of lower-lobe tumours (67% v 17%). Mediastinoscopy had the considerable advantage of 100% specificity. In the assessment of hilar lymphadenopathy computed tomography had a sensitivity of 38% and a specificity of 64%. In cases where computed tomography showed a normal mediastinum or enlargement of the hilar glands only, mediastinal exploration conferred no additional information and could have been omitted. A computed tomography scan showing mediastinal abnormality is an indication for mediastinoscopy and not a contraindication to surgery. In 23 patients computed tomography showed some abnormality of the mediastinum, confirmed at mediastinoscopy in 12 cases. The remaining 11 patients underwent thoracotomy, resection being carried out in nine. Postsurgical staging showed that six of these tumours were N0 lesions without invasion; in two further N0 cases there was a minor degree of mediastinal invasion which did not prevent resection, and the remaining tumour was N1 without invasion.     

Preoperative assessment and surgical indication for malignant pleural mesothelioma

The standard surgical procedure for patients with malignant pleural mesothelioma (MPM) is extrapleural pneumonectomy (EPP). However, high morbidity and mortality rates have been reported in patients who received EPP, whereas survival rates after EPP remain unsatisfactory. Thus, a carefully and precise preoperative assessment to select appropriate candidates for EPP is essential in patients with MPM, and we conducted a surgical staging with laparoscopy, mediastinoscopy and contralateral thoracoscopy for potentially resectable MPM patients. Among 5 consective patients who received the preoperative surgical staging during past 10 months, 1 patient was judged not to be a surgical candidate due to the presence of contralateral pleural metastasis. In conclusion, this surgical staging is a useful preoperative evaluation to prevent an unnecessary operation.     

Multimodal treatment of non small cell lung cancer

The primary treatment of lung cancer depends on tumor stage. Chest CT scan and bronchoscopy are used to define the TNM stage and resectability. In case of lung cancer without mediastinal lymph node enlargement or direct mediastinal involvement (clinical stage I-IIb + T3N1) surgical treatment is recommended. The use of adjuvant chemotherapy has to be defined, but will be indicated in stage II and IIIa. Expected 5-year survival achieves 40 to 80 % depending on tumor stage. Exceeds the shorter diameter of mediastinal lymph nodes in chest CT scan more than 1 cm (or in case of positive PET scan) mediastinoscopy is indicated. In case of N2-disease and after tumor response to preoperative chemotherapy (about 60 %) secondary resection of the tumor leads to higher 5-year survival rates (20-40 %) compared to patients without induction therapy (5-20 %). In these patients and after unexpected detection of solitary lymph node metastasis by primary resection adjuvant mediastinal radiotherapy should be added. If the tumor has infiltrated the mediastinum or the upper sulcus (T3/4) and/or mediastinal lymph nodes are obviously tumor burden (e. g. > 3 cm, N2 bulky, N3) radical primary resection may not be possible. In these patients combined radio- and chemotherapy induces a high percentage of tumor regression and can be used before secondary resection (5-year survival 5-20 %). Locally advanced tumors infiltrating the main bronchus close to the carina or the carina itself and tumors with metastases in the same lobe, both without mediastinal lymph node metastases (T3/4N0-1), can be resected by sleeve pneumonectomy and lobectomy with satisfactory results respectively. In patients with resectable lung cancer and no clinical sign of tumor disease (f. e. anemia, weight loss, pain) limited staging procedure with chest CT scan including upper abdomen and bronchoscopy is reasonable. In the remaining patients complete staging is necessary. We recommend an interdisciplinary approach to patients with lung cancer.     

PET, CT, and MRI with Combidex for mediastinal staging in non-small cell lung carcinoma.

BACKGROUND: To determine the relative utility of positron emission tomography (PET), computed tomography (CT), and magnetic resonance imaging with Combidex (MRI-C) in the non-invasive staging of non-small cell lung cancer (NSCLC) mediastinal lymph nodes (MLN), we compared the three tests' individual performance with surgical mediastinal sampling. In contrast to prior studies, cytology was not used. METHODS: The MLN were evaluated using PET and CT in 64 NSCLC patients. MRI-C was performed in 9 of these patients. MLN with a PET standard uptake value greater than or equal to 2.5, or greater than 1 cm in the short axis by CT or lack of MRI-C signal change were considered positive for metastatic disease. All MLN were sampled and subjected to standard pathologic analysis. PET, CT, and MRI-C scans were interpreted blinded to the histopathological results. Sensitivity, specificity, and accuracy for each scan type to appropriately stage MLN was determined using pathologic results as the standard. RESULTS: Thirty patients had stage I disease, 8 stage II, 9 stage IIIA, 7 stage IIIB, and 10 stage IV. Two-hundred-and-thirty MLN were sampled. Sixteen patients had metastatic mediastinal disease. Compared to the pathological results, PET, CT, and MRI-C had a sensitivity, specificity, and accuracy of 70%, 86%, 84%; 65%, 79%, 76%; 86%, 82%, and 83%, respectively. PET and MRI-C were statistically more accurate than CT (p<0.001). In cases where PET and CT did not identify MLN involvement with NSCLC, 8% (2/25) were pathologically positive. CONCLUSIONS: PET and MRI-C are statistically more accurate than CT. However, the differences are small and may not be clinically relevant. No technique was sensitive or specific enough to change the current recommendation to perform mediastinoscopy for MLN staging in NSCLC.     

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.     

27例中晚期结肠癌的多层螺旋CT诊断及临床价值探讨

为探讨多层螺旋CT（MSCT）三维重建技术在中晚期结肠癌诊断中的应用价值,回顾分析27例经病理证实的中晚期结肠癌患者资料,患者术前均行MSCT多期扫描及后处理（包括多平面重建、最大密度投影和CT血管造影等）,并将MSCT显示的影像特征与手术证实的结果进行对比分析。结果显示,MSCT能显示肠腔及肠壁的改变、病灶与周围组织的关系,并可显示周围组织器官的侵犯情况及有无远处转移。本组MSCT显示结肠癌的敏感性达100％（27／27）;对大肠癌TNM分期的准确率为：T分期92．59％（25／27）,N分期88．89％（24／27）,M分期85．19％（23／27）;显示肿瘤供血血管准确率为100％（27／27）。1例T2期高估为T3期,1例T1期高估为T3期。3例淋巴结转移和4例远处转移未检出。结果表明,MSCT三维重建技术可以较好地显示病灶及病灶与周围脏器的关系,对中晚期结肠癌TNM分期的判断准确性高,对临床评估肿瘤的可切除性及制定治疗方案具有重要意义。     

Is Mediastinoscopy Necessary in the Evaluation of Lung Cancer?

The records of 96 consecutive patients who underwent mediastinoscopy and were ultimately shown to have bronchogenic carcinoma were reviewed. Indirect tests for mediastinal tumor metastases in these patients included bronchoscopy and chest roentgenograms in all 96, mediastinal laminagrams in 65, esophagograms in 27, carinal biopsy in 23, bronchograms in 5, pulmonary angiograms in 5, azygograms in 2, and aortograms in 2 patients. Of the 43 patients in this series in whom all indirect tests revealed no metastases, mediastinoscopy showed nodal involvement in 11 (28%), who were thus spared unnecessary thoracotomy. On the other hand, if negative mediastinoscopy had not cast doubt on the validity of indirect tests that seemed to show metastases, an operation might actuallly have been denied to 14 patients who were ultimately proved to have anatomically resectable disease.