Mediastinoscopy, thoracoscopy, and video-assisted thoracic surgery in the diagnosis and staging of lung cancer

Video-assisted thoracoscopic surgery simulation and training: a comprehensive literature review

BACKGROUND

Video-assisted thoracic surgery (VATS) has become the standard for lung cancer diagnosis and treatment. However, this surgical technique requires specific and dedicated training. In the past 20 years, several simulator systems have been developed to promote VATS training. Advances in virtual reality may facilitate its integration into the VATS training curriculum. The present review aims to first provide a comprehensive overview of the simulators for thoracoscopic surgery, focused especially on simulators for lung lobectomy; second, it explores the role and highlights the possible efficacy of these simulators in the surgical trainee curriculum.

METHODS

A literature search was conducted in the PubMed, EMBASE, Science Direct, Scopus and Web of Science databases using the following keywords combined with Boolean operators "AND" and "OR": virtual reality, VR, augmented reality, virtual simulation, mixed reality, extended reality, thoracic surgery, thoracoscopy, VATS, video-assisted thoracoscopic surgery, simulation, simulator, simulators, training, and education. Reference lists of the identified articles were hand-searched for additional relevant articles to be included in this review.

RESULTS

Different types of simulators have been used for VATS training: synthetic lung models (dry simulators); live animals or animal tissues (wet simulators); and simulators based on virtual or augmented reality. Their role in surgical training has been generally defined as useful. However, not enough data are available to ascertain which type is the most appropriate.

CONCLUSIONS

Simulator application in the field of medical education could revolutionize the regular surgical training curriculum. Further studies are required to better define their impact on surgeons' training programs and, finally, on patients' quality of care.

Uncertain resection of highest mediastinal lymph node positive among pN2 non-small cell lung cancer patients: survival analysis of postoperative radiotherapy and driver gene mutations

BACKGROUND AND PURPOSE

The role of postoperative radiotherapy (PORT) in uncertain resection of pN2 non-small cell lung cancer (NSCLC) with highest mediastinal lymph node positive has not been determined. We aim to evaluate the effect of PORT and driver gene mutation status (DGMS) on survival in such patients.

METHODS

140 selected patients were grouped according to whether they received PORT and their DGMS. Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) of each group were evaluated by Kaplan-Meier analyses. COX regression was used to evaluate the effects of various factors on DFS and OS.

RESULTS

Of 140 patients, thirty-four patients (24.3%) received PORT, and forty (28.6%) had positive driver gene mutation status (DGp). PORT significantly prolonged LRFS (p = 0.002), DFS (p = 0.019) and OS (p = 0.02), but not DMFS (p = 0.062). By subgroup analysis, in patients with negative driver gene mutation status (DGn), those receiving PORT had notably longer LRFS (p = 0.022) and DFS (p = 0.033), but not DMFS (p = 0.060) or OS (p = 0.215), compared to those not receiving PORT. Cox analysis showed that the number of positive lymph nodes (PLNs) and administration of PORT were independent prognostic factors of DFS, and pathology, PLNs, and DGMS may be prognostic factors of OS (all p < 0.05).

CONCLUSION

Postoperative radiotherapy may improve locoregional recurrence-free and disease-free survival in patients with pN2 NSCLC with positive highest mediastinal lymph nodes, while driver gene mutation status impacted OS significantly. Only patients with positive driver gene mutations experienced significant overall survival benefits from postoperative radiotherapy.

Feasibility of quantitative parameters of dynamically enhanced patterns of spiral computed tomography scanning integrated into tumour progression before targeted treatment of non-small cell lung cancer

INTRODUCTION

The relationship between quantitative parameters of contrast-enhanced computed tomography (CT) and non-small cell lung cancer (NSCLC) progression remains controversial. We aimed to explore the usefulness of contrast-enhanced spiral CT scanning for confirming the time of tumour progression before targeted treatment of NSCLC.

METHODS

Contrast-enhanced spiral CT scanning was performed on 33 NSCLC patients with a biopsy-proven diagnosis of NSCLC. All the patients were divided into three groups according to times of tumour progression (<6 weeks, 6-20 weeks, and >20 weeks). The perfusion CT data were used to calculate quantitative parameters, including enhanced peak values, peak time of tumour enhancement, ratio of tumour mass and enhanced aorta peak value and perfusion value of blood flow. Variance analysis was used for statistical analysis among the three groups using SAS 9.13 statistical software.

RESULTS

Tumour perfusion values among the three group with different stage of TTP were significantly different from each other with P = 0.0129 (<6 weeks, perfusion value = 0.35 ± 0.15 mL/(min × mL); 6-20 weeks, perfusion value = 0.41 ± 0.086 mL/(min × mL); > 20 weeks, perfusion value = 0.47 ± 0.087 mL/(min × mL)). However, no significant differences were found in other parameters (enhanced peak values, peak time of tumour enhancement, ratios of tumour mass, and enhanced aorta peak value) among three groups (P > 0.05).

CONCLUSION

The NSCLC patients with high perfusion value before targeted therapy are more sensitive to targeted therapy, and further experiments with larger sample size are needed.

Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) of mediastinal lesions

BACKGROUND

Mediastinal endoscopic ultrasound guided fine needle aspiration (EUS-FNA) is a recognized diagnostic and staging procedure for non-small cell lung carcinoma (NSCLC). The aim of this study was to report the experience of mediastinal EUS in an Australian tertiary hospital.

METHODS

A retrospective review was conducted on all patients undergoing mediastinal EUS from February 2002 until August 2007 at St Vincent's Hospital, Melbourne. Data were obtained from the EUS databases at St Vincent's Hospital and patient endoscopy reports. The results of EUS-FNA were compared with final diagnosis to calculate sensitivity and specificity. Surgical pathology or long-term follow-up was used to identify false positive or negative results.

RESULTS

One hundred forty-eight mediastinal EUS procedure were performed. Males comprised 63.5% and the mean age was 64.3 (range 27-85). Referrals (47%) were from respiratory physicians and 27% were from cardiothoracic surgeons. Indications for EUS-FNA included unexplained mediastinal lymphadenopathy and/or lung lesion for investigation and staging of known NSCLC. Full data were available on 124 (83.8%) cases. Data were analysed from a subset of 112 where FNA was performed. For each indication, EUS-FNA had a high sensitivity and specificity: staging of known NSCLC (sensitivity 92.9%, specificity 88.9%), mediastinal lymphadenopathy (sensitivity 100%, specificity 100%) and lung lesion (sensitivity 94.4%, specificity 85.7%). There were no major complications.

CONCLUSION

This large series of mediastinal EUS shows that it is an important and useful tool for the assessment of mediastinal pathology. It is safe and highly accurate, and should be incorporated into the staging algorithm for NSCLC.

Endoscopic ultrasound of the upper gastrointestinal tract and mediastinum: diagnosis and therapy

Endoscopic ultrasound (EUS) has developed significantly over the last two decades and has had a considerable impact on the imaging and staging of mass lesions within or in close proximity to the gastrointestinal (GI) tract. In conjunction with conventional imaging such as helical computed tomography and magnetic resonance imaging, the indications for EUS include (1) differentiating between benign and malignant lesions of the mediastinum and upper GI tract, (2) staging malignant tumors of the lung, esophagus, stomach, and pancreas prior to surgery or oncological treatment, (3) excluding common bile duct stones before laparoscopic cholecystectomy, thereby avoiding the need for endoscopic retrograde cholangiopancreatography (ERCP) in some patients, and (4) assessing suspected lesions that are either equivocal or not seen on conventional imaging. In recent years, EUS has charted a course similar to that taken by ERCP, evolving from a purely diagnostic modality to one that is interventional and therapeutic. These indications include (5) obtaining a tissue diagnosis by EUS-guided fine-needle aspiration or trucut-type needle biopsy and (6) providing therapy such as coeliac plexus neurolysis and pancreatic pseudocyst drainage--in many cases, more accurately and safely than conventional techniques. Emerging investigational techniques include EUS-guided enteric anastomosis formation and fine-needle injection therapy for malignant disease.

Indications for mediastinoscopy and comparison of lymph node dissections in candidates for lung cancer surgery

A prospective phase II study of indications for surgery, using video-assisted mediastinoscopy (VAM) to detect mediastinal lymph node metastasis was conducted in patients with resectable primary lung cancer of clinical stages I-IIIA. According to the indication criteria for VAM, Group A patients had primary tumor resection and lymph node sampling without VAM. Patients without detected metastasis by VAM underwent thoracotomy and systematic lymph node dissection (Group B). Cases with mediastinal lymph node involvement confirmed by VAM were treated with chemotherapy followed by radiotherapy (Group D) or by thoracotomy (Group C) with extended dissection of mediastinal lymph nodes via median sternotomy. Of the 359 eligible patients, 209 underwent VAM (Group V) and 150 had thoracotomy without VAM (Group A). Of the VAM patients, 158 were negative for mediastinal involvement and underwent thoracotomy (Group B). Fifty-one patients had metastases and were given chemotherapy or chemo-radiotherapy. After two courses of chemotherapy, 22 patients with partial response (PR) or stable disease (SD) but reduced tumor markers received surgery with mediastinal lymph node dissection (Group C). The 2- and 5-year survival rates were 93.0 and 88.5% for Group A, and 89.5 and 61.5% for Group B, while the 2-year rate in Group C was 60.3%. In stage IA patients, Group A 2- and 5-year survival rates were 98.6 and 95.1%, the respective Group B rates being 96.3 and 89.9%. The more favorable Group A outcomes indicated both successful selection by these criteria of patients not requiring mediastinal examination, and the superfluity of complete lymph node dissection in early stage cancer.

The effect of race on invasive staging and surgery in non-small-cell lung cancer

PURPOSE

Black patients with early-stage non-small-cell lung cancer (NSCLC) have worse overall survival than white patients. Decreased likelihood of resection has been implicated. To isolate the effect of decision making from access to care, we used receipt of surgical staging as a proxy for access and willingness to undergo invasive procedures, and examined treatments and outcomes by race.

PATIENTS AND METHODS

We examined registry and claims data of Medicare-eligible patients with nonmetastatic NSCLC in areas monitored by the Surveillance, Epidemiology, and End Results program from 1991 to 2001. Patients who obtained invasive staging, defined as bronchoscopy, mediastinoscopy, or thoracoscopy, were included. Logistic regression and Cox modeling calculated the odds of having staging and surgery, and survival outcomes.

RESULTS

A total of 14,224 patients underwent staging, and 6,972 had surgery for lung cancer. Black patients were less likely to undergo staging (odds ratio [OR] = 0.75; 95% CI, 0.67 to 0.83), and once staged, were still less likely to have surgery than whites (OR = 0.55; 95% CI, 0.47 to 0.64). Survival for blacks and whites was equivalent after resection (hazard ratio = 1.02; P = .06). Staged black patients were less likely to receive a recommendation for surgery when it was not clearly contraindicated (67.0% v 71.4%; P < .05), and were more likely to decline surgery (3.4% v 2.0%; P < .05).

CONCLUSION

Black patients obtain surgery for lung cancer less often than whites, even after access to care has been demonstrated. They are more likely not to have surgery recommended, and more likely to refuse surgery. Additional research should focus on the physician-patient encounter as a potential source of racial disparities.

Combined Video-Assisted Mediastinoscopy and Thoracoscopy in the Management of Lung Cancer: A Five-Year Experience

OBJECTIVE

The aim of this study was to assess the usefulness of combined video-assisted mediastinoscopy (VM) and video-assisted thoracoscopy (VT) in the management of patients with lung cancer.

METHODS

A prospective observational study was performed over a 5-year period. Indications for combined VM and VT included inconclusive findings from imaging techniques concerning locoregional extension and resectability; possible involvement of different structures not accessible to a single procedure; and failure to obtain a histologic diagnosis with a single technique.

RESULTS

An indication for combined exploration was established in 30 patients, representing 2.6% of all the patients referred to us for diagnosis, staging, and/or resection of lung cancer. Combined VM and VT was completed in 28 patients, as pleural carcinosis was found at VT in 2 cases. There was no mortality or morbidity in our series. Histologic diagnosis was obtained in 12/13 patients without preoperative histologic typing. In all the evaluated patients, combined VM and VT was useful in clinical decision-making, leading to immediate surgery (n=10), induction treatments (n=8), or nonsurgical therapy (n=12). Among the patients who underwent immediate surgery, combined VM and VT never failed to assess the T factor. The N factor was correctly evaluated in 8/10 patients, and in 2 patients it failed to recognize a minimal N2 disease.

CONCLUSION

Combined VM and VT is a safe and useful tool in the management of selected patients with lung neoplasms. Both the extent of primary tumor and the possible intrathoracic spread can be thoroughly evaluated.

The utility of EUS-guided FNA in the diagnosis of metastatic breast cancer to the esophagus and the mediastinum

BACKGROUND

Breast cancer can metastasize to the esophagus and the mediastinum. EUS-guided FNA (EUS-FNA) is being used increasingly as a less invasive alternative to mediastinoscopy for procuring a tissue diagnosis of mediastinal disease and may be useful for the diagnosis of breast cancer metastatic to the esophagus and the mediastinum.

METHODS

Twelve women (age range 54-82 years) with a history of breast cancer presented with dysphagia or other symptoms between 1 and 15 years after initial diagnosis and treatment. CT and endoscopy with biopsies suggested a mediastinal mass or lymphadenopathy with extrinsic esophageal compression but failed to provide a tissue diagnosis. EUS-FNA was performed for diagnosis.

RESULTS

Cytologic evaluation of specimens obtained by EUS-FNA confirmed breast cancer metastases in 11 of 12 patients (91%). Recurrent disease was found in intramural masses and periesophageal lymph nodes. No complication resulted from any EUS-FNA procedure.

CONCLUSIONS

EUS-FNA is safe and effective for the diagnosis of breast cancer metastases to the esophagus and the mediastinum. EUS-FNA may be useful as a first-line method of evaluation when breast cancer metastasis to the esophagus and the mediastinum is suspected.

Current concepts in the mediastinal lymph node staging of nonsmall cell lung cancer

OBJECTIVE

To review the current concepts in the mediastinal staging of nonsmall cell lung cancer (NSCLC), evaluating traditional and modern staging modalities.

SUMMARY BACKGROUND DATA

Staging of NSCLC includes the assessment of mediastinal lymph nodes. Traditionally, computed tomography (CT) and mediastinoscopy are used. Modern staging modalities include magnetic resonance imaging (MRI), positron emission tomography (PET), and endoscopic ultrasound with fine-needle aspiration (EUS-FNA) METHODS: Literature was searched with PubMed and SUMSearch for original, peer-reviewed, full-length articles. Studies were evaluated on inclusion criteria, sample size, and operating characteristics. Endpoints were accuracy, safety, and applicability of the staging methods.

RESULTS

CT had moderate sensitivities and specificities. With few exceptions magnetic resonance imaging (MRI) offered no advantages when compared with CT, against higher costs. PET was significantly more accurate than CT. Mediastinoscopy and its variants were widely used as gold standard, although meta-analyses were absent. Percutaneous transthoracic needle biopsy (PTNB) and transbronchial needle biopsy (TBNA) were moderately sensitive and specific. EUS-FNA had high sensitivity and specificity, is a safe and fast procedure, and is cost-effective. EUS-FNA evaluates largely a nonoverlapping mediastinal area compared with mediastinoscopy.

CONCLUSIONS

PET has the highest accuracy in the mediastinal staging of NSCLC, but is not generally used yet. EUS-FNA has the potential to perform mediastinal tissue sampling more accurate than TBNA, PTNB, and mediastinoscopy, with fewer complications and costs. Although promising, EUS-FNA is still experimental. Mediastinoscopy is still considered as gold standard for mediastinal staging of NSCLC.

Postinduction video-mediastinoscopy is as accurate and safe as video-mediastinoscopy in patients without pretreatment for potentially operable non-small cell lung cancer

BACKGROUND

Prospective assessment of accuracy and safety of video-mediastinoscopy (VMS) in patients without pretreatment and those after induction therapy for potentially operable non-small cell lung cancer.

METHODS

Between 1996 and 1999, 219 patients underwent VMS at our institution: 195 patients without pretreatment and 24 after completion of induction therapy. Mediastinal lymph nodes were dissected and biopsied according to the American Thoracic Society (ATS) lymph node mapping system using a video-assisted approach. The accuracy of VMS was assessed for each patient according to the results obtained from mediastinal lymph node dissection (MLND) performed during lung resection.

RESULTS

Video-mediastinoscopy in patients without pretreatment revealed a sensitivity, specificity, and accuracy as compared with MLND of 87%, 100%, and 95.6%, respectively, and a procedure-related complication rate of 4% (8/195 patients). Video-mediastinoscopy in patients after induction therapy revealed a sensitivity, specificity, and accuracy of 81%, 100%, and 91% as compared with MLND, without apparent complications.

CONCLUSIONS

Video-mediastinoscopy performed after induction therapy for non-small cell lung cancer is as accurate as mediastinoscopy in patients without pretreatment and did not confer additional morbidity.

Positron emission tomography in lung cancer

Carcinoma of the lung is one of the most frequent malignancies and a major cause of mortality. The use of positron emission tomography (PET) has been extensively investigated in patients with carcinoma of the lung and has established clinical utility and cost-effectiveness in characterization of solitary pulmonary nodules and preoperative staging of carcinoma of the lung. Evolving applications in carcinoma of the lung include detection of recurrence, assessment of treatment response, radiotherapy planning, and prognosis. In addition, there is developing interest in combined anatomic/metabolic imaging and new tracer techniques, in particular gene expression imaging. This review aims to present existing data supporting the use of PET in carcinoma of the lung and to explore the evolving indications and future prospects of PET and lung cancer.

Diagnosis and management of early lung cancer

Bronchogenic carcinoma remains the leading cause of cancer deaths in the United States. Approximately 80% of newly diagnosed cases are non-small cell lung cancer (NSCLC); 80% of these present with disseminated or locally advanced disease. Unfortunately, only 10% are potentially surgically curable patients with early-stage disease (T1N0/T2N0). Most patients with early-stage disease are asymptomatic, with their lung cancer detected as a result of non-cancer related procedures. Studies have shown that chest radiography as a screening modality resulted in a higher discovery of early disease, but did not translate to a significant reduction in lung cancer mortality. Recent work on low-dose helical CT, however, has renewed interest in the challenge of detecting early-stage lung cancer.

Video-assisted thoracoscopic surgery for diagnosis, staging, and management of lung cancer with suspected mediastinal lymphadenopathy

The aim of this report was to evaluate the effectiveness of video-assisted thoracoscopic surgery (VATS) in staging, diagnosis, and treatment of lung cancer. Fifty-two patients were scheduled for mediastinal lymph node VATS biopsy at the Oncologic Thoracic Surgery Department of the National Cancer Institute in Milan. Fifty patients underwent lymph nodal thoracoscopic biopsy (96%), whereas for the other 2 patients, histologic diagnosis was done by pleural metastatic nodule thoracoscopic biopsy (4%). We performed 17 lymph nodal biopsies in level 5 (33%), 14 in level 6 (27%), 12 in level 7 (23%), and 7 in level 8 (13%). No postoperative complications were observed, and 19 subjects (36%) underwent open lung resection. The histologic diagnosis was adenocarcinoma in 25 cases (48%), epidermoid carcinoma in 14 (27%), microcytoma in 9 (17%), and giant-cell lung carcinoma in 4 (8%); 10 patients were at stage I (19%), 9 at stage II (17%), 31 at stage III (60%), and 2 at stage IV (4%). The use of VATS allowed diagnosis of the suspected involved mediastinal lymph nodes in lung cancer patients and obviated the need for painful thoracotomy, enabling accurate staging and thus selection of the optimal treatment.

Extended cervical mediastinoscopy in the diagnosis of anterior mediastinal masses

BACKGROUND

Although transthoracic needle biopsy (TNB) has been the preferred method for the diagnosis of anterior mediastinal masses, it has inherent limitations in accuracy. In particular, lymphoma and thymoma are diagnosed less reliably using needle biopsy. Videothoracoscopy has been advocated as an alternative method for diagnosis. Our goal was to assess the usefulness of extended cervical mediastinoscopy (ECM) in the diagnosis of anterior mediastinal masses.

METHODS

The ECM technique was performed in 9 patients in whom TNB and Tru-cut biopsies had been inefficient for histologic diagnosis. All lesions were in the anterior mediastinum. Extended cervical mediastinoscopy was carried out using the same incision as in a standard cervical mediastinoscopy and dissection was performed behind the sternum as previously published. Mean operative time was 50 minutes (range 40 to 70 minutes) and mean hospital stay was 8 hours (range 5 to 36 hours).

RESULTS

Diagnosis of lymphoma in 4 cases, thymoma in 3 cases, and thymic hyperplasia in 2 cases were obtained by ECM. In 1 of 2 patients with suspected thymoma who underwent resectional surgical procedures, final histologic diagnosis was non-small cell lung carcinoma. There was no surgical mortality or intraoperative complication. One patient had minimal pneumothorax requiring no intervention.

CONCLUSIONS

We conclude that ECM in the diagnosis of anterior mediastinal masses is technically feasible and provides an alternative to the conventional approaches in patients with paraaortic or aortopulmonary masses.

Combined video-assisted mediastinoscopy and video-assisted thoracoscopy in the management of lung cancer

BACKGROUND

This study seeks to assess the safety and usefulness of combined video-assisted mediastinoscopy and video-assisted thoracoscopy in the management of patients with lung cancer.

METHODS

Ten consecutive patients with lung neoplasms were evaluated. Indications for this combined approach included inconclusive findings from imaging techniques concerning locoregional extension and resectability; possible involvement of different structures not accessible to a single procedure; and failure to obtain histologic diagnosis by a single technique. RESULTS; Histologic diagnosis was obtained in 6 patients without preoperative histologic typing. In 3 patients, in contrast with preoperative imaging studies, combined thoracoscopy and mediastinoscopy showed the resectability of the primary tumor and the absence of metastatic mediastinal lymph nodes. These findings were confirmed at thoracotomy. In 3 other patients prevascular lymph nodes metastases were found. They underwent neoadjuvant chemotherapy; at subsequent operation, a complete resection was possible. In the remaining four cases combined exploration proved definitive contraindications for operation (recognition of oat-cell carcinoma, n = 2; T4 status, n = 1; T3N2, n = 1).

CONCLUSIONS

Combined video-assisted mediastinoscopy and video-assisted thoracoscopy seems to be a safe and useful tool in the management of selected patients with lung neoplasms. Both the extent of primary tumor and the possible intrathoracic spread may be exhaustively evaluated. In patients with left lung cancer a complete exploration of the aortopulmonary window is possible.

Mediastinal lymphadenopathy: diagnostic yield of transbronchial mediastinal lymph node biopsy with CT fluoroscopic guidance-initial experience

PURPOSE

To determine whether the use of computed tomographic (CT) fluoroscopy to guide transbronchial needle aspiration (TBNA) of mediastinal lymph nodes can improve the diagnostic yield.

MATERIALS AND METHODS

CT fluoroscopy was used to guide TBNA in 12 consecutive patients with mediastinal lymphadenopathy who had previously undergone nondiagnostic conventional TBNA. CT fluoroscopy was used to confirm the location of the biopsy needle by using a "quick-check" technique (ie, fluoroscopy was performed sparingly after needle insertion). The location of each needle, the total procedural and fluoroscopic times, and any complications were recorded.

RESULTS

All CT fluoroscopic procedures were performed in less than 1 hour, and a tissue diagnosis was established in all patients. Eighteen lymph nodes with a diameter of 0.8-2.4 cm were sampled with 116 needle passes. CT fluoroscopy documented inadequate positioning in 48 of the 116 (41.3%) needle passes. Eighteen (15.5%) needles did not fully penetrate the tracheobronchial tree. Six needles (5.2%) were placed into the great vessels. Malignant disease was diagnosed in nine patients, and benign disease was diagnosed in three. The mean fluoroscopic exposure time was 20.5 seconds +/- 12.7. No pneumothoraces or substantial hemorrhage were observed.

CONCLUSION

CT fluoroscopic guidance for TBNA procedures is a safe and efficient means of providing diagnostic material and should be considered for patients who have previously undergone nondiagnostic blinded TBNA.

Survival of patients with resected N2 non-small-cell lung cancer: evidence for a subclassification and implications

PURPOSE

Patients who suffer from non-small-cell lung cancer (NSCLC) with ipsilateral mediastinal lymph node involvement (N2) belong to a heterogeneous subgroup of patients. We analyzed the prognosis of patients with resected N2 NSCLC to propose homogeneous patient subgroups.

PATIENTS AND METHODS

The present study comprised 702 consecutive patients from six French centers who underwent surgical resection of N2 NSCLC. Initially, two groups of patients were defined: patients with clinical N2 (cN2) and those with minimal N2 (mN2) disease were patients in whom N2 disease was and was not detected preoperatively at computed tomographic scan, respectively.

RESULTS

The median duration of follow-up was 52 months (range, 18 to 120 months). A multivariate analysis using Cox regression identified four negative prognostic factors, namely, cN2 status (P <. 0001), involvement of multiple lymph node levels (L2+; P <.0001), pT3 to T4 stage (P <.0001), and no preoperative chemotherapy (P <. 01). For patients treated with primary surgery, 5-year survival rates were as follows: mN2, one level involved (mN2L1, n = 244): 34%; mN2, multiple level involvement (mN2L2+, n = 78): 11%; cN2L1 (n = 118): 8%; and cN2L2+ (n = 122): 3%. When only patients with mN2L1 disease were considered, the site of lymph node involvement according to the American Thoracic Society numbering system had no prognostic significance (P =.14). Preoperative chemotherapy was associated with a better prognosis for those with cN2 (P <.0001). Five-year survival rates were 18% and 5% for cN2 patients treated with and without preoperative chemotherapy, respectively.

CONCLUSION

This study has identified homogeneous N2 NSCLC prognostic subgroups and suggests different therapeutic approaches according to the subgroup profile.

Semi-invasive and invasive procedures for the diagnosis and staging of lung cancer. II. Bronchoscopic and surgical procedures

Each of the various techniques used for the diagnosis and staging of lung cancer has its advantages and limitations (Table 1). Imaging has a major role in guiding these procedures and deciding which of them is most appropriate in a given clinical setting. A CT examination by which the size and location of the parenchymal lesion and the presence and location of enlarged lymph nodes can be determined is a prerequisite for all sampling procedures. As a general rule, when attempting to diagnose a solitary pulmonary nodule or mass, central lesions are more easily approached by the bronchoscopic route, whereas a transthoracic route is preferred for peripheral lesions. Bronchoscopy is often performed using fluoroscopic guidance, and the recently developed CT fluoroscopy and endoscopic ultrasound have the potential to facilitate transbronchial needle aspiration. A recent advent in imaging of lung cancer has been the introduction of positron emission tomography to the diagnostic work-up of lung cancer. Although this technique has been shown to be highly accurate in determining the malignant or benign nature of lesions, it does not enable histologic diagnosis. In each case, the most appropriate diagnostic procedure should be tailored to suit the specific requirements determined by the characteristics of the disease process, institutional availability of the various diagnostic procedures, and patient preferences, when possible.

Surgical management of early stage lung cancer

For patients with lung cancer, the greatest hope for cure rests with patients with early stage disease. Surgery has been the standard of care for this group with the best 5-year survival of only 65% being achieved in patients with earliest pathologic Stage IA disease. Using strategies gained from the management of patients with advanced disease, clinicians are investigating the use of perioperative chemotherapy and radiotherapy to improve survival. In addition, biologic and molecular markers are being evaluated to assist in predicting prognosis and to identify those patients at increased risk for recurrent disease. Postoperative surveillance of patients using helical computed tomography (CT) scanning is being investigated to detect early recurrences and second primary lesions. With such treatment and management plans on the horizon, the prognosis of patients with early stage non-small cell lung cancer (NSCLC) may be improved.

Lung cancer

Lung cancer remains a major worldwide health problem, accounting for more than a sixth of cancer deaths. The proportion of cancers that are adenocarcinomas is increasing in North America and to some degree in Europe, leading to a changing clinical picture characterised by early development of metastases. Newer diagnostic techniques have allowed for more accurate tumour staging and treatment planning. In patients with non-small-cell cancer, surgical resection offers substantial cure rates in early-stage cases. Combined chemotherapy plus radiation therapy has clearly improved the treatment results for patients with locally advanced cancers, and patients with metastatic disease are now candidates for newer chemotherapy regimens with more favourable results than in the past. Small-cell lung cancer is highly responsive to chemotherapy, and recent advances in radiation therapy have improved the prospects for long survival. New techniques for screening, and innovative approaches to both local and systemic treatment offer hope for substantial progress against this disease in the near future.

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.

Mathematical model of fluorescence endoscopic image formation

We present a mathematical model that describes the spatial distribution of photons in fluorescence endoscopic images, resulting in expressions for image signal-to-noise ratio and resolution. This model was applied to quantitative analysis of fluorescence images collected from human colonic mucosa with a fiber-optic and an electronic endoscope. It provides a tool for the design of fluorescence endoscopic imaging systems and for extraction of quantitative information about image features. The results apply generally to endoscopic imaging of remote structures in biological and industrial settings, in which light of weak intensity such as fluorescence as well as reflected white light is used.