Metabolic staging of lung cancer

Linear EBUS in staging non-small cell lung cancer and diagnosing benign diseases

As an evolving technique, linear endobronchial ultrasound is becoming the first choice and standard of care not only to diagnose the malignant and benign mediastinal lesions but also to stage non-small cell lung cancer. Lung cancer is the leading cause of cancer-related mortality in both men and women. The disease causes more death compared with colorectal, breast, and prostate cancers combined in the United States. Staging of lung cancer determines the prognosis. The type of lung cancer has changed in the past few decades. The frequency of adenocarcinoma has increased, whereas squamous cell carcinoma now is less frequent. Determining the cell type and its molecular characteristics allow targeted treatments in adenocarcinoma. The diagnosis of indeterminate mediastinal lymph nodes or masses and staging lung cancer might be challenging. This article will review the principles and clinical utility of endobronchial ultrasound in mediastinal lesions.

Efficacy of convex probe endobronchial ultrasound (CP-EBUS) assisted transbronchial needle aspiration for mediastinal staging in non-small cell lung cancer cases with mediastinal lymphadenopathy

BACKGROUND AND OBJECTIVE

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a sampling method for the patients with non-small cell lung cancer (NSCLC) that have enlarged mediastinal lymph nodes that are detected with computed tomography (CT). We aimed to investigate the value of EBUS-TBNA in sampling enlarged mediastinal lymph nodes in the patient with NSCLC.

PATIENTS AND METHOD

From January 2007 to May 2009, patients were diagnosed NSCLC with CT scans showing enlarged lymph nodes (node >1 cm) or a positron emission tomography (PET/CT) finding of the mediastinum underwent EBUS-TBNA.

RESULTS

EBUS-TBNA was successfully performed in all 52 patients (mean age, 52 years; 45 men) from 93 mediastinal lymph nodes. EBUS detected lymph node metastasis in 40 patients (77%). 12 patients (23%) with negative lymph node samples were underwent mediastinoscopy. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBUS-TBNA in the detection of mediastinal metastasis were 95 %, 100%, 100%, 83%, and 96%, respectively. EBUS-TBNA was uneventful, and there were no complications.

CONCLUSION

EBUS-TBNA is an effective, safe and minimally invasive procedure following PET/CT or CT scanning in the mediastinal staging of potentially operable NSCLC.

Transbronchial needle aspiration under direct endobronchial ultrasound guidance of PET-positive isolated mediastinal adenopathy in patients with previous malignancy

BACKGROUND

The diagnostic accuracy of endobronchial ultrasound-guided transbronchial needle aspiration for the diagnosis of isolated mediastinal lymphadenopathy in patients with previous malignancy is not well defined. Positron emission tomography scanning has been proven to be a significant advance, but false-positive results are common. The purpose of this prospective and controlled study was to assess the yield of endobronchial ultrasound-guided transbronchial needle aspiration to reveal mediastinal lymph node metastases in patients with previous malignancy and possible mediastinal involvement on computed tomography and positron emission tomography.

METHODS

Seventy-three lymph nodes were tested by transbronchial needle aspiration on 48 consecutive patients, each patient underwent to mediastinoscopy or thoracoscopy immediately after needle aspiration for histological confirmation. A cytological sampling adequate for diagnosis was obtained in 45 patients (93.7%); the three cases of inadequate sampling resulted as negative for cancer.

RESULTS

The endobronchial ultrasound guided transbronchial needle aspiration gives a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 97.4%, 100%, 100%, 87.5%, and 97.7% respectively. Disease prevalence was 84.4%. All the endoscopic procedures were well tolerated and no immediate complications were recorded.

CONCLUSIONS

Transbronchial needle aspiration under endobronchial ultrasound guidance is a valuable technique for cytological diagnosis of isolated mediastinal lymphadenopathy in patients with history of malignancy. Tissue sampling by invasive surgical procedures (mediastinoscopy or thoracoscopy) remains mandatory in case of inadequate or negative transbronchial needle aspiration cytology.

Nutritional channels in breast cancer

Breast cancers increase glucose uptake by increasing expression of the facilitative glucose transporters (GLUTs), mainly GLUT1. However, little is known about the relationship between GLUT1 expression and malignant potential in breast cancer. In this study, expression and subcellular localization of GLUT1 was analysed in vivo in breast cancer tissue specimens with differing malignant potential, based on the Scarff-Bloom-Richardson (SBRI, II, III) histological grading system, and in vitro in the breast cancer cell lines, MDA-MB-468 and MCF-7, and in MDA-MB-468 cells grown as xenografts in nude athymic BALB/c male mice. In situ hybridization analyses demonstrated similar levels of GLUT1 mRNA expression in tissue sections from breast cancers of all histological grades. However, GLUT1 protein was expressed at higher levels in grade SBRII cancer, compared with SBRI and SBRIII, and associated with the expression of the proliferation marker PCNA. Immunolocalization analyses in SBRII cancers demonstrated a preferential localization of GLUT1 to the portions of the cellular membrane that faced neighbouring cells and formed ‘canaliculi-like structures’, that we hypothesize could have a potential role as ‘nutritional channels’. A similar pattern of GLUT1 localization was observed in confluent cultures of MDA-MB-468 and MCF-7, and in MDA-MB-468 cells grown as xenografts, but not in the normal breast epithelial cell line HMEC. However, no relationship between GLUT1 expression and malignant potential of human breast cancer was observed. Preferential subcellular localization of GLUT1 could represent a physiological adaptation of a subset of breast cancer cells that form infiltrative tumours with a nodular growth pattern and that therefore need a major diffusion of glucose from blood vessels.

Prevalence of occult metastatic disease in patients undergoing 18F-FDG PET for primary diagnosis or staging of lung carcinoma and solitary pulmonary nodules

BACKGROUND

Accurate staging of lung cancer is essential in determining the most appropriate management plan, as detection of occult metastasis can significantly alter management.

AIMS

The aims of this study are to determine the prevalence of occult metastasis in patients undergoing 2-(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET) for evaluation of suspected/proven lung carcinoma and correlate pre-PET TNM stage with prevalence of metastasis.

METHODS

FDG-PET, which identified patients with metastasis on institutional database, was re-evaluated by a nuclear medicine physician blinded to clinical information. The confidence level of metastasis was scored on a 5-point scale, with a score of >/=4 considered positive.

RESULTS

There were 67 of 645 (10%) patients identified with suspected occult metastasis on FDG-PET. Twelve patients scoring </=3 were excluded. Prevalence of occult metastasis was 10/156 (6%) in solitary pulmonary nodules (SPN); 22/319 (7%) and 23/170 (14%) in proven and suspected lung cancer, respectively. Positive predictive value of FDG-PET for metastasis was 8/10 (80%) in solitary pulmonary nodules, 14/20 (70%) and 17/21 (81%) in proven and suspected lung cancer, respectively. (18)F-FDG-avid lesions classified as false positives were patients with cholelithiasis, rib fractures and those with equivocal/negative bone scans or computed tomography on follow up. There was a higher incidence of true positive occult metastasis in patients in all stages of disease, particularly stage III disease.

CONCLUSION

(18)F-FDG PET is predictive for occult metastatic disease in patients with solitary pulmonary nodules and proven or suspected lung cancer and is more likely to be present in all stages, particularly in stage III. PET findings should be actively pursued with correlative investigation to identify benign pathology in patients who remain candidates for curative treatment.

Comparison of endobronchial ultrasound, positron emission tomography, and CT for lymph node staging of lung cancer

STUDY OBJECTIVES

To perform a prospective comparison of direct real-time endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA), positron emission tomography (PET), and thoracic CT for detection of mediastinal and hilar lymph node metastasis in patients with lung cancer considered for surgical resection.

DESIGN

Prospective patient enrollment.

SETTING

University teaching hospital.

PATIENTS

One hundred two potentially operable patients with proven (n = 96) or radiologically suspected (n = 6) lung cancer were included in the study.

INTERVENTIONS

CT, PET, and EBUS-TBNA were performed prior to surgery for the evaluation of mediastinal and hilar lymph node metastasis. The convex probe EBUS, which is integrated with a convex scanning probe on its tip, was used for EBUS-TBNA. Surgical histology was used as the "gold standard" to confirm lymph node metastasis unless patients were found inoperable for N3 or extensive N2 disease proven by EBUS-TBNA.

MAIN RESULTS

EBUS-TBNA was successfully performed in all 102 patients (mean age, 67.8 years) from 147 mediastinal and 53 hilar lymph nodes. EBUS-TBNA proved malignancy in 37 lymph node stations in 24 patients. CT identified 92 positive lymph nodes, and PET identified 89 positive lymph nodes (4 supraclavicular, 63 mediastinal, 22 hilar). The sensitivities of CT, PET, and EBUS-TBNA for the correct diagnosis of mediastinal and hilar lymph node staging were 76.9%, 80.0%, and 92.3%, respectively; specificities were 55.3%, 70.1%, and 100%, and diagnostic accuracies were 60.8%, 72.5%, and 98.0%. EBUS-TBNA was uneventful, and there were no complications.

CONCLUSION

Compared to CT and PET, EBUS-TBNA has a high sensitivity as well as specificity for mediastinal and hilar lymph node staging in patients with lung cancer. EBUS-TBNA should be considered for evaluation of the mediastinum early in the staging process of lung cancer.

Whole-body PET/CT: spectrum of physiological variants, artifacts and interpretative pitfalls in cancer patients

Accurate diagnosis and staging in oncology is essential in the evaluation of cancer for optimal patient outcome. Conventional imaging techniques, such as computed tomography (CT), rely basically on morphological changes for tumour detection. Clinical experience, however, shows that morphological criteria may be misleading and may not always allow differentiation between benign and malignant lesions. Positron emission tomography (PET) with [F]fluorodeoxyglucose (FDG) is rapidly gaining a critical role in the clinical evaluation of patients with cancer. However, PET lacks anatomical landmarks for topographic orientation, and identification of abnormal glucose metabolic activity in regions close to organs with variable physiological FDG uptake can be difficult. To overcome these difficulties, a combined PET/CT scanner that acquires both functional (PET) and CT images has been recently developed. Proper interpretation of PET (and PET/CT) images requires a thorough understanding of the normal physiological distribution of FDG in the body, along with a knowledge of frequently encountered physiological variations in FDG distribution, and recognition of non-malignant causes of FDG uptake that can be confused with a malignant neoplasm. In addition, because of the utilization of the CT transmission information for the correction of the attenuation of the PET emission data (and for the reconstruction of the PET images), some artifacts may be generated. As a consequence, CT based attenuation correction of PET images may result in erroneous PET/CT interpretations. The aim of this extensively illustrated paper is to demonstrate several potential pitfalls encountered during the interpretation of PET/CT images so that radiologists can avoid false positive diagnoses and recognize inherently non-specific findings on PET/CT images obtained for oncological diagnosis.

Etiology of solitary extrapulmonary positron emission tomography and computed tomography findings in patients with lung cancer

PURPOSE

The aim of this prospective study was to assess the incidence and the nature of solitary extrapulmonary [18F] fluorodeoxyglucose (FDG) accumulations in patients with non-small-cell lung cancer (NSCLC) staged with integrated positron emission tomography and computed tomography (PET/CT) and to evaluate the impact on management.

PATIENTS AND METHODS

A total of 350 patients with NSCLC underwent whole-body PET/CT imaging. All solitary extrapulmonary FDG accumulations were evaluated by histopathology, further imaging, or clinical follow-up.

RESULTS

PET/CT imaging revealed extrapulmonary lesions in 110 patients. In 72 patients (21%), solitary lesions were present. A diagnosis was obtained in 69 of these patients, including 37 (54%) with solitary metastases and 32 (46%) with lesions unrelated to the lung primary. Histopathologic examinations of these 32 lesions revealed a second clinically unsuspected malignancy or a recurrence of a previous diagnosed carcinoma in six patients (19%) and a benign tumor or inflammatory lesion in 26 patients (81%). The six malignancies consisted of carcinoma of the breast in two patients, and carcinoma of the orbit, esophagus, prostate, and non-Hodgkin's lymphoma in one patient each. Benign tumors and inflammatory lesions included eight colon adenomas, four Warthin's tumors, one granuloma of the lower jaw, one adenoma of the thyroid gland, one compensatory muscle activity due to vocal chord palsy, two occurrences of arthritis, three occurrences of reflux esophagitis, two occurrences of pancreatitis, two occurrences of diverticulitis, one hemorrhoidal inflammation, and one rib fracture.

CONCLUSION

Solitary extrapulmonary FDG accumulations in patients with newly diagnosed lung cancer should be analyzed critically for correct staging and optimal therapy, given that up to half of the lesions may represent unrelated malignancies or benign disease.

Positron emission tomography with selected mediastinoscopy compared to routine mediastinoscopy offers cost and clinical outcome benefits for pre-operative staging of non-small cell lung cancer

PURPOSE

(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is an important staging procedure in patients with non-small cell lung cancer (NSCLC). We aimed to demonstrate, through a decision tree model and the incorporation of real costs of each component, that routine FDG-PET imaging as a prelude to curative surgery will reduce requirements for routine mediastinoscopy and overall hospital costs.

METHODS

A decision tree model comparing routine whole-body FDG-PET imaging to routine staging mediastinoscopy was used, with baseline variables of sensitivity, specificity and prevalence of non-operable and metastatic disease obtained from institutional data and a literature review. Costings for hospital admissions for mediastinoscopy and thoracotomy of actual patients with NSCLC were determined. The overall and average cost of managing patients was then calculated over a range of FDG-PET costs to derive projected cost savings to the community.

RESULTS

The prevalence of histologically proven mediastinal involvement in patients with NSCLC presenting for surgical assessment at our institution is 20%, and the prevalence of distant metastatic disease is 6%. Based on literature review, the pooled sensitivity and specificity of FDG-PET for detection of mediastinal spread are 84% and 89% respectively, and for mediastinoscopy, 81% and 100%. The average cost of mediastinoscopy for NSCLC in our institution is 4,160 AUD, while that of thoracotomy is 15,642 AUD. The cost of an FDG-PET scan is estimated to be 1,500 AUD. Using these figures and the decision tree model, the average cost saving is 2,128 AUDper patient.

CONCLUSION

Routine FDG-PET scanning with selective mediastinoscopy will save 2,128 AUD per patient and will potentially reduce inappropriate surgery. These cost savings remain robust over a wide range of disease prevalence and FDG-PET costs.

PET imaging for suspected residual tumour or thoracic recurrence of non-small cell lung cancer after pneumonectomy

F-18 fluorodeoxyglucose-positron emission tomography (PET) was investigated in patients with suspected residual disease or intrathoracic recurrence after pneumonectomy. Patients were identified from a prospective database. Impact of PET on staging and patient management was assessed. Clinical outcome was used to assess appropriateness of management. PET was performed in 17 cases, either post-operatively (n = 8), or later for suspected recurrence (n = 9) in patients with good performance status and without extensive disease on conventional imaging. PET changed treatment in 10 cases (59%). In five patients (29%), PET changed treatment intent (curative versus non-curative) from radical radiotherapy (RT) to palliative RT (n = 1), or observation or supportive care (n = 3), or from palliative to radical RT (n = 1). In a further patient with unexplained pain, PET appropriately showed no evidence of disease. In additional five cases (29%), PET influenced choice of RT dose and the use of concurrent chemotherapy (n = 3) or target volume (n = 2). Patients without tumour or with limited disease on PET had favourable outcomes whereas those with extensive disease suffered early tumour progression. PET was discordant with conventional assessment in >50% of cases. PET may be valuable after pneumonectomy if the patient is being considered for adjuvant or salvage radiotherapy although specificity may be reduced due to post-operative inflammatory changes.

Surgical exploration of the mediastinum: mediastinoscopy and intraoperative staging

Lung resection remains the therapy of choice offering the greatest potential for cure in non-spread lung cancer. Prognostic importance of lymph-node involvement has been underlined by several studies. So, exploration of the mediastinum is of major importance for defining the therapeutic strategy in a possibly curative setting. Pre-resectional exploration of the mediastinal lymph-nodal status is mandatory to define tumour stage exactly and establish specific therapy. Cervical mediastinoscopy is the primary diagnostic procedure and remains the gold standard in invasive surgical staging. Complementary, parasternal mediastinoscopy, extended mediastinoscopy, and video-assisted thoracoscopy may be performed. These techniques allow accurate assessment of mediastinal lymph-node involvement, resulting in an appropriate judgement as to resectability and possible treatment options. Different techniques are established for intraoperative exploration and staging. In terms of curative surgery of lung cancer we demand accurate staging which is achieved by systematic and complete Lymph-node dissection. So, individually and dependent on primary tumour site, accurate mediastinal staging of Lung cancer should be performed in combination with definitive lung resection.

Randomized controlled trial of the role of positron emission tomography in the management of stage I and II non-small-cell lung cancer

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 standard diagnostic work-up before decisions about surgical management of NSCLC. The resource implications of its widespread use in staging NSCLC are significant.

METHODS

A randomized 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 randomly 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.

The tumor suppressor p53 down-regulates glucose transporters GLUT1 and GLUT4 gene expression

Tumorigenesis is associated with enhanced cellular glucose uptake and increased metabolism. Because the p53 tumor suppressor is mutated in a large number of cancers, we evaluated whether p53 regulates expression of the GLUT1 and GLUT4 glucose transporter genes. Transient cotransfection of osteosarcoma-derived SaOS-2 cells, rhabdomyosarcoma-derived RD cells, and C2C12 myotubes with GLUT1-P-Luc or GLUT4-P-Luc promoter-reporter constructs and wild-type p53 expression vectors dose dependently decreased both GLUT1 and GLUT4 promoter activity to approximately 50% of their basal levels. PG(13)-Luc activity, which was used as a positive control for functional p53 expression, was increased up to approximately 250-fold by coexpression of wild-type p53. The inhibitory effect of wild-type p53 was greatly reduced or abolished when cells were transfected with p53 with mutations in amino acids 143, 248, or 273. A region spanning -66/+163 bp of the GLUT4 promoter was both necessary and sufficient to mediate the inhibitory effects of p53. Furthermore, in vitro translated p53 protein was found to bind directly to two sequences in that region. p53-DNA binding was completely abolished by excess unlabeled probe but not by nonspecific DNA and was super-shifted by the addition of an anti-p53 antibody. Taken together, our data strongly suggest that wild-type p53 represses GLUT1 and GLUT4 gene transcription in a tissue-specific manner. Mutations within the DNA-binding domain of p53, which are usually associated with malignancy, were found to impair the repressive effect of p53 on transcriptional activity of the GLUT1 and GLUT4 gene promoters, thereby resulting in increased glucose metabolism and cell energy supply. This, in turn, would be predicted to facilitate tumor growth.

PET scanning in lung cancer: current status and future directions

Positron emission tomography (PET) represents a dramatic advance in the imaging of lung cancer. It is valuable for the diagnosis, staging, prognosis, and restaging of disease, and is most useful in patients considered for potentially curative therapy for non-small-cell lung cancer (NSCLC). In this work the current status and potential future applications of PET scanning in lung cancer are discussed. The relevant literature is also discussed, with an emphasis on studies with clinical applicability. Most of these studies involved the use of 18F-fluorodeoxyglucose (FDG). Numerous studies of the use of PET to assess undiagnosed pulmonary nodules have reported significant improvements in accurate diagnosis or exclusion of malignancy compared to conventional structural imaging alone. All of these studies, including metaanalysis, have shown that PET is more accurate than CT-based structural imaging in staging the mediastinum in surgical candidates. PET may have value in radiotherapy planning, and PET-based staging more accurately predicts survival in radiotherapy-treated patients than conventional staging. The rate of unsuspected distant metastasis detection in stage III disease exceeds 20%. PET also facilitates an accurate assessment of response in patients treated with radical chemoradiation or neoadjuvant therapy prior to surgery. PET has rapidly become an indispensable part of the evaluation of patients with potentially curable lung cancer; however, more work is required to define its role.

Endoscopic ultrasound, positron emission tomography, and computerized tomography for lung cancer

Staging of patients with lung cancer to determine operability is intended to efficiently limit futile thoracotomies without denying possibly curative surgery. Currently available staging tests are imperfect alone and in combination. Imaged suspected metastases often require tissue confirmation before surgery can be denied. Endoscopic ultrasound (EUS) may help identify inoperable patients by providing tissue proof of inoperability in a single staging test, with similar sensitivity for identifying inoperable patients as other staging tests. Therefore, we compared computed tomography, positron emission tomography (PET), and EUS with fine-needle aspiration under conscious sedation, each test interpreted blinded with respect to the other tests, for identifying inoperable patients in a consecutive cohort of 79 potentially operable patients with suspected or proven lung cancer. An economic analysis was also performed. Thirty-nine patients were found inoperable (a 40th patient's inoperability was missed by all preoperative staging tests). The sensitivity of computerized tomography was 43%. PET and EUS each had similar sensitivities (68 and 63%, respectively) and similar negative predictive values (64 and 68%, respectively), but EUS's superior specificity (100 vs. 72% for PET) and considerably lower expense means it may be preferred to PET early in staging to identify inoperable patients.

Current status of positron emission tomography in oncology

Positron emission tomography (PET) has emerged as a powerful diagnostic tool in oncology patients. There is evidence of the superior utility over conventional imaging methods of the principal PET tracer 18F-fluoro-2-deoxy-glucose in the staging of a range of cancers and monitoring disease recurrence, as well as changing patient management to more appropriate therapy. The methods for evaluating the evidence for PET remain complex, particularly as the standard evidence-based approach of randomized controlled trials is not generally applicable to imaging technologies. PET has the potential to dramatically improve our ability to manage patients with cancer and is also making major contributions to the development of new therapies.

FDG-PET imaging in the management of non-small-cell lung cancer

Lung cancer is currently the leading cause of cancer-related death in both men and women in most Western countries. Tumour stage is the strongest prognostic factor and the most important parameter guiding treatment decision making. Metabolic positron emission tomography imaging with fluorodeoxyglucose (FDG-PET) has consistently proved superior to conventional imaging for staging of non-small-cell lung cancer and provides information of greater prognostic significance than can be obtained using conventional approaches. FDG-PET has been approved in the USA, Germany and the UK as a basic and invaluable tool in the management of lung cancer.

[A man with lung cancer and tuberculosis: a false positive by positron emission tomography and its clinical repercussions]

Positron emission tomography (PET) has come to play an increasingly important role in the evaluation of lung cancer patients, both for diagnostic staging and post-treatment follow-up. As is true for other techniques, PET gives false positive and negative results. False positives have been described in the presence of certain active infections and inflammatory lesions, such as tuberculous granulomas, coccidioidomycosis, aspergillosis and histoplasmosis. We report the case of a man whose PET gave a false positive and in whom both lung cancer and tuberculosis were present. A radical change in therapeutic approach was required, making the case interesting.

Impact of FDG-labelled positron emission tomography imaging on the management of non-small-cell lung cancer

Lung cancer is currently the leading cause of cancer-related death in both men and women in most Western countries. Although 5-year survival rates have doubled from 1960s, they are low compared with survival rates for other cancer types. Tumour stage is the strongest prognostic factor and the most important parameter that guides treatment decision making. Metabolic imaging with fluorodeoxyglucose-labelled positron emission tomography (FDG-PET) has proved superior to conventional imaging for staging of non-small-cell lung cancer. This new imaging modality permits more accurate planning of treatment with surgery and radiotherapy and provides information of greater prognostic significance than what can be obtained with conventional approaches. FDG-PET has been approved in the USA and the UK as a basic and invaluable tool in the management of lung cancer. This paper reviews current trends in clinical practice on the applications of FDG-PET in the management of non-small-cell lung cancer.

Treatment of stage I and II non-small-cell lung cancer

BACKGROUND

The appropriate staging and treatment of patients with stage I and II non-small-cell lung cancer (NSCLC) are important in that the potential for a lost curative opportunity in this population is greater than for those presenting with advanced NSCLC.

METHODS

Treatment options -- surgery, radiation therapy, and chemotherapy -- for stage I and II NSCLC are reviewed, and the impact of newer staging modalities on patient survival is discussed, including altering both the lead-time and clinicopathologic stage biases that exist in the diagnosis and treatment of NSCLC. Some predictions are also made regarding how that standard may change for clinicians in the near future, and methods for further improvements in posttreatment survival in this group are discussed.

RESULTS

Whenever possible, patients with early-stage NSCLC should be treated with surgical resection. Patients for whom resection is not an option may benefit from radiation as definitive therapy. Positive results with neoadjuvant chemotherapy have led to an ongoing randomized trial (Intergroup S9900) to compare surgery alone to neoadjuvant chemotherapy plus surgery.

CONCLUSIONS

Staging bias may affect the overall low survival of early-stage NSCLC. However, true stage-specific survival may improve with newer imaging modalities. Future advances, including closed transthoracic radiation, thermal ablative therapy techniques, and gene therapy, may supplant the need to surgically resect these tumors to achieve local control.

The fusion of anatomic and physiologic imaging in the management of patients with cancer

Imaging is of major clinical importance in the noninvasive evaluation and management of patients with cancer. Computed tomography (CT) and other anatomic imaging modalities, such as magnetic resonance imaging (MRI) or ultrasound, have a high diagnostic ability by visualizing lesion morphology and by providing the exact localization of malignant sites. Nuclear medicine provides information on the function and metabolism of cancer. Over the last decade, there have been numerous attempts to combine data obtained from different imaging techniques. Fused images of nuclear medicine and CT (or to a lesser extent, MRI) overcome the inherent limitations of both modalities. Valuable physiologic information benefits from a precise topographic localization. Coregistered data have been shown to be useful in the evaluation of patients with cancer at diagnosis and staging, in monitoring the response to treatment, and during follow up, for early detection of recurrence. Time-consuming and difficult realignment and computation for fusion of independent studies have, until now, limited the use of registration techniques to pilot studies performed in a small number of patients. The development of the new technology of single photon emission computed tomography/CT and positron emission tomography/CT that allows for combined functional and anatomic data acquisition has the potential to make fusion an everyday clinical tool.

Solitary pulmonary nodules: new wine in old bottles

Management strategies for solitary pulmonary nodules have evolved slowly during the last 50 years. The goal has always been to facilitate the resection of malignant nodules without undue delay and to avoid exploratory thoracotomy for benign nodules. In the past decade, the development of reliable nodule enhancement techniques has replaced or become incorporated within some of the older strategies. In addition, some of the well-accepted concepts of the past have been undergoing critical reviews and reevaluations. These concepts include retrospective study of nodule diameters to recognize 2-year stability, the use of a watch-and-wait strategy using standard chest radiographs for prospective determination of stability, detection and recognition of calcification patterns on standard chest radiographs, and computed tomography for mediastinal staging.

Clinical role of positron emission tomography in oncology

Positron emission tomography (PET) is now in routine use in oncology, through the success of metabolic imaging, mainly with fluorodeoxyglucose (FDG). Clear benefit is obtained with FDG PET in the assessment of patients with recurrent or residual disease, especially colorectal cancer and lymphoma. Preoperative staging of non-small-cell lung cancer with FDG PET is of proven benefit. Staging and restaging of patients with melanoma of stage II or greater is useful, and FDG PET has also been successfully used to investigate single pulmonary nodules. Tumour grading has been assessed, especially in the brain, but an important and emerging indication is the evaluation of tumour response with PET. Rapid decline of FDG uptake has been observed in responsive cancers. Further advances are being made with other fluorine-18-labelled and generator-based PET tracers, the only ones that can be used in units without dedicated cyclotrons.

Current status of positron emission tomography in oncology

Positron emission tomography (PET) has emerged as a powerful diagnostic tool in oncology patients. There is evidence of the superior utility over conventional imaging methods of the principal PET tracer 18F-fluoro-2-deoxy-glucose in the staging of a range of cancers and monitoring disease recurrence, as well as changing patient management to more appropriate therapy. The methods for evaluating the evidence for PET remain complex, particularly as the standard evidence-based approach of randomized controlled trials is not generally applicable to imaging technologies. PET has the potential to dramatically improve our ability to manage patients with cancer and is also making major contributions to the development of new therapies.