Lung cancer staging and management: comparison of contrast-enhanced and nonenhanced helical CT of the thorax

The influence of contrast enhancement and experience of observers on the assessment of mediastinal lymph nodes in sarcoidosis patients

Purpose

The aim of this study was to assess the influence of contrast enhancement (CE) and experience of observers on the assessment of chest lymph nodes in patients with sarcoidosis.

Material and methods

A retrospective analysis of chest lymph nodes on computed tomography (CT) examinations, including CE and non-contrast-enhanced (non-CE) phase, was performed on 40 patients with proven diagnosis of sarcoidosis. Phases were separated, anonymized, and randomized. The assessment was performed by 5 observers: 2 general radiologists, 2 residents, and a senior chest CT expert.

Results

There were no significant differences between radiologists and residents, apart from the determination of the 4R node short diameter on CE images. Agreement between the reference observer and both residents and specialists was equally high, without any significant difference in the assessment all chest nodes and hilar nodes, and between non-CE and CE images. There was a significant difference between all observers in the determination of the largest 4R node short diameter on non-CE images, but not on CE images. The number of affected node levels was found to be significantly higher when evaluated on CE images than on non-CE images. Compared to CE images, non-CE computed tomography has sensitivity of 0.94-1.00 and specificity of 0.98-1.00, depending on the observer.

Conclusions

The application of contrast medium has a limited impact on the quality of assessment of the chest lymph nodes in patients with sarcoidosis, regardless of the experience of the observer.

Management of Early-Stage Resected Non-Small Cell Lung Cancer: Consensus Statement of the Lung cancer Consortium

BACKGROUND

Management of early-stage non-small cell lung cancer (ES-NSCLC) has evolved over the last few years especially in terms of work-up and the use of systemic therapy. This consensus statement was developed to present updated guidelines for the management of this disease.

METHODS

Multidisciplinary team (MDT) of lung cancer experts convened to discuss a set of pertinent questions with importance relevance to the management of ES-NSCLC. ES-NSCLC includes stages I, II and resected stage III. The experts included consultants in chest imaging, thoracic surgery, radiation oncology, and medical oncology. Questions were discussed in virtual meetings and then a written manuscript with supporting evidence was drafted, reviewed, and approved by the team members.

RESULTS

The Consensus Statement included 9 questions addressing work-up and management of ES-NSCLC. Background information and literature review were presented for each question followed by specific recommendations to address the questions by oncology providers. The Statement was endorsed by various oncology societies in the Gulf region.

CONCLUSION

The Consensus Statement serves as a guide for thoracic MDT members in the management of ES-NSCLC. Adaptation of these to the local setting is dictated usually by available resources and expertise, however, all efforts should be excreted to provide the optimal care to all patients whenever possible.

Dosimetric study of Hounsfield number correction effect in areas influenced by contrast product in lungs case

BACKGROUND

The aim of the study was dosimetric effect quantification of exclusive computed tomography (CT) use with an intravenous (IV) contrast agent (CA ), on dose distribution of 3D-CRT treatment plans for lung cancer. Furthermore, dosimetric advantage investigation of manually contrast-enhanced region overriding, especially the heart.

MATERIALS AND METHODS

Ten patients with lung cancer were considered. For each patient two planning CT sets were initially taken with and without CA. Treatment planning were optimized based on CT scans without CA. All plans were copied and recomputed on scans with CA. In addition, scans with IV contrast were copied and density correction was performed for heart contrast enhanced. Same plans were copied and replaced to undo dose calculation errors that may be caused by CA. Eventually, dosimetric evaluations based on dose volume histograms (DVHs) of planning target volumes (PTV) and organs at-risk were studied and analyzed using the Wilcoxon's signed rank test.

RESULTS

There is no statistically significant difference in dose calculation for the PTV maximum, mean, minimum doses, spinal cord maximum doses and lung volumes that received 20 and 30 Gy, between planes calculated with and without contrast scans (p > 0.05) and also for contrast scan, with manual regions overriding.

CONCLUSIONS

Dose difference caused by the contrast agent is negligible and not significant. Therefore, there is no justification to perform two scans, and using an IV contrast enhanced scan for dose calculation is sufficient.

Management guidelines for stage III non-small cell lung cancer

Management of stage III non- small cell lung cancer (NSCLC) is very challenging due to being a group of widely heterogeneous diseases that require multidisciplinary approaches with timely and coordinated care. The standards of care had significant changes over the last couple of years because of the introduction of consolidation therapy with checkpoint inhibitor following concurrent chemo-radiotherapy and the evolving new role of tyrosine kinase inhibitors in the adjuvant setting. The manuscript presents evidence-based recommendations for the workup, staging, treatment and follow up of the various subtypes of stage III NSCLC. The guidelines were developed by experts in various fields of thoracic oncology and guidelines development. The guidelines consider the sequence of interventions and the role of each discipline in the management of the disease taking into account the recent development and included required resources to help physicians provide better care.

Generation of Virtual Non-Contrast CT From Intravenous Enhanced CT in Radiotherapy Using Convolutional Neural Networks

Objective: To generate virtual non-contrast (VNC) computed tomography (CT) from intravenous enhanced CT through convolutional neural networks (CNN) and compare calculated dose among enhanced CT, VNC, and real non-contrast scanning.

Method: 50 patients who accepted non-contrast and enhanced CT scanning before and after intravenous contrast agent injections were selected, and two sets of CT images were registered. A total of 40 and 10 groups were used as training and test datasets, respectively. The U-Net architecture was applied to learn the relationship between the enhanced and non-contrast CT. VNC images were generated in the test through the trained U-Net. The CT values of non-contrast, enhanced and VNC CT images were compared. The radiotherapy treatment plans for esophageal cancer were designed, and dose calculation was performed. Dose distributions in the three image sets were compared.

Results: The mean absolute error of CT values between enhanced and non-contrast CT reached 32.3 ± 2.6 HU, and that between VNC and non-contrast CT totaled 6.7 ± 1.3 HU. The average CT values in enhanced CT of great vessels, heart, lungs, liver, and spinal cord were all significantly higher than those of non-contrast CT (p < 0.05), with the differences reaching 97, 83, 42, 40, and 10 HU, respectively. The average CT values of the organs in VNC CT showed no significant differences from those in non-contrast CT. The relative dose differences of the enhanced and non-contrast CT were −1.2, −1.3, −2.1, and −1.5% in the comparison of mean doses of planned target volume, heart, great vessels, and lungs, respectively. The mean dose calculated by VNC CT showed no significant difference from that by non-contrast CT. The average γ passing rate (2%, 2 mm) of VNC CT image was significantly higher than that of enhanced CT image (0.996 vs. 0.973, p < 0.05).

Conclusion: Designing a treatment plan based on enhanced CT will enlarge the dose calculation uncertainty in radiotherapy. This paper proposed the generation of VNC CT images from enhanced CT images based on U-Net architecture. The dose calculated through VNC CT images was identical with that obtained through real non-contrast CT.

Diagnostic accuracy of non-contrast abdominal CT scans performed as follow-up for patients with an established cancer diagnosis: a retrospective study

OBJECTIVES

To determine the accuracy and non-detection rate of cancer related findings (CRFs) on follow-up non-contrast-enhanced CT (NECT) versus contrast-enhanced CT (CECT) images of the abdomen in patients with a known cancer diagnosis.

METHODS

A retrospective review of 352 consecutive CTs of the abdomen performed with and without IV contrast between March 2010 and October 2014 for follow-up of cancer was included. Two radiologists independently assessed the NECT portions of the studies. The reader was provided the primary cancer diagnosis and access to the most recent prior NECT study. The accuracy and non-detection rates were determined by comparing our results to the archived reports as a gold standard.

RESULTS

A total of 383 CRFs were found in the archived reports of the 352 abdominal CTs. The average non-detection rate for the NECTs compared to the CECTs was 3.0% (11.5/383) with an accuracy of 97.0% (371.5/383) in identifying CRFs. The most common findings missed were vascular thrombosis with a non-detection rate of 100%. The accuracy for non-vascular CRFs was 99.1%.

CONCLUSION

Follow-up NECT abdomen studies are highly accurate in the detection of CRFs in patients with an established cancer diagnosis, except in cases where vascular involvement is suspected.

Imaging wisely: patient safety in CT

The past decade has seen a significant growth in diagnostic CT imaging as a direct result of the clinical value provided by CT imaging. At the same time, many new techniques and resources are now available to make CT imaging safe. This article presents the basics of CT dosimetry and their usage in clinical practices, methods to implement CT dose reduction, followed by a summary of legislation, and guidelines related to patient safety in diagnostic CT imaging. Also, CT radiation dose diagnostic reference levels from published regional and national surveys are reviewed and applied in a CT dose tracking and monitoring program.

Prospective study evaluating the use of IV contrast on IMRT treatment planning for lung cancer

PURPOSE

To investigate the impact of exclusively using intravenous (IV) contrast x-ray computed tomography (CT) scans on lung cancer intensity-modulated radiation therapy (IMRT) treatment planning.

METHODS

Eight patients with lung cancer (one small cell, seven nonsmall cell) scheduled to receive IMRT consented to acquisition of simulation CT scans with and without IV contrast. Clinical treatment plans optimized on the noncontrast scans were recomputed on contrast scans and dose coverage was compared, along with the γ passing rates.

RESULTS

IV contrast enhanced scans provided better target and critical structure conspicuity than the noncontrast scans. Using noncontrast scan as a reference, the median absolute/relative differences in mean, maximum, and minimum doses to the planning target volume (PTV) were -4.5 cGy/-0.09%, 41.1 cGy/0.62%, and -19.7 cGy/-0.50%, respectively. Regarding organs-at-risk (OARs), the median absolute/relative differences of maximum dose to heart was -13.3 cGy/-0.32%, to esophagus was -63.4 cGy/-0.89%, and to spinal cord was -16.3 cGy/-0.46%. The median heart region of interest CT Hounsfield Unit (HU) number difference between noncontrast and contrast scans was 136.4 HU (range, 94.2-161.8 HU). Subjectively, the regions with absolute dose differences greater than 3% of the prescription dose were small and typically located at the patient periphery and/or at the beam edges. The median γ passing rate was 0.9981 (range, 0.9654-0.9999) using 3% absolute dose difference/3 mm distance-to-agreement criteria. Overall, all evaluated cases were found to be clinically equivalent.

CONCLUSIONS

PTV and OARs dose differences between noncontrast and contrast scans appear to be minimal for lung cancer patients undergoing IMRT. Using IV contrast scans as the primary simulation dataset could increase treatment planning efficiency and accuracy by avoiding unnecessary scans, manually region overriding, and planning errors caused by nonperfect image registrations.

Optimal imaging protocols for lung cancer staging: CT, PET, MR imaging, and the role of imaging

Chest radiography, the most commonly performed imaging technique for the detection of lung disease, is limited in accurately detecting early lung cancer. The main imaging modality for the staging of lung cancer is computed tomography (CT), supplemented by positron emission tomography (PET), usually as a hybrid technique in conjunction with CT (PET/CT). Magnetic resonance (MR) imaging is a useful diagnostic tool for specific indications and has the advantage of not using ionizing radiation. This article discusses the optimal imaging protocols for lung cancer staging using CT, PET (PET/CT), and MR imaging, and the role of imaging in patient management.

Minimising medically unwarranted computed tomography scans

As computed tomography (CT) is such a superb diagnostic tool and individual CT risks are small, whenever a CT scan is clinically warranted, the CT benefit/risk balance is by far in the patient's favour. However, if a CT scan is not clinically warranted, this balance shifts dramatically. It is likely that at least 25% of CT scans fall into this latter category, in that they could either be replaced with alternative imaging modalities or could be avoided entirely. Use of clinical decision rules for CT usage represents a powerful approach for slowing down the increase in CT usage, because they have the potential to overcome some of the major factors that result in some CT scans being undertaken when they may not be clinically helpful.

Mediastinal atlas creation from 3-D chest computed tomography images: application to automated detection and station mapping of lymph nodes

One important aspect of lung cancer staging is the assessment of mediastinal lymph nodes in 3-D chest computed tomography (CT) images. In the current clinical routine this is done manually by analyzing the 3-D CT image slice by slice to find nodes, evaluate them quantitatively, and assign labels to them for describing the clinical and pathologic extent of metastases. In this paper we present a method to automate the process of lymph node detection and labeling by creation of a mediastinal average image and a novel lymph node atlas containing probability maps for mediastinal, aortic, and N1 nodes. Utilizing a fast deformable registration approach to match the atlas with CT images of new patients, our method can maintain an acceptable runtime. In comparison to previously published methods for mediastinal lymph node detection and labeling it also shows a good sensitivity and positive predictive value.

Coping with the unexpected at surgery

In lung cancer surgery, it is best to avoid surprises; this requires knowledge of the reliability of preoperative assessment and careful planning. If this has been done, most of the more common situations should be manageable. If there is limited chest wall, mediastinal or N2 node involvement, one should proceed with resection. Unanticipated T4 tumors or bulky pN2 disease should not come as a surprise, and such patients should be sent to a more experienced center. One has to be careful to practice within the scope of one's knowledge and abilities as well as the sophistication of the institution. It only makes a mistake worse if an intraoperative surprise prompts one to embark on an operation that is beyond the means at hand. Collaborative organization via multidisciplinary tumor boards or inter-institutional interaction allows collective wisdom to promote better outcomes for all.

Lung cancer metastasis to the scapula and spine: a case report

BACKGROUND

The objective of this case report is to describe the clinical presentation of a patient who complained of shoulder pain and was diagnosed with carcinoma of the scapula and spine that metastasized from the lung.

CASE PRESENTATION

A 76-year-old man without a history of cancer sought chiropractic care for right shoulder pain. Careful evaluation, radiographs, and subsequent imaging revealed primary and metastatic lung cancer. The patient was referred to his primary care physician for immediate medical care. Diagnostic images are included in this case to provide a comprehensive depiction of the scope of the patient's disease.

CONCLUSION

Musculoskeletal symptoms are commonly encountered in chiropractic practice. It is important to recognize that primary lung cancer may be unidentified, and musculoskeletal symptoms may reflect the first sign of primary or metastatic pulmonary disease. Thoughtful evaluative procedure and clinical decision making, combined with the use of appropriate diagnostic tests may allow timely identification of primary or metastatic disease.

Detection of mediastinal and hilar lymph nodes by 16-row MDCT: Is contrast material needed?

PURPOSE

To retrospectively evaluate whether contrast administration is necessary in the detection of mediastinal and hilar lymph nodes when thin slice axial and coronal MDCT images are used.

MATERIALS AND METHOD

This study was approved by our Institutional Review Board, informed consent was not required. Thirty-five patients who needed a chest CT (0.75 mm x 16) for various reasons were included. Four different image sets were reconstructed for each patient: non-enhanced axial (N-Ax), non-enhanced coronal MPR (N-Co), enhanced axial (E-Ax) and enhanced coronal MPR (E-Co). All the images were 1mm thick and interval. Two board-certified chest radiologists independently evaluated whether a lymph node with a short diameter, larger than 5mm, existed in each nodal station of the mediastinum and hilum. Two different board-certified chest radiologists assessed all four image sets together and established a reference standard by consensus. Interobserver agreement between the two readers was assessed by kappa statistics. Accuracy was calculated on each image set and compared to each other by McNemar's test.

RESULTS

A total of 211 nodal stations, including 113 mediastinal and 98 hilar, were defined to be present and this was the reference standard. Except for N-Ax, the kappa values were within moderate to substantial (0.53-0.81). The accuracy for hilar nodes detection was significantly higher for the contrast enhanced images both in the axial (p<0.001) and coronal (p<0.01) data sets. The addition of contrast material did not significantly increase accuracy for the detection of mediastinal nodes (axial: p=0.542, coronal p=0.727).

CONCLUSION

Contrast administration is recommended in the detection of hilar lymph nodes both on axial and MPR views, however, for assessment of mediastinal lymph nodes its contribution is low.

Literature-based recommendations for treatment planning and execution in high-dose radiotherapy for lung cancer

BACKGROUND AND PURPOSE

To review the literature on techniques used in high-dose radiotherapy of lung cancer in order to develop recommendations for clinical practice and for use in research protocols.

PATIENTS AND METHODS

A literature search was performed for articles and abstracts that were considered both clinically relevant and practical to use. The relevant information was arbitrarily categorized under the following headings: patient positioning, CT scanning, incorporating tumour mobility, definition of target volumes, radiotherapy planning, treatment delivery, and scoring of response and toxicity.

RESULTS

Recommendations were made for each of the above steps from the published literature. Although most of the recommended techniques have yet to be evaluated in multicenter clinical trials, their use in high-dose radiotherapy to the thorax appears to be rational on the basis of current evidence.

CONCLUSIONS

Recommendations for the clinical implementation of high-dose conformal radiotherapy for lung tumours were identified in the literature. Procedures that are still considered to be investigational were also highlighted.

Non-Hodgkin lymphoma and Hodgkin disease: coregistered FDG PET and CT at staging and restaging--do we need contrast-enhanced CT?

PURPOSE

To retrospectively compare diagnostic value of coregistered fluorine 18 fluorodeoxyglucose positron emission tomographic (PET) and computed tomographic (CT) scans obtained with low-dose nonenhanced CT (PET/CT) with those routinely obtained with contrast material-enhanced CT for staging and restaging of disease in patients with Hodgkin disease or high-grade non-Hodgkin lymphoma.

MATERIALS AND METHODS

Sixty patients (mean age, 39.6 years +/- 17.1 [standard deviation]) with Hodgkin disease (n = 42) or high-grade non-Hodgkin lymphoma (n = 18) were included in this retrospective study. All patients underwent PET/CT and contrast-enhanced CT within a maximum of 24 days (mean, 9.1 days +/- 7.0) of each other for staging (n = 19) or first follow-up examination (n = 41). Findings were extracted from original written reports (PET/CT, contrast-enhanced CT) and compared with findings of reference standard, which included biopsy or follow-up with clinical, laboratory, or other imaging findings. For statistical analysis, sensitivity and specificity were calculated with findings of the reference standard. Agreement of both methods was determined with Cohen kappa and McNemar tests on a per-patient basis.

RESULTS

For evaluation of lymph node involvement, sensitivity of PET/CT and contrast-enhanced CT was 94% and 88%, and specificity was 100% and 86%, respectively. For evaluation of organ involvement, sensitivity of PET/CT and contrast-enhanced CT was 88% and 50%, and specificity was 100% and 90%, respectively. Agreement of both methods was excellent (kappa = 0.84) for assignment of lymph node involvement but only fair (kappa = 0.50) for extranodal disease. A difference with P <.05 (McNemar test) was considered significant in regard to exclusion of disease with PET/CT, compared with contrast-enhanced CT.

CONCLUSION

PET/CT performed with nonenhanced CT is more sensitive and specific than is contrast-enhanced CT for evaluation of lymph node and organ involvement, especially regarding exclusion of disease, in patients with Hodgkin disease and high-grade non-Hodgkin lymphoma.

Lung cancer staging

The staging of lung cancer is a continuously progressing field, with advances in technology not only improving prognostic accuracy, but fundamentally changing pre-operative investigation algorithms. Noninvasive staging is currently undergoing revolutionary developments with the advent of Positron Emission Tomography, whereas Video-Assisted Thoracic Surgery has already been established as an essential, minimally invasive diagnostic tool for invasive histological staging. Molecular staging may transform future lung cancer staging, promising extremely accurate substaging, and potentially prompting a revision of our anatomically based conceptualization of lung cancer spread. This review presents an appraisal of current lung cancer staging modalities, and presents an overview of recent developments in molecular staging.

Bronchoscopy and surgical staging procedures and their correlation with imaging

Bronchoscopy, computed tomography (CT) and surgical staging procedures are complimentary methods of investigating patients with lung cancer. CT has been shown to be of value prior to bronchoscopy in the investigation of haemoptysis and malignancy, with excellent correlation between the detection of disease within the large airways on CT and direct visualisation at bronchoscopy. The utility of CT has been further increased by the development of multislice scanners with the generation of volumetric data enabling multiplanar image acquisition. Additionally the advent of CT co-registered with positron emission tomography will play an important role in guiding the choice of surgical staging procedures The increasing use of multidisciplinary medical care requires radiologists to have a greater understanding of the abilities and limitations of both bronchoscopy and surgical staging procedures in evaluating disease demonstrated on imaging.

Staging of non-small cell lung cancer: imaging of intrathoracic disease

This article reviews the contribution of diagnostic imaging to the intrathoracic staging of non-small cell lung cancer. The principle features of the current staging system are discussed along with the relative roles of the various imaging modalities in the evaluation of the primary tumour and metastatic disease. The emerging role of positron emission tomography with fluorodeoxyglucose (FDG-PET) as a clinically useful, potentially cost effective, complementary imaging technique is also reviewed.

Extra-thoracic staging of lung cancer

This article reviews the staging of extra-thoracic metastatic lung cancer. The imaging strategy, including when to screen as well as the different modalities available for different sites of spread of disease are discussed. The emerging role of whole body positron emission tomography in screening for metastases is also explored.

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

In the past 5 years, metabolic imaging with positron emission tomography (PET) using 18F-fluoro-2-deoxy-glucose (FDG) has become an important imaging modality in lung cancer patients. FDG-PET consistently proved to be superior to structure-based imaging modalities in both the diagnosis and staging of lung cancer. At this moment the use of FDG-PET in these indications needs further validation in multi-centre large-scale randomised studies, focusing mainly on treatment outcome parameters, survival and cost-efficacy. More recently, interesting findings have also been reported in the response assessment to cytotoxic treatments providing information of greater prognostic significance than can be obtained using conventional approaches. This review focuses on the potential role of FDG-PET in the diagnosis of lung nodules and masses, and in locoregional and extrathoracic staging of non-small cell lung cancer. Emphasis is put on the potential clinical implementation of the numerous data of the last decade.

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.

Impact of computed tomography-positron emission tomography fusion in staging patients with thoracic malignancies

BACKGROUND

Positron emission tomography (PET) has been demonstrated to improve staging in patients with thoracic malignancies. This study evaluates the ability of a new imaging technique to improve the spatial resolution and accuracy of PET.

METHODS

Patients with known or suspected malignancy (n = 21) who were referred for a dedicated PET scan were also evaluated with a new camera-based PET system, which uniquely allows simultaneous computed tomography (CT) and fusion of the camera-based PET images with the CT images. The dedicated PET scan was obtained 1 hour after intravenous injection of fluorodeoxyglucose. The camera-based PET imaging was fused with the CT images at approximately 2 hours after injection. The camera-based PET and CT-PET fusion images were read independently and blindly by 2 experienced observers and the presence and location of abnormalities was compared with dedicated PET scans.

RESULTS

Dedicated PET identified 18 sites in the chest as abnormal. The CT-PET fusion was superior to the camera-based PET alone, concordant with the dedicated PET in 16 of 21 patients compared with 13 of 21 by camera-based PET. The lesions missed by the camera-based PET were less than 1 cm in diameter. Fused CT-PET images provided superior anatomic localization and spatial resolution compared with dedicated PET and camera-based PET.

CONCLUSIONS

CT-PET fusion images were more accurate than camera-based PET alone. CT-PET fusion improves the spatial resolution compared with dedicated PET and may improve the availability and efficacy of staging of patients with thoracic malignancies.

Lung cancer staging

Accurate staging of lung cancer is essential for proper treatment and management of the disease, and allows predictions for patient survival. Several different invasive and noninvasive modalities exist for staging, and the determination of the best approach of one or a combination of those methods depends on the clinical situation and the clinician's assessment of the most appropriate means of staging evaluation. This review discusses the elements and framework of lung cancer staging, with particular emphasis on those newer modalities, especially positron emission tomography and endoscopic ultrasound needle biopsy, which will be expected to be used increasingly more common in clinical practice.

T1 lung cancers: sensitivity of diagnosis with fluorodeoxyglucose PET

PURPOSE

To determine the sensitivity of fluorodeoxyglucose (FDG) positron emission tomography (PET) in patients with T1 (< or =3 cm) lung cancers.

MATERIALS AND METHODS

One hundred eighty-five patients with 192 histopathologically proved T1 lung cancers underwent FDG PET imaging at the time of diagnosis. PET results were correlated with tumor size, histopathologic findings, and patient outcome by using the two-sample t test, exact chi(2) test, and log rank test, respectively.

RESULTS

Of the 192 lesions, 183 (95%) that ranged in size from 0.5 to 3.0 cm in diameter (mean, 2.0 cm) were positive at PET (ie, demonstrated increased FDG uptake). Of the 192 lesions, nine (5%) that ranged in size from 0.3 to 2.5 cm in diameter (mean, 1.3 cm) were negative at PET (ie, demonstrated low FDG uptake). Patients with small tumors, as well as those with carcinoid tumors and bronchioloalveolar cell carcinoma, were more likely to have a negative PET scan (P =.004, P =.003, respectively). In addition, patients with a negative PET scan who subsequently proved to have cancer had significantly longer survival than did patients with a positive scan and cancer (P =.043).

CONCLUSION

Most T1 lung cancers show increased FDG uptake on PET scans.

[Influence of computed tomography of the abdomen for staging lung cancer]

OBJECTIVES

To analyze the influence of routine imaging of the upper abdomen by conventional computed tomography (CT) to stage bronchopulmonary carcinoma and to detect liver or adrenal metastasis. A second objective was to describe the characteristics of a large group of patients in our practice.

MATERIAL AND METHODS

Retrospective study of 387 patients (367 men and 20 women; mean age [+/-SD] 62.3 +/- 10.4 years, range 34-90 years) who had received a diagnosis of lung cancer (203 epidermoid carcinoma, 75 adenocarcinoma, 15 non-small cell carcinoma, 68 small cell carcinoma and 25 mixed tumors). CT images were obtained of the chest and upper abdomen with intravenous contrast except in patients with a history of allergy or renal insufficiency. The characteristics associated with abdominal CT images aiding or confusing diagnosis were analyzed by Spearman coefficient. Differences related to sex or histology were studied using a Mann-Whitney U-test and Kruskal-Wallis test.

RESULTS

The upper abdominal CT changed the staging of 27 patients (7%): non-small cell carcinoma 5% (16/319) and small-cell carcinoma 16.2% (11/68). Twelve patients (3.1%) showed evidence of unconfirmed adrenal or hepatic metastasis. Change of staging after CT was associated with a high creatinine concentration in blood (p = 0.032), whereas confusion of diagnosis after CT was more common for women (p = 0.002) and patients for whom the diagnosis was established by cytology of sputum or bronchial aspirate (p = 0.019). Differences between men and women were found for from pathology (p = 0.027), confusion after CT (p = 0.002), hemoglobin (p = 0.011), hematocrit (p = 0.019) and smoking (p = 0.000).

CONCLUSION

Given the considerable limitations of CT imaging of the upper abdomen, new technologies should be developed to facilitate a more rational approach to the problem.

Endoscopic ultrasound-guided fine needle aspiration for staging patients with carcinoma of the lung

BACKGROUND

Endoscopic ultrasound (EUS)-guided fine needle aspiration is a safe, cost-effective procedure that can confirm the presence of mediastinal lymph node metastases and mediastinal tumor invasion. We studied the accuracy of EUS in a large population of lung cancer patients with and without enlarged mediastinal lymph nodes on computed tomographic (CT) scan.

METHODS

From 1996 to 2000 all patients referred to our institution with lung tumors and no proven distant metastases were considered for EUS and surgical staging. Patients had endoscopic ultrasound with fine needle aspiration of abnormal appearing mediastinal lymph nodes and evaluation for mediastinal invasion of tumor (stage III or IV disease). Patients without confirmed stage III or IV disease had surgical staging.

RESULTS

Two hundred seventy-seven patients met the inclusion criteria, including 121 who had EUS. Endoscopic ultrasound and fine needle aspiration detected stage III or IV disease in 85 of 121 (70%). Among patients with enlarged lymph nodes on CT, 75 of 97 (77%) had stage III or IV disease detected by EUS. Among a small cohort of patients without enlarged mediastinal lymph nodes on CT, 10 of 24 (42%) had stage III or IV disease detected by EUS. For mediastinal lymph nodes only, the sensitivity of endoscopic ultrasound and CT was 87%. The specificity of EUS (100%) was superior to that of CT (32%) (p < 0.001).

CONCLUSIONS

Endoscopic ultrasound with fine needle aspiration identified and histologically confirmed mediastinal disease in more than two thirds of patients with carcinoma of the lung who have abnormal mediastinal CT scans. Although mediastinal disease was more likely in patients with an abnormal mediastinal CT, EUS also detected mediastinal disease in more than one third of patients with a normal mediastinal CT and deserves further study. Endoscopic ultrasound should be considered a first line method of presurgical evaluation of patients with tumors of the lung.

The role of positron emission tomography with 18F-fluoro-2-deoxy-D-glucose in respiratory oncology

In the past 5 yrs, positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG) has become an important imaging modality in lung cancer patients. At this time, the indication of FDG-PET as a complimentary tool to computed tomography in the diagnosis and staging of nonsmall cell lung cancer has gradually gained more widespread acceptance and also reimbursement in many European countries. This review focuses on the data of FDG-PET in the diagnosis of lung nodules and masses, and in locoregional and extrathoracic staging of nonsmall cell lung cancer. Emphasis is put on the potential clinical implementation of the currently available FDG-PET data. The use of FDG-PET in these indications now needs further validation in large-scale multicentre randomized studies, focusing mainly on treatment outcome parameters, survival and cost-efficacy. Interesting findings with 18F-fluoro-2-deoxy-D-glucose-positron emission tomography have also been reported for the evaluation of response to radio- or chemotherapy, in radiotherapy planning, recurrence detection and assessment of prognosis. Finally, a whole new field of application of positron emission tomography in molecular biology, using new radiopharmaceuticals, is under extensive investigation.

Non-small cell lung cancer: FDG PET for nodal staging in patients with stage I disease

PURPOSE

To determine the accuracy of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the evaluation of regional lymph nodes in patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Imaging and clinical findings obtained during 5 years in 84 patients (mean age, 66 years) were reviewed. Patients had thoracic computed tomographic findings of stage I NSCLC, an FDG PET study, and histopathologic proof of lung cancer. At the time of diagnosis, disease stage was assigned on the basis of FDG PET results and was compared with the histopathologic stage to determine the accuracy of PET.

RESULTS

When PET stage was compared with histopathologic stage, the disease in 72 (86%) patients was accurately staged with PET, understaged in two (2%), and overstaged in 10 (12%). The overall sensitivity, specificity, and positive and negative predictive values for PET of regional lymph nodal metastases were 82%, 86%, 47%, and 97%, respectively.

CONCLUSION

FDG PET enables accurate staging of regional lymph node disease in patients with stage I NSCLC. A negative PET scan in these patients suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy.

Lung cancer and positron emission tomography with fluorodeoxyglucose

Over the past years, positron emission tomography (PET) with fluoro-2-deoxy-D-glucose (FDG) has emerged as an important imaging modality. In the thorax, FDG-PET has been shown to differentiate benign from malignant pulmonary lesions and stage lung cancer. Preliminary studies have shown its usefulness in assessing tumor recurrence, and assisting in radiotherapy planning. FDG-PET is often more accurate than conventional imaging studies, and has been proven to be cost-effective in evaluating lung cancer patients. This review will discuss the current applications of FDG-PET as compared with conventional imaging in diagnosing, staging, and following patients with lung cancer.

Comparison of biopsy techniques in assessment of solitary pulmonary nodules

A wide variety of diagnostic tests are available to evaluate solitary pulmonary nodules, ranging from noninvasive to invasive. Given the virulence of lung cancer, those techniques that can provide cytological and pathological information are often chosen. However, the choice of which procedure to perform is complicated by numerous factors, including the sensitivity and specificity of the test, as well as the prevalence of disease. Additional considerations also include complications, availability and expertise in performing procedures, and overall cost of the diagnostic algorithm. Rather than make specific recommendations for diagnostic workup, it is more appropriate to consider that this will vary from institution to institution based on the above factors.

Intravenous extension of lung carcinoma to the left atrium: demonstration by positron emission tomography with CT correlation

Intravenous extension of lung carcinoma is rare. A right upper lobe bronchogenic carcinoma with unusually elongated intravenous extension to the left atrium was first visualized with positron emission tomography (PET) and then confirmed with dynamic CT. The PET appearance of intravascular tumour spread is striking, and presents only a short differential diagnosis.

Staging non-small cell lung cancer with whole-body PET

PURPOSE

To compare the accuracies of whole-body 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) and conventional imaging (thoracic computed tomography [CT], bone scintigraphy, and brain CT or magnetic resonance [MR] imaging) in staging bronchogenic carcinoma.

MATERIALS AND METHODS

Within 20 months, 100 patients with newly diagnosed bronchogenic carcinoma underwent whole-body FDG PET and chest CT. Ninety of these patients underwent radionuclide bone scintigraphy, and 70 patients underwent brain CT or MR imaging. For each patient, all examinations were completed within 1 month. A radiologic stage was assigned by using PET and conventional imaging independently and was compared with the pathologic stage. The accuracy, sensitivity, specificity, and negative and positive predictive values were calculated.

RESULTS

PET staging was accurate in 83 (83%) patients; conventional imaging staging was accurate in 65 (65%) patients (P < .005). Staging with mediastinal lymph nodes was correct by using PET in 67 (85%) patients and by using CT in 46 (58%) patients (P < .001). Nine (9%) patients had metastases demonstrated by using PET that were not found with conventional imaging, whereas 10 (10%) patients suspected of having metastases because of conventional imaging findings were correctly shown with PET to not have metastases.

CONCLUSION

Whole-body PET was more accurate than thoracic CT, bone scintigraphy, and brain CT or MR imaging in staging bronchogenic carcinoma.