Positron emission tomographic imaging with fluorodeoxyglucose isefficacious in evaluating malignant pulmonary disease

Characterization of 18F-fluorodeoxyglucose metabolic spatial distribution improves the differential diagnosis of indeterminate pulmonary nodules and masses with high fluorodeoxyglucose uptake

Background

The aim of this study was to investigate the value of visual assessment of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) metabolic spatial distribution (V-FMSD) in the diagnosis of indeterminate pulmonary nodules and masses with high ¹⁸F-FDG uptake.

Methods

A total of 301 patients with indeterminate pulmonary nodules or masses who underwent ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) imaging were retrospectively studied. The characteristics of ¹⁸F-FDG metabolic spatial distribution (FMSD) in the proximal and distal regions of the lesions were visually analyzed using a 5-point scoring system. The sensitivity, specificity, accuracy, and area under receiver operating characteristic curve (AUC) were compared between V-FMSD and conventional PET/CT methods for the diagnosis of hypermetabolic indeterminate pulmonary nodules and masses.

Results

The V-FMSD results showed that 180 (92.8%) malignant lesions had a score of ≥3 and 78 (72.9%) benign lesions had a score of ≤2. This indicated that the FMSD in the proximal region of malignant lesions was significantly higher than that of the distal region, and the FMSD in the proximal region of benign lesions was significantly lower than that of the distal region. V-FMSD had a specificity of 72.9%, which was markedly higher than those of the maximum standard uptake value (SUV_max; 0%, P<0.001) and the retention index (RI; 26.2%, P<0.001). The AUC of V-FMSD was 0.886, which was significantly larger than those of the SUV_max (0.626, P<0.001), RI (0.670, P<0.001), and PET/CT (0.788, P<0.05).

Conclusions

Our study found that pulmonary benign and malignant lesions have distinct FMSD characteristics. V-FMSD can therefore be used as a novel auxiliary marker to improve the diagnostic accuracy of hypermetabolic indeterminate pulmonary nodules and masses.

Evaluation of Fluorodeoxyglucose Positron Emission Tomography Imaging in Metastatic Transitional Cell Carcinoma with and without Prior Chemotherapy

INTRODUCTION

This study was designed to determine the value of fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of metastatic transitional cell carcinoma (TCC).

METHODS

Fifty-eight FDG PET scans were performed on 46 consecutive patients with TCC. Results were correlated with radiologic, pathologic, and histologic findings in these patients and the sensitivity of PET for detecting malignancy in untreated TCC patients (n = 48) was compared to the sensitivity in patients who had undergone prior chemotherapy (n = 10).

RESULTS

Of 48 scans in patients who had no prior systemic chemotherapy, 10 had increased uptake in proven metastatic TCC lesions and 3 PET studies failed to reveal metastatic TCC (sensitivity 76.9%). In patients free of metastatic disease, 33 revealed no abnormal uptake and 1 study revealed a suspicious area in a patient free of metastases (specificity = 97.1%). However, in 10 patients imaged after receiving chemotherapy, the sensitivity fell to 50% for the detection of histologically confirmed residual/recurrent tumor by PET.

CONCLUSIONS

FDG PET detects increased metabolic activity. After chemotherapy, viable cancer cells may still be present but with a diminished metabolic rate. As a result, PET imaging is often useful in the evaluation of untreated metastatic TCC metastasis but should be interpreted with caution in patients who have received prior chemotherapy.

Noninvasive staging of non-small cell lung cancer: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

Correctly staging lung cancer is important because the treatment options and the prognosis differ significantly by stage. Several noninvasive imaging studies including chest CT scanning and positron emission tomography (PET) scanning are available. Understanding the test characteristics of these noninvasive staging studies is critical to decision making.

METHODS

Test characteristics for the noninvasive staging studies were updated from the first iteration of the lung cancer guidelines using systematic searches of the MEDLINE, HealthStar, and Cochrane Library databases up to May 2006, including selected metaanalyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The pooled sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were 51% (95% confidence interval [CI], 47 to 54%) and 85% (95% CI, 84 to 88%), respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, the pooled estimates of sensitivity and specificity for identifying mediastinal metastasis were 74% (95% CI, 69 to 79%) and 85% (95% CI, 82 to 88%), respectively. These findings demonstrate that PET scanning is more accurate than CT scanning. If the clinical evaluation in search of metastatic disease is negative, the likelihood of finding metastasis is low.

CONCLUSIONS

CT scanning of the chest is useful in providing anatomic detail, but the accuracy of chest CT scanning in differentiating benign from malignant lymph nodes in the mediastinum is poor. PET scanning has much better sensitivity and specificity than chest CT scanning for staging lung cancer in the mediastinum, and distant metastatic disease can be detected by PET scanning. With either test, abnormal findings must be confirmed by tissue biopsy to ensure accurate staging.

Positron Emission Tomography: False Positive Result Due to Splenic Uptake in an Extension Study in Bronchial Carcinoma. A Case Report

Lung cancer is one of the most common malignant diseases. Many tests and techniques are used in the staging of this disease, including positron emission tomography. This is probably the most recently introduced test and is capable of providing information on all the structures affected by malignancy. We present a case of a false positive result due to increased splenic uptake of the tracer.

Impact thérapeutique de l’imagerie TEP-FDG en carcinologie bronchopulmonaire

BACKGROUND

Because of the expected high performances of scintigraphic scans with [18F]-fluorodeoxyglucose (FDG) not only in diagnostics and but also in therapeutic impact, especially in thoracic oncology, there are a lot of French nuclear medicine departments which will soon be equipped with a positron emission tomograph (PET).

MATERIAL AND METHODS

The Nuclear Medicine Department of the Hôpital d'Instructions des Armées du Val-de-Grâce, Paris, led a retrospective study among physicians interested in 338 FDG-PET exams performed between may 2000 and march 2002 in order to compare its own results with international literature concerning four indications for lung cancer: pulmonary nodule or mass malignancy diagnostic, lung carcinoma extension evaluation, therapeutic efficiency, recurrence suspicion.

RESULTS

There seems to be no divergence, regarding limitation induced by the not exhaustive analysis of the retrospective study: more than every two FDG-PET exam highly influenced the effective therapy.

CONCLUSION

That is why clinical FDG-PET has to be widely developed to investigate lung cancer.

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.

Seeking a home for a PET, part 2: Defining the appropriate place for positron emission tomography imaging in the staging of patients with suspected lung cancer

In patients who have a high likelihood of having lung cancer, there is little role for positron emission tomography (PET) imaging for diagnosis of the primary lesion. The primary impact of PET imaging is in extrathoracic staging, but it should not replace a clinical evaluation by a physician experienced in lung cancer. PET imaging is most useful for confirmation of the presumed extrathoracic stage in patients with intermediate stages of lung cancer. The role of PET imaging is limited in patients with strong clinical signs of metastatic disease, or in patients with a clinical stage I lung cancer and a negative clinical evaluation. With regard to intrathoracic staging, PET imaging has a definite role in communities in which mediastinoscopy is not available, whereas the impact is limited in institutions in which invasive mediastinal staging is available. The data suggest that a positive PET result in the mediastinum should be confirmed by biopsy. A mediastinoscopy is also reasonable in patients with clinical stage III lung cancer who have no mediastinal PET uptake. It is unclear and controversial whether a biopsy is needed in patients with clinical stage II lung cancer who have no PET uptake in the mediastinum.

Follow-up strategies and management of recurrence in urologic oncology bladder cancer:

A surveillance program following cystectomy should consider a patient's individual risk for the development of local and distant recurrences and any specific needs related to the urinary tract reconstruction performed (Table 1). Well-documented recurrence patterns following cystectomy are available from many large surgical series and provide the background information needed for tailoring follow-up based on pathologic criteria. Economic issues also must be considered, given that the health care-related expenses of treating and following patients with bladder cancer is twice as much as that expended for the treatment of prostate cancer. Because of the ever-increasing fiscal constraints placed on clinicians, risk-adjusted follow-up strategies are reasonable, but will require prospective evaluation to validate their appropriateness.

Differentiating solitary pulmonary metastases in patients with extrapulmonary neoplasmas using FDG-PET

The purpose of this preliminary study is to evaluate the characteristics of solitary pulmonary lesions in patients using extrapulmonary neoplasmas with 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Thirty-two patients with extrapulmonary neoplasmas who had solitary pulmonary lesions and were suspected for pulmonary metastasis underwent an oncological survey with FDG-PET. Standard uptake value (SUV) and the ratio of lesion-to-background (L/B ratio) were used as parameters to differentiate and characterize the solitary pulmonary lesions. Using SUV > 2.5 or L/B ratio > 3 as the cutoff to diagnose malignancy, FDG-PET correctly identified 29 true-positive cases. However, FDG-PET failed to interpret two false-positive and one false-negative cases. The accuracy of FDG-PET was 91%. We concluded that FDG-PET is an accurate modality to differentiate solitary pulmonary lesions in patients with extrapulmonary neoplasmas.

Mediastinal lymph node staging in suspected lung cancer: comparison of positron emission tomography with F-18-fluorodeoxyglucose and mediastinoscopy

BACKGROUND

In patients with bronchogenic carcinoma, mediastinal lymph node staging is essential for determining treatment options. In this retrospective analysis we compared the results of positron emission tomography (PET) using F-18 fluorodeoxyglucose with those of mediastinoscopy in nodal staging for suspected bronchogenic carcinoma.

METHODS

From March 1997 to June 2001, 102 patients (86 male,16 female, age 62 +/- 9 years) underwent both PET and mediastinoscopy for radiologically suspected mediastinal lymph node disease in bronchogenic carcinoma. Total body emission scans were acquired 90 to 150 minutes after injection of 230 MBq of F-18 fluorodeoxyglucose. Mediastinoscopic evaluation of lymph node stations was performed according to the method of Mountain and Dresler (1R, 1L, 2L, 2R, 4L, 4R,7). Patients were eligible if surgical staging was performed within 6 weeks after the PET scan. RESULTS. Of the 102 patients, benign lesions were diagnosed in 15. In 87 patients malignant disease was proven by histology, and bronchogenic carcinoma was found in 82. Of 469 nodal stations analyzed, malignancy was documented by histology in 84. In PET analysis 79 true-positive and 304 true-negative samples were found. Five lymph node stations were false negative, and 81 samples were false positive. False-positive findings in PET frequently were seen in inflammatory lung disease. The sensitivity of PET was 94.1%, specificity was 79% with a diagnostic accuracy of 81.6%. The positive predictive value of PET was 49.3%, and the negative predictive value was 98.4%.

CONCLUSIONS

In patients with positive PET scan results histologic verification appears necessary for exact lymph node staging. In view of the negative predictive value mediastinoscopy can be omitted in patients with bronchogenic carcinoma whose PET scan results were negative.

The influences of blood glucose and duration of fasting on myocardial glucose uptake of [18F]fluoro-2-deoxy-D-glucose

During the study of chest using positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG), a significant myocardial FDG uptake can prevent detection of the lesion that is located either behind or closely attached to the heart border. Two well-known and possible factors of myocardial FDG uptake are blood glucose level and fasting duration before FDG PET scanning. This study investigates whether the two factors are related to myocardial FDG uptake. Our study also explores the possibility of eliminating myocardial FDG uptake by controlling patients' blood glucose level and/or fasting duration. Whole-body FDG PET scans performed on 270 consecutive patients performed were reviewed. The study subjects were classified into four grades of myocardial FDG uptake according to the visual interpretation of the FDG PET image hard-copy films. For all study subjects, the blood sugar level and fasting duration before FDG injection were recorded. Then, the blood sugar levels and fasting duration were compared to the visual grade of myocardial FDG uptake for each study subject. About half of the study subjects showed graded 0 myocardial FDG uptake when the blood glucose levels were < or = 120 mg x dl(-1) or when the fasting duration was between 5 and 12 h. One hundred and thirty-one of the 142 (92%) patients with graded 0 uptake were asked to fast for > or = 4 h and had blood glucose levels < or = 120 mg x dl(-1). Based on our findings, we conclude that controlling the patients' blood glucose levels to < or = 120 mg x dl(-1) and at least 5 h fasting should be recommended to decrease myocardial FDG uptake.

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.

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.

Positron emission tomography (PET) and combined imaging modalities for staging lung cancer

FDG PET in its current form supplements but does not yet replace other noninvasive imaging modalities for the evaluation and staging of the patient with NSCLC. Clinicians await further data from well-designed clinical trials to help integrate FDG PET into current clinical practice. Looking forward, sophisticated radiolabeling techniques promise to improve both the diagnostic accuracy of PET and our ability to deliver targeted cancer therapy to patients.

Positron emission tomography (PET) of non-small cell lung cancer

Positron emission tomography (PET) with FDG has shown to be of substantial value in differential diagnosis of pulmonary lesions and in the assessment of lymph node involvement with higher sensitivity and specificity than CT. A negative PET scan of the mediastinum suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy. The method is also useful for the visualization of distant metastases. Since changes of treatment may result after identification of distant metastases PET is also cost-effective [Eur J Nucl Med 27(2000)1598; Australas Radiol 45(2001)9]. Furthermore, changes of tumor metabolism can be detected with PET at early stages after treatment, which can be used for therapy monitoring and for the detection of recurrent tumor tissue after completion of treatment.

Positron emission tomography in the diagnosis and staging of lung cancer: a systematic, quantitative review

Lung cancer is the cause of 32% of all male cancer deaths and 25% of all female cancer deaths. Because the prognosis depends on early diagnosis and staging, continuous evaluation of the diagnostic tools available is important. The aim of this study was to assess the diagnostic value of dedicated positron emission tomography (PET) and gamma-camera PET in the diagnostic investigation of non-small-cell lung cancer (NSCLC). A systematic literature search was carried out in the MEDLINE and EMBASE databases and the Cochrane Controlled Trials Register. We identified 55 original works on the diagnostic performance of PET with fluorodeoxyglucose in the investigation of NSCLC. For diagnosis of NSCLC, the mean sensitivities and specificities were, respectively, 0.96 (SE 0.01) and 0.78 (0.03) for dedicated PET, and 0.92 (0.04) and 0.86 (0.04) for gamma-camera PET. In the mediastinal staging of NSCLC, the results were 0.83 (0.02) and 0.96 (0.01) for dedicated PET and 0.81 (0.04) and 0.95 (0.02) for ganuna-camera PET. We conclude that dedicated PET could be a valuable tool in the diagnosis and staging of NSCLC. However, studies of populations with a lower prevalence of NSCLC are recommended.

Outcome of thoracoscopic pulmonary metastasectomy evaluated by confirmatory thoracotomy

BACKGROUND

The aim of this study was to determine the feasibility, accuracy, and outcome of thoracoscopic resection of peripherally located pulmonary metastases.

METHODS

The 28 patients had three or fewer solitary metastases, located in the periphery of the lung, with a diameter 3 cm or less on computed tomography scan. A thoracoscopic resection was performed to remove all identified lesions evaluated by confirmatory thoracotomy.

RESULTS

A thoracoscopic resection was technically impossible in 10 patients. In 1 patient a confirmatory thoracotomy was not performed because the lesion was diagnosed as carcinoid. Among the 17 patients who underwent confirmatory thoracotomy, 12 patients had a complete thoracoscopic resection and 5 patients had residual disease. The success rate appeared to be higher (p = 0.01) in patients with one lesion (11 of 12 patients), than in patients with more than one lesion (1 of 5 patients) found by preoperative computed tomography scan.

CONCLUSIONS

Thoracoscopic resection can be considered a viable treatment option for patients who present with a solitary pulmonary metastasis with a diameter of 3 cm or less, when the lesion is located in the periphery of the lung.

Treatment Outcome of Lung Cancer Patients as Optimized by Preoperative Whole-Body Positron Emission Tomography Fluorodeoxyglucose Imaging

Positron emission tomography (PET) fluorodeoxyglucose (FDG) imaging may be more accurate than computed tomography (CT) scanning for staging of lung cancer disease. In the present study, we evaluate whether whole-body PET-FDG imaging can accurately stratify lung cancer patients by stage and thus predict patient outcome. Forty-one consecutive patients underwent whole-body PET and CT scanning for preoperative staging, which was then confirmed by mediastinoscopy, thoracotomy, and/or other tests revealing distant metastases. The effect of PET on patient management was determined. PET was significantly more accurate than CT for staging of lung cancer (97.6% vs. 70.7%). One-year follow-up for survival rate and treatment response was also compared in different patient groups. PET accurately identified patients with resectable disease (Group A). Group B patients, with medically inoperable disease, and Group C patients, with unresectable advanced disease, had 100% and 53% incidence of adverse events (defined as recurrence, evidence of new disease, or death), respectively. Group A patients with resectable disease who underwent surgery showed the best patient outcome, with only 7% incidence of adverse events. In conclusion, whole-body PET can be useful in identifying a group of lung cancer patients with resectable disease most likely to benefit from surgical resection. Further studies are needed to explore whether PET can predict patient outcome of various lung cancer patients receiving different treatment regimens.

Positron emission tomography with f18-fluorodeoxyglucose in the staging and preoperative evaluation of malignant pleural mesothelioma

OBJECTIVES

The purpose of this study was to evaluate the utility of positron emission tomography with F18-fluorodeoxyglucose in the preoperative evaluation and staging of malignant mesothelioma in patients who were candidates for aggressive combined modality therapy.

METHODS

Eighteen consecutive patients with biopsy-proven malignant mesothelioma underwent positron emission tomographic scanning. The results of positron emission tomographic imaging were compared with results obtained by computed tomography, mediastinoscopy, thoracoscopy, and pathologic examination of surgical specimens. All patients fasted and received an average of 14.5 +/- 2.7 mCi of F18-fluorodeoxyglucose for positron emission tomographic scanning. Attenuation-corrected whole-body and regional emission images of the chest and upper abdomen were acquired and formatted into transaxial, coronal, and sagittal images.

RESULTS

All primary malignant mesotheliomas accumulated F18-fluorodeoxyglucose, and the mean standardized uptake value was 7. 6 (range, 3.33-14.85; n = 9). There were no false-negative results of positron emission tomography. Identification of occult extrathoracic metastases by positron emission tomography was the basis for excluding two patients from surgical therapy. There were two false-positive results of positron emission tomography: increased F18-fluorodeoxyglucose uptake in the contralateral chest that was negative by thoracoscopic biopsy (n = 1) and increased abdominal F18-fluorodeoxyglucose uptake after partial colectomy for diverticular disease (n = 1).

CONCLUSIONS

Positron emission tomography can identify malignant pleural mesothelioma and appears to be a useful noninvasive staging modality for patients being considered for aggressive combined modality therapy.

Solitary pulmonary nodule: time to think small

The challenge presented by a solitary pulmonary nodule has faced physicians and patients since the advent of the chest radiograph. Is the nodule malignant or benign? When should something be done about it and what should that be? The majority of solitary nodules are benign, but the detection of a nodule may be the first and only chance for cure in the patient with lung cancer. The expanding availability and use of computed tomography are leading to increased numbers and decreased size of nodules detected. Surgical resection remains the most sensitive and specific method of analysis but introduces morbidity and mortality that may be unnecessary and avoidable. Advances in radiographic techniques have improved the ability to noninvasively identify whether a nodule is likely malignant or benign. Application of these techniques may ease the decision making and reduce the incision making.