Lymph Node Staging in Lung Cancer Using [18F]FDG-PET

PET Scan Contribution in Chest Tumor Management: A Systematic Review for Thoracic Surgeons

Aims and background

In the 90s, the introduction of positron emission tomography (PET) represented a milestone in the staging of thoracic tumors. In the last 10 years, PET scan has been widely adopted in thoracic oncology, showing high accuracy in diagnosis and staging and with promising issues in defining prognosis. The aim of this systematic review was to focus on the results and pitfalls of PET scan use in the modern management of chest tumors.

Methods and study design.

The literature search was performed on May 2010 in PubMed, Embase, and Cochrane according to PRISMA protocol. The search was restricted to publications in English, using in the same string the word “PET” with 9 different chest tumors; results were then filtered by eliminating technical articles, focusing only on papers in which surgery was considered as a potential diagnostic or therapeutic tool. From 6600 papers initially selected, 99 manuscripts were fully analyzed.

Results

Glucose uptake is a metabolic marker useful in the diagnosis and staging of chest tumors. In lung cancer screening, standard uptake value is helpful in defining the risk of malignancy of isolated pulmonary nodules. The addition of PET scan to conventional staging increases detection of nodal and distant metastases in lung cancer, esophageal cancer and malignant mesothelioma. In thymoma, a close relationship between standard uptake value, histology, and Masaoka stage has been advocated. This link between glucose uptake and prognosis suggests that PET translates biological tumor behavior into clinically detectable findings.

Conclusions

PET scan has a crucial role in thoracic oncology due to its impact on diagnosis, staging and prognosis. PET scan expresses the biological behavior of tumors, opening interesting perspectives in chest tumor management and improving detection and stage grouping in lung cancer. It anticipates the diagnosis in long-incubating diseases such as mesothelioma and increases biological knowledge of rare diseases, such as thymoma and other mediastinal tumors.

Investigation of the imaging characteristics of the ALBIRA II small animal PET system for 18F, 68Ga and 64Cu

AIM

In this study the performance characteristics of the Albira II PET sub-system and the response of the system for the following radionuclides ¹⁸F, ⁶⁸Ga and ⁶⁴Cu was analyzed.

MATERIALS AND METHODS

The Albira II tri-modal system (Bruker BioSpin MRI GmbH, Ettlingen, Germany) is a pre-clinical device for PET, SPECT and CT. The PET sub-system uses single continuous crystal detectors of lutetium yttrium orthosilicate (LYSO). The detector assembly consists of three rings of 8 detector modules. The transaxial field of view (FOV) has a diameter of 80mm and the axial FOV is 148mm. A NEMA NU-4 image quality phantom (Data Spectrum Corporation, Durham, USA) having five rods with diameters of 1, 2, 3, 4 and 5mm and a uniform central region was used. Measurements with ¹⁸F, ⁶⁸Ga and ⁶⁴Cu were performed in list mode acquisition over 10h. Data were reconstructed using a maximum-likelihood expectation-maximization (MLEM) algorithm with iteration numbers between 5 and 50. System sensitivity, count rate linearity, convergence and recovery coefficients were analyzed.

RESULTS

The sensitivities for the entire FOV (non-NEMA method) for ¹⁸F, ⁶⁸Ga and ⁶⁴Cu were (3.78±0.05)%, (3.97±0.18)% and (3.79±0.37)%, respectively. The sensitivity based on the NEMA protocol using the ²²Na point source yielded (5.53±0.06)%. Dead-time corrected true counts were linear for activities ≤7MBq (¹⁸F and ⁶⁸Ga) and ≤17MBq (⁶⁴Cu) in the phantom. The radial, tangential and axial full widths at half maximum (FWHMs) were 1.52, 1.47 and 1.48mm. Recovery coefficients for the uniform region with a total activity of 8MBq in the phantom were (0.97±0.05), (0.98±0.06), (0.98±0.06) for ¹⁸F, ⁶⁸Ga and ⁶⁴Cu, respectively.

CONCLUSION

The Albira II pre-clinical PET system has an adequate sensitivity range and the system linearity is suitable for the range of activities used for pre-clinical imaging. Overall, the system showed a favorable image quality for pre-clinical applications.

Clinical PET-MR Imaging in Breast Cancer and Lung Cancer

Hybrid imaging systems have dramatically improved thoracic oncology patient care over the past 2 decades. PET-MR imaging systems have the potential to further improve imaging of thoracic neoplasms, resulting in diagnostic and therapeutic advantages compared with current MR imaging and PET-computed tomography systems. Increasing soft tissue contrast and lesion sensitivity, improved image registration, reduced radiation exposure, and improved patient convenience are immediate clinical advantages. Multiparametric quantitative imaging capabilities of PET-MR imaging have the potential to improve understanding of the molecular mechanisms of cancer and treatment effects, potentially guiding improvements in diagnosis and therapy.

ANG1005 for breast cancer brain metastases: correlation between 18F-FLT-PET after first cycle and MRI in response assessment

PURPOSE

Improved therapies and imaging modalities are needed for the treatment of breast cancer brain metastases (BCBM). ANG1005 is a drug conjugate consisting of paclitaxel covalently linked to Angiopep-2, designed to cross the blood-brain barrier. We conducted a biomarker substudy to evaluate ¹⁸F-FLT-PET for response assessment.

METHODS

Ten patients with measurable BCBM received ANG1005 at a dose of 550 mg/m² IV every 21 days. Before and after cycle 1, patients underwent PET imaging with ¹⁸F-FLT, a thymidine analog, retention of which reflects cellular proliferation, for comparison with gadolinium-contrast magnetic resonance imaging (Gd-MRI) in brain metastases detection and response assessment. A 20 % change in uptake after one cycle of ANG1005 was deemed significant.

RESULTS

Thirty-two target and twenty non-target metastatic brain lesions were analyzed. The median tumor reduction by MRI after cycle 1 was -17.5 % (n = 10 patients, lower, upper quartiles: -25.5, -4.8 %) in target lesion size compared with baseline. Fifteen of twenty-nine target lesions (52 %) and 12/20 nontarget lesions (60 %) showed a ≥20 % decrease post-therapy in FLT-PET SUV change (odds ratio 0.71, 95 % CI: 0.19, 2.61). The median percentage change in SUV_max was -20.9 % (n = 29 lesions; lower, upper quartiles: -42.4, 2.0 %), and the median percentage change in SUV₈₀ was also -20.9 % (n = 29; lower, upper quartiles: -49.0, 0.0 %). Two patients had confirmed partial responses by PET and MRI lasting 6 and 18 cycles, respectively. Seven patients had stable disease, receiving a median of six cycles.

CONCLUSIONS

ANG1005 warrants further study in BCBM. Results demonstrated a moderately strong association between MRI and ¹⁸F-FLT-PET imaging.

The maximum standardized FDG uptake on PET-CT in patients with non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) accounts for approximately 80% of new diagnoses of pulmonary carcinoma. This study investigated the correlation between 18 F-fluorodeoxyglucose uptake in computerized tomography integrated positron emission tomography and tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC.

Methods

The records of 151 NSCLC patients (139 male, 12 female; mean age 59.60 years) were evaluated retrospectively.

Results

Forty-one cases were adenocarcinomas; 45 squamous cell carcinomas; and 65 unspecified NSCLC. When the cases were categorized according to tumor size (group 1, ≤ 3 cm; group 2, > 3 and ≤ 5 cm; group 3, > 5 cm), the maximum standardized uptake value (SUVmax) was significantly lower in groups 1 and 2 compared with group 3 (p = 0.006 for each). Considering all cases, tumor SUVmax was not correlated with age, gender, or histopathological type. Lymph node metastases were pathologically proven in 24 cases: 24% of these were adenocarcinomas, 6% squamous cell carcinomas, and 16% unspecified NSCLC. Neither lymph node involvement nor distant metastases were correlated with tumor SUVmax, although lymph node size was positively correlated with lymph node SUVmax (r = 0.775; p < 0.001).

Conclusions

SUVmax was significantly associated with tumor size, but not with distant metastases or lymph node involvement. Therefore, SUVmax on positron emission tomography is not predictive of the presence of metastases.

18F-FDG PET/CT in mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic country: consideration of lymph node calcification and distribution pattern to improve specificity

PURPOSE

The aim of the study was to assess the accuracy of (18)F-fluorodeoxyglucose (FDG) PET/CT in mediastinal lymph node staging of patients with non-small-cell lung cancer (NSCLC) in a region with a high prevalence of granulomatous disease.

METHODS

Between March 2004 and February 2006, all patients with NSCLC underwent FDG PET/CT and contrast-enhanced thoracic CT, and subsequent surgical resection. PET/CT and contrast-enhanced CT images of 182 patients (126 men and 56 women; mean age 60.7 years) with NSCLC were acquired. Mediastinal node staging was determined using the American Joint Committee on Cancer (AJCC) staging system. Surgical and histological findings served as the reference standard.

RESULTS

A total of 182 patients with 778 mediastinal node stations were evaluated. Sensitivity and specificity of contrast-enhanced CT were 36% and 80% on a per-patient basis and 23% and 92% on a per-node station basis. Sensitivity and specificity of PET/CT were 81% and 73% on a per-patient basis and 75% and 85% on a per-node station basis. After lymph nodes with calcification and bilateral hilar distribution were considered benign, sensitivity and specificity of PET/CT were 75% and 89% on a per-patient basis and 66% and 96% on a per-node station basis.

CONCLUSION

This prospective study suggests that FDG PET/CT can more accurately stage mediastinal lymph nodes than CT. Considering lymph node calcification and distribution pattern could improve specificity at the cost of a decrease in sensitivity.

Relationship between maximum standardized uptake value (SUVmax) of lung cancer and lymph node metastasis on FDG-PET

PURPOSE

To evaluate the relationship between SUVmax of primary lung cancers on FDG-PET and lymph node metastasis.

METHOD AND MATERIALS

The subjects were a total of consecutive 66 patients with lung cancer who were examined by FDG-PET and subsequently underwent surgery between October 2004 and January 2008. There were 41 males and 25 females, ranging in age from 45 to 83 years with an average of 68 years. The pathological subtypes of the lung cancers consisted of 49 adenocarcinomas, 11 squamous cell carcinomas, 2 adenosquamous carcinoma, 1 large cell carcinoma, 1 small cell carcinoma, 1 pleomorphic carcinoma and 1 mucoepidermoid carcinoma. We statistically compared (1) the mean SUVmax of lung cancer between the groups with and without lymph node metastasis (2) the frequency of lymph node metastasis between higher and lower SUVmax of lung cancer groups that were classified by using the median SUVmax of lung cancer, and (3) evaluated the relationship between the SUVmax of lung cancer and frequency of lymph node metastases, and (4) correlations between the SUVmax of lung cancer and number of the metastatic lymph nodes and pathological n stages.

RESULTS

The difference in the average of the SUVmax of lung cancer between the cases with and without lymph node metastases was statistically significant (p = 0.00513). Lymph node metastasis was more frequently seen in the higher SUVmax of lung cancer group (17/33, 52%) than in the lower SUVmax of lung cancer group (7/33, 21%) with a statistically significant difference. There was no lymph node metastasis in lung cancers with an SUVmax of lung cancer less than 2.5, and lung cancers with an SUVmax of lung cancer more than 12 had a 70% frequency of lymph node metastasis. There were moderate correlations between SUVmax of lung cancer, and the number of the metastatic lymph nodes (gamma = 0.404, p = 0.001) and pathological n stage (gamma = 0.411, p = 0.001).

CONCLUSIONS

The likelihood of lymph node metastasis increases with an increase of the SUV of a primary lung cancer.

Thin-section CT of the mediastinum in preoperative N-staging of non-small cell lung cancer: comparison with FDG PET

PURPOSE

To compare diagnostic capability of preoperative N-staging of lung cancer between thin-section CT of the mediastinum and FDG PET, and 5mm slice thickness CT.

MATERIALS AND METHODS

The subjects were 34 patients with lung carcinoma who were examined by both CT and PET, and subsequently underwent surgery between May 2005 and January 2007. CT was carried out with a 16 detector row helical CT scanner. The raw data were reconstructed into 5 mm slice thickness and 1mm slice thickness (thin-section CT). A total of 251 lymph node stations were retrospectively assessed for the presence of lymph node metastasis with thin-section CT, 5 mm CT and PET. In the interpretations of thin-section CT and 5 mm CT, we employed multi-criteria as follows: nodular calcification and intranodal fat as benign criteria, and short-axis diameter more than 10 mm (size criterion), focal low density other than fat, surrounding fat infiltration and convex margin in hilar lymph nodes, as malignant criteria. On PET, maximum standardized uptake value (SUVmax) of 2.5 or more was used as the criterion of malignancy. Sensitivity and specificity were compared between these examinations using McNemar test.

RESULTS

Sensitivities and specificities of thin-section CT, 5 mm CT and PET were 25%, 25%, 25%, and 97%, 94%, 98%, respectively. The statistical analysis revealed that the specificity of 5 mm CT was significantly lower than those of thin-section CT (p=0.039) and PET (p=0.006), while no difference was present between thin-section CT and PET.

CONCLUSION

Thin-section CT of the mediastinum using multiple criteria was comparable to PET in preoperative N-staging of lung cancer.

Diagnostic performance of (18)F-FDG PET/CT for lymph node staging in patients with operable non-small-cell lung cancer and inflammatory lung disease

As (18)F-fluorodeoxyglucose (FDG) is taken up by inflammatory lymph nodes, it could be falsely interpreted as metastasis. Therefore, we evaluated the diagnostic ability of positron emission tomography/computed tomography (PET/CT) for lymph node staging of lung cancer when inflammatory lung disease coexisted. Patients with operable non-small-cell lung cancer and FDG-avid lymph nodes were retrospectively classified into two groups; those with inflammatory lung disease (ILD) and those without it (NILD). Receiver operating characteristic (ROC) curve analysis was performed for maximum standardized uptake value (SUVmax), pattern of FDG uptake, maximum Hounsfield unit, and size, and then the areas under the ROC curves (AUCs) were compared between subgroups. There were 124 patients (ILD/NILD = 38/86) and 396 FDG-avid lymph nodes (ILD/NILD = 140/256). The average number of FDG-avid lymph nodes was greater in ILD (3.7 vs. 2.9, p = 0.039), whereas the proportion of metastasis was higher in NILD (25.4% vs. 11.4%, p = 0.002). With all N1-N3 lymph nodes and the NILD group, the AUC values of all four parameters were significantly greater than 0.5 (p < 0.05), and SUVmax was the most valuable parameter for lymph node metastasis. However, in the ILD group, only the AUC value of SUVmax was significantly greater than 0.5. These results were reproduced when analyses were performed with N1-N2 lymph nodes. In conclusion, SUVmax was the most valuable PET/CT parameter for assessment of lymph node metastasis in patients with operable non-small-cell lung cancer. In addition, it was the only valuable parameter when inflammatory lung disease coexisted.

False positive 18F-FDG-PET/CT in a patient after talc pleurodesis

A 61-year-old man presented with spontaneous pneumothorax. After diagnosis of emphysemic bullae, the patient underwent talc pleurodesis and had no further complaints. Five years later a routine chest X-ray showed suspicious pleural lesions in addition to the emphysema, which was deemed compatible with the known history of talc pleurodesis. Subsequent chest CT, however, revealed one lesion in the right lung that appeared not typical for this condition in addition to multiple lesions in pleural proximity. FDG-PET/CT demonstrated high glucose uptake in all the lesions. Subsequent needle biopsy of the suspicious intrapulmonary and also of one mediastinal lesion yielded the histopathological diagnosis of talcum granuloma with long-standing calculous fibrotic changes and no evidence of malignancy. This report on PET/CT after talc pleurodesis addresses the potential pitfalls caused by this condition, as chronic granulomatous reactions, like other inflammatory lesions, may account for highly increased FDG uptake which should be interpreted with caution and not simply read as a sign of malignancy. PET/CT offers the opportunity to exactly localize the areas of increased FDG uptake within regions of pleural thickening caused by talc deposition, however, the dilemma of misleading FDG accumulation cannot be solved by this hybrid imaging modality.

Predictors of Survival and Disease-Free Survival in Patients With Resected N1 Non-Small Cell Lung Cancer

BACKGROUND

Factors that predict poor survival or increased risk of recurrence for patients with N1 disease may be dependent on tumor characteristics.

METHODS

This study was a retrospective review of a prospective database of consecutive patients who had clinical or pathologic N1 non-small cell lung cancer (NSCLC) who underwent preoperative 2-[18F] fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) scans and complete resection with thoracic lymphadenectomy.

RESULTS

There were 135 patients (88 men). The 5-year disease-free rate was 55%. Kaplan-Meier analysis showed that poor differentiation (p = 0.036), multiple N1 stations (p = 0.010), and the lack of adjuvant chemotherapy (p = 0.039) were all associated with a shorter 5-year disease-free rate. Multivariate disease-free analysis demonstrated that only multiple stations (p = 0.002) were independently associated with recurrence. The overall 5-year survival was 48%. Univariate analysis showed that multiple nodes within one station (p = 0.016), multiple station involvement (p = 0.041), and lack of adjuvant chemotherapy (p = 0.039) and moderate-to-poor tumor differentiation (p = 0.046) were associated with decreased survival. Multivariate analysis found that multiple stations, multiple nodes, and lack of adjuvant chemotherapy were independent predictors of poor survival. Integrated PET-computed tomography (CT) was significantly more sensitive for staging N1 disease than dedicated FDG-PET (p = 0.032). Neoadjuvant chemotherapy given to 48 nonrandomized patients did not seem to impact disease recurrence or overall 5-year survival rates (p = 0.349).

CONCLUSIONS

Factors that predict a poor outcome in patients with resected N1 NSCLC are the involvement of multiple N1 stations, multiple N1 nodes, and the lack of adjuvant chemotherapy. Integrated PET-CT is more sensitive for detecting N1 disease then dedicated PET. These data may influence preoperative or postoperative therapy, or both.

Multispectral imaging autofluorescence microscopy in colonic and gastric cancer metastatic lymph nodes

BACKGROUND & AIMS

The lymphadenectomy and extended lymphadenectomy procedures have been points of controversy in surgical oncology. The methods available for the detection of metastatic lymph nodes are numerous. These include lymphoscintigraphy and radiolabeled antibody detection, but in most cancers the currently used technique is sentinel lymph node identification, performed primarily through the use of immunohistochemistry. We propose the application of autofluorescence (AF)-based techniques for lymph node evaluation in colorectal and gastric tumors.

METHODS

We studied 30 clinical cases: 15 colorectal cancers and 15 gastric cancers. All of the patients were in the advanced stages of the disease and were candidates for adjuvant therapy. Autofluorescence microspectroscopy and multispectral imaging autofluorescence microscopy have been used to analyze the AF emission of metastatic lymph node sections, excited with 365-nm wavelength radiation. The AF spectra were recorded in the range of 400-700 nm. Monochrome AF images were acquired sequentially through interference filters peaked at 450, 550, and 650 nm, and then combined together in a single red-green-blue image. The AF pattern and the emission spectrum of metastatic lymph nodes have unique characteristics that can be used to distinguish them from the normal ones.

RESULTS

The results, compared with standard histopathologic procedures and with specific staining methods, supplied a satisfactory validation of the proposed technique, revealing the possibility of improving the actual diagnostic procedures for malignant lymph node alterations.

CONCLUSIONS

With the development of appropriate instrumentation, the proposed technique could be particularly suitable in intrasurgical diagnosis of metastatic lymph nodes.

[18F-FDG PET and bone scintigraphy to search for bone metastasis of lung cancer]

Initial staging of lung cancer is essential to determine the appropriate therapeutic strategy. 18F-FDG PET is currently considered to be the gold standard. 99mTc bisphonate bone scintigraphy has long been indicated to search for bone metastases but it is not know whether this exploration adds further information after an 18F-FDG PET scan. In order to answer this question, two observers unaware of the clinical situation reread PET scans and bone scintigraphies and results compared with other imaging findings. Between February 2001 and March 2004, 39 patients (13F, 26M, 62 +/- 11 yr) underwent 18FFDG PET and bone scintigraphy (mean interval 17 +/- 17 d). When the two explorations agreed for the diagnosis of bone extension, we considered that bone scintigraphy added nothing. When the two explorations were in disagreement, the other imaging examinations, the clinical features and laboratory results during the five-month minimal follow-up were used to establish the reference diagnosis. 18F-FDG PET and bone scintigraphy were in agreement in 29 patients (74%) with positive results in 12 (31%) and negative results in 17 (43%). The two explorations were in disagreement in 10 patients (26%). Among the five disagreement cases with positive bone scintigraphy and no bone anomaly on the 18F-FDG PET, the anomalies were benign and explained by clinical features (3 patients) or were not confirmed by the clinical course and laboratory results (2 patients). Among the 5 cases with a bone anomaly on the 18F FDG PET, no metastasis could be identified during clinical follow-up. Bone scintigraphy does not enable identification of any bone metastases which were not recognized on the PET scan and therefore should not be performed systematically. Using a computed tomography scan with the 18F-FDG PET could further limit the contribution of bone scintigraphy by providing more precision concerning foci identified on the PET scan.

Intérêt de la tomographie par émission de positons au [18F]-fluoro-2-désoxyglucose dans la détermination des volumes cibles de radiothérapie. Application à l'irradiation conformationnelle des cancers bronchiques non à petites cellules

Traditional radiation treatment planning relies on density imaging such as Computed Tomography for anatomic information of various structures of interest including target and normal tissues. However, the difficulties to distinguish malignant from normal tissue on CT slides often leads to inaccurate outlining of the GTV and/or to geographic misses. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has shown an increase in both sensitivity and specificity over CT in locoregional staging of patients with non-small cell lung cancer (NSCLC). The co registration of FDG-PET images to the data of the CT planning offers the radiation oncologist the possibility to include functional information into the target outlining. For the treatment of patients with NSCLC, it has been shown that the use of FDG-PET images: 1) modified the shape and volume of radiation fields in 22-62% of cases, mainly due to a better nodal staging and distinction of atelectasis from tumor and; 2) significatively reduced the interobserver and intraobserver variability. This paper reviews the results reported in the literature. Challenges and proposed solutions are discussed.

Preoperative assessment for lung cancer surgery

PURPOSE OF REVIEW

Pulmonary resection remains the only curative treatment option for lung cancer surgery. This review summarizes recent advances in the preoperative functional evaluation of the patient with lung cancer.

RECENT FINDINGS

The workup of patients with bronchogenic carcinoma covers three areas: tumor type, tumor extent, and patient cardiopulmonary reserves. Significant advances have been made in the latter two areas. Traditionally lobectomy was regarded as the minimum resection for lung cancer; new studies are challenging this view and suggesting that segmentectomy is acceptable for stage Ia cancers < or =20 mm. An important change relating to cardiopulmonary reserves of the patient is the shift in emphasis toward early exercise testing and, in particular, the use of stair climbing as a surrogate marker of maximal oxygen consumption. New studies confirm the benefit of combined lung volume reduction surgery and lung cancer surgery in certain patients who might otherwise be excluded from surgery because of poor lung function.

SUMMARY

Advances in the preoperative workup of lung cancer patients and in surgical techniques are permitting resections in previously inoperable patients. A new, simplified algorithm for the preoperative workup of lung cancer patients assessing the value of stair climbing as a surrogate marker of maximal oxygen consumption is proposed.

Cost-effectiveness analysis of strategies introducing FDG-PET into the mediastinal staging of non-small-cell lung cancer from the French healthcare system perspective

AIM

To determine the most cost-effective strategy using PET for mediastinal staging of potentially operable non-small-cell lung cancer (NSCLC).

METHODS

Four decision strategies based on French NSCLC work-up practices for the selection of potential surgical candidates were compared, comprising CT only, PET for negative CT, PET for all with anatomical CT, and CT and PET for all cases. The medical literature was surveyed to obtain values for all variables of interest. Costs were assessed with reimbursements from the French healthcare insurance for the year 1999. Expected cost and life expectancy were calculated for all possible outcomes of each strategy. Sensitivity analysis was performed to determine the effects of changing variables on the expected cost and life expectancy.

RESULTS

Compared with the CT only strategy, CT and PET for all resulted in a relative reduction of 70% of surgery for persons with mediastinal lymph node metastasis. PET for all with anatomical CT was shown to be a cost-effective alternative to the CT only, with life expectancy increased by 0.10 years and expected cost savings of 61 euros. This strategy was more favourable than PET for negative CT. Overall, sensitivity analyses showed the robustness of the results.

CONCLUSION

The introduction of thoracic PET for NSCLC staging is potentially cost-effective in France. Further clinical investigation might help to validate this result.

Fluorodeoxyglucose-PET in characterizing solitary pulmonary nodules, assessing pleural diseases, and the initial staging, restaging, therapy planning, and monitoring response of lung cancer

Fluorodeoxyglucose-PET imaging has secured an important role in the assessment and management of a multitude of pulmonary disorders, including solitary pulmonary nodules, lung cancer, and pleural diseases. While conventional imaging modalities such as chest radiography and CT are considered essential in these settings, FDG-PET can provide new information and complement structural imaging techniques in the evaluation of such disorders. In this review, the authors present a growing body of evidence that demonstrates and supports the utility of FDG-PET in the differentiation of benign and malignant pulmonary nodules, the assessment of lung cancer in various stages of disease, and the characterization of pleural diseases. In addition, new developments--such as prospects for potential utility of novel radiotracers and delayed imaging--that can further refine the role of FDG scans in the work-up of lung nodules and cancer and forecast the future place of PET in these common modalities are discussed.