Maximum Standard Uptake Value of Mediastinal Lymph Nodes on Integrated FDG-PET-CT Predicts Pathology in Patients with Non-Small Cell Lung Cancer

Positron emission tomography in nonsmall cell lung cancer

PURPOSE OF REVIEW

[(8)F]2-Fluoro-2-deoxy-glucose positron emission tomography is an important functional imaging technique for the diagnosis, staging and follow-up of patients with nonsmall cell lung cancer. We review recent developments with the emphasis on impact of positron emission tomography in early diagnosis, staging, restaging and prognosis of nonsmall cell lung cancer.

RECENT FINDINGS

Data on the use and interpretation of positron emission tomography became available for small pulmonary nodules. We should abandon the 'magic' standardized uptake value threshold of 2.5 and rather make a visual assessment in this setting. The high negative predictive value of positron emission tomography in mediastinal staging was confirmed in a large prospective study. Tissue confirmation of all qualitative or quantitative suspicious mediastinal lymph nodes at positron emission tomography remains required. Minimally invasive techniques such as endobronchial ultrasound-guided transbronchial needle aspiration seem promising in this setting with sensitivities up to 90%. Recent data also point at integrated positron emission tomography/computed tomography as a tool for response assessment of mediastinal nodes and, more interestingly, of the primary tumor. Positron emission tomography has the potential to predict survival based on baseline positron emission tomography stage and standardized uptake value, visual [(18)F]2-fluoro-2-deoxy-glucose uptake at the time of suspected recurrence, and change in [(18)F]2-fluoro-2-deoxy-glucose uptake after neoadjuvant therapy.

SUMMARY

Refinements in diagnosis and staging, as well as newer applications such as guidance of endoscopy and assessment of treatment, are described.

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.

Fibrosing mediastinitis as a rare sequel of iatrogenic rupture of bronchogenic cyst--a case report

Fibrosing mediastinitis is a chronic disease process with a spectrum of etiology. We report a 51-year-old female who underwent incision and drainage procedure in the neck for deep neck and mediastinal abscess. Five years later she developed fibrosing mediastinitis. This lesion infiltrated from neck base into the upper mediastinum with tracheal compression and vessel encasement. She had resection of the lesion which proved to be a ruptured bronchogenic cyst with chronic inflammation. This rare case illustrates the importance of including inflammatory bronchogenic cyst in the etiology of deep neck abscess formation. And we further find a ruptured bronchogenic cyst with chronic inflammation as an etiology of fibrosing mediastinitis.

Ratio of the maximum standardized uptake value on FDG-PET of the mediastinal (N2) lymph nodes to the primary tumor may be a universal predictor of nodal malignancy in patients with nonsmall-cell lung cancer

BACKGROUND

The maximum standardized uptake value (maxSUV) on F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) scan of mediastinal (N2) lymph nodes may predict pathology in patients with nonsmall-cell lung cancer. However, the maxSUV varies among PET scanners. Thus, we evaluated the ratio of the maxSUV of the lymph node to the primary tumor at different centers to determine whether it was a universal predictor of lymph node malignancy.

METHODS

This is a retrospective review of a prospective database. Patients with nonsmall-cell lung cancer, a dedicated FDG-PET with the maxSUV of the primary lung tumor and FDG-avid mediastinal (N2) nodes reported (before therapy), and who underwent lymph node removal were eligible.

RESULTS

There were 239 patients with 335 FDG-PET-positive N2 nodes at 14 different PET centers. The median ratio of the maxSUV of the lymph node to the maxSUV of the primary tumor of the pathologically proven malignant nodes was 0.58 (range, 0.32 to 1.61). Benign nodes had a median ratio of 0.40 (range, 0.21 to 1.10, p = 0.02). The median value was similar for all centers except one. Receiver operating characteristics analysis determined the optimal value of the ratio that maximized sensitivity to be 0.56 or greater (+LR 6.6, sensitivity 94%, specificity 72%).

CONCLUSIONS

The ratio of the maxSUV of the mediastinal (N2) lymph node to the maxSUV of the primary tumor in patients with nonsmall-cell lung cancer predicts mediastinal nodal pathology across different PET centers. When the ratio is 0.56 or greater, there is a 94% chance that the node is malignant. The ratio may take into account the different techniques used at different centers.

Surgery of non-small cell lung cancer in the elderly

PURPOSE OF REVIEW

The aim of this review is to analyze recent evidence for optimal treatment of elderly patients with non-small cell lung cancer, focusing on surgery, and possibly to foresee the future strategies to apply in these patients.

RECENT FINDINGS

Surgery in elderly patients affected by non-small cell lung cancer is safe and feasible when careful preoperative respiratory and cardiac studies have been carried out and the disease has been properly staged. The surgical treatment is not to be denied in elderly patients due to age per se, but when a major contraindication to surgery has been recognized. Long term survival for elderly patients with early stage lung cancer treated by anatomical pulmonary resection is comparable to the survival rate of younger patients. Pneumonectomy, extended surgical procedure or preoperative induction chemotherapy are major risk factors for an increased postoperative morbidity and mortality rate. When co-morbidities are present or a patient is 80 years or older, there is evidence that a non-anatomical resection can be performed without affecting long-term results.

SUMMARY

Due to the aging of the general population, elderly patients will become a large percentage of the cases of non-small cell lung cancer to be treated. Implementing preoperative cardiologic studies and redefining selective respiratory criteria specifically could dramatically improve results.

The clinical stage of non–small cell lung cancer as assessed by means of fluorodeoxyglucose–positron emission tomographic/computed tomographic scanning is less accurate in cigarette smokers

OBJECTIVE

The treatment of non-small cell lung cancer depends on the stage, and this is clinically best determined by using fluorodeoxyglucose-positron emission tomography/computed tomography. We evaluated the effect smoking has on the accuracy of this test.

METHODS

We performed a prospective cohort study evaluating the accuracy of clinical stage compared with pathologic stage between cigarette smokers and nonsmokers with non-small cell lung cancer. All patients were assigned a clinical TNM stage after fluorodeoxyglucose-positron emission tomographic/computed tomographic scanning and then underwent meticulously pathologic TNM staging. If N2, N3, or M1 negative, patients underwent thoracotomy with complete thoracic lymphadenectomy. The clinical and pathologic stages were compared.

RESULTS

There were 246 patients: 52 never smoked (NS group), 112 quit at least 1 month before fluorodeoxyglucose-positron emission tomography/computed tomography (Q group), and 82 were still smokers (S group). The 3 groups were similar for stage and histology. The overall accuracy was 83%, 80%, and 64% for the NS, Q, and S groups, respectively (P = .03). The accuracy for the T status was 88%, 84%, and 86%; accuracy for the N2 lymph nodes was 96%, 75%, and 72%; and accuracy for the N1 lymph nodes was 92%, 78%, and 80%, respectively, favoring the NS group. The greater the pack-year history, the greater the N2 inaccuracy (P = .04). Multivariate analysis showed that status of smoking (P = .026) and maxSUV value (P = .014) were independent predictors of fluorodeoxyglucose-positron emission tomography/computed tomography accuracy.

CONCLUSIONS

Patients with non-small cell lung cancer who continue to smoke at the time of their fluorodeoxyglucose-positron emission tomographic/computed tomographic scan have less accurate clinical staging compared with those who stopped 1 month before or who never smoked. As the pack-years increase, the accuracy for the N2 nodes decrease. Nonsmokers have the most accurate clinical staging.

The maximum standardized uptake values on integrated FDG-PET/CT is useful in differentiating benign from malignant pulmonary nodules

BACKGROUND

Positron emission tomography (PET) is often used for an indeterminate pulmonary nodule.

METHODS

This is a prospective study on a consecutive series of patients who had an indeterminate pulmonary nodule that was 2.5 cm or less, underwent integrated positron emission tomography using fluorodeoxyglucose-PET/computed tomographic [FDG-PET/CT] scan with the maximum standardized uptake values (maxSUVs) reported, and who underwent complete resection.

RESULTS

There were 585 patients (401 men). A total of 496 patients had a malignant nodule and the median maxSUV was 8.5 (range, 0 to 36). Eighty-nine patients had a benign nodule and the median maxSUV was 4.9 (range, 0 to 28, p < 0.001). If the maxSUV was between 0 and 2.5 there was a 24% chance the nodule was malignant, if between 2.6 and 4.0 it was 80%, and if 4.1 or greater it was 96%. False negative FDG-PET/CT was from bronchoalveolar carcinoma in 11 patients, carcinoid in 4, and renal cell in 2. False positives included fungal infections in 16 patients. Nodal involvement, whether malignant or infectious, was more likely with a pulmonary mass that had a higher maxSUV (8.4 vs 3.8 for nonmalignant lesions, 9.8 vs 4.5 for malignant lesions).

CONCLUSIONS

Although integrated FDG-PET/CT is a valuable study for an indeterminate pulmonary nodule, one must be aware of causes of false positives and negatives. There is a 24% chance a suspicious nodule that has a maxSUV of 0 to 2.5 is cancer. The higher the maxSUV of the primary mass the more likely the nodes are to be involved with either malignancy or infection, and this may help direct nodal biopsy instead of pulmonary resection.