Yoshiki Demura

Evaluation of Dual–Time-Point 18F-FDG PET for Staging in Patients with Lung Cancer

18F-FDG PET is increasingly used for lung cancer; however, some insufficient results have been reported. The purpose of this study was to evaluate the efficacy of dual–time-point 18F-FDG PET for staging lung cancer and for differentiating metastatic from nonmetastatic lung cancer lesions. Methods: One hundred fifty-five lung cancer patients with known or suspected mediastinal and hilar lymph node involvement or distant metastases underwent whole-body 18F-FDG PET at 2 time points: scan 1 at 60 min (early imaging) and scan 2 at 180 min (delayed imaging) after 18F-FDG injection. 18F-FDG PET findings of nodal and distant metastases were evaluated using conventional imaging, clinical follow-up findings, and the results of autopsy or biopsy. Results: A total of 580 lesions (155 primary lesions, 315 metastatic lesions, and 110 nonmetastatic lesions) were used for analysis. A closer correlation between the primary lesions and metastases was observed for the retention index (RI) standardized uptake value (SUV) than for early and delayed SUV. There was no relationship between the RI SUV results of primary lesions and those of nonmetastatic lesions. The RI SUV of metastatic lesions was approximately 0.5–2 times the RI SUV of primary tumors. We found that the accuracy of 18F-FDG PET was improved when RI SUV was used for detecting lymph node and distant metastases, because of the significant improvement in specificity relative to early and delayed SUV. Conclusion: RI SUV raised the accuracy for diagnosis of metastases and was superior to early and delayed imaging in terms of differentiating malignancy from nonmetastatic uptake.

Pathophysiologic Correlation Between 62Cu-ATSM and 18F-FDG in Lung Cancer

The purpose of this study was to delineate the differences in intratumoral uptake and tracer distribution of 62Cu-diacetyl-bis(N4-methylthiosemicarbazone) (62Cu-ATSM), a well-known hypoxic imaging tracer, and 18F-FDG in patients with lung cancer of pathohistologically different types. Methods: Eight patients with squamous cell carcinoma (SCC) and 5 with adenocarcinoma underwent 62Cu-ATSM and 18F-FDG PET within a 1-wk interval. For 62Cu-ATSM PET, 10-min static data acquisition was started at 10 min after a 370- to 740-MBq tracer injection. After image reconstruction, 62Cu-ATSM and 18F-FDG images were coregistered, and multiple small regions of interest were drawn on tumor lesions of the 2 images to obtain standardized uptake values (SUVs). The regression lines were determined between SUVs for 62Cu-ATSM and 18F-FDG in each tumor. The slope values were compared between SCC and adenocarcinoma to observe pathohistologic differences in intratumoral distribution of the tracers. Results: SUVs for 62Cu-ATSM were lower than those for 18F-FDG in both SCC and adenocarcinoma. SCC tumors showed high 62Cu-ATSM and low 18F-FDG uptakes in the peripheral region of tumors but low 62Cu-ATSM and high 18F-FDG uptakes toward the center (spatial mismatching). The relationship of SUVs for the 2 tracers was negatively correlated with a mean regression slope of −0.07 ± 0.05. On the other hand, adenocarcinoma tumors had a spatially similar distribution of 62Cu-ATSM and 18F-FDG, with positive regression slopes averaging 0.24 ± 0.13. The regression slopes for 62Cu-ATSM and 18F-FDG differed significantly between SCC and adenocarcinoma (P < 0.001). Conclusion: The intratumoral distribution patterns of 62Cu-ATSM and 18F-FDG were different between SCC and adenocarcinoma in lung cancers, indicating that intratumoral regions of high glucose metabolism and hypoxia could differ with the pathohistologic type of lung cancer. The identification of regional biologic characteristics in tumors such as hypoxia, energy metabolism, and proliferation could play a significant role in the clinical diagnosis and therapy planning for non–small cell lung cancer patients.

Reappraisal of Clindamycin IV Monotherapy for Treatment of Mild-to-Moderate Aspiration Pneumonia in Elderly Patients

BACKGROUND As the number of elderly people has increased in Japan, the occurrence of aspiration pneumonia has also increased. Guidelines for the treatment of pneumonia have been proposed, in which the use of antibiotics, such as beta-lactam plus beta-lactamase inhibitor, clindamycin, and carbapenem, has been recommended as effective against anaerobic bacteria in the treatment of aspiration pneumonia. However, to our knowledge, a prospective comparison of these antibiotics regarding their clinical efficacy in aspiration pneumonia has not been performed. STUDY OBJECTIVES We compared the effects of IV administration of a half dose of ampicillin/sulbactam (SBT/ABPC), normal dose of SBT/ABPC, IV clindamycin, and IV panipenem/betamiprom (PAPM/BP) for treatment of mild-to-moderate aspiration pneumonia in elderly patients. DESIGN Randomized prospective study. PATIENTS One hundred adult patients with compatible signs and symptoms of aspiration pneumonia. ASSESSMENTS Patients were assessed before, during, and after treatment regarding symptoms, as well as results of laboratory values, chest radiograph examinations, and sputum bacterial cultures. RESULTS We found few differences between the groups regarding cure rate, duration of IV medication, and occurrence of adverse effects with the tested therapies. However, clindamycin therapy was less expensive and was associated with a lower rate of posttreatment occurrence of methicillin-resistant Staphylococcus aureus. CONCLUSIONS Clindamycin therapy for mild-to-moderate aspiration pneumonia is clinically effective, and provides economic advantages as compared to SBT/ABPC or PAPM/BP therapy.

The Effectiveness of 18F-FDG PET/CT Combined with STIR MRI for Diagnosing Nodal Involvement in the Thorax

The purpose of this study was to compare the efficacy of short-τ inversion-recovery (STIR) MRI and 18F-FDG PET/CT for the detection of metastasis in mediastinal and hilar lymph nodes in patients with lung cancer. Methods: Ninety-three patients with known or suspected lung cancer with mediastinal and hilar lymph node swelling underwent STIR MRI and 18F-FDG PET/CT examinations. STIR MRI scans were obtained with a 2% copper sulfate phantom placed along the back of each patient, with the lymph node–to–phantom ratio calculated for quantitative analysis. For qualitative analysis, the results of all STIR MRI scans were evaluated using a 5-point visual scoring system. To evaluate the diagnostic capabilities of STIR MRI and 18F-FDG PET/CT, we used receiver-operating-characteristic curve analysis to determine the optimal thresholds for the lymph node–to–phantom ratio, visual score, and maximal standardized uptake value. Further, the capability of each to determine N-stage was compared in each patient using the McNemar test. Results: A total of 137 lymph nodes (82 malignant lesions, 55 benign lesions) were analyzed. When optimal threshold values were adopted, the quantitative and qualitative sensitivity, specificity, and accuracy of STIR MRI were not significantly different from those of 18F-FDG PET/CT. However, 18F-FDG PET/CT in combination with qualitative STIR MRI analysis had a significantly higher capability to detect nodal involvement on an individual-patient basis (96.9% specificity, 90.3% accuracy) than did 18F-FDG PET/CT alone (65.6% specificity, 81.7% accuracy). Conclusion: We found that the diagnostic capability of STIR MRI was not significantly different from that of 18F-FDG PET/CT. However, when those methods were combined, the diagnostic capability for N-staging was significantly improved.

Changes in HRCT findings in patients with respiratory bronchiolitis-associated interstitial lung disease after smoking cessation

High-resolution computed tomography (HRCT) findings in patients with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) are varied and nonspecific. There is no known report of changes in HRCT findings and respiratory function test results for RB-ILD patients following the cessation of smoking. Five patients with RB-ILD, confirmed by surgical lung biopsy, were retrospectively studied. Each stopped cigarette smoking and did not receive corticosteroid therapy after diagnosis. The clinical symptoms, respiratory function test results and HRCT findings obtained at the final observation were compared with those from the time of diagnosis. Ground-glass opacity and centrilobular nodules corresponding to pathological respiratory bronchiolitis, as well as intralobular fine linear-reticular opacity corresponding to fibrosis involving the subpleural alveolar septa, showed computed tomography–pathological correlations. Both clinical symptoms and the diffusing capacity of the lungs for carbon monoxide improved significantly following smoking cessation, as did ground-glass opacity and centrilobular nodules seen during the initial HRCT examination. Centrilobular nodules and ground-glass opacity, which are the main features of high-resolution computed tomography of respiratory bronchiolitis-associated interstitial lung disease patients and represent pathological respiratory bronchiolitis, can be improved by smoking cessation. The diffusing capacity of the lung for carbon monoxide in respiratory function tests can be also improved.

Utility of high-resolution computed tomography for predicting risk of sputum smear-negative pulmonary tuberculosis

BACKGROUND To diagnose sputum smear-negative pulmonary tuberculosis (PTB) is difficult and the ability of high-resolution computed tomography (HRCT) for diagnosing PTB has remained unclear in the sputum smear-negative setting. We retrospectively investigated whether or not this imaging modality can predict risk for sputum smear-negative PTB. METHODS We used HRCT to examine the findings of 116 patients with suspected PTB despite negative sputum smears for acid-fast bacilli (AFB). We investigated their clinical features and HRCT-findings to predict the risk for PTB by multivariate analysis and a combination of HRCT findings by stepwise regression analysis. We then designed provisional HRCT diagnostic criteria based on these results to rank the risk of PTB and blinded observers assessed the validity and reliability of these criteria. RESULTS A positive tuberculin skin test alone among clinical laboratory findings was significantly associated with an increase of risk of PTB. Multivariate regression analysis showed that large nodules, tree-in-bud appearance, lobular consolidation and the main lesion being located in S1, S2, and S6 were significantly associated with an increased risk of PTB. Stepwise regression analysis showed that coexistence of the above 4 factors was most significantly associated with an increase in the risk for PTB. Ranking of the results using our HRCT diagnostic criteria by blinded observers revealed good utility and agreement for predicting PTB risk. CONCLUSIONS Even in the sputum smear-negative setting, HRCT can predict the risk of PTB with good reproducibility and can select patients having a high probability of PTB.

Prognostic value of dual‐time‐point 18F‐fluorodeoxyglucose positron emission tomography in patients with pulmonary sarcoidosis

Background and objective:  The value of dual‐time‐ point 18F‐FDG PET was investigated to predict the prognosis of patients with pulmonary sarcoidosis.

Reproducibility of Semi-quantitative Parameters in FDG-PET Using Two Different PET Scanners: Influence of Attenuation Correction Method and Examination Interval

PurposeThe aim of this study is to evaluate the reproducibility of semi-quantitative parameters obtained from two 2-deoxy-2-[F-18]fluoro-d-glucose-positron emission tomography (FDG–PET) studies using two different PET scanners.MethodsForty-five patients underwent FDG–PET examination with two different PET scanners on separate days. Two PET images with different attenuation correction method were generated in each patient, and three regions of interest (ROIs) were placed on the lung tumor and normal organs (mediastinum and liver) in each image. Mean and maximum standardized uptake values (SUVs), tumor-to-mediastinum and tumor-to-liver ratios (T/M and T/L), and the percentage difference in parameters between two PET images (% Diff.) were compared.ResultsAll measured values except maximum SUV in the liver and tumor-related parameters (SUV in lung tumor, T/M, T/L) showed no significant difference between two PET images.ConclusionThe mean measured values showed high reproducibility and demonstrate that follow-up study or measurement of tumor response to anticancer drugs can be undertaken by FDG–PET examination without specifying the particular type of PET scanner.

Imaging the early response to chemotherapy in advanced lung cancer with diffusion‐weighted magnetic resonance imaging compared to fluorine‐18 fluorodeoxyglucose positron emission tomography and computed tomography

To evaluate the feasibility of diffusion‐weighted magnetic resonance imaging (DW‐MRI) for assessment of the early response to chemotherapy and outcome in patients with advanced lung cancer through comparison with fluorine‐18 fluorodeoxyglucose positron emission tomography (FDG‐PET) and computed tomography (CT).

Multi-arterial infusion chemotherapy for non-small cell lung carcinoma—Significance of detecting feeding arteries and tumor staining

The present study examines the significance of defining feeding arteries to arterial infusion chemotherapy for patients with non-small cell lung carcinoma. We retrospectively studied feeding arteries and findings from 32 patients treated by arterial infusion chemotherapy. We graded tumor staining by angiography and compared grade in the bronchial artery with that of total staining in all detected feeding arteries, and investigated the relationship between grade and treatment response. One patient achieved a complete response and 16 achieved a partial response with no serious adverse effects. Many feeding arteries were detected and the grade of total tumor staining in these patients was significantly higher than that of tumor staining in the bronchial artery. The number of lesions that responded was significantly increased among those with a higher grade of total tumor staining. Precise definition of feeding arteries and sufficient tumor staining are vital to ensure a successful outcome of arterial infusion chemotherapy for patients with NSCLC.