Hiroaki Nomori

Diffusion-weighted magnetic resonance imaging for diagnosing malignant pulmonary nodules/masses: Comparison with positron emission tomography

Introduction: Recent developments of diffusion-weighted magnetic resonance imaging (DWI) make it possible to image malignant tumors to provide tissue contrast based on difference in the diffusion of water molecules among tissues, which can be measured by apparent diffusion coefficient (ADC) value. The aim of this study is to examine the usefulness of DWI for benign/malignant discrimination of pulmonary nodules/masses compared with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Methods: PET and DWI were carried out prospectively in 104 patients with 140 pulmonary nodules/masses before surgery. FDG uptake of each lesion was quantitatively measured by a contrast ratio of standard uptake value (SUV-CR) between the lesions and contralateral lung. Diffusion of water molecule in each lesion was quantitatively measured by a minimum ADC (ADC-min). The diagnostic results were compared between the two modalities. Results: The receiver operating characteristics curve showed cutoff values of the ADC-min and the SUV-CR for benign/malignant discrimination to be 1.1 × 10−3 mm2/s and 0.37, respectively. DWI and PET showed sensitivities of 0.70 and 0.72 and specificities of 0.97 and 0.79, respectively. Although there was no significant difference in sensitivity between the two methods, DWI showed a significantly higher specificity than PET because of fewer false-positives for active inflammatory lesions (p = 0.03). The ADC-min and SUV-CR values showed a significant reverse correlation (r = −0.504, p < 0.001). Conclusions: DWI may be able to be used in place of FDG-PET to distinguish malignant from benign pulmonary nodules/masses with fewer false-positive results compared with FDG-PET.

Japanese lung cancer registry study of 11,663 surgical cases in 2004: demographic and prognosis changes over decade.

Background: The Japan Lung Cancer Society, the Japanese Association for Chest Surgery, and the Japanese Respiratory Society jointly established the Japanese Joint Committee for Lung Cancer Registration, which has regularly conducted lung cancer registries for surgical cases in 5-year periods. We analyzed data obtained in these registries to reveal the most recent surgical outcomes and trends related to lung cancer surgery in Japan. Methods: Using data from the registry in 2010 for cases of surgery performed in 2004, demographics, surgical results, and stage-specific prognoses were analyzed. In addition, trends for those parameters over 10 years were assessed. Results: The 5-year survival rate for all cases (n = 11,663, 7369 males, mean age 66.7 years) was 69.6%. The 5-year survival rates by c-stage and p-stage were as follow: IA, 82.0% (n = 6295) and 86.8% (n = 4978); IB, 66.8% (n = 2339) and 73.9% (n = 2552); IIA, 54.5% (n = 819) and 61.6% (n = 941); IIB, 46.4% (n = 648) and 49.8% (n = 848); IIIA, 42.8% (n = 1216) and 40.9% (n = 1804); IIIB, 40.3% (n = 90) and 27.8% (n = 106); and IV, 31.4% (n = 256) and 27.9% (n = 434), respectively. The percentages of female patients, cases with adenocarcinoma, stage I or II disease, and tumors sized less than 2 cm were increased, while those of operative and hospital deaths were decreased. Furthermore, the prognoses of all cases and cases in each stage improved over the decade. Conclusion: In Japanese cases of lung cancer surgery, demographics, surgical results, and stage-specific prognoses changed over the 10-year study period, while the 5-year survival rate for surgical cases improved to 69.6% in 2004.

What is the advantage of a thoracoscopic lobectomy over a limited thoracotomy procedure for lung cancer surgery

BACKGROUND To clarify any advantages of video-assisted thoracoscopic surgery (VATS) over anterior limited thoracotomy (ALT) for lobectomy in lung cancer, we compared the two procedures in a retrospective analysis. METHODS Sex- and age-matched (+/- 5 years) lung cancer patients in clinical stage I who underwent lobectomy by means of VATS (n = 33) or ALT (n = 33) were compared in terms of the number of resected lymph nodes, operating time, intraoperative blood loss, duration of postoperative chest tube drainage, and chest pain. Pain was evaluated using a visual analog scale and analgesic requirements. Vital capacity (VC), respiratory muscle strength, and results of a 6-minute walking (6 MW) test were also compared preoperatively and 1 and 2 weeks postoperatively. RESULTS Compared with the ALT group, the VATS group experienced less pain between postoperative day (POD) 1 and POD 7 (p < 0.05 to 0.001) and had lower analgesic requirements up to POD 7 (p < 0.001). However, there were no significant differences in pain on POD 14. There were also no significant differences in intraoperative factors or in the postoperative impairment of VC, respiratory muscle strength, and 6 MW test results. CONCLUSIONS Although VATS lobectomy reduces chest pain during the first week after surgery compared with ALT, this advantage is lost within 2 weeks. Both techniques result in similar impairments of pulmonary function, respiratory muscle strength and walking capacity. Therefore, if curative resection of lung cancer by VATS would be technically difficult for any reason, including the surgeons skill and experience, a limited open thoracotomy would be preferable from the standpoints of safety and the patients prognosis.

Diffusion-weighted magnetic resonance imaging can be used in place of positron emission tomography for N staging of non–small cell lung cancer with fewer false-positive results

OBJECTIVE One of the deficiencies of positron emission tomography for N staging in lung cancer is a false-positive result caused by concurrent lymphadenitis. Recently, diffusion-weighted magnetic resonance imaging has been reported to be able to image tumors of body organs. The aim of this study is to examine the usefulness of diffusion-weighted magnetic resonance imaging for N staging of non-small cell lung cancer compared with positron emission tomography-computed tomography. METHODS Both positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging were prospectively used in 88 patients before surgical intervention for non-small cell lung cancer to examine 734 lymph node stations. The diagnostic results of positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging were compared. The diameters of the metastatic foci within lymph nodes were measured on hematoxylin and eosin-stained sections to compare the detectable size of metastatic foci between positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging. RESULTS The accuracy of N staging in the 88 patients was 0.89 with diffusion-weighted magnetic resonance imaging, which was significantly higher than the value of 0.78 obtained with positron emission tomography-computed tomography (P = .012), because of less overstaging in the former. Among the 734 lymph node stations examined pathologically, 36 had metastases, and the other 698 did not. Although there was no significant difference in the diagnosis of the 36 metastatic lymph node stations between the 2 methods, diffusion-weighted magnetic resonance imaging was more accurate for diagnosing the 698 nonmetastatic stations than positron emission tomography-computed tomography because of fewer false-positive results (P = .002). The detectable size of metastatic foci within lymph nodes was 4 mm in both positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging. CONCLUSIONS Diffusion-weighted magnetic resonance imaging can be used in place of positron emission tomography-computed tomography for N staging of non-small cell lung cancer with fewer false-positive results compared with positron emission tomography-computed tomography.

Time-schedule dependency of the inhibiting activity of various anticancer drugs in the clonogenic assay

SummaryTo analyze the discrepancy between the in vitro response in the clonogenic assay and the clinical response, the time-schedule dependencies of various anticancer drugs were determined by comparing the inhibiting effect against colony formation by PC-7 cells treated with the drugs for 1 h with that of those treated for 24h. According to their schedule dependency the drugs can be divided into a schedule-dependent drug group (5-fluorouracil, methotrexate, bleomycin, pepleomycin, etoposide, cisplatin, teniposide, vindesine, and vinblastine) and a non-schedule-dependent drug group (adriamycin, actinomycin D, ranomustine, mitomycin C, aclacinomycin, daunomycin, nimustine, melphalan, and KW 2083). In the clonogenic assay, the 1-h exposure schedule is appropriate for predicting clinical response for the non-schedule-dependent drugs. However, the effect of the schedule-dependent drugs was underestimated in the same conditions. Therefore, it is necessary to test these drugs in the assay by 24-h exposure for a more accurate assessment of their antitumor activity.

Prognostic significance of [18F]fluorodeoxyglucose uptake on positron emission tomography in patients with pathologic stage I lung adenocarcinoma

[18F]Fluoro‐2‐deoxyglucose uptake on positron emission tomography (FDG‐PET) has been frequently used for diagnosis and staging of lung cancer. The prognostic significance of FDG uptake on PET was evaluated in patients with pathologic Stage I lung adenocarcinoma (tumor stages were based on the TNM classification of the International Union Against Cancer).

Differentiating between atypical adenomatous hyperplasia and bronchioloalveolar carcinoma using the computed tomography number histogram

BACKGROUND Both atypical adenomatous hyperplasia (AAH) and bronchioloalveolar carcinoma (BAC) appear as ground glass opacity (GGO) lesions by computed tomography (CT) and are sometimes difficult to differentiate. To aid distinction between the two, we examined their CT number histograms. METHODS Histograms of pixel CT numbers were made for AAH (n = 9) and nonmucinous BAC (n = 8), and the peak and mean CT numbers on the histogram were quantified. RESULTS Although there was no significant difference in lesion size between AAH and BAC, all AAHs were less than or equal to 1 cm in diameter. All AAHs and BACs manifested one histogram peak. Both the peak and mean CT numbers on the histogram were significantly lower for AAH than for BAC (p < 0.001). However, the degree of overlap between AAH and BAC was less for the peak CT number than for the mean CT number. CONCLUSIONS The peak CT number on the histogram can help the radiologic differentiation between AAH and BAC. GGO lesions less than or equal to 1 cm in diameter that are diagnosed as AAH from the CT number histogram can be safely followed by CT.

Difference in the Impairment of Vital Capacity and 6-Minute Walking After a Lobectomy Performed by Thoracoscopic Surgery, an Anterior Limited Thoracotomy, an Anteroaxillary Thoracotomy, and a Posterolateral Thoracotomy

Abstract.Purpose: Postoperative vital capacity (VC) and the 6-min walking (6MW) test were used to compare the differences in impairment of the pulmonary function and walking capacity in patients undergoing a lobectomy by video-assisted thoracoscopic surgery (VATS), an anterior limited thoracotomy (ALT), an anteroaxillary thoracotomy (AAT), or a posterolateral thoracotomy without muscle sparing (PLT). Methods: The study was a retrospective analysis. Lung cancer patients who underwent a lobectomy by VATS, ALT, AAT, or PLT (28 in each group) were matched by sex and age (±5 years). VC was measured before surgery and at 1, 2, 4, 12, and 24 weeks after surgery. The distance covered during the 6MW test (6MWD) was measured before surgery and in a postoperative test 1 week after surgery. Results: Compared with the VATS, ALT, and AAT groups, PLT patients showed a significant impairment of VC from 1 to 24 weeks after surgery (P < 0.05–0.001) and also a significant impairment of 6MWD 1 week after surgery (P < 0.01–0.001). The AAT group showed a significant impairment of 6MWD 1 week after surgery compared with the VATS and ALT groups (P < 0.001 and P < 0.05, respectively). There was no significant difference in the impairment of either VC or 6MWD between VATS and ALT. Conclusions: The PLT without a muscle sparing procedure therefore cannot be recommended for general lung cancer surgery because of the impairment of both walking capacity and pulmonary function which continues long after surgery. VATS and ALT are better procedures than AAT regarding the recovery of walking capacity early after surgery. VATS and ALT are similar to each other regarding the impairment of pulmonary function and walking capacity after surgery.

Ground-Glass Opacities on Thin-Section Helical CT: Differentiation Between Bronchioloalveolar Carcinoma and Atypical Adenomatous Hyperplasia

OBJECTIVE The purpose of our study was to investigate the differentiation between bronchioloalveolar carcinoma and atypical adenomatous hyperplasia manifesting pure ground-glass opacity (GGO) based on selected features on thin-section helical CT scans. MATERIALS AND METHODS We evaluated 35 bronchioloalveolar carcinomas and 17 atypical adenomatous hyperplasias that were histologically confirmed and that manifested pure GGO on thin-section helical CT scans. We recorded the age, sex, and smoking history (Brinkman index) of the patients. Two board-certified radiologists measured the maximum diameter and mean attenuation value of the nodules; the measured values were averaged for each nodule. Using a 3-point scale, they visually assessed the images for consensus with respect to nodular sphericity, marginal irregularity, vascular convergence, pleural retraction, and findings of an internal air bronchogram. CT findings of atypical adenomatous hyperplasia and bronchioloalveolar carcinoma were compared using univariate and multivariate logistic regression analysis; the odds ratio was computed using the atypical adenomatous hyperplasia group as the reference group. RESULTS By univariate analysis, the patient age, nodular maximum diameter, mean attenuation value, and findings of an internal air bronchogram were statistically significantly associated with bronchioloalveolar carcinoma (odds ratio [OR] = 1.10 [p = 0.012], OR = 1.27 [p < 0.01], OR = 1.01 [p = 0.023], and OR = 25.30 [p < 0.001], respectively), and sphericity was significantly associated with atypical adenomatous hyperplasia (OR = 0.059, p < 0.001). By multivariate analysis, sphericity was significantly associated with atypical adenomatous hyperplasia (OR = 0.125, p = 0.042) and findings of an internal air bronchogram were associated with bronchioloalveolar carcinoma (OR = 16.10, p = 0.007). CONCLUSION Nodular sphericity and an internal air bronchogram were useful at thin-section helical CT performed to differentiate between bronchioloalveolar carcinoma and atypical adenomatous hyperplasia. Interobserver agreement was high for each finding.

Double stenting for esophageal and tracheobronchial stenoses

BACKGROUND We examined the complications and outcomes of placing stents for both esophageal and tracheobronchial stenoses. METHODS We placed stents for both esophageal and tracheobronchial stenoses in 8 patients (7 with esophageal cancer and 1 with lung cancer). Covered or noncovered metallic stents were used for the esophageal stenoses, except in 1 patient treated with a silicone stent. Silicone stents were used for the tracheobronchial stenoses. The grades of esophageal and tracheobronchial stenoses were scored. RESULTS All patients experienced improvement of grades of both dysphagia and respiratory symptoms after stent therapy. The complications were: (1) 2 patients suffered respiratory distress after placement of the esophageal stent because of compression of the trachea by the stent; and (2) 3 patients developed new esophago-tracheobronchial fistulae, and 2 patients had recurring fistula symptoms because of growth of preexisting fistulae after the stent placement, which were caused by pressure from the 2 stents. Despite the fistulae, the 5 patients treated with covered metallic stents did not complain of fistula symptoms, but 2 patients treated with noncovered metallic or silicone stents did complain. CONCLUSIONS For patients with both esophageal and tracheobronchial stenoses, a stent should be introduced into the tracheobronchus first. Because placement of stents in both the esophagus and tracheobronchus has a high risk of enlargement of the fistula, a covered metallic stent is preferable for esophageal cancer involving the tracheobronchus.