鈴木 秀海

BACKGROUND: Elastography is a relatively new technology that can generate images reflective of tissue stiffness (elasticity). Neoplastic tissue is usually stiffer than normal structures. OBJECTIVES: The aim of this study was to evaluate the feasibility and utility of elastography when combined with convex-probe endobronchial ultrasound (CP-EBUS) for predicting and localizing metastatic lymph nodes during endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA). METHODS: Consecutive results of endobronchial elastography of lymph nodes performed using EBUS- TBNA were prospectively collected and retrospectively analyzed. Elastography images were acquired as JPEG images and also recorded as video clips. Stiff area ratios [(stiff areas as blue pixels) / (lymph node areas as region of interest pixels)] for each lymph node determined by elastography were collated with the results of pathological diagnosis. We also performed elastography of surgically resected lymph nodes and compared image findings with pathological sections. RESULTS: We evaluated 49 lymph nodes in 21 patients by CP-EBUS. There were 16 metastatic nodes (10 lung cancer metastases and 6 metastases from extrathoracic malignancies). Mean stiff area ratios were significantly greater for metastatic lymph nodes (0.478) than for benign nodes (0.216; p = 0.0002). Using a cutoff value of 0.311 for stiff area ratios, the sensitivity and specificity for predicting metastatic disease were 0.81 and 0.85, respectively. The stiff area was histologically compatible with metastatic distribution in surgically resected lymph nodes. CONCLUSIONS: Endobronchial elastography is feasible for lymph nodes when combined with CP-EBUS. Stiff area ratios are useful for predicting metastatic lymph nodes, which may be an efficient guide for TBNA.

PURPOSES: The purpose of this study was to investigate the compensatory phenomena after lung resection in clinical cases by evaluating the spirometric and radiological parameters. METHODS: Forty patients undergoing lobectomy for stage IA lung cancer were divided into the following groups: (A) patients with <10 (n = 20) and (B) patients with ≥10 resected subsegments (n = 20). Comparisons were made of the predicted and observed postoperative values of spirometry and radiological parameters, such as lung volumetry and the "estimated lung weight". Predicted values were based on the number of resected subsegments. The postoperative time to re-evaluation was at least 1 year for both groups. RESULTS: The predicted postoperative values of spirometry underestimated the actual values, and the differences were more significant in group B (forced vital capacity, p = 0.006, forced expiratory volume in 1 s, p = 0.011). Focusing on the remnant lungs on the surgical side, group B had significantly larger % postoperative lung volumes (161 ± 6.0 %) and % estimated lung weight (124 ± 5.4 %) than did group A (114 ± 3.8%, p < 0.0001; 89.5 ± 4.4%, p < 0.0001, respectively). CONCLUSIONS: Major lung resection in clinical cases causes a compensatory restoration of the pulmonary function and tissue.

PURPOSE: The purpose of this study was to determine the impact of pulmonary fibrosis (PF) on postoperative complications and on long-term survival after surgical resection in lung cancer patients with chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: A retrospective chart review was conducted of 380 patients with COPD who had undergone pulmonary resection for lung cancer at the University Hospital between 1990 and 2005. The definition of COPD was a preoperative forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio of less than 70%; PF was defined as obvious bilateral fibrous change in the lower lung fields, confirmed by computed tomography. RESULTS: PF was present in 41 patients (10.8%) with COPD; the remaining 339 patients (89.2%) did not have PF. The preoperative FVC/FEV1 was significantly lower in the group of patients with PF than in the group without (p < 0.05). Acute lung injury and home oxygen therapy were significantly more common in the PF group; however, the 30-day mortality was similar between the groups. The cumulative survival at 3 and 5 years was 53.6 and 36.9%, respectively, in the PF group and 71.4 and 66.1%, respectively, in the non-PF group (p = 0.0009). Increased age, decreased body mass index, advanced pathologic stage, and the existence of PF were identified as independent risk factors for decreased survival. CONCLUSION: PF is a risk factor for decreased survival after surgical treatment in lung cancer patients with COPD.

BACKGROUND: Patterns of intrapulmonary metastasis, particularly metastasis outside tumor-bearing segments, were investigated in lung cancer patients to address the rationale for segmentectomy. METHODS: In a consecutive series of patients who underwent resection of two or more pulmonary segments for primary lung cancer, intrapulmonary spread patterns, such as segmental/intersegmental node metastasis and pulmonary parenchymal metastasis, were pathologically examined. RESULTS: Eligible 244 lesions included 167 adenocarcinomas, 66 squamous cell carcinomas, and 11 large cell carcinomas. Pathologic stages included 0 to IA (n=111), IB (n=56), IIA (n=31), IIB (n=20), IIIA (n=23), and IIIB to IV (n=3); and N1 (n=26) and N2 (n=22). Intrapulmonary spread was observed in 24 cases (9.8%). Of these, metastasis outside tumor-bearing segments was only observed in 4 cases (1.6%), and such cancer spread was more frequently seen in cases with extrapulmonary (hilar to mediastinal) nodal metastasis (7.9%) than in cases without extrapulmonary metastasis (0.5%; p=0.01). Metastasis outside tumor-bearing segments was not observed in 64 tumors with pure or mixed ground glass opacity features on computed tomography. Although tumor location (peripheral or central/intermediate) was not related to the incidence of metastasis outside tumor-bearing segments, intrapulmonary spread was observed in only 1 of 52 peripheral small (≤20 mm) tumors. CONCLUSIONS: Metastasis outside tumor-bearing segments is rarely observed in cases with tumors (1) without extrapulmonary nodal metastasis and (2) with ground glass opacity or peripheral small (≤20 mm) features.

BACKGROUND: Primary chest wall tumors are uncommon and there is limited information in the literature regarding treatment strategies for these tumors. METHODS: We retrospectively reviewed 14 patients who were referred for surgical resection for a primary chest wall tumor. RESULTS: Except for neurogenic tumors, 14 primary chest wall tumors were resected among 3,260 surgical cases during a 13-year period in our institution. Complete resection was attempted for all 14 patients;8 had benign tumors and 6 had malignant tumors. Tumor pathology was extremely varied as they arose from all anatomic structures of the chest wall. Chest wall reconstruction was performed for 7 patients;2 patients underwent an additional extended resection because their tumors were diagnosed as malignant during or after surgery;and only 1 patient with a primitive neuroectodermal tumor died of recurrence after surgery. CONCLUSIONS: The data and results for primary chest tumors are limited due to the uncommon nature of this entity and the extremely variable histology. In general, a preoperative diagnosis is difficult and a definitive diagnosis can only be made during or after surgery. Wide radical resection of these tumors should be attempted, particularly if malignancy is diagnosed.