Objective. There is a wide variety of technical approaches to video-assisted thoracic surgery (VATS) lobectomy. We have reported the clinical outcome of our approach of VATS lobectomy in which only a thoracoscopic view is used. Experience and training along with exact definition of its surgical approach are indispensable for the standardization of VATS lobectomy as lung cancer operation techniques. In this paper, we investigate the feasibility and learning curve for our approach of VATS lobectomy in order to established as one of the standard methods. Methods. We reviewed 80 consecutive patients with clinical T1N0M0 non-small cell lung cancer (NSCLC) from April 2003 to November 2007. Surgery was performed in a similar manner by either of two registered respiratory surgeons with over 25-years-experience. Clinical parameters related to the procedure were compared between the first 40 cases and the last 40 subsequent cases. Results. The background of the patients of the both groups was similar. Values of clinical parameters show in average as follows. Operation time, blood loss during the operation, size of incision for access thoracotomy, duration of chest tube drainage and length of hospital stay changed from 253 to 195 minutes (p<0.0001), from 143 to 94 gram (p=0.009), from 4.0 to 3.4 cm (0.0064), from 3.7 to 2.6 days (p=0.048) and from 8.0 to 6.9 days (p=0.0098) in the first and the last groups, respectively. They were significantly reduced in the last 40 cases than in the first 40 cases. Postoperative morbidity, especially incidence of prolonged air leakage over 7 days was also lower in the last 40 cases, however not with statistical significance. The results of systematic mediastinal lymphadenectomy and rate of conversion to thoracotomy did not significantly differed between the two groups. In the first 40 cases and the last 40 cases, the operation time over 4 hours and blood loss during the operation of more than 100 g were 24 vs 5 cases and 21 vs 13 cases, respectively. Conclusion. Minimally invasive VATS lobectomy under only a thoracoscopic view yields acceptable feasibility and safety. Moreover, most of the clinical parameters improved in the 40 cases with second group. This technique of the VATS seems to be reliably acquired after 20 to 30 cases experience with an appropriate training system.

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Purpose. We considered the significance of intrathecal chemotherapy from examination of whether there we are enforced or not, duration of intrathecal chemotherapy, change of cytology and symptom and duration from diagnosis of lung cancer to diagnosis of meningeal carcinomatosis for meningeal carcinomatosis associated with primary lung cancer. Methods. We analyzed 17 cases of the 700 cases with primary lung cancer who were admitted to our hospital from May 2000 through May 2007. Results. First cytologic examination results for cerebrospinal fluid were positive in 16 of the 17 cases. We administered methotrexate (0.15-0.3 mg/kg, once or twice a week) for intrathecal chemotherapy in 13 of the 17 cases. Duration of intrathecal chemotherapy was from 7 days to 5 months. After beginning intrathecal chemotherapy, cytologic examination results of cerebrospinal fluid were negative in 6 of the 17 cases, among which 5 cases were negative two or more times. Improvement of symptoms was seen in 9 of the 17 cases, among which 3 cases had never been negative, 1 case had been negative only once and 5 cases had been negative on two or more cytologic examinations of cerebrospinal fluid. When the results of cytologic examination of cerebrospinal fluid were negative twice or more, the survival duration increased from 4 to 5 months. Conclusion. Intrathecal chemotherapy for meningeal carcinomatosis associated with primary lung cancer can improve symptoms and prolong survival.

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Objective. Large cell neuroendocrine carcinoma (LCNEC) is an uncommon tumor of the lung that is a newly recognized clinicopathologic entity. A small percentage of LCNEC is histologically heterogeneous. The aim of this study is to elucidate the clinicopathologic characteristics of lung carcinoma with a component of LCNEC. Study Design. We retrospectively reviewed 4 cases diagnosed as combined LCNEC or combined small cell carcinoma (SCC) with a component of LCNEC between April 2003 and March 2008. Results. The age of the patients ranged from 65 to 85 years (mean 76.8 years), all were male and had been smokers. In all cases, preoperative positron emission tomography (PET) with ¹⁸F-fluorodeoxyglucose (FDG) revealed high FDG accumulation in the lesions. The surgical modalities were segmentectomy in 1 case, and lobectomy in 3 cases. Two cases were classified as stage I, 1 stage II and 1 stage III. The components with LCNEC were squamous cell carcinoma in 1 case, adenocarcinoma in 1 case and small cell carcinoma in 2 cases. One case had recurrence 10 months after surgery. Conclusion. We could not clarify the prognosis of lung carcinoma with a component of LCNEC in this study. But since preoperative FDG-PET revealed high FDG accumulation at the lesions in all cases, lung carcinoma with a component of LCNEC is considered to be a high-grade malignant tumor of the lung. We need further experience of such cases to elucidate optimal therapy and prognosis of this tumor of the lung.

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Background. Recent technological advances in MRI-DWI now allow it to be applied to the whole body. A patient with a recurrent thymoma was accurately diagnosed using MRI-DWI. Case. A 30-year-old woman was given a diagnosis of thymoma (Masaoka's stage IVa) with myasthenia gravis (type IIb) and received induction chemotherapy and underwent an operation. She also received chemoradiation therapy postoperatively. Three years and 9 months later, an intrathoracic recurrence appeared and the lesion was resected. Five years and 9 months after the initial operation, FDG-PET/CT revealed accumulation of FDG in the para-aortic lesion and the posterior side of the right XIth intercostal space. In contrast, MRI-DWI revealed a high intensity of these lesions and 5 other small lesions in the right thoracic cavity, which showed no FDG accumulation in FDG-PET/CT. The lesions were completely resected and all 7 lesions were confirmed to be recurrent thymoma. Conclusion. Small recurrent thymomas could be successfully detected using MRI-DWI, but not FDG-PET/CT. MRI-DWI was therefore considered to be a useful tool for detecting disseminated lesions of thymoma in this case.

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Background. We report a rare case of mediastinal Hodgkin's disease associated with a large thymic cyst. Case. A 23-year-old woman was found to have an abnormal shadow on a chest X-ray obtained during a pre-employment health check in March 2007. A chest CT showed a large anterior mediastinal mass, for which she was referred to our hospital. The mass comprised a solid part with a contrast effect and a cystic part with no contrast effect. There was no invasion into the surrounding tissue. For purposes of diagnosis and treatment, an extended thymectomy was performed via a median sternotomy in April 2007. During surgery, adhesion (to the mass) to the left branchiocephalic vein and the right phrenic nerve was observed. It was possible to separate these tissue and to perform a complete resection. Histopathology revealed that the tumor was Hodgkin's disease associated with a thymic cyst. After surgery, the patient was treated with ambulatory chemotherapy, and she has not shown signs of recurrence. Conclusion. When a multilocular thymic cyst is observed, it is necessary to consider a possible association with a malignant tumor.

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Background. Pulmonary carcinosarcoma is an extremely rare subtype of malignant lung tumors. Preoperative diagnosis is very difficult, and there is no established method of treatment. Case. A 69-year-old man developed exertional dyspnea and visited a local physician. Left pneumothorax and pleural effusion were identified, and pleural drainage was performed. Afterwards, a CT scan revealed a tumor. The man was then transferred to our hospital. The CT showed a large tumor in the left side of the thoracic cavity. An 18-fluorodeoxyglucose positron emission tomography (FDG-PET) scan showed an extremely high SUV. A percutaneous needle biopsy did not obtain a definitive diagnosis. However, because the tumor was growing rapidly, we performed emergency surgery to try to save the man's life. A postoperative pathologic diagnosis identified the disease as pulmonary carcinosarcoma with the epithelial component of high-grade adenocarcinoma of fetal lung type (H-FLAC). The patient was released from the hospital but died 81 days later from residual tumor growth. Conclusion. In Japan, there have been no case reports of this disease in the medical literature. Preoperative diagnosis is very difficult, and immunostaining for beta-catenin is very useful to diagnose H-FLAC. Since the prognosis of this disease is invariably bad, it is essential to develop effective preoperative diagnostic and treatment methods.

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Background. Even though the head and neck are common metastatic sites in lung cancer patients, paranasal metastases are rare. We report a patient with lung cancer who had paranasal sinus metastases. Case. A 56-year-old man with lung cancer presented with nasal hemorrhage 1.5 years after the initiation of chemotherapy. On CT, mass shadows were seen in bilateral frontal sinuses, maxillary antra, the left ethmoidal sinus, the sphenoidal sinus, and the nasal cavity. Biopsies of the lesion in the nasal cavity showed adenocarcinoma, confirming that the lesions in the paranasal sinuses were lung cancer metastases. The cranial MRI done at the time of the first admission was reviewed, and a small nodule was found in left ethmoidal sinus. Conclusion. Paranasal sinus metastases are found in a patient with NSCLC who don't have symptoms related to the paranasal sites. Paranasal sites should be carefully evaluated in patients with advanced NSCLC.

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There are no reliable and safe laboratory tests to establish the diagnosis of drug-induced lung injury, and the imaging findings of drug-induced lung injury are nonspecific. It is mandatory to integrate clinical, laboratory, and imaging findings for a correct diagnosis of drug-induced lung injury. The reliablity of the diagnosis remains relatively low and clinical level. A diffuse alveolar damage pattern on images indicates an unfavourable prognosis. Preexisting destructive lung diseases such as chronic interstitial pneumonia is one of the predisposing factors of mortality and the morbidity of drug-induced lung injury. The roles of imaging in the management of patients with drug-induced lung injury include the detection of preexisting interstitial pneumonia, estimation of severity, and prognosis of drug-induced lung injury, aid in differential diagnosis, determination of methods of follow-up and ways of detecting complications.

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A case control study of gefitinib showed the following 3 important points. 1. Accompanying chronic interstitial pneumonia is a risk factor for higher frequency of drug induced lung diseases and poor prognosis. 2. Decreased amount of normal lung before treatment is also a risk factor for the frequency of drug induced lung diseases and poor prognosis. 3. Increased amount of the areas where respiratory movement is restricted due to adhesion improves prognosis.

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To treat lung cancer patients with preexisting interstitial pneumonia is a clinical challenge. Recent reports suggest that lung cancer patients with preexisting interstitial pneumonia are prone to drug-induced lung injury or acute exacerbation of interstitial pneumonia. We studied 52 lung cancer patients with preexisting interstitial pneumonia (male/female of 49/3, mean age of 70.5±7.5 years old (non-small-cell lung cancer: NSCLC/small-cell lung cancer: SCLC of 42/10). Among 19 of 30 nonresectable NSCLC patients who were treated with anti-cancer drugs, 3 experienced acute exacerbation during second line chemotherapy (paclitaxel 2, gefitinib 1), and one patient in 12 patients without chemotherapy developed acute exacerbation. Among 7 of 10 SCLC patients who were treated with anti-cancer drugs, no acute exacerbation case was observed. We conclude that lung cancer patients should be carefully evaluated for preexisting interstitial pneumonia and if interstitial pneumonia exists, informed decision-making on chemotherapy is crucial.

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Because of the introduction of various new drugs to treat cancer or collagen vascular diseases, drug-induced lung injury has increased recently and has become an important problem in clinical practice. Because drug-induced lung injury shows non-specific radiological findings, differential diagnosis between drug-induced lung injury and infections, pulmonary edema, or extension of predisposing diseases may be difficult. Therefore, it is necessary to accurately evaluate the radiographs and CT images for the analysis of the disease process. To support the research of drug-induced lung injury, the non-profit organization (NPO) -the Japan Thoracic Radiology Group (JTRG)- has participated in various research projects as members of the committee to evaluate radiological findings. In addition, the JTRG plans to start the consulting system of drug-induced lung injury to provide support to physicians. This article briefly describes the activities of the JTRG.

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Some computer-aided diagnosis (CAD) systems are already commercially available, and in many cases evaluation has commenced at the clinical level. The purpose of CAD is to achieve efficiency in diagnostic work by reducing reading time and improving accuracy. CAD has a great potential for future development by linking imaging equipment such as computed radiography (CR) and flat panel detectors (FPDs) to picture archiving and communications system (PACS). Temporal subtraction is a technique in which a previous chest radiograph is automatically registered with and subtracted from a current radiograph in order to enhance interval changes. On the other hand, nodule detection is expected to be of some help toward the screening of the lung cancer by the use of the digital chest radiography. Temporal subtraction and nodule detection systems for digital chest radiographs have been integrated into our hospital's PACS. Image data of digital chest radiographs were stored in PACS with the digital image and communication in medicine (DICOM) protocol. Moreover, temporal subtraction and nodule detection images were produced automatically in an exclusive server. Reference style of CAD images was changed from the prefetch method into the web technology type. Thus, chest radiologists of our hospital can now perform comparative interpretation of chest radiographs and refer to CAD images with the internet explorer. Furthermore, we have evaluated these CAD systems by various experimental studies. In this review, technique for temporal subtraction and nodule detection for digital chest radiographs and the integration methods of these CAD system into our hospital's PACS were explained.

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Computer-aided detection or diagnosis (CAD) refers to the computerized detection and/or characterization of radiological abnormalities aimed at improving the diagnostic performance of radiologists, physicians, or surgeons with the help of the quantitative information provided by computerized analysis. The development of CAD in chest radiology has been recently accelerated by growing interest in lung cancer screening with low-dose CT as well as by increasing acquisition of volume data of the lungs due to the widespread use of multidetector-row CT scanners in routine clinical practice. In this review, we discuss the recent advancement of CAD in chest radiology.

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Multi-slice helical CT technology can provide exact information about the chest structure in a single scanning of procedure. Therefore, development of the algorithm that analyzes lung internal-organs has also been developed. In this review, we present two newly developed software programs using multi-slice CT images and its limitations. The first one is for the segmentation of mediastinal lymph node stations from contrast-enhanced chest CT scans which was useful for evaluation of the effects for various therapies, surgical planning, educational tool and diagnostic imaging. The second one is for the segmentation of pulmonary segments which was used before lung operation for small lung cancers.

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Primary lung cancer is a worldwide problem, but many patients are non-surgical candidates due to comorbidities. Percutaneous radiofrequency (RF) ablation is a newly developed therapeutic option for unresectable lung cancer. Several authors have reported preliminary and midterm results of this therapy, including its usefulness and minimal invasiveness. However, its technique is not well established. RF ablation for lung cancer has been performed at Okayama University since June 2001 after we obtained approval from our institutional review board. A total of 312 patients with 853 tumors have been treated as of the end of April 2007. Primary and secondary technique effectiveness rate at 3 years is 58% and 66%, respectively. Survival after this therapy seems promising, especially for those patients with unresectable stage-I non small cell lung cancer (NSCLC), with intrapulmonary recurrence after resection of primary NSCLC, and with pulmonary metastases from colorectal cancer. In this paper, we describe the indications, ablation planning, techniques, results, complications, and prospects for the future of this therapy, based on our 6-year experience.

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Percutaneous radiofrequency ablation (RFA) for malignant lung tumors become increasingly widespread. We therefore conducted a multi-center phase I/II clinical study to evaluate its safety and efficacy. Eligibility criteria included a lesion of longer axis 1-2.5 cm with abnormal accumulation on FDG-PET and of which was also considered to be difficult to curatively resect. Lesion of the diameters of which was difficult to measure, and close to the mediastinum, pleura or major blood vessels or bronchi larger than 5 mm is excluded. Percutaneous puncture was performed under image guidance using local anesthesia. Output power is gradually elevated from a low power. Overlapping ablation is carried out if necessary to cover the entire lesion. Safety was evaluated before and after the procedure by patient observation, CT, MRI, blood biochemical tests, respiratory function test and so on. The efficacy was evaluated by visual analysis of abnormal accumulation of FDG-PET before the procedure, 3 months later and 6 months later. Of the 30 cases (primary 6, metastasis 24) reported until now, the mean diameter was 1.53 cm. Pneumothorax was observed in 46.7% and a chest tube needed to be inserted in one case of them. There were no severe complications. The rate of efficacy evaluated by FDG-PET was 91.7%. Data should be analyzed in more detail in the future.

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[in Japanese]

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