Mitsuo Nakayama

Imaging of Ventilation with Dual-Energy CT during Breath Hold after Single Vital-Capacity Inspiration of Stable Xenon

PURPOSEnTo assess single-breath-hold technique for ventilation mapping by using dual-energy computed tomography (CT) in phantom experiments and volunteers.nnnMATERIALS AND METHODSnInstitutional review board approved this study, and written informed consent was obtained from all volunteers. A rubber bag filled with a mixture of xenon (0%-35.4%) and oxygen was scanned with dual-source dual-energy CT (80 kV and 140 kV with tin [Sn] filter [Sn/140 kV] and 100 kV and Sn/140 kV). A cylinder containing six tubes of identical sizes with different apertures was ventilated once with a mixture of 35% xenon and 65% oxygen and was scanned in dual-energy mode (80 kV and Sn/140 kV). Xenon-enhanced images were derived by using three-material decomposition technique. Four volunteers were scanned twice in dual-energy mode (80 kV and Sn/140 kV) during breath hold after a single vital-capacity inspiration of air (nonenhanced) and of 35% xenon. Xenon-enhanced images were obtained by using two methods: three-material decomposition and subtraction of nonenhanced from xenon-enhanced images. Regression analysis with t and F tests was applied to the data of the rubber bag scans, with the significance level set at .05.nnnRESULTSnMean pixel values of gas in the bag were linearly related to xenon concentration for all x-ray tube voltages (r(2) = 1.00, P < .00001). Pixel values of the xenon-enhanced images of the tubes were related to their aperture size. Nearly homogeneous (coefficient of variation: 0.22, 0.23, and 0.34) pixel values were found in the lungs of healthy volunteers, with higher pixel values in the trachea and lower pixel values in the bullae. Xenon-enhanced images calculated by using three-material decomposition had better image quality on visual comparison than those calculated by using subtraction.nnnCONCLUSIONnXenon-enhanced dual-energy CT with the single-breath-hold technique could depict ventilation in phantoms and in four volunteers.

Migration of a Kirschner Wire From the Clavicle Into the Intrathoracic Trachea

We report a 70-year-old man who had a rare complication related to the insertion of Kirschner wires for fixation of a right clavicle fracture. Eight months after the placement of the Kirschner wires, he presented with cough and hemosputum. Chest roentgenograms, chest computed tomographic scans, and bronchoscopy revealed that one of the Kirschner wires had migrated through the lung and into the intrathoracic trachea. Immediate thoracotomy was performed to remove the wire. His postoperative course was uneventful.

Prediction of postoperative pulmonary function: preliminary comparison of single-breath dual-energy xenon CT with three conventional methods.

PurposeTo assess the use of xenon ventilation maps (Xe-images) for predicting postoperative pulmonary function.Materials and methodsAfter study approval by the institutional review board, written informed consent was obtained from 30 patients with lung tumors who underwent pre- and postoperative spirometry, pulmonary perfusion SPECT and dual-energy CT (80xa0kV and 140xa0kV/Sn) after single-breath inspiration of 35xa0% xenon. Xe-images were calculated by three-material decomposition. Sum of pixel values of the part to be resected (A) and of the whole lung (B) on Xe-images or lung perfusion SPECT, and volumes or the number of segments of the part to be resected (A) and of the whole lung (B) on Xe-images were enumerated, respectively. We multiplied (1xa0−xa0A/B) by each preoperative value from spirometry for prediction. Predictions by each of the four methods were compared with postoperative values.ResultsPredicted values for vital capacity (VC), forced vital capacity (FVC) and forced expiratory volume in 1xa0s (FEV1) by the four methods regressed significantly with measured values (R2xa0=xa00.56–0.77, pxa0<xa00.001 for all).ConclusionAnalysis of Xe-images can predict postoperative VC, FVC and FEV1 with accuracy comparable to that of CT volumetry.

Syndrome of inappropriate secretion of antidiuretic hormone after chemotherapy with vinorelbine

PurposeTo describe a case of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after administration of vinorelbine (VNB) for recurrence of lung cancer.CaseA 76-year-old man underwent bronchial arterial infusion (BAI) of VNB for postoperative recurrence of lung cancer. Seven days later, hyponatremia and natriuresis developed. Based on his clinical and laboratory findings, we diagnosed him with SIADH. He improved within a couple of days with fluid restriction only.ConclusionsAdministration of VNB may potentially cause SIADH. This is the second report of the SIADH caused by VNB. It is important to monitor the serum sodium level and clinical findings after chemotherapy with VNB.

Multicenter prospective study of sublobar resection for c-stage I non-small cell lung cancer patients unable to undergo lobectomy (KLSG-0801): complete republication.

BackgroundLocal therapy for stage I non-small cell lung cancer (NSCLC) is divided into surgical and radiation treatment, and given to patients unable to tolerate a lobectomy. A prospective phase II study of cases that received stereotactic body radio therapy (SBRT) (JCOG0403) revealed an overall 3-year survival rate (3-YSR) of 76.0xa0%, 3-year relapse free survival rate (3-YRFS) of 69.0xa0%, and rate of morbidity of grade 3 or greater of 9xa0%. However, few prospective multicenter studies have reported regarding surgery for high-risk stage I NSCLC patients.MethodsWe investigated this issue in the setting of a prospective multicenter observational study. Thirty-two high-risk NSCLC patients (30 males, 2 females; median age 74xa0years, 61–85xa0years) were analyzed.ResultsTwo (6.3xa0%) showed morbidity of grade 3 or greater, though there were no postoperative deaths. The margin local control rate was 97.0xa0% (surgical margin recurrence, 1) and local recurrence control rate was 75.0xa0% (ipsilateral thorax recurrence, 8), while the 3-YSR and 3-YRFS was 79.0 and 75.9xa0%, respectively.ConclusionA sublobar pulmonary resection for patients unable to tolerate a lobectomy with stage I NSCLC was shown to be safe and provided results comparable with those of SBRT.

A highly specific and sensitive massive parallel sequencer-based test for somatic mutations in non-small cell lung cancer

Molecular targeting therapy for non-small cell lung cancer (NSCLC) has clarified the importance of mutation testing when selecting treatment regimens. As a result, multiple-gene mutation tests are urgently needed. We developed a next-generation sequencer (NGS)-based, multi-gene test named the MINtS for investigating driver mutations in both cytological specimens and snap-frozen tissue samples. The MINtS was used to investigate the EGFR, KRAS, BRAF genes from DNA, and the ERBB2, and the ALK, ROS1, and RET fusion genes from RNA. We focused on high specificity and sensitivity (≥0.99) and even included samples with a cancer cell content of 1%. The MINtS enables testing of more than 100 samples in a single run, making it possible to process a large number of samples submitted to a central laboratory, and reducing the cost for a single sample. We investigated 96 cytological samples and 190 surgically resected tissues, both of which are isolated in daily clinical practice. With the cytological samples, we compared the results for the EGFR mutation between the MINtS and the PNA-LNA PCR clamp test, and their results were 99% consistent. In the snap-frozen tissue samples, 188/190 (99%) samples were successfully analyzed for all genes investigated using both DNA and RNA. Then, we used 200 cytological samples that were serially isolated in clinical practice to assess RNA quality. Using our procedure, 196 samples (98%) provided high-quality RNA suitable for analysis with the MINtS. We concluded that the MINtS test system is feasible for analyzing “druggable” genes using cytological samples and snap-frozen tissue samples. The MINtS will fill a needs for patients for whom only cytological specimens are available for genetic testing.

Syndrome of inappropriate secretion of antidiuretic hormone after chemotherapy with vinorelbine (Cancer Chemotheraphy and Pharmacology DOI: 10.1007/s00280-007-0636-z)

Purpose nTo describe a case of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after administration of vinorelbine (VNB) for recurrence of lung cancer.

Metastatic thymic tumor arising from spermatic cord leiomyosarcoma

We report the first known case of a metastatic thymic tumor arising from spermatic cord leiomyosarcoma, occurring in a 35-year-old man. He had undergone an orchiectomy 24xa0months previously and a surgical excision of a subcutaneous metastasis 4xa0months prior to his current presentation. Computed tomography revealed a 1.5-cm, round-shaped anterior mediastinal mass. A thymectomy was performed and the diagnosis of metastatic leiomyosarcoma was made.

Generation of ventilation/perfusion ratio map in surgical patients by dual-energy CT after xenon inhalation and intravenous contrast media

BackgroundWhile many studies have evaluated the change in lung volume before and after lung resection and correlated this with pulmonary function test results, there is very little evidence on the changes in ventilation perfusion ratio (V/Q) before versus after lung resection. In the present pilot study, we evaluated if V/Q mapping can be constructed using dual energy CT images.MethodsThirty-one lung cancer patients planned for pulmonary resection were included in this study. To evaluate ventilation, Xenon-enhanced CT was performed. This was immediately followed by perfusion CT. The two images were registered manually as well as using dedicated softwares, and division between ventilation pixels and perfusion pixels were done to produce the V/Q map. Also, in order to characterize the distribution of the V/Q, the following numerical indices were calculated; mean, median, mode, standard deviation (SD), coefficient of variation (CV), skewness, kurtosis, and fractal dimension (FD). Pulmonary function tests and blood gas parameters were measured using standard institutional procedures.ResultsIn the whole group, VC, %VC, and FEV1 decreased significantly after resection. FEV1.0% was increased significantly after resection. No significant changes were seen in PaO2, PaCO2, and DLCO/VA before and after resection. The mean, median, mode, SD, skewness, kurtosis and FD of the V/Q did not change significantly before and after resection. A marginal but significant decrease in CV was seen before versus after resection.ConclusionsOverall, it was considered that the V/Q maps could be adequately generated in this study. With further accumulation of data, V/Q map generated by dual energy CT may become one of the potentially useful tools for functional lung imaging.Trial registrationThis trial was registered in University Medical Information Network in Japan (UMIN000010023) on 13Feb2013.

Thoracoscopic surgery versus open surgery for lung metastases of colorectal cancer: a multi-institutional retrospective analysis using propensity score adjustment†

OBJECTIVESnThoracoscopic surgery for lung metastasectomy remains controversial. The study aimed at determining the efficacy of thoracoscopic surgery for lung metastasectomy.nnnMETHODSnThis was a multi-institutional, retrospective study that included 1047 patients who underwent lung metastasectomy for colorectal cancer between 1999 and 2014. Prognostic factors of overall survival were compared between the thoracoscopic and open thoracotomy groups using the multivariate Cox proportional hazard model. The propensity score, calculated using the preoperative covariates, included the era of lung surgery as a covariate. A stepwise backward elimination method, with a probability level of 0.15, was used to select the most powerful sets of outcome predictors. The difference between the radiological tumour number and the resected tumour number (delta_num) was also evaluated.nnnRESULTSnThe c -statistics and the P -value of the Hosmer-Lemeshow Chi-square of the propensity score model were 0.7149 and 0.1579, respectively. After adjusting for the propensity score, the thoracoscopy group had a better survival rate than the open group (stratified log-rank test: P u2009=u20090.0353). After adjusting for the propensity score, the most powerful predictive model for overall survival was that which combined thoracoscopy [hazard ratio (HR): 0.468, 95% CI: 0.262-0.838, P u2009=u20090.011] and anatomical resection (HR: 1.49, 95% CI: 1.134-1.953, P u2009=u20090.004). Before adjusting for the propensity score, the delta_num was significantly greater in the open group than in the thoracoscopy group (thoracoscopy: 0.06, open: 0.33, P u2009=u20090.001); however, after adjustment, there was no difference in the delta_num (thoracoscopy: 0.04, open: 0.19, P u2009=u20090.114).nnnCONCLUSIONSnThoracoscopic metastasectomy showed better overall survival than the open approach in this analysis. The thoracoscopic approach may be an acceptable option for resection of pulmonary metastases in terms of tumour identification and survival outcome in the current era.