Yukikiyo Kawakami

18F-fluorodeoxyglucose positron emission tomography/computed tomography is useful in postoperative follow-up of asymptomatic non-small-cell lung cancer patients

OBJECTIVES Postoperative follow-up and surveillance after curative resection for non-small-cell lung cancer (NSCLC) patients are generally performed. However, there is no consensus on the best programme at this time. The aim of this study was to evaluate the diagnostic capability of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in postoperative NSCLC patients without clinical and radiological evidence of recurrence, as a follow-up and surveillance programme. METHODS Between January 2005 and April 2010, a total of 101 NSCLC patients underwent potentially curative operations and follow-up FDG-PET/CT was performed in patients without clinical and radiological evidence of recurrence at least once a year in principle. A total of 233 FDG-PET/CT studies were entered and retrospectively reviewed. RESULTS Eighteen (18%) asymptomatic patients had recurrent diseases and 22 recurrent sites were confirmed. Of 22 recurrent sites, recurrence was diagnosed by histological examination in 9 (41%) sites and by imaging examination in 13 (59%) sites. FDG-PET/CT correctly diagnosed recurrence in 17 of the 18 (94%) patients and 21 of the 22 (95%) recurrent sites. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.4, 97.6, 89.5, 98.8 and 97.0%, respectively. On the other hand, in 3 patients, other diseases were detected and treated appropriately. Post-recurrence therapies were performed in all patients with recurrence, but 4 (22%) patients died of the original diseases. The median post-recurrence survival was 25.2 months, and the 1- and 2-year post-recurrence survival rates were 83.3 and 69.6%, respectively. CONCLUSIONS FDG-PET/CT is a useful tool that has high capability to detect recurrences in asymptomatic NSCLC patients after a potentially curative operation. However, a large-scale multi-institutional randomized control trial may be needed to ascertain the benefit of surveillance with FDG-PET/CT.

Fluoroscopy-assisted thoracoscopic resection after computed tomography-guided bronchoscopic metallic coil marking for small peripheral pulmonary lesions

OBJECTIVES To re-evaluate the efficacy of fluoroscopy-assisted thoracoscopic resection after computed tomography (CT)-guided bronchoscopic metallic coil marking (FATS-CM), which was our original method for small peripheral pulmonary lesions. METHODS Fifty-eight patients with 63 lesions underwent FATS-CM. A metallic coil was installed in the bronchus nearest to the lesion under CT fluoroscopic guidance with ultrathin bronchoscopy. The virtual bronchoscopic navigation (VBN) system was used in 14 cases. Afterwards, we basically performed wide wedge resection (WWR) using a C-arm-shaped roentgenographic fluoroscope during thoracoscopic surgery initially, and then the final procedure was determined by intraoperative histological diagnosis. Moreover, we prospectively treated ground-glass opacity (GGO) lesions of <20 mm diameter according to our treatment protocol from September 2004. RESULTS We could install coils in the objective bronchi in all cases. The average time required for the marking procedure was 38.9 (15-120) min. Pneumothorax was recognized in 1 (1.7%) case as a complication, but no fatal complications occurred. We could also install coils for each lesion in 4 cases (9 lesions) with multiple lesions. In 14 cases with the VBN system, the examination time and CT number were significantly reduced (P < 0.05 and <0.001, respectively), compared with those of 40 cases without the VBN system. The average interval between the CM and the operation was 5.6 (0-30) days. We never experienced a case of migration preoperatively. Sixty-two (98.4%) lesions were definitively identified, and WWRs were performed using three trocars in 58 (92.1%) cases during thoracoscopic surgery. Lobectomy was initially performed in only 1 case owing to coil migration. Thirty-seven of 40 cases (92.5%) were in line with the treatment protocol. There were no local-regional recurrences in all cases undergoing WWR. CONCLUSIONS We could prospectively show that our method was suitable to perform WWR with a sufficient margin for small GGO lesions of <20 mm. Moreover, we reconfirmed that the advantages of our method were safety, permitting flexibility in scheduling operations and a high ability to deal with multiple lesions. Additionally, our method became a minimally invasive and mature technique by using a new VBN system.

18F-fluorodeoxyglucose positron emission tomography/computed tomography and the relationship between fluorodeoxyglucose uptake and the expression of hypoxia-inducible factor-1α, glucose transporter-1 and vascular endothelial growth factor in thymic epithelial tumours.

OBJECTIVES The objective of this study was to evaluate the usefulness of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the relationships among the expressions of hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (Glut-1) and vascular endothelial growth factor (VEGF), histological type, other clinical factors and FDG uptake in thymic epithelial tumours. METHODS Thirty-three patients who underwent FDG-PET/CT before treatment were reviewed. All types of tumours were reclassified into three subgroups: low-risk thymomas (types A, AB and B1), high-risk thymomas (types B2 and B3) and thymic carcinomas. Tumour contour, pattern of FDG uptake, tumour size and maximum standardized uptake value (SUVmax) were obtained. Expressions of HIF-1α, Glut-1 and VEGF were analysed immunohistochemically, and these expressions were evaluated using grading scales. RESULTS FDG uptake was visually recognized in all (100%) tumours. A homogeneous pattern of FDG uptake was increasingly observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas (P = 0.016). SUVmax for thymic carcinomas was significantly higher than that for thymomas (P = 0.008). With the optimal cut-off value of SUVmax of 5.6, the sensitivity, specificity and accuracy for diagnosing thymic carcinoma were 0.75, 0.80 and 0.79, respectively. Regarding the mean scoring of HIF-1α, Glut-1 and VEGF, increasing trends were observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas. Tumour size revealed a significant correlation with SUVmax (r = 0.60, P < 0.001), and the expression of HIF-1α showed a moderate association, but the expression of Glut-1 showed no correlation with SUVmax. Regarding correlations between the expression of the three markers, there were moderate associations between HIF-1α and Glut-1, and HIF-1α and VEGF, and a significant correlation between Glut-1 and VEGF (r = 0.60, P < 0.001). In type B1 thymoma, HIF-1α and Glut-1 were partly expressed in non-neoplastic immature lymphocytes. CONCLUSIONS FDG-PET/CT should be performed in patients with tumours in the anterior mediastinum because the pattern of FDG uptake and SUVmax are useful in the differential diagnosis of thymic epithelial tumours. Furthermore, the expressions of HIF-1α, Glut-1 and VEGF might be associated with malignancy of thymic epithelial tumours. In contrast, FDG uptake might be dependent on tumour size rather than Glut-1 overexpression.

Non-invasive monitoring of anticancer effects of cisplatin on lung cancer in an orthotopic SCID mouse model using [18F] FDG PET-CT

Positron emission tomography-computed tomography (PET-CT) with [18F] fluorodeoxyglucose (FDG) has recently been applied for evaluating tumor response to anticancer therapy. The aim of the present study was to evaluate the utility of FDG PET-CT in monitoring non-invasively and repeatedly the inhibitory effect of cisplatin (CDDP) on an orthotopic lung cancer model. Validation of in vivo FDG uptake in human lung cancer Ma44-3 cell line in an orthotopic SCID mouse model was carried out. Next, we assessed the use of FDG PET-CT to monitor the response of orthotopic lung cancer to the anticancer effect of CDDP. SCID mice were divided into the CDDP group (7 mg/kg single dose intraperitoneally) and the control group. Tumor volume and maximal standardized uptake value (SUV max) were calculated for all mice. All mice were sacrificed for histopathologic analysis. Validation of FDG PET-CT showed that tumor volume and SUV max were significantly correlated with postmortem tumor length measured in specimens (P=0.023) and (P=0.012), respectively, and there was a significant correlation between SUV max and tumor volume (P=0.048). Response monitoring showed that significant growth inhibition by CDDP in the form of SUV max of the CDDP group was significantly lower than that of the control group on day 8 (P=0.02) and on day 13 (P=0.003). Tumor volume of the CDDP group was significantly lower than that of the control group on day 13 (P=0.03). The present study supports using FDG PET-CT in monitoring tumor progression and therapeutic response of lung cancer in an orthotopic model non‑invasively and repeatedly.

A feasibility study of postoperative adjuvant chemotherapy with fluoropyrimidine S‐1 in patients with stage II‐IIIA non‐small cell lung cancer

BACKGROUND Adjuvant chemotherapy with uracil tegafur (UFT) improved survival among patients with completely resected stage I lung adenocarcinoma. S-1, an oral dihydropyrimidine dehydrogenase (DPD)-inhibitory 5-fluorouracil, is a more potent DPD inhibitor than UFT;therefore, we hypothesized that postoperative adjuvant chemotherapy with S-1 would be effective for advanced non-small cell lung cancer (NSCLC). We conducted a feasibility study of S-1 as postoperative adjuvant chemotherapy in patients with curatively resected pathological stage bold I back 10 bold I and bold I back 10 bold I back 20 bold I A NSCLC. METHODS Adjuvant chemotherapy consisted of 9 courses (4-week administration, 2-week withdrawal) of S-1 at 80-120 mg/body per day. Twenty-four patients with completely resected NSCLC were enrolled in this study from November 2007 through December 2010. The primary endpoint was the rate of completion of the scheduled adjuvant chemotherapy. The secondary endpoints were safety, overall survival, and relapse-free survival. RESULTS Five patients were censored because of disease recurrence. The planned 9 courses of S-1 were administered to completion in 8 patients. Twelve patients completed more than 70% of the planned courses. Grade 3 adverse reactions, such as elevated total bilirubin (4.2%) and pneumonitis (4.2%), were observed, but there were no Grade 4 adverse reactions. Patients who completed more than 70% of the 9 courses demonstrated better overall survival than those who completed less than 70%. CONCLUSION Postoperative administration of S-1 may be possible with few severe adverse events as adjuvant chemotherapy for patients with curatively resected pathological stage bold I back 10 bold I -bold I back 10 bold I back 20 bold I A NSCLC. J. Med. Invest. 65:90-95, February, 2018.

Autofluorescence for the diagnosis of visceral pleural invasion in non-small-cell lung cancer

OBJECTIVES This study was conducted to evaluate the accuracy of autofluorescence as a mode of diagnosis for visceral pleural invasion of non-small-cell lung cancer compared with white-light by means of clinical questions to several thoracic surgeons. METHODS Eight independent thoracic surgeons evaluated visceral pleural invasion in 25 cases of non-small-cell lung cancer attached to the visceral pleura on lung windows of preoperative computed tomography images. At the first study meeting to evaluate the accuracy of visceral pleural invasion diagnosis using conventional white-light images, the surgeons diagnosed visceral pleural invasion based on information in preoperative computed tomography images, histological types and videos recorded with white-light mode using a thoracoscope. At the second study meeting to evaluate the accuracy of visceral pleural invasion diagnosis using autofluorescence, the same surgeons diagnosed visceral pleural invasion based on information in 2 videos recorded in white-light mode and in autofluorescence mode using the thoracoscope. RESULTS The overall average sensitivity, specificity and accuracy of visceral pleural invasion diagnosis by white-light versus autofluorescence mode were 64.6% vs 83.3%, 53.9% vs 73.7% and 56.5% vs 76.0%, respectively. CONCLUSIONS The sensitivity, specificity and accuracy of visceral pleural invasion diagnosis was improved through the additional use of the autofluorescence mode compared with the white-light mode alone.

Frequent silencing of RASSF1A by DNA methylation in thymic neuroendocrine tumours

OBJECTIVES Aberrant methylation of promoter CpG islands (CGIs) of tumour suppressor genes is a common epigenetic mechanism underlying cancer pathogenesis. The methylation patterns of thymic tumours have not been studied in detail since such tumours are rare. Herein, we sought to identify genes that could serve as epigenetic targets for thymic neuroendocrine tumour (NET) therapy. MATERIALS AND METHODS Genome-wide screening for aberrantly methylated CGIs was performed in three NET samples, seven thymic carcinoma (TC) samples, and eight type-B3 thymoma samples. The methylation status of thymic epithelial tumours (TETs) samples was validated by pyrosequencing in a larger cohort. The expression status was analysed by quantitative polymerase chain reaction (PCR) and immunohistochemistry. RESULTS We identified a CGI on a novel gene, RASSF1A, which was strongly hypermethylated in NET, but not in thymic carcinoma or B3 thymoma. RASSF1A was identified as a candidate gene statistically and bibliographically, as it showed frequent CGI hypermethylation in NET by genome-wide screening. Pyrosequencing confirmed significant hypermethylation of a RASSF1A CGI in NET. Low-grade NET tissue was more strongly methylated than high-grade NET. Quantitative PCR and immunohistochemical staining revealed that RASSF1A mRNA and protein expression levels were negatively regulated by DNA methylation. CONCLUSIONS RASSF1A is a tumour suppressor gene epigenetically dysregulated in NET. Aberrant methylation of RASSF1A has been reported in various tumours, but this is the first report of RASSF1A hypermethylation in TETs. RASSF1A may represent an epigenetic therapeutic target in thymic NET.

Monitoring of exhaled carbon monoxide and carbon dioxide during lung cancer operation

OBJECTIVE Carbon monoxide (CO) is expelled mainly via the lungs, so that exhaled carbon monoxide (Ex-CO) concentration reflects endogenous production. Recent reports have shown that Ex-CO levels are increased in critically ill patients and after anaesthesia and surgery. However, there has been no investigation of the changes in Ex-CO level during a lung operation. We continuously monitored Ex-CO and exhaled carbon dioxide (Ex-CO2) concentrations during surgery for lung cancer. METHODS Eighteen lung cancer patients who underwent elective lung cancer lobectomy were enrolled in this study. All patients were endotracheally intubated and ventilated under general anaesthesia. Ex-CO and Ex-CO2 concentrations were separately monitored and recorded continuously using two sets of Carbolyzer® breath analysers (Taiyo Inc., Osaka, Japan). RESULTS Ex-CO concentration increased rapidly in response to changes in body position from supine to decubitus and was significantly decreased when patients were once again lying back (supine 2). Upon restarting bilateral ventilation, Ex-CO concentration in the operated lung was significantly higher than that in the breathing lung. In the lateral decubitus position, Ex-CO2 concentration showed the same pattern of increase as seen for Ex-CO. In the operated lung, the Ex-CO2 concentrations changed significantly at clamping, declamping and supine 2. In the re-ventilated, operated lung, the Ex-CO2 concentration was significantly lower than in the breathing lung. In the breathing lung, the Ex-CO2 concentration did not exhibit any significant changes over the course of the operation. CONCLUSIONS When breathing was restarted, the Ex-CO level of the target lung was significantly higher than that of the breathing lung. The Ex-CO concentration was also affected by the surgical body position and this change was marked and transient.