Osaka International Research Articles

Efficacy of surgery in the management of multiple recurrences of retroperitoneal dedifferentiated liposarcoma.

Retroperitoneal dedifferentiated liposarcoma is associated with a high risk of recurrence; however, treatment strategies that are more effective than surgery remain to be established. This study aimed to determine the optimal number of surgeries that would be effective for patients with recurrent disease. Furthermore, the improvement in prognosis was evaluated according to the malignancy level. The effect of each type of surgery on the prognosis of 118 patients with retroperitoneal dedifferentiated liposarcoma treated at the Osaka International Cancer Institute between 1997 and 2022 was investigated. Among the 118 patients, 103 underwent initial surgery, while 54 and 30 patients underwent second and third surgeries, respectively. The overall and disease-free survival rates of each group were compared using the Kaplan-Meier method, and the log-rank test was used to determine statistical significance in univariate analysis. 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was used to assess malignancy. Maximum standardized uptake values (SUVmax) of ≥ 4 and < 4 were classified as high and low malignancy, respectively. The first and second surgeries resulted in a significant improvement in the overall survival rate, regardless of the malignancy level (p < 0.001); however, no significant improvement in prognosis was observed after the third surgery (p = 0.077). Low-grade malignancies are associated with a better postoperative prognosis, even in cases of recurrence. In contrast, high-grade malignancies exhibit a reduction in surgical efficacy. This study highlights the importance of considering the tumor malignancy level and the patient's overall condition when deciding whether to perform repeated surgical interventions. Surgical treatment can prolong overall survival, even in patients with recurrence; however, it is advisable to assess malignancy levels when determining the suitability of surgery beyond the second recurrence.

Challenges and initiatives regarding the extension of operating hours at Osaka International Airport

Osaka International Airport is an urban airport located near the city center, and its operating hours are set at 14 hours, from 7:00 a.m. to 9:00 p.m. The airport extends its hours under unavoidable circumstances and allows takeoffs and landings after 9:00 p.m. However, the airport has long conflicted with local communities over aircraft noise at night, and now, the airport receives harsh opinions especially regarding noise at night and takeoffs and landings after 9:00 p.m. And the number of flights taking-off and landing outside of the operating hours has been on the rise, reaching a record high in FY2022, despite all the countermeasures described later. This is caused not only by the congestion of air traffic flow seen for the last several years, but also by severe weather events around the airport, such as frequent typhoons and thunderclouds triggered by the recent intensifying climate changes. It is becoming even more critical to ensure on-time performance and to gain the understanding of local communities about the circumstances above. The presentation will introduce many initiatives to assess the situation accurately, ensure punctuality in cooperation with airlines, and engage in regular dialogues with residents in the surrounding area.

Real-world assessment of comprehensive genome profiling impact on clinical outcomes: A single-institution study in Japan.

Comprehensive genome profiling (CGP) has revolutionized healthcare by offering personalized medicine opportunities. However, its real-world utility and impact remain incompletely understood. This study examined the extent to which CGP leads to genomically matched therapy and its effectiveness. We analyzed data from advanced solid tumor patients who underwent CGP panel between December 2019 and May 2023 at the Osaka International Cancer Institute. Patient demographics, specimen details, and expert panel assessments were collected. Turnaround time (TAT) and genomically matched therapy outcomes were analyzed. Gene alterations and their co-occurrence patterns were also assessed. Among 1437 patients, 1096 results were available for analysis. The median TAT was 63 [28-182] days. There were 667 (60.9%) cases wherein recommended clinical trials were presented and there were 12 (1.1%) cases that could be enrolled in the trial and 25 (2.3%) cases that could lead to therapies under insurance reimbursement. The median progression free survival of the trial treatment was 1.58 months (95% CI: 0.66-4.37) in clinical trials and 3.66 months (95% CI: 2.14-7.13) in treatment under insurance. Pathologic germline variants were confirmed in 15 patients (1.3%). Co-alteration of CDKN2A, CDKN2B, and MTAP was significantly observed in overall population. The effectiveness of the genomically matched therapy based on the CGP panel was unsatisfactory. Expansion of clinical trials and utilization of remote clinical trials are required to ensure that the results of the CGP panel can be fully returned to patients.

Oil blotting paper for formalin fixation increases endoscopic ultrasound-guided tissue acquisition-collected sample volumes on glass slides.

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA. This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist. All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035). Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

Prognostic Effect of Incidental Pulmonary Embolism on Long-Term Mortality in Cancer Patients.

The effect of incidental pulmonary embolism (PE) on long-term prognosis in cancer patients is unclear. This study assessed the characteristics of cancer and venous thromboembolism (VTE) and the effect of incidental PE identified by oncologists on long-term survival of patients with cancer.Methods and Results:This single-center, retrospective, cohort study used hospital-based cancer registry data from the Osaka International Cancer Institute linked with electronic medical records and administrative data from Japan's Diagnosis Procedure Combination Per-diem Payment System. Overall, 15,689 cancer patients underwent contrast-enhanced thoracic computed tomography during 2010-2018. After excluding patients with missing data, symptomatic patients, or patients with suspected PE, 174 with incidental PE (PE+ group) and 13,197 with no PE (PE- group) were identified. The total incidence of incidental PE was 1.3%. No deaths from thrombotic events were identified in the PE+ group. Both groups were adjusted for cancer- and VTE-related characteristics using inverse probability weighting. After adjusting for immortal time bias in the PE+ group, Kaplan-Meier analysis revealed that all-cause mortality was higher in the PE+ group (hazard ratio, 2.26; 95% confidence interval, 1.53-3.33). A Cox proportional hazard model revealed that metastatic cancer and a history of curative treatment were significant prognostic factors, whereas central PE and residual proximal deep vein thrombosis were not. Incidental PE in cancer patients indicates poorer prognosis. Cancer-related but not thrombosis-related factors determine prognosis.

Issues facing Osaka International Airport and its dialogues with the surrounding communities

Osaka International Airport is an urban airport located close to the city center, and its operating hours are set at 14 hours, from 7:00 to 21:00. In the past, the airport had conflicts with local residents over aircraft noise. Even today, the airport needs to pay careful attention to the communities to ensure smooth operation of the noise-generating airport. The flight schedule is set to allow enough time for takeoffs and landings in order not to exceed 21:00 based on the agreements with the surrounding communities; however, recently there have been many delayed flights, takeoffs and landings outside of the operating hours, due to weather conditions or for other unavoidable reasons. We have gained a certain level of understanding of the surrounding communities for delayed flights by sharing appropriate information and holding regular dialogues with them. In addition, Osaka International Airport has set specific flight paths called noise preferential routes to minimize the impact of aircraft noise around the airport and is using a system to monitor deviations from NPRs. This presentation is to introduce the current status of these activities and methods for properly analyzing the information to provide to the community.

Significance of tumor size and number of positive nodes in patients with FIGO 2018 stage IIIC1 cervical cancer.

This study aimed to investigate the prognostic significance of tumor size and number of positive pelvic lymph nodes (PLN) in International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IIIC1 cervical cancer patients. Clinical data from 626 women with cervical cancer treated at Osaka International Cancer Center in 2010-2020 were retrospectively reviewed. Using the cutoff value obtained on the receiver operating characteristic analysis, the prognostic significance of tumor size and number of positive PLN in stage IIIC1 patients was first evaluated via uni- and multivariate analyses. Then, the impact of incorporating tumor size and number of positive PLN into the FIGO staging system was investigated using the Kaplan-Meier method. Among 196 women with Stage IIIC1 disease, larger tumors (>4cm) and multiple PLN metastases (≥4) were independent predictors of progression-free survival (PFS) in patients with stage IIIC1 cervical cancer. The PFS of patients with stage IIIC1 disease was inversely associated with the number of risk factors. Although patients with stage IIIC1 disease had significantly increased survival rates compared to those with stage IIIA or IIIB disease in the original FIGO 2018 staging system, this reversal phenomenon was resolved by incorporating larger tumors (>4cm) and multiple PLN metastases (≥4) into the revised staging system. Incorporating tumor size and number of metastatic lymph nodes into the FIGO staging system allows additional risk stratification for women with stage IIIC1 cervical cancer and improves survival prediction performance.

Feasibility of underwater endoscopic mucosal resection for endoscopic management of gastric neoplasms in patients with familial adenomatous polyposis.

Underwater endoscopic mucosal resection (UEMR) has been developed as an effective endoscopic intervention for colon, rectum, and duodenum neoplasms. However, there are no comprehensive reports regarding the stomach, and its safety and efficacy are unknown. We aimed to examine the feasibility of UEMR for gastric neoplasms in patients with familial adenomatous polyposis (FAP). We retrospectively extracted data of patients with FAP who underwent endoscopic resection (ER) for gastric neoplasms at Osaka International Cancer Institute from February 2009 to December 2018. Elevated gastric neoplasms of ≤ 20mm in diameter were extracted, and conventional endoscopic mucosal resection (CEMR) and UEMR were compared. Furthermore, outcomes after ER until March 2020 were examined. 91 endoscopically resected gastric neoplasms were extracted from 31 patients with 26 pedigrees, and 12 neoplasms underwent CEMR and 25 neoplasms underwent UEMR was compared. The procedure time was shorter for UEMR than for CEMR. There was no significant difference between en bloc resection and R0 resection rates by EMR methods. CEMR and UEMR showed postoperative hemorrhage rates of 8% and 0%, respectively. Residual/local recurrent neoplasms were identified in four lesions (4%), but additional endoscopic intervention (three UEMR and one cauterization) resulted in a local cure. UEMR was feasible in gastric neoplasms of FAP patients, especially in elevated lesions and those of ≤ 20mm in diameter.

Tumor Deposit Is an Independent Factor Predicting Early Recurrence and Poor Prognosis in Gastric Cancer

BackgroundAccurate prognostic estimation is crucial; however, the prognostic value of tumor deposits in gastric cancer remains controversial. This study aimed to investigate their prognostic significance. MethodsClinicopathological and prognostic data of 1012 gastric cancer patients who underwent R0 or R1 surgery from 2010 to 2017 at the Osaka International Cancer Institute were retrospectively reviewed. ResultsOverall, 6.3% patients had tumor deposits, which were associated with Borrmann type, surgical procedure, type of gastrectomy, extent of lymphadenectomy, tumor size, histology, pT, pN, pM, pStage, lymphatic invasion, vascular invasion, preoperative chemotherapy, and postoperative chemotherapy. Tumor deposit-positive patients had worse 5-year disease-free survival (32.60% vs. 92.45%) and overall survival (41.22% vs. 89.37%) than tumor deposit-negative patients. Subgroup analysis regarding pStage II–III also showed significant differences between patients with and without tumor deposits for 5-year disease-free survival (34.15% vs. 80.98%) and overall survival (43.17% vs. 75.78%). Multivariable analysis showed that older age, undifferentiated histology, deeper tumor invasion, lymph node metastasis, distant metastasis, and presence of tumor deposits were significantly correlated with early tumor recurrence and shorter survival time; these factors were identified as independent prognostic factors. The 5-year disease-free survival of tumor deposit-positive patients was significantly worse than that of patients in the pStage III group and comparable to that of patients in the pT4, pN3, and pM1 groups. The 5-year overall survival of tumor deposit-positive patients was comparable to that of the pT4, pN3, pM1, and pStage III groups. ConclusionsTumor deposits are strong and independent predictors of tumor recurrence and poor survival.

WEO Newsletter.

WEO Newsletter.

NI-13 THE RATIO OF T1-WEIGHTED TO T2-WEIGHTED SIGNAL INTENSITY AND IDH MUTATION IN GLIOMA

Abstract Purpose The current study aims to test the hypothesis that the ratio of T1-weighted image to T2-weighted image signal intensity (T1w/T2w-Ratio: rT1/T2), an imaging surrogate developed for myelin integrity, is predictive of histologically lower-grade glioma's IDH mutation status. Materials and Methods 25 histologically and molecularly confirmed lower-grade glioma patients with eight IDH-wildtype (IDHwt) and 17 IDH-mutant (IDHmt) tumors at Asahikawa Medical University Hospital (AMUH) were used as a test cohort. Twenty-nine patients (IDHwt: 13, IDHmt: 16) from Osaka International Cancer Institute (OICI) and 101 patients from the Cancer Imaging Archive (TCIA) / Cancer Genome Atlas (TCGA) dataset (IDHwt: 19, IDHmt: 82) were used as external cohorts. rT1/T2 images were calculated from T1- and T2-weighted images using a recommended signal correction. The relationship between the mean rT1/T2 (mrT1/T2) and the IDH mutation status was investigated. Moreover, t-Distributed Stochastic Neighbor Embedding (t-SNE) investigated the difference in MRI qualities and characteristics between the three cohorts. Results The test cohort at AMUH revealed that mrT1/T2 of IDHwt tumors was significantly higher than that of IDHmt tumors (p &amp;lt; 0.05) and that the optimal cut-off of mrT1/T2 for discriminating IDHmt was 0.666-0.677, (AUC = 0.75, p &amp;lt; 0.05), which finding was validated by the external domestic cohort at OICI (AUC = 0.75, p = 0.02). However, the external international cohort deriving from TCIA/TCGA could not validate this (AUC = 0.63, p = 0.08). t-SNE analysis revealed that the difference in image characteristics within the cohort was more diverse for the TCIA/TCGA than for the two domestic cohorts. Conclusion The current study revealed that mrT1/T2 was able to discriminate IDHwt and IDHmt tumors in two domestic cohorts significantly. This was not validated by the TCIA/TCGA cohort due to the wide variety in the original imaging characteristics of the TCIA/TCGA cohort.

Fibroblast Activation Protein and Tertiary Lymphoid Structure in Colorectal Cancer Recurrence.

Fibroblast activation protein (FAP) is known to have prognostic significance in colorectal cancer (CRC). However, FAP and tertiary lymphoid structures (TLSs) have not been associated with each other in predicting the prognosis of CRC recurrence. FAP expression was evaluated by real-time reverse transcription polymerase chain reaction in 195 CRC patients at Osaka International Cancer Institute (first data set). Immunohistochemistry (IHC) was then performed to stain FAP at the invasive margin (IM) and in the central tumour (CT) in 159 CRC patients at Osaka University Hospital (second data set). Consecutive slides were used to evaluate the presence of TLSs in 159 CRC patients from Osaka University Hospital. The high FAP mRNA expression group (n=82) was associated with poor recurrence-free survival (RFS) compared with the low FAP expression group (n=83) (p=0.004). In the second data set, patients with high FAP expression in CT and TLS absence (n=49) showed significantly poorer RFS compared with those with low expression of FAP in CT and presence of TLSs (n=101) (p=0.002). FAP in the CT combined with TLSs was shown to have significant prognostic value in predicting CRC recurrence after curative resection.

Diagnosis of Depth of Submucosal Invasion in Colorectal Cancer with AI Using Deep Learning.

The submucosal invasion depth predicts prognosis in early colorectal cancer. Although colorectal cancer with shallow submucosal invasion can be treated via endoscopic resection, colorectal cancer with deep submucosal invasion requires surgical colectomy. However, accurately diagnosing the depth of submucosal invasion via endoscopy is difficult. We developed a tool to diagnose the depth of submucosal invasion in early colorectal cancer using artificial intelligence. We reviewed data from 196 patients who had undergone a preoperative colonoscopy at the Osaka University Hospital and Osaka International Cancer Institute between 2011 and 2018 and were diagnosed pathologically as having shallow submucosal invasion or deep submucosal invasion colorectal cancer. A convolutional neural network for predicting invasion depth was constructed using 706 images from 91 patients between 2011 and 2015 as the training dataset. The diagnostic accuracy of the constructed convolutional neural network was evaluated using 394 images from 49 patients between 2016 and 2017 as the validation dataset. We also prospectively tested the tool from 56 patients in 2018 with suspected early-stage colorectal cancer. The sensitivity, specificity, accuracy, and area under the curve of the convolutional neural network for diagnosing deep submucosal invasion colorectal cancer were 87.2% (258/296), 35.7% (35/98), 74.4% (293/394), and 0.758, respectively. The positive predictive value was 84.4% (356/422) and the sensitivity was 75.7% (356/470) in the test set. The diagnostic accuracy of the constructed convolutional neural network seemed to be as high as that of a skilled endoscopist. Thus, endoscopic image recognition by deep learning may be able to predict the submucosal invasion depth in early-stage colorectal cancer in clinical practice.

Impact of endoscopic surveillance on mortality of metachronous esophageal and head and neck cancer after esophageal endoscopic resection.

As more superficial esophageal cancer (EC) patients are being treated with endoscopic resection (ER), it is important to understand the outcomes, including survival data, of patients who develop metachronous EC and head and neck cancer (HNC). We aimed to evaluate the long-term surveillance and survival outcomes of metachronous EC and HNC after esophageal ER. This study included 627 patients who underwent ER of superficial esophageal squamous cell carcinoma from 2008 to 2016 and were generally followed by annual or biannual esophagogastroduodenoscopy up to 2019 at Osaka International Cancer Institute. Data on metachronous cancer development and causes of death were collected from an integrated database of hospital-based cancer registry and Vital Statistics of Japan. During a median (range) follow-up period of 67.4 (3.8-142.7) months, 230 patients (36.7%) developed 500 metachronous ECs and 126 patients (20.1%) developed 239 metachronous HNCs, post-ER of index EC. The 3-year, 5-year, and 7-year cumulative incidences were 25.8%, 36.0%, and 43.6% for metachronous EC and 10.9%, 16.0%, and 26.9% for metachronous HNC, respectively. No patients died of metachronous EC, and only seven patients (1.1%) died of metachronous HNC. The 3-year, 5-year, and 7-year disease-specific survival rates were 99.8%, 99.6%, and 98.6%, respectively. The incidences of metachronous EC and HNC increase with time over 5years after esophageal ER; therefore, surveillance endoscopy should be continued over 5years. Endoscopic surveillance is useful for survivors after esophageal ER given the high incidence and extremely low mortality of metachronous EC and HNC.

Risk Factors for Predicting Lymph Node Metastasis in Submucosal Colorectal Cancer.

Objectives: The cornerstone of treating colorectal cancer (CRC) is generally a surgical resection with lymph node (LN) dissection. The tools for predicting lymph node metastasis (LNM) in submucosal (SM) CRC are useful to avoid unnecessary surgical resection. Methods: Retrospectively, we analyzed 526 consecutive patients with SM CRC who underwent surgical resection at the Osaka International Cancer Institute, Osaka University Hospital, and Minoh City Hospital, Japan, between 1984 and 2012. The Osaka International Cancer Institute group and the Osaka University Hospital group were randomly divided into a training set and a test set of 2:1. The prediction model was validated in Minoh City Hospital. Results: We partitioned patients using three risk factors involved in the presence or absence of LNM in SM CRC: lymphatic invasion (Ly), budding grade (BD) and the depth of submucosal invasion (DSI) (cut-off value 2789 μm) that were significantly different in the multivariate analysis. As a result, a predictive model of “LNM <5%” when “Ly negative and DSI <2789 μm” was evaluated. We similarly partitioned by DSI 3000 μm as easy-to-evaluate values in clinical use. We developed the additional model for predicting LNM is 1.05%, that is, LNM <5%, when there are “Ly negative and DSI <3000 μm.” Conclusions: As a limitation, only patients who underwent surgical resection were included in this study. This predictive model could help clinicians and CRC patients decide on the additional surgery required after endoscopic resection.

Indication of emergency colonoscopy after colorectal endoscopic submucosal dissection: A proposal of hematochezia scale.

Hematochezia is a major adverse event associated with colorectal endoscopic submucosal dissection (ESD). This study aimed to distinguish between hematochezia that required endoscopic hemostasis and hematochezia that required no hemostasis. This retrospective study included consecutive patients who underwent ESD for colorectal tumors at the Osaka International Cancer Institute between September 2017 and August 2020. The exclusion criteria were as follows: patients with coexisting advanced colorectal cancers or inflammatory bowel diseases, patients who received incomplete ESD or emergency surgery, or patients who underwent ESD for multiple lesions. We evaluated whether the patients had hematochezia and underwent emergency colonoscopy and hemostasis during hospitalization. The degree of hematochezia in the saved photographs was assessed using the hematochezia scale and classified as mild, moderate, or severe. Blood pressure, heart rate, time from ESD to first hematochezia, and total number of hematochezia episodes were also evaluated. Among the 437 patients who underwent ESD, 44 were excluded, and 393 patients were evaluated. Hematochezia was observed in 100 patients (25%). Emergency colonoscopy was performed in 12 patients (3%), and hemostasis was required in six patients (2%). For patients with hematochezia, only mild hematochezia and hematochezia that developed ≤48h after ESD were significantly associated with no intervention for hemostasis. The positive predictive value for no intervention for hemostasis was 100% (93-100%) for mild hematochezia and 98% (93-100%) for hematochezia ≤48h. Mild hematochezia and hematochezia ≤48h were negative predictors of hemostasis, in which emergency colonoscopy may be avoided.

Moisturization of the Surgical Field during Cancer Resection Reduces Perioperative Complications in Reconstruction Surgery.

Background:Intraoperative tissue desiccation is a risk factor for infection and wound necrosis. We hypothesized that maintaining a moist environment in the surgical field would reduce perioperative complications in free flap reconstruction for head and neck cancer surgery.Methods:A total of 331 patients who underwent free flap reconstruction after head and neck cancer surgery from January 2013 to December 2017 at Osaka International Cancer Institute were included in the study. We classified patients into two groups: those in whom saline was sprayed only during reconstruction (control group: 162 patients) and those in whom saline was sprayed in the surgical field intermittently during cancer resection and reconstruction (moisturized group: 169 patients). We compared perioperative complications, including intraoperative arterial anastomotic thrombosis, between the two groups. Other candidate risk factors for intraoperative arterial thrombosis that were assessed included a history of preoperative irradiation, history of neck surgery, advanced age, and flap type.Results:Rates of abscess formation and intraoperative arterial thrombosis were significantly lower in the moisturized group than in the control group (6.5% versus 12.7%, P < 0.05 and 3.0% versus 11.1%, P < 0.01, respectively). Binomial logistic regression analysis revealed that, in addition to no moisturization during cancer resection, advanced age and jejunal flap use were significant risk factors for intraoperative arterial thrombosis.Conclusions:Moisturization of the surgical field during cancer resection reduced the rate of perioperative complications in free flap reconstruction. Although simple, preventing desiccation of the surgical field by spraying saline solution intermittently had significant benefits on postoperative complications.

Non-adjacent interlobar lymph node metastasis distant from small-sized peripheral non-small cell lung cancer.

The optimal extent of lymph node dissection (LND) during segmentectomy is unclear. During segmentectomy, it is more challenging to dissect the non-adjacent interlobar lymph node (non-aiLN) away from the primary tumor than to dissect the adjacent interlobar lymph node (aiLN), as injury to the preserved parenchyma and bronchus may occur. We examined whether dissection of non-aiLNs was required during intentional segmentectomy. This retrospective cohort study included 310 patients who underwent lobectomy and mediastinal LND for non-small cell lung cancer of ≤ 2cm at the Osaka International Cancer Institute during January 2006 to December 2015. We investigated LN metastasis distribution and evaluated metastases in non-aiLNs distant from the primary lesion. Six (1.9%) patients had iLN metastasis. Patients with iLN metastasis did not have primary lesions in the right upper lobe or left upper segment. Of the six patients with iLN metastasis, three had non-aiLN metastasis with a tumor diameter of ≥ 15mm, with high positron emission tomography standard uptake values (> 3.5). Two patients had multiple LN metastases, and one had solitary LN metastasis. Non-aiLN dissection may be unnecessary during segmentectomy of the right upper lobe or left upper segment; however, it should be considered during lower-lobe segmentectomy.

Manual route modification using an oblique method following automatic virtual bronchoscopic navigation.

Virtual automatic bronchoscopic navigation (VBN) systems to determine the route to peripheral pulmonary lesions (PPLs) in lung cancer can improve diagnostic biopsy yields. However, compared with VBN, drawing manual routes using computed tomography images, especially with oblique methods, can identify more routes. The Ziostation2 VBN system combines the benefits of these 2 methods; we evaluated this performance by comparing 3 different route-determining methods.We retrospectively collected data from 50 patients with PPLs measuring <30 mm who underwent transbronchial biopsy with an ultrathin bronchoscope at the Osaka International Cancer Institute during January to December 2018. We compared automatic VBN (Ziostation2), manual route modification using an oblique method after automatic VBN, and manual navigation using a general application computed tomography viewer. Concordance between predicted and actual branching were determined. We also compared the predicted relationship between the terminal bronchi and the lesion by 2 of the methods with ultrasonographic images (radial-probe endobronchial ultrasonography [radial-EBUS]).Manual modification after automatic VBN significantly increased the rate of determining routes to the target (66%) versus with the automatic VBN alone (32%) (P < .001). Expected route bifurcations were exact matches with actual branching in 45/48 of the patients using manual modification after automatic VBN. The predicted relationship between the terminal bronchi and the lesion using manual modification after VBN matched the radial-EBUS images in 35/50 of the patients.Manual modification of routes to PPLs using an oblique method after automatic VBN predicted actual radial-EBUS route imaging and could help determine appropriate patients for bronchoscopy.

NI-14 estimation of property of MRI non-contrast enhanced lesion of Glioblastoma using T1/T2 ratio

Background: Tumor mass of glioblastoma is considered to exist beyond gadolinium-enhancing lesion into T2/FLAIR-high intensity lesions (T2/FL-HIL) on MRI. However, it is challenging to differentiate non-enhancing tumor region (NET) from pure brain edema for T2/FL-HIL. The T1/T2 ratio (rT1/T2) is an MRI metric considered to semi-quantify the tissue relaxation time on MRI. This research tested the hypothesis that rT1/T2 is useful for identifying NET within T2/FL-HIL by comparing it with 11C-methionine positron emission tomography (MET-PET). Method: Forty-six glioblastoma (GBM) patients at Osaka International Cancer Institute and Osaka University Hospital where T1-, T2- and contrast-enhanced T1-weighted MRI and MET-PET were available were included in this study. rT1/T2 maps were obtained after signal corrections were performed, as reported previously. Region-of-interests (ROIs) were defined within T2/FL-HILs beyond the gadolinium-enhanced lesion. MET-PET and rT1/T2 maps were co-registered to the same coordinate system, and the relationship between methionine uptake and rT1/T2 values was examined in a voxel-wise manner.ResultApproximately three million voxels were included for analysis. Lesions with methionine uptake higher than 5.0 on T/N showed 0.7 < rT1/T2 < 0.98. For those with methionine uptake higher than 3.0, rT1/T2 was between 0.70 and 1.04.DiscussionThis report suggested that rT1/T2 represents histological characteristics of the glioblastoma within T2/FL-HIL. It also indicated that rT1/T2 could be a useful biomarker for detecting NET within T2/FL-HIL for glioblastoma.