Larger size extracellular vesicle as early biomarker in patients with metastatic pancreatic cancer

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Background: Current research suggests that tumor-derived extracellular vesicles (EVs) play an important role in tumor progression especially with regard to metastasis. Atypically large EVs have been reported to have the ability to transport bioactive molecules through the blood stream. Therefore, EV physical properties such as diameters and concentrations may have a biological impact on tumor progression. However, it has not been described which characteristics are clinically relevant in the longitudinal assessment of tumor progression and chemo-response. Methods: Plasma from 19 metastatic PDAC patients was collected at treatment-naïve baseline and in more than 2 consecutive assessments during chemotherapy between May 2015 and July 2016. EVs from plasma were isolated using a sequential centrifugation protocol, confirmed as described previously and analyzed using the Particle Metrix (Zetaview, Diessen, Germany) and proprietary software. The clinical variables along with concentration and size distribution of EVs were analyzed to identify prognostic factors associated with chemo-response. Results: Mean EV size and concentration were 122.85 nm and 4.13x109/mL plasma at treatment naïve baseline, 123.62 nm and 4.39x109/mL plasma at first response assessment during chemotherapy. Median overall and progression-free survivals were 256 and 165 days, respectively. The change of CA 19-9 (hazard ratio 17.477, p = 0.001, 95% CI 0.995-1.045) and proportion of EVs larger than 150nm (hazard ratio 11.022, p = 0.017, 95% CI 3.183-95.964) was a significant independent predictor of progression-free survival at first response assessment during chemotherapy. In addition, we observed a dramatic increase in the proportion of larger EVs earlier than the increases in CA 19-9. Conclusions: Our data suggests that increases in the amounts of larger EVs are independent predictors of tumor progression and chemo-response in metastatic pancreatic cancer patients. Furthermore, the increases in the amounts of larger EVs may potentially be more clinically useful than CA19-9 in the earlier stages of progression. Concentrations of larger-sized EVs could be a valuable component of more sophisticated diagnostics in liquid biopsies.

A randomized, multicenter, phase III study of gemcitabine combined with capecitabine versus gemcitabine alone as first-line chemotherapy for advanced pancreatic cancer in South Korea

BACKGROUND

This phase III trial compared the efficacy and safety of gemcitabine plus capecitabine (GemCap) versus single-agent gemcitabine (Gem) in advanced pancreatic cancer as first-line chemotherapy.

METHODS

A total of 214 advanced pancreatic cancer patients were enrolled from 16 hospitals in South Korea between 2007 and 2011. Patients were randomly assigned to receive GemCap (oral capecitabine 1660 mg/m plus Gem 1000 mg/m by 30-minute intravenous infusion weekly for 3 weeks followed by a 1-week break every 4 weeks) or Gem (by 30-minute intravenous infusion weekly for 3 weeks every 4 weeks).

RESULTS

Median overall survival (OS) time, the primary end point, was 10.3 and 7.5 months in the GemCap and Gem arms, respectively (P = 0.06). Progression-free survival was 6.2 and 5.3 months in the GemCap and Gem arms, respectively (P = 0.08). GemCap significantly improved overall response rate compared with Gem alone (43.7% vs 17.6%; P = 0.001). Overall frequency of grade 3 or 4 toxicities was similar in each group. Neutropenia was the most frequent grade 3 or 4 toxicity in both groups.

CONCLUSION

GemCap failed to improve OS at a statistically significant level compared to Gem treatment. This study showed a trend toward improved OS compared to Gem alone. GemCap and Gem both exhibited similar safety profiles.

Similar Efficacies of Endoscopic Ultrasound-guided Transmural and Percutaneous Drainage for Malignant Distal Biliary Obstruction

BACKGROUND & AIMS

Although percutaneous transhepatic biliary drainage (PTBD) is the standard method for draining a malignant biliary obstruction after failed endoscopic retrograde cholangiopancreatographies (ERCPs), use of endoscopic ultrasound-guided transmural biliary drainage (EUS-BD) is increasing. We performed a multicenter, open-label, randomized trial to compare EUS-BD vs PTBD for malignant distal biliary obstruction after a failed ERCP.

METHODS

Patients with unresectable malignant distal biliary obstructions and failed primary ERCP, caused by inaccessible papilla, were assigned to groups that underwent EUS-BD with an all-in-one device for direct deployment of a partially covered metal stent (without further fistula tract dilation, n = 34) or PTBD (n = 32). The procedures were performed at 4 tertiary academic referral centers in South Korea from October 2014 through March 2015; patients were followed up through June 2015. The primary end point was technical success, which was calculated using a noninferiority model. Secondary end points were functional success, procedure-related adverse events, rate of unscheduled re-intervention, and quality of life (QOL).

RESULTS

The rates of primary technical success were 94.1% (32 of 34) in the EUS-BD group and 96.9% (31 of 32) in the PTBD group (1-sided 97.5% confidence interval lower limit, -12.7%; P = .008 for a noninferiority margin of 15%). The rates of functional success were 87.5% (28 of 32) in the EUS-BD group and 87.1% (27 of 31) in the PTBD group (P = 1.00). The proportions of procedure-related adverse events were 8.8% in the EUS-BD group vs 31.2% in the PTBD group (P = .022); the mean frequency of unscheduled re-intervention was 0.34 in the EUS-BD group vs 0.93 in the PTBD group (P = .02). The QOL was similar between groups.

CONCLUSIONS

EUS-BD and PTBD had similar levels of efficacy in patients with unresectable malignant distal biliary obstruction and inaccessible papilla based on rates of technical and functional success and QOL. However, EUS-BD produced fewer procedure-related adverse events and unscheduled re-interventions. Clinical trial registration no: cris.nih.go.kr/KCT0001370.

Quantitative temperature measurement of multi-layered semiconductor devices using spectroscopic thermoreflectance microscopy

Thermoreflectance microscopy is essential in understanding the unpredictable local heating generation that occurs during microelectronic device operation. However, temperature measurements of multi-layered semiconductor devices represent a challenge because the thermoreflectance coefficient is quite small and is dramatically changed by the optical interference inside transparent layers of the device. Therefore, we propose a spectroscopic thermoreflectance microscopy system using a systematic approach for improving the quantitative temperature measurement of multi-layered semiconductor devices. We demonstrate the quantitative measurement of the temperature profile for physical defects on thin-film polycrystalline silicon resistors via thermoreflectance coefficient calibration and effective coefficient κ estimation.

Simultaneous multicolor imaging of wide-field epi-fluorescence microscopy with four-bucket detection

We demonstrate simultaneous imaging of multiple fluorophores using wide-field epi-fluorescence microscopy with a monochrome camera. The intensities of the three lasers are modulated by a sinusoidal waveform in order to excite each fluorophore with the same modulation frequency and a different time-delay. Then, the modulated fluorescence emissions are simultaneously detected by a camera operating at four times the excitation frequency. We show that two different fluorescence beads having crosstalk can be clearly separated using digital processing based on the phase information. In addition, multiple organelles within multi-stained single cells are shown with the phase mapping method, demonstrating an improved dynamic range and contrast compared to the conventional fluorescence image. These findings suggest that wide-field epi-fluorescence microscopy with four-bucket detection could be utilized for high-contrast multicolor imaging applications such as drug delivery and fluorescence in situ hybridization.

Diffusion-weighted magnetic resonance imaging of gallbladder adenocarcinoma: analysis with emphasis on histologic grade

PURPOSE

To investigate the value of diffusion-weighted imaging (DWI) for differentiating gallbladder adenocarcinoma from adenoma, and predicting histologic grades of gallbladder adenocarcinoma.

MATERIALS AND METHODS

Fourty-three gallbladder adenocarcinomas and 8 adenomas were included. We compared apparent diffusion coefficient (ADC) values between adenocarcinoma and adenoma, and ADC values of gallbladder adenocarcinoma among the histologic grade.

RESULTS

Gallbladder adenocarcinoma (1.041×10(-3)mm(2)/s) showed significantly lower ADC values than adenoma (2.039×10(-3)mm(2)/s) (P<.001). Well-differentiated adenocarcinoma (1.290×10(-3)mm(2)/s) showed significantly higher ADC values than higher-grades (1.104×10(-3) and 0.915×10(-3)mm(2)/s in moderately- and poorly-differentiated, respectively) (P<.001).

CONCLUSION

DWI can help to differentiate gallbladder adenocarcinoma from adenoma, and well-differentiated from higher-grade adenocarcinoma.

Minimally invasive genomic and transcriptomic profiling of visceral cancers by next-generation sequencing of circulating exosomes

BACKGROUND

The ability to perform comprehensive profiling of cancers at high resolution is essential for precision medicine. Liquid biopsies using shed exosomes provide high-quality nucleic acids to obtain molecular characterization, which may be especially useful for visceral cancers that are not amenable to routine biopsies.

PATIENTS AND METHODS

We isolated shed exosomes in biofluids from three patients with pancreaticobiliary cancers (two pancreatic, one ampullary). We performed comprehensive profiling of exoDNA and exoRNA by whole genome, exome and transcriptome sequencing using the Illumina HiSeq 2500 sequencer. We assessed the feasibility of calling copy number events, detecting mutational signatures and identifying potentially actionable mutations in exoDNA sequencing data, as well as expressed point mutations and gene fusions in exoRNA sequencing data.

RESULTS

Whole-exome sequencing resulted in 95%-99% of the target regions covered at a mean depth of 133-490×. Genome-wide copy number profiles, and high estimates of tumor fractions (ranging from 56% to 82%), suggest robust representation of the tumor DNA within the shed exosomal compartment. Multiple actionable mutations, including alterations in NOTCH1 and BRCA2, were found in patient exoDNA samples. Further, RNA sequencing of shed exosomes identified the presence of expressed fusion genes, representing an avenue for elucidation of tumor neoantigens.

CONCLUSIONS

We have demonstrated high-resolution profiling of the genomic and transcriptomic landscapes of visceral cancers. A wide range of cancer-derived biomarkers could be detected within the nucleic acid cargo of shed exosomes, including copy number profiles, point mutations, insertions, deletions, gene fusions and mutational signatures. Liquid biopsies using shed exosomes has the potential to be used as a clinical tool for cancer diagnosis, therapeutic stratification and treatment monitoring, precluding the need for direct tumor sampling.

Diffusion-weighted magnetic resonance imaging for non-neoplastic conditions in the hepatobiliary and pancreatic regions: pearls and potential pitfalls in imaging interpretation

Potentially, diffusion-weighted magnetic resonance imaging (DWI) can assess the functional information on concerning the status of tissue cellularity, because increased cellularity is associated with impeded diffusion. DWI in the hepatobiliary and pancreatic regions has demonstrated the usefulness to detect malignant lesions and differentiate them from benign lesions. However, it has been shown more recently that there is some overlap in ADC values for benign and malignant neoplasms. Moreover, some non-neoplastic lesions in the hepatobiliary and pancreatic regions exhibit restricted diffusion on DWI, because of pus, inflammation, or high cellularity. Focal eosinophilic liver disease, hepatic inflammatory myofibroblastic tumor, granulomatous liver disease, acute cholecystitis, xanthogranulomatous cholecystitis, focal pancreatitis, or autoimmune pancreatitis frequently exhibit restricted diffusion on DWI, which may be confused with malignancy in the hepatobiliary and pancreatic regions. Thus, DWI should not be interpreted in isolation, but in conjunction with other conventional images, to avoid the diagnostic pitfalls of DWI. Nevertheless, the presence of diffusion restriction in the non-neoplastic lesions sometimes provides additional information regarding the diagnosis, in problematic patients where conventional images have yielded equivocal findings. DWI may help differentiate hepatic abscess from malignant necrotic tumors, gallbladder empyema from dense bile or sludge in the gallbladder, and pylephlebitis from bland thrombosis in the portal vein. Therefore, knowledge of DWI findings to conventional imaging findings of diffusion-restricted non-neoplastic conditions in the hepatobiliary and pancreatic regions helps establishing a correct diagnosis.

Factors Associated With Outcomes in Endoscopic Submucosal Dissection of Gastric Cardia Tumors: A Retrospective Observational Study

Tumors of the gastric cardia are among the most technically difficult lesions to remove by endoscopic submucosal dissection (ESD). This study aimed to evaluate the therapeutic outcomes of ESD in gastric cardia tumors according to clinicopathologic characteristics, and to assess the predictive factors for incomplete resection.We conducted a retrospective observational study of 82 patients with adenomas and early cancers of the gastric cardia who underwent ESD between January 2006 and December 2013 at the Pusan National University Hospital. Therapeutic outcomes of ESD and procedure-related complications were analyzed.En bloc resection, complete resection, and curative resection rates were 87%, 79%, and 66%, respectively. Deep submucosal invasion was the most common cause of noncurative resection in the cases in which complete resection was achieved. On multivariate analyses, hemispheric distribution (anterior hemisphere; odds ratio [OR] 4.808) and depth of tumor invasion (submucosal cancer; OR 22.056) were independent factors associated with incomplete resection. The rates of procedure-related bleeding, perforation, and stenosis were 6%, 1%, and 0%, respectively; none of the complications required surgical intervention.In conclusion, ESD is a safe, effective, and feasible treatment for gastric cardia tumors. However, the complete resection rate decreases for tumors that are located in the anterior hemisphere or have deep submucosal invasion.

Effects of guar gum ingestion on postprandial blood pressure in older adults

OBJECTIVES

The aim of this study was to investigate the effects of guar gum on postprandial blood pressure in older people.

DESIGN

A randomized, double-blind, placebo-controlled, cross-over design.

SETTING

Community senior centers in B city, South Korea.

PARTICIPANTS

Twenty-two older female adults aged 67 to 88 with postprandial hypotension.

INTERVENTION

The participants were randomly assigned to guar gum (semi-fluid food with 9 gram) or placebo intervention during the first treatment phase. After a washout period of 1 week, the two interventions were switched to the other in the second treatment phase.

MEASUREMENTS

Blood pressure was measured during both phases before having a meal and every 15 minutes during 120 minutes after a meal with automated sphygmomanometer.

RESULTS

Change in systolic blood pressure (SBP) over time was significantly different between guar gum and placebo groups (F=4.07, p=0.001). Compared with placebo group, guar gum group had significantly low prevalence of postprandial hypotension (PPH) (guar gum group=18.2% vs. placebo group=72.7%; χ² =13.20, p<0.001). It also had significant difference in change of diastolic blood pressure (DBP) over time between guar gum and placebo groups (F=2.49, p=0.027).

CONCLUSION

This findings show that guar gum could be effective on postprandial drops in blood pressure in older female adults.

[Prognostic factors in patients with advanced pancreatic cancer treated with gemcitabine chemotherapy: clinical characteristics of long-term survivors]

BACKGROUND/AIMS

Gemcitabine-based chemotherapy has been used as a standard treatment in patients with unresectable pancreatic cancer. However, the clinical outcomes of this regimen are still unsatisfactory in prolonging survival. We retrospectively analyzed clinical characteristics of patients with advanced pancreatic cancers who received gemcitabine-based chemotherapy and showed long-term survival.

METHODS

We enrolled 49 patients who underwent treatment with more than three cycles of gemcitabine-based chemotherapy. Long-term survivor was defined as patient who has survived more than 12 months after diagnosis. The clinical characteristics were analyzed to compare the differences between long-term and short-term survivors. Univariate or multivariate analyses were performed to identify prognostic factors associated with chemo-responses.

RESULTS

Twenty patients (41%) survived more than 12 months. Long-term survivors had smaller tumor size (OR 2.190, p=0.049, 95% CI 1.005-4.773) and higher serum BUN level (OR 0.833, p=0.039, 95% CI 0.701-0.990) compared to short-term survivors. Overall median and progression-free survivals were 11 and 4 months, respectively. Presence of distant metastasis (hazard ratio 1.441, p=0.035, 95% CI 1.002-2.908) was a significant independent predictor of progression-free survival. Tumor size (hazard ratio 1.534, p=0.004, 95% CI 1.150-2.045) was associated with overall survival.

CONCLUSIONS

Gemcitabine chemotherapy may be more effective and allow longer survivals in patients with clinical characters of smaller tumor size and normal serum BUN level at diagnosis. We suggest a well-designed large controlled study to evaluate the prognostic factors such as clinical characteristics and molecular biological features in patients with advanced pancreatic cancers who receive gemcitabine-based chemotherapy.

[A single institution's experience of infundibulotomy in patients taking antiplatelet agents: outcomes, safety and complications]

BACKGROUND/AIMS

The diagnostic and therapeutic utility of endoscopic retrograde cholangiopancreatography (ERCP) has been well demonstrated for biliary and pancreatic diseases. Biliary access can be allowed by infundibulotomy if failed by using the standard cannulation methods. However, no data are available regarding ERCP-related complications in patients taking antiplatelet agents who are undergoing infundibulotomy. Therefore, we aimed to assess the frequency of ERCP-related complications after infundibulotomy in patients taking antiplatelet agents.

METHODS

We performed a retrospective study, and enrolled 835 patients who underwent ERCP at Pusan National University Hospital from January 2011 to December 2012. Seventy-two patients had been taking antiplatelet agents prior to the procedure. Patients were classified into two groups according to the utilization of infundibulotomy: 20 patients underwent infundibulotomy (group 1), and 52 patients did not undergo infundibulotomy (group 2). Complications after ERCP were defined as bleeding, post-ERCP pancreatitis, and perforation according to Cotton's criteria.

RESULTS

Between group 1 and 2, there were no significant differences in baseline characteristics. ERCP was successfully performed in all cases. Clinically significant bleeding was observed in one patient in group 1 (5%, 1/20) versus none in group 2. Post-ERCP pancreatitis was observed in 2 patients (10.0%, 2/20) in group 1, and 7 patients (13.5%, 7/52) in group 2 (p=0.691). However, none of these differences were statistically significant. No perforation occurred in both groups.

CONCLUSIONS

Considering the low incidence of bleeding after infundibulotomy in patients taking antiplatelet agents, infundibulotomy may be safely performed in this group of patients.

Factors Associated with Diffusely Increased Splenic F-18 FDG Uptake in Patients with Cholangiocarcinoma

Objectives

Although diffuse splenic ¹⁸F-fluorodeoxyglucose (F-18 FDG) uptake exceeding hepatic activity, is considered abnormal, its clinical significance is rarely discussed in the literature. The aim of this study was to determine the contributing factors causing diffusely increased splenic FDG uptake in patients with cholangiocarcinoma.

Methods

From January 2010 to March 2013, 140 patients (84 men, 56 women) were enrolled in this study. All patients had been diagnosed with cholangiocarcinoma and underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) for the pretreatment staging work up. Clinical records were reviewed retrospectively. Various hematological parameters, C-reactive protein (CRP) level, CEA, CA19-9, pancreatic enzymes and liver function tests were conducted within 2 days after the F-18 FDG PET/CT study.

Results

Diffuse splenic uptake was observed in 23 patients (16.4%). Of those, 19 patients (82.6%) underwent endoscopic retrograde cholangiopancreastography (ERCP) 7 days before F-18 FDG PET/CT. The CRP level (p < 0.001) and white blood cell count (p = 0.023) were significantly higher in the group of patients with diffuse splenic FDG uptake. The hemoglobin (p < 0.001) and the hematocrit (p < 0.001) were significantly lower in patients with diffuse splenic FDG uptake. Pancreatic enzymes, liver function test results, and tumor markers were not significantly different between the patients who did or did not have diffusely increased splenic FDG uptake. The significant factors for diffuse splenic F-18 FDG uptake exceeding hepatic F-18 FDG uptake on multivariate analysis included: performing ERCP before F-18 FDG PET-CT (odds ratio [OR], 77.510; 95% CI, 7.624-132.105), and the presence of leukocytosis (OR, 12.436; 95% CI, 2.438-63.445) or anemia (OR, 1.211; 95% CI, 1.051-1.871).

Conclusion

In conclusion, our study demonstrated that concurrent inflammation could be associated with diffusely increased splenic FDG uptake. We suggest that performing ERCP before F-18 FDG PET/CT could cause acute inflammation which may induce splenic FDG activity.

Prevalence of anti-ganglioside antibodies and their clinical correlates with guillain-barré syndrome in Korea: a nationwide multicenter study

Background and Purpose

No previous studies have investigated the relationship between various anti-ganglioside antibodies and the clinical characteristics of Guillain-Barré syndrome (GBS) in Korea. The aim of this study was to determine the prevalence and types of anti-ganglioside antibodies in Korean GBS patients, and to identify their clinical significance.

Methods

Serum was collected from patients during the acute phase of GBS at 20 university-based hospitals in Korea. The clinical and laboratory findings were reviewed and compared with the detected types of anti-ganglioside antibody.

Results

Among 119 patients, 60 were positive for immunoglobulin G (IgG) or immunoglobulin M antibodies against any type of ganglioside (50%). The most frequent type was IgG anti-GM1 antibody (47%), followed by IgG anti-GT1a (38%), IgG anti-GD1a (25%), and IgG anti-GQ1b (8%) antibodies. Anti-GM1-antibody positivity was strongly correlated with the presence of preceding gastrointestinal infection, absence of sensory symptoms or signs, and absence of cranial nerve involvement. Patients with anti-GD1a antibody were younger, predominantly male, and had more facial nerve involvement than the antibody-negative group. Anti-GT1a-antibody positivity was more frequently associated with bulbar weakness and was highly associated with ophthalmoplegia when coupled with the coexisting anti-GQ1b antibody. Despite the presence of clinical features of acute motor axonal neuropathy (AMAN), 68% of anti-GM1- or anti-GD1a-antibody-positive cases of GBS were diagnosed with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) by a single electrophysiological study.

Conclusions

Anti-ganglioside antibodies were frequently found in the serum of Korean GBS patients, and each antibody was correlated strongly with the various clinical manifestations. Nevertheless, without an anti-ganglioside antibody assay, in Korea AMAN is frequently misdiagnosed as AIDP by single electrophysiological studies.

Diffusion-weighted MRI for differentiation of benign from malignant lesions in the gallbladder

AIM

To investigate the value of diffusion-weighted imaging (DWI) for differentiating benign from malignant gallbladder lesions.

MATERIALS AND METHODS

One hundred and twenty-six patients who had undergone magnetic resonance imaging (MRI) with DWI, in whom the histopathological diagnosis of their gallbladder lesions was confirmed by biopsy or surgery were retrospectively analysed. Thirty-six malignant and 90 benign lesions were included. Two radiologists categorized gallbladder lesions into seven types on two imaging sets [T2-weighted imaging (WI) alone and combined T2WI and DWI (b = 800 s/mm(2))] according to the presence of wall thickening, layered patterns, morphology of the mass, and diffusion restriction. Disagreements were resolved in consensus. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each imaging set for diagnosing gallbladder carcinoma were calculated. The diagnostic performance of each imaging set was calculated using receiver operating characteristic (ROC) curve analysis. Additionally, ADC values of malignant and benign gallbladder lesions were compared separately for 1.5 and 3 T MRI.

RESULTS

The sensitivity, specificity, PPV, and NPV of diagnosis at T2WI were 97.2%, 86.7%, 74.5%, and 98.7%, respectively. The sensitivity, specificity, PPV, and NPV using combined T2WI and DWI were 97.2%, 92.2%, 83.3%, and 98.8%, respectively. Diagnostic accuracy for gallbladder carcinoma slightly improved after adding DWI, from 0.92 to 0.95 (p < 0.05). ADC values for gallbladder carcinoma were significantly lower than those for benign lesions. Mean ADC values of malignant and benign lesions were 0.97 ± 0.25 × 10(-3) and 1.72 ± 0.56 × 10(-3) mm(2)/s, respectively, at 1.5 T (p < 0.001), and 1.04 ± 0.38 × 10(-3) and 2.2 ± 0.72 × 10(-3) mm(2)/s, respectively, at 3 T (p < 0.001).

CONCLUSION

DWI can improve diagnostic accuracy for differentiating benign from malignant gallbladder lesions.

Fast mapping of absorbing defects in optical materials by full-field photothermal reflectance microscopy

We report a technique for rapidly mapping absorbing defects in optical materials, which act as laser-induced damage precursors, based on full-field photothermal reflectance microscopy. An intensity-modulated pump beam heats absorbing defects in the optical sample, creating localized, modulated refractive-index variations around the defects. A probe beam then illuminates the defect sites, and the measured amplitude of the reflectance variation is used to map the distribution of defects in the medium. Measurements show that this method offers a faster defect mapping speed of about 0.03 mm(2) per minute and a detectivity of a few tens of nanometers comparable to that of conventional scanning photothermal deflection microscopy.

High-speed thermoreflectance microscopy using charge-coupled device-based Fourier-domain filtering

We present a Fourier-domain filtering method for charge-coupled device (CCD)-based thermoreflectance microscopy to improve the thermal imaging speed while maintaining high thermal sensitivity. The time-varying reflected light distribution from the surface of bias-modulated microresistor was recorded by a CCD camera in free-run mode and converted to the frequency domain using the fast Fourier transform (FFT) for all pixels of the CCD. After frequency peak filtering followed by inverse FFT, a thermoreflectance image was obtained. The imaging results of the proposed method were quantitatively compared with those of the conventional four-bucket method, showing that the Fourier-domain filtering method can provide thermal imaging 24-42 times faster than the four-bucket method, depending on the required thermal sensitivity.

Endoscopic resection of gastrointestinal lipomas: a single-center experience

BACKGROUND

Gastrointestinal (GI) lipomas are benign, slow-growing subepithelial tumors. Most lipomas are detected incidentally at endoscopy, but they can cause GI bleeding, abdominal pain, intestinal obstruction, and intussusception, particularly if they are larger than 2 cm in diameter. The aim of this study was to investigate the efficacy, safety, and long-term prognosis of endoscopic treatment of GI lipomas.

METHODS

A total of 28 GI lipomas treated endoscopically from January 2005 to June 2012 were retrospectively reviewed. Endoscopic treatment was performed by four methods: the unroofing technique, endoscopic mucosal resection (EMR), EMR after precutting (EMR-P), and endoscopic submucosal dissection (ESD).

RESULTS

Of 28 GI lipomas, 5 were located in the stomach, 2 in the duodenum, and 21 in the colon. Thirteen lipomas were <2 cm in diameter (small lipoma), and the other 15 were ≥2 cm (large lipoma). The unroofing technique was performed in 2 cases, EMR in 17 cases, EMR-P in 4 cases, and ESD in 5 cases. En bloc resection was performed with 21 lesions (75 %), and endoscopic complete resection was achieved with 26 lesions (93 %). Incomplete resection occurred in the 2 cases treated by the unroofing technique. On pathologic examination, complete resection was achieved with 21 lesions (75 %). Delayed bleeding was observed in one patient. There were no serious complications such as perforation or post-procedural stricture. During the mean follow-up period of 19 months (range 2-91 months), no recurrence was observed.

CONCLUSIONS

Endoscopic treatment appears to be a safe and effective treatment for GI lipomas, including large lipomas (≥2 cm in diameter).

Management of gastric epithelial neoplasia in patients requiring esophagectomy for esophageal cancer

Esophageal squamous cell carcinoma is occasionally associated with malignancies located in other regions of the alimentary tract, as well as in the head, neck, and upper respiratory tract. The stomach is most commonly used for reconstruction of the alimentary tract after esophagectomy for esophageal cancer. When synchronous tumors are located in the stomach, it is often unsuitable for use in esophageal reconstruction. In such cases, an invasive procedure involving anastomosis between the esophagus and the colon must be performed. However, this procedure is associated with a high incidence of mortality and morbidity. Seven patients with synchronous esophageal cancer and gastric epithelial neoplasia were encountered. First, endoscopic submucosal dissection (ESD) was performed for the gastric epithelial neoplasia. Then, following successful ESD, Ivor-Lewis esophagectomy for esophageal cancer was planned 1 to 2 weeks later. A total of 11 gastric epithelial lesions were found in seven patients. En bloc resection by ESD was possible in all 11 lesions and histologically complete resection was achieved in all 11 lesions. Follow-up endoscopy was done 1-2 weeks after ESD; six patients with well-healing ulcers underwent esophagectomy the next day (8 or 15 days after ESD). In one patient with a poorly healed ulcer, a second follow-up endoscopy was done 1 week later and then esophagectomy was performed the next day (22 days after ESD). Post-surgical complications related to ESD, such as bleeding or mediastinal leak, were not seen in any of the seven patients. In patients with synchronous esophageal cancer and gastric epithelial neoplasia, ESD for gastric epithelial neoplasia followed by Ivor-Lewis esophagectomy 1 to 2 weeks later is an effective choice of treatment.

Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a single-center experience

BACKGROUND

In Korea, endoscopic submucosal dissection (ESD) has been widely accepted for the treatment of early gastric cancers (EGCs). However, the understanding of the long-term clinical outcome of ESD for EGC remains insufficient. Therefore, the aim of the present study was to assess the long-term clinical outcome and efficacy of ESD for the treatment of EGCs, including the clinical application of the expanded criteria for ESD.

METHODS

From January 2006 to December 2010, a total of 515 patients with 522 EGCs were treated by ESD in our hospital; study enrollment was based on the expanded criteria. Comparisons of resectability (en bloc or piecemeal resection), curability (curative or non-curative), and complications (bleeding and perforation) between the standard and expanded groups were assessed. Thereafter, 336 patients with 342 EGCs were finally included in a long-term analysis of local tumor recurrence, development of synchronous and metachronous cancers, and overall and disease-specific survival rates.

RESULTS

En bloc and curative resection rates of 96.7 % and 88.3 %, respectively, were achieved. The curative resection rate was significantly lower in the expanded group than in the standard group (82.1 % vs. 91.5 %, p = 0.001). During a median follow-up of 24 months, the local tumor recurrence rate was also higher in the expanded group than in the standard group (7.0 % vs. 1.8 %, p = 0.025). Local recurrence was more frequent in lesions with non-curative resection than in those with curative resection (20.0 % vs. 1.3 %, p < 0.001). The 5-year overall and disease-specific survival rates were 88 % and 100 %, respectively; the difference between the standard and expanded groups was not significant (p = 0.834).

CONCLUSIONS

ESD appears to be a feasible and effective method for treating EGCs, based on the standard and expanded criteria. Close follow-up surveillance, after ESD, should be standard for all patients.