Limitations of and Solutions to Using 6 mm Corneal Spherical Aberration and Q Value after Laser Refractive Surgery.

This study aimed to evaluate the spherical aberration (SA) in different corneal areas before and after femtosecond laser-assisted in situ keratomileusis (fLASIK) and transepithelial photorefractive keratectomy (tPRK), with the goal of identifying the limitations of and potential improvements in using SA within a 6 mm area. The study included 62 patients who underwent fLASIK and tPRK. Complete eye examinations including keratometry, corneal epithelial thickness, central corneal thickness, and topography were performed preoperatively and postoperatively. Anterior, posterior, and total corneal aberrations were measured preoperatively and three months postoperatively, with pupil diameters ranging from 2 to 8 mm. In the fLASIK group, compared to the preoperative SA, the anterior and total SA increased postoperatively in the 6 and 7 mm areas. In the tPRK group, meanwhile, the anterior and total SA of the 5 mm or larger areas increased postoperatively. An area of 6 mm or larger showed an increase in correlation with the changes in Q value and refractive correction. As the corneal SA and asphericity in the 6 mm zone cannot specifically demonstrate the status of areas smaller than 6 mm or changes in the optical zone after laser refractive surgery, comparison with normal values in various areas of the cornea is necessary.

Characterization of Pseudomonas sp. NIBR-H-19, an Antimicrobial Secondary Metabolite Producer Isolated from the Gut of Korean Native Sea Roach, Ligia exotica.

The need to discover new types of antimicrobial agents has grown since the emergence of antibiotic-resistant pathogens that threaten human health. The world's oceans, comprising complex niches of biodiversity, are a promising environment from which to extract new antibiotics-like compounds. In this study, we newly isolated Pseudomonas sp. NIBR-H-19 from the gut of the sea roach Ligia exotica and present both phenotypes and genomic information consisting of 6,184,379 bp in a single chromosome possessing a total of 5,644 protein-coding genes. Genomic analysis of the isolated species revealed that numerous genes involved in antimicrobial secondary metabolites are predicted throughout the whole genome. Moreover, our analysis showed that among twenty-five pathogenic bacteria, the growth of three pathogens, including Staphylococcus aureus, Streptococcus hominis and Rhodococcus equi, was significantly inhibited by the culture of Pseudomonas sp. NIBR-H-19. The characterization of marine microorganisms with biochemical assays and genomics tools will help uncover the biosynthesis and action mechanism of antimicrobial metabolites for development as antagonistic probiotics against fish pathogens in an aquatic culture system.

Latex-Based Polystyrene Nanocomposites with Non-Covalently Modified Carbon Nanotubes.

We prepared electrically conductive polystyrene (PS) nanocomposites by incorporating non-covalently surface-modified carbon nanotubes (CNTs) with hydrophilic polymers such as polydopamine (PDA) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Further, ethylene glycol (EG) was introduced as a second dopant to improve the electrical properties of the nanocomposites prepared with PEDOT:PSS-wrapped CNTs. All conductive PS nanocomposites were prepared through latex-based process, and the morphology and properties of the nanocomposites were investigated. The electrical properties of the nanocomposites with PEDOT:PSS-wrapped CNTs were better than those of the nanocomposites with PDA-coated CNTs owing to the conducting nature of PEDOT:PSS, although the dispersions of both types of modified CNTs in the PS matrix were excellent, as evidenced by morphology and rheology. In the case of PEDOT:PSS modification, the electrical properties of the nanocomposites with EG-doped PEDOT:PSS-wrapped CNTs were superior to those of the nanocomposites without EG treatment.

A Hybrid Approach to Industrial Augmented Reality Using Deep Learning-Based Facility Segmentation and Depth Prediction.

Typical AR methods have generic problems such as visual mismatching, incorrect occlusions, and limited augmentation due to the inability to estimate depth from AR images and attaching the AR markers onto physical objects, which prevents the industrial worker from conducting manufacturing tasks effectively. This paper proposes a hybrid approach to industrial AR for complementing existing AR methods using deep learning-based facility segmentation and depth prediction without AR markers and a depth camera. First, the outlines of physical objects are extracted by applying a deep learning-based instance segmentation method to the RGB image acquired from the AR camera. Simultaneously, a depth prediction method is applied to the AR image to estimate the depth map as a 3D point cloud for the detected object. Based on the segmented 3D point cloud data, 3D spatial relationships among the physical objects are calculated, which can assist in solving the visual mismatch and occlusion problems properly. In addition, it can deal with a dynamically operating or a moving facility, such as a robot-the conventional AR cannot do so. For these reasons, the proposed approach can be utilized as a hybrid or complementing function to existing AR methods, since it can be activated whenever the industrial worker requires handing of visual mismatches or occlusions. Quantitative and qualitative analyses verify the advantage of the proposed approach compared with existing AR methods. Some case studies also prove that the proposed method can be applied not only to manufacturing but also to other fields. These studies confirm the scalability, effectiveness, and originality of this proposed approach.

Clinical outcomes of topography-guided femtosecond laser-assisted in situ keratomileusis after multifocal intraocular lens implantation.

This retrospective study is to evaluate refractive and visual outcomes of topography-guided femtosecond laser-assisted in situ keratomileusis (TGL) for correcting corneal high-order aberrations (HoA) after multifocal intraocular lens (mIOL) implantation. Twenty-eight eyes of 28 patients with both corrected distance visual acuity (CDVA) under 20/25 and subjective visual discomfort at 3 months after mIOL implantation were included in the study. TGL was performed to correct corneal HoA. Visual acuity, manifest refraction, and corneal HoA were measured 3 months after TGL. CDVA was improved in 22 (78.57%) of 28 eyes after TGL. Uncorrected distance visual acuity (0.12 ± 0.16 logMAR) and uncorrected near visual acuity (0.081 ± 0.16 logMAR) were better than those before TGL (P < 0.001). Residual refractive astigmatism showed no difference compared to that before TGL. Root mean square (RMS) of HoA (P = 0.012), spherical aberration (P = 0.013), and RMS of coma (P = 0.001) were reduced relative to those before TGL. Amount of improvement in CDVA was correlated with amount of reduced coma RMS (R = 0.524; P = 0.005) and spherical aberration (R = 0.443; P = 0.021). TGL showed to improve both refractive and visual outcomes in patients with mIOL implantation by correcting corneal HoA.

Comparison of outcomes after topography-modified refraction versus wavefront-optimized versus manifest topography-guided LASIK.

BACKGROUND: To compare the outcomes of myopia and myopic astigmatism corrected with topography-modified refraction laser in situ keratomileusis (TMR-LASIK), wavefront-optimized (WFO) LASIK, and topography-guided (TG) LASIK with a correction target based on the manifest refraction (manifest TG-LASIK). METHODS: This observational, retrospective cohort study included patients who underwent LASIK using the WaveLight® EX500 excimer laser to correct myopia and myopic astigmatism between August 2016 and July 2017. Patients who underwent TMR-LASIK (85 patients), WFO-LASIK (70 patients), or manifest TG-LASIK (40 patients) were enrolled, and only one eye from each patient was analyzed. All participants underwent measurement of the uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BCVA), manifest refraction, vector analysis of astigmatic change, corneal topography, and corneal wavefront analysis at baseline and at every posttreatment visit. RESULTS: Three months postoperatively, a UDVA of 0.0 logMAR or better and manifest refraction spherical equivalent (MRSE) within ±0.5 diopters (D) did not differ across the TMR-, WFO-, and manifest TG-LASIK groups. However, the residual cylinder in the TMR group was significantly larger than that in the WFO and manifest TG groups. The magnitude of error in the TMR group measured using astigmatism vector analysis was significantly higher than that in the WFO and manifest TG groups. CONCLUSIONS: Although these three LASIK platforms achieved the predicted surgical outcomes, TMR-LASIK overcorrected astigmatism and showed a higher residual postoperative astigmatism compared with WFO- and manifest TG-LASIK.

Percutaneous full endoscopic treatment of cystic lymphangioma of cauda equina: a case report.

Intraspinal epidural lymphangioma of cauda equina are extremely rare, only three cases have been reported in the past. We report a 63-year-old female with lymphangioma at S1-S2 level which was resected under epidural anesthesia using a percutaneous full endoscope with no evidence of recurrence at 19 months follow-up.

Topography-guided versus wavefront-optimized laser in situ keratomileusis for myopia: Surgical outcomes.

PURPOSE: To compare the outcomes of topography-guided and wavefront-optimized surgery in patients having laser in situ keratomileusis (LASIK) for myopia. SETTING: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, and BALGEUN-EYE21 Operation Center, Gwangju, South Korea. DESIGN: Prospective case study. METHODS: Patients had topography-guided LASIK in 1 eye and wavefront-optimized LASIK in the contralateral eye using Contoura Vision software and the WaveLight EX500 excimer laser. Refractive and visual outcomes were analyzed 3 months postoperatively. RESULTS: The study comprised 43 patients. In both groups, the postoperative uncorrected distance visual acuity (UDVA) was 0.0 logarithm of the minimum angle of resolution or better in 90.7% of eyes and the residual spherical equivalent (SE) refractive error was ±0.75 diopter (D) in 81.4% of eyes. The UDVA, residual SE refractive error, and astigmatism did not differ significantly between the 2 groups. There was significant induction of higher-order aberrations (HOAs) in both groups, although corneal coma and trefoil did not increase and ocular trefoil decreased significantly in the topography-guided group (P = .038). However, in the wavefront-optimized group, corneal coma and trefoil increased significantly (P < .001 and P = .046, respectively) and ocular trefoil did not change significantly. In addition, topography-guided LASIK induced significantly fewer corneal total HOAs (P < .001), coma (P < .001), and trefoil (P = .020) than wavefront-optimized LASIK. CONCLUSION: Although both topography-guided LASIK and wavefront-optimized LASIK safely and effectively achieved the predicted refractive and visual outcomes, topography-guided LASIK induced fewer HOAs and significantly decreased ocular trefoil, corneal total HOAs, and coma.

Transforaminal Epiduroscopic Basivertebral Nerve Laser Ablation for Chronic Low Back Pain Associated with Modic Changes: A Preliminary Open-Label Study.

Background: Chronic low back pain (CLBP) arising from degenerative disc disease continues to be a challenging clinical and diagnostic problem whether treated with nonsurgical, pain intervention, or motion-preserving stabilization and arthrodesis. Methods: Fourteen patients with CLBP, greater than 6 months, unresponsive to at least 4 months of conservative care were enrolled. All patients were treated successfully following screening using MRI findings of Modic type I or II changes and positive confirmatory provocative discography to determine the affected levels. All patients underwent ablation of the basivertebral nerve (BVN) using 1414 nm Nd:YAG laser-assisted energy guided in a transforaminal epiduroscopic approach. Macnab's criteria and visual analog scale (VAS) score were collected retrospectively at each follow-up interval. Results: The mean age was 46 ± 9.95 years. The mean symptoms duration was 21.21 ± 21.87 months. The mean follow-up was 15.3 ± 2.67 months. The preoperative VAS score of 7.79 ± 0.97 changed to 1.92 ± 1.38, postoperatively (P < 0.01). As per Macnab's criteria, seven patients (50%) had excellent, six patients (42.85%) had good, and one patient (7.14%) had fair outcomes. Conclusion: The transforaminal epiduroscopic basivertebral nerve laser ablation (TEBLA) appears to be a promising option in carefully selected patients with CLBP associated with the Modic changes.

A Mobile Outside-in Technique of Transforaminal Lumbar Endoscopy for Lumbar Disc Herniations.

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are two techniques for the introduction of a working cannula with respect to disc-outside-in and inside-out. The aim of this prospective study is to describe the technical aspects of a novel mobile outside-in method in dealing with different types of disc prolapse. A total of 184 consecutive patients with unilateral lower limb radiculopathy due to lumbar disc prolapse were operated on with the mobile outside-in technique of PETLD. Their clinical outcomes were evaluated based on the type of disc prolapse they had, a visual analog scale (VAS) leg pain score, the Oswestry Disability Index (ODI), and the Macnab criteria. The completeness of the decompression was documented with a postoperative magnetic resonance imaging. The mean age of the patients was 50 ± 16 years and the male/female ratio was 2:1. The mean follow-up was 19 ± 6 months. A total of 190 lumbar levels were operated on (L1-L2: n = 4, L2-L3: n = 17, L3-L4: n = 27, L4-5: n = 123, and L5-S1: n = 19). Divided into types, the patient distribution was central: n = 14, paracentral: n = 74, foraminal: n = 28, far lateral: n = 13, superior-migrated: n = 8, inferior migrated: n = 38, and high canal compromise: n = 9. The mean operative time was 35 ± 12 (25 - 56) min and the mean hospital stay was 1.2 ± 0.5 (1-3) days. The VAS score for leg pain improved from 7.5 ± 1 to 1.7 ± 0.9. The ODI improved from 70 ± 8.3 to 23 ± 5. According to the Macnab criteria, 75 patients (40.8%) had excellent results, 104 patients (56.5%) had good results, and 5 patients (2.7%) had fair results. Recurrence (including early and late) was seen in 15 out of the 190 levels that were operated on (7.89%). This article presents a novel outside-in approach that relies on a precise landing within the foramen in a mobile manner and does not solely depend upon the enlargement of the foramen. It is more versatile in application and useful in the management of all types of disc prolapse, even in severe canal compromise and high migration.

Full Endoscopic Lumbar Discectomy using the Calcification Floating Technique for Symptomatic Partially Calcified Lumbar Herniated Nucleus Pulposus.

BACKGROUND: Partially calcified lumbar herniated nucleus pulposus (HNP) can cause severe radiating pain and neurologic symptoms requiring surgical treatment. As it is not safe to enforce conventional endoscopic lumbar discectomy using trephine or burr to remove the partially calcified disc, we report a calcification floating technique using a working channel for the treatment of these cases. METHODS: We retrospectively analyzed 31 patients who underwent full endoscopic discectomy using this technique for partially calcified lumbar HNP between April 2009 and June 2013. Calcification floating technique was performed by inserting the working channel around the partially calcified HNP and then rotating the working channel around it to remove the lesion. We analyzed the outcomes with a Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and complication rate. RESULTS: The mean follow-up period was 26.58 ± 11.2 months. The interlaminar approach was used in 15 cases, and the transforaminal approach was used in 16 cases. The mean VAS of 8.19 ± 0.65 before surgery was decreased to 1.29 ± 0.69 at the last follow-up. The mean ODI score before surgery was decreased at the last follow-up, from 41.32 ± 2.87 to 9.87 ± 3.47. Mean operative duration was 45 ± 12 minutes per level. None of the patients required revision surgery or developed any major complication. CONCLUSIONS: Calcification floating technique is a safe and effective method for the treatment of partially calcified lumbar HNP.

Feasibility of Full Endoscopic Spine Surgery in Patients Over the Age of 70 Years With Degenerative Lumbar Spine Disease.

OBJECTIVE: Degenerative spine disease, encompassing disc prolapse and stenosis, is a common ailment in old age. This prospective study was undertaken to evaluate the role of endoscopic spine surgery in elderly patients (above 70 years of age) with clinical and radiological follow-up. METHODS: In this study, a prospective analysis was conducted of 53 patients with lumbar disc prolapse or spinal stenosis who were treated with percutaneous endoscopic discectomy or decompression from November 2015 to June 2017. Clinical follow-up was done at 1 week, 3 months, and 1 year, and at yearly intervals thereafter. The outcomes were assessed using the modified Macnab criteria, a visual analogue scale, and the Oswestry Disability Index. RESULTS: Of the 53 patients, 21 were men and 32 were women. Their mean age was 76±4 years. The mean follow-up period was 17 months. Percutaneous endoscopic discectomy was performed in 24 patients and endoscopic decompression in 24 patients, while 5 patients underwent combined surgery. An excellent outcome in terms of the MacNab criteria was observed in 9 patients (16.98%), a good outcome in 38 patients (71.7%), and a poor outcome in 6 patients (11.3%). Of the 6 patients with a poor outcome, 5 (9.4%, 5 of 53) developed recurrent disc prolapse, and 1 developed hematoma with motor weakness. All 6 of these cases required revision surgery. CONCLUSION: Managing degenerative spine disease in elderly patients with multiple comorbidities is a challenging task. Percutaneous endoscopic spine surgery is pivotal for addressing this concern. The authors have shown that optimal results can be achieved with various types of disc prolapse and stenosis with favorable long-term outcomes.

Cancer panel analysis of circulating tumor cells in patients with breast cancer.

Liquid biopsy using circulating tumor cells (CTCs) is a noninvasive and repeatable procedure, and is therefore useful for molecular assays. However, the rarity of CTCs remains a challenge. To overcome this issue, our group developed a novel technology for the isolation of CTCs on the basis of cell size difference. The present study isolated CTCs from patients with breast cancer using this method, and then used these cells for cancer gene panel analysis. Blood samples from eight patients with breast cancer were collected, and CTCs were enriched using size-based filtration. Enriched CTCs were counted using immunofluorescent staining with an epithelial cell adhesion molecule (EpCAM) and CD45 antibodies. CTC genomic DNA was extracted, amplified, and screened for mutations in 400 genes using the Ion AmpliSeq Comprehensive Cancer Panel. White blood cells (WBCs) from the same patient served as a negative control, and mutations in CTCs and WBCs were compared. EpCAM+ cells were detected in seven out of eight patients, and the average number of EpCAM+ cells was 8.6. The average amount of amplified DNA was 32.7 µg, and the percentage of reads mapped to any targeted region relative to all reads mapped to the reference was 98.6%. The detection rate of CTC-specific mutations was 62.5%. The CTC-specific mutations were enhancer of zeste polycomb repressive complex 2 subunit, notch 1, AT-rich interaction domain 1A, serine/threonine kinase 11, fms related tyrosine kinase 3, MYCN proto-oncogene, bHLH transcription factor, APC, WNT signaling pathway regulator, and phosphatase and tensin homolog. The technique used by the present study was demonstrated to be effective at isolating CTCs at a sufficiently high purity for genomic analysis, and supported the use of comprehensive cancer panel analysis as a potential application for precision medicine.

Percutaneous Endoscopic Interlaminar Unilateral Ventral Dural Approach for Symptomatic Bilateral L5-S1 Herniated Nucleus Pulposus: Technical Note.

BACKGROUND: Percutaneous endoscopic lumbar diskectomy is a good treatment modality for lumbar disk herniation. However, when a patient complains of bilateral lower limb radicular pain with severe disk protrusion at the L5-S1 level, the transforaminal approach is often unable to resolve both lesions owing to anatomical limitations. It is also very difficult to resolve both lesions in an ipsilateral direction using the percutaneous interlaminar approach. We report our surgical technique and clinical results using a ventral dural approach of percutaneous endoscopic interlaminar lumbar diskectomy for L5-S1 herniated nucleus pulposus (HNP) in patients with bilateral radiculopathy due to a severe disk protrusion. METHODS: Twenty-seven patients with severe L5-S1 HNP complaining of back pain and bilateral lower limb pain were included in the study. The unilateral ventral dural approach of percutaneous full endoscopic interlaminar lumbar diskectomy technique was used. The visual analog scale (VAS) and Macnab criteria were used for clinical evaluation. All assessments were completed 1 day before surgery, 1 week after surgery, 6 months after surgery, and at final follow-up after surgery. RESULTS: The mean preoperative back and leg pain VAS scores decreased from 5.67 ± 0.78 and 7.81 ± 0.83 to 2.44 ± 0.58 and 2.26 ± 0.53 at 1 week, 1.78 ± 0.51 and 1.52 ± 0.58 at 6 months, and 1.56 ± 0.70 and 1.67 ± 0.96, respectively, at the final follow-up after surgery. With respect to the Macnab criteria, 51.85% of the results were excellent, 44.44% were good, and 3.70% were fair. Four cases recurred: three patients underwent conservative treatment and one patient operated with percutaneous endoscopic interlaminar lumbar diskectomy. CONCLUSION: According to the results of this study, the ventral dural approach of percutaneous full endoscopic interlaminar lumbar diskectomy in patients with L5-S1 HNP associated with bilateral lower limb pain due to a severely protruded HNP is a good option for a minimally invasive surgical approach.

Magnetic Resonance Imaging Undetectable Epiduroscopic Hotspot in Chronic Diskogenic Back Pain-Does Sinuvertebral Neuropathy Actually Exist?

BACKGROUND: The causes of chronic diskogenic back pain have not yet been clearly identified. Neural ingrowth around the annulus is widely considered to be one of the possible cause. However, neuropathy around the annulus has yet to be observed visually. We report a case of a hotspot that was observed in an epiduroscopic view, but not in imaging findings. CASE DESCRIPTION: A 46-year-old woman was admitted with pain in the back, left buttock, and posterior thigh for 2 years. A straight leg raising test was positive on the left side, and left great toe dorsiflexion was decreased to grade 3/5. The Visual Analog Scale pain score was 7/10. On the basis of her symptoms, epidural block, medial branch block, sacroiliac joint block, piriformis muscle injection, physical therapy, and medication were attempted, but no improvement in symptoms was observed. A provocation test was performed at the L3-L4, L4-L5, and L5-S1 intervertebral disks, and severe pain was induced in the L5-S1 intervertebral disk, which was not suspicious on magnetic resonance imaging. We performed transforaminal epiduroscopic laser ablation on L5-S1 and found a hotspot on L5-S1 during the procedure. During laser provocation of the hotspot, the patient complained of severe pain in her lower back and legs, and her pain decreased after ablation of hotspot with laser and improvement in motor weakness was noticed. CONCLUSION: In this study, we observed annulus hotspots, which have not been observed in imaging studies such as computed tomography or magnetic resonance imaging in patients with chronic back pain and leg pain, and observed remarkable symptom improvement after transforaminal epiduroscopic laser ablation.

Acute Bilateral Isolated Foot Drop: Changing the Paradigm in Management of Degenerative Spine Surgery with Percutaneous Endoscopy.

BACKGROUND: Acute bilateral isolated foot drop due to lumbar disk prolapse with canal stenosis is rare with only 3 cases reported in literature. Our patient was managed using the percutaneous full endoscopic technique. This is mainly to highlight the ease of access and patient outcome with preoperative and postoperative images to support our minimally invasive treatment for this rare condition. CASE DESCRIPTION: A 46-year-old male presented with sudden-onset severe back pain with bilateral foot drop. Clinical examination showed a bilateral L5 radiculopathy with normal perianal sensation. Investigations excluded other causes of bilateral foot drop. A magnetic resonance imaging scan showed disk herniation at the right L4-L5 (inferior migrated) and L5-S1 level (paracentral and extraforaminal) with spinal canal stenosis at the L2-L3 and L5-S1 levels due to ligamentum flavum hypertrophy. The patient underwent percutaneous endoscopic stenosis lumbar decompression at the L2-L3 and L5-S1 level. At the right L4-L5, L5-S1 level, transforaminal endoscopic diskectomy was done using the conventional percutaneous approach. The inferior migrated disk of the L4-L5 level was removed using a left L5-S1 contralateral approach. The patient recovered with favorable outcome and added benefits of minimally invasive surgery. CONCLUSION: Lumbar disk prolapse with canal stenosis should be considered in patients presenting with bilateral isolated foot drop. To our best knowledge, this is the first report of percutaneous endoscopic treatment to address multiple-lumbar-level pathology for this rare condition of acute bilateral isolated foot drop.

Lumbar chronic subdural hematoma mimicking an intradural extramedullary tumor: A case report.

BACKGROUND: Chronic spinal subdural hematomas are extremely rare with only 28 cases reported in the literature. Nevertheless, they should be considered among the differential diagnoses for spinal intradural/extramedullary lesions. CASE REPORT: A 65-year-old male presented with progressive back pain and right S1 radiculopathy. Magnetic resonance imaging scan revealed a right-sided posterolateral intradural/extramedullary lesion at the L5-S1 level. It was hyperintense on T1 and hypointense on T2-weighted images; on the short TI inversion recovery sequence it was hyperintense. The lesion was excised through a right L5 hemilaminectomy, and the patient was neurologically intact postoperatively. Histopathology revealed a chronic subdural hematoma. CONCLUSION: Chronic spinal subdural hematoma can mimic intradural extramedullary spinal tumors even in the absence of trauma and/or coagulopathies.

Cancer gene panel analysis of cultured circulating tumor cells and primary tumor tissue from patients with breast cancer.

Although numerous effective therapies have improved the survival rate of patients with breast cancer, a number of patients present with tumor recurrence and metastasis. A liquid biopsy of circulating tumor cells (CTC) is a non-invasive method to obtain tumor cells and may be used as substitute for a tumor tissue biopsy. The present study focuses on determining whether CTC culture is an optimal method of obtaining sufficient amounts of CTCs for molecular analysis. The current study demonstrates a method of isolating and culturing CTCs from patients with breast cancer and the construction of a molecular profile of cultured cells using the Ion AmpliSeq Cancer Gene Panel V2. Gene mutations that were observed in cultured CTCs were compared with those observed in primary tumor tissues. CTCs were isolated and cultured from the blood of six patients with breast cancer. Mutations from the Catalogue Of Somatic Mutation In Cancer (COSMIC) were detected in Platelet-Derived Growth Factor Receptor Alpha, MET (also known as Hepatocyte Growth Factor Receptor), Phosphatase and Tensin Homolog, Harvey Rat Sarcoma Viral Oncogene Homolog, SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin Subfamily B Member 1, Cyclin Dependent Kinase Inhibitor 2A and MutL Homolog 1 genes in 5/6 samples. A comparison between mutations detected in cultured CTCs and mutations detected in primary tumor tissues demonstrated that a large number of mutations that were identified in CTCs were also detected in primary tumor tissues. The results from the current study describe a novel cell culture approach that may be used to obtain an optimal number of CTCs for molecular analysis. This novel approach is able to be used as a tool for liquid biopsy during breast cancer treatment.

Evaluation of a novel approach to circulating tumor cell isolation for cancer gene panel analysis in patients with breast cancer.

Liquid biopsy isolation of circulating tumor cells (CTCs) allows the genomic analysis of CTCs, which is useful in the determination of personalized cancer therapy. In the present study, CTCs from patients with breast cancer were enriched and successfully analyzed using cancer gene panel analysis. Blood samples from 11 patients with breast cancer were collected and CTCs enriched for using size-based filtration. The enriched CTCs were analyzed using immunofluorescence staining with antibodies directed against epithelial cell adhesion molecule (EpCAM) and cluster of differentiation 45. The genomic DNA of CTCs was extracted, amplified and 50 genes screened for mutations using the Ion AmpliSeq™ Cancer Hotspot Panel v2. EpCAM staining detected CTCs in 10/11 patients and the average CTC count was 3.9 in 5 ml blood. The average purity of enriched CTCs was 14.2±29.4% and the average amount of amplified DNA was 28.6±11.9 µg. Catalogue Of Somatic Mutations In Cancer mutations were detected in the CTCs and included IDH2, TP53, NRAS, IDH1, PDGFRA, HRAS, STK11, EGFR, PTEN, MLH1, PIK3CA, CDKN2A, KIT and SMARCB1. In conclusion, a novel size-based filtration approach for the isolation of CTCs was evaluated and successfully applied for the genomic analysis of CTCs from patients with breast cancer.