Invasive Method Research Articles

Immunoglobulin repertoire sequencing and de novo sequencing – Powerful tools for identifying free light chains from patients with light chain cast nephropathy

In patients with light chain cast nephropathy (LCCN), abundantly produced monoclonal immunoglobulin free light chains (FLCs) play a vital role in pathogenesis. Determining the precise sequences of patient-derived FLCs is therefore highly desirable. Although immunoglobulin repertoire sequencing (5′ RACE-seq) has been proven to be sensitive enough to provide full-length V(D)J region (variable, diversity and joining genes) of FLCs using bone marrow samples, an invasive and bone marrow independent method is still in demand. Here a de novo sequencing workflow based on the bottom-up proteomics for patient-derived FLCs was established. PEAKS software was used for the de novo sequencing of peptides that were further assembled into full-length FLC sequences. This de novo protein sequencing method can obtain the full-length amino acid sequences of FLCs, and had been shown to be as reliable as 5′ RACE-seq. The two LCCN sequences derived from above the two methods were identical, and they possessed more hydrophobic or nonpolar amino acids compared with the corresponding germline, which may be associated with the pathogenesis.

Spontaneous intracerebral hemorrhage: a review of the prevalence, trigger factors, therapeutic and surgical treatment

Spontaneous intracerebral hemorrhage is the second most common subtype of stroke and is a significant cause of mortality and morbidity worldwide. Trigger factors that “accelerate” disease onset may include hypertension, excessive alcohol consumption, constant smoking, hypocholesterolemia, medications, male sex, advanced age, living in an underdeveloped country, ethnicity, chronic kidney disease, cerebral amyloid angiopathy, and microhemorrhages. Therapeutic solutions for spontaneous intracerebral hemorrhage aimed at stopping the progression of hemorrhage, reducing the clot volume of intraventricular and parenchymal hematoma, combating perihematomal edema and inflammation, rapidly reducing blood pressure, and providing hemostatic therapy with transfusion of platelets and other coagulation complexes. Clinical trials on minimally invasive methods of surgical evacuation (endoscopic surgery, stereotactic aspiration, and invasive craniopuncture) are ongoing and may provide positive results because of the shorter operation time and use of local anesthesia. Minimally invasive surgery methods can theoretically improve the outcomes of open surgery by reducing damage to collateral tissues and reducing anesthesia time; however, they cannot be a full-fledged alternative.

Sharp needle reconstructs peripheral outflow for patients with malfunctional arteriovenous fistula

Objective To investigate the feasibility and efficacy of combining ultrasound-guided sharp needle technique with percutaneous transluminal angioplasty (PTA) for treating outflow stenosis or dysfunction in arteriovenous fistula (AVF) among hemodialysis patients. Methods From October 2021 to March 2023, patients with occluded or malfunctional fistula veins not amenable to regularly angioplasty were retrospectively enrolled in the study. They underwent ultrasound-guided sharp needle intervention followed by PTA. Data on the location and length between the two veins, technical success, clinical outcomes, and complications were collected. Patency rates post-angioplasty were calculated through Kaplan-Meier analysis. Results A total of 23 patients were included. The mean length of the reconstructed extraluminal segment was 3.18 cm. The sharp needle opening was performed on the basilic vein (60.9%), brachial vein (26.1%), or upper arm cephalic vein (13%) to create outflow channels. Postoperatively, all cases presented with mild subcutaneous hematomas around the tunneling site and minor diffuse bleeding. The immediate patency rate for the internal fistulas was 100%, with 3-month, 6-month, and 12-month patency rates at 91.3%, 78.3%, and 43.5%, respectively. Conclusion Sharp needle technology merged with PTA presents an effective and secure minimally invasive method for reconstructing the outflow tract, offering a new solution for recanalizing high-pressure or occluded fistulas.

IMPLANTABLE MEDICAL DEVICES: A NON INVASIVE AND COSMETIC FRONTIER FOR WOUND CLOSURE

Abstract Cardiovascular implantable electronic devices (CIEDs) implantation procedures have undergone continuous improvement. Every aspect of the procedure can contribute to these improvements, including incision closure. The aim of this study was to assess the accuracy and validity of a non–invasive method using adhesive skin closure strips for wound closure of CIEDs in older adults, instead of surgical suture, evaluating parameters such as infection, erythema, skin reaction, itching, pain, oedema, time for closure, cosmetic outcomes and patients’ satisfaction. A retrospective study was carried out in 152 subjects (mean age 81 +9.3 years).undergoing application of adhesive strips after CIEDs substitution/implant and 132 usual care control subjects (mean age 76.6+8.9). Variables considered were: age, gender, risk factors for wound complications. Wound evaluation was conducted by using the Visual Analogue Scale (VAS) and the Patient and Observer Scar Assessment Scale (POSAS). Operative time for closing the incision and for removing sutures or strips were significantly lower in both application and removal in the adhesive strip group. At follow–up evaluations, each parameter considered by evaluation of the patients and staff was significantly better than in the control group. Fewer complications were observed in the patients undergoing wound closure wit adhesive strips. Previoulsy, to the best of our knowledge, the use of adhesive strips in closing surgical wounds of patients undergoing CIEDs implant/replacement has never been considered. Adhesive strips for wound closure of CIEDs incision are characterized by shorter procedural time, optimal early and late cosmetic results, fewer complications in older patients and is cheaper. Its use for CIEDs wound closure is reasonably supported.

Comparing skin swabs, buccal swabs, and toe clips for amphibian genetic sampling, a case study with a small anuran (acris blanchardi)

Abstract Multiple methods for collecting genetic samples from amphibians exist, each with their own implications for study design, animal welfare, and costs. Toe clipping is one common method, but there is ongoing debate regarding its potential detriment. Less invasive methods should be implemented, if efficacious, as amphibians are a particularly vulnerable vertebrate group. Skin and buccal swabbing are less invasive methods for genetic sampling, but the potential for contamination and a lower yield of DNA may exist. To compare these methods, we gathered skin swabs, buccal swabs, and toe clips from the same individuals of a relatively small anuran species, Blanchard’s Cricket Frog (Acris blanchardi). We then compared DNA yield, DNA purity, amplification success rate, and genotypic data quality among sample types. We found toe clips and buccal swabs generated similar DNA yield and purity, with skin swabs yielding significantly less DNA of significantly lower purity than the other sample types. Amplification success rate was significantly higher using toe clips compared to the other sample types, though buccal swab samples amplified more readily than skin swabs. Genotypic data from toe clips and buccal swabs did not differ significantly in quality, but skin swab data quality was significantly lowest among sample types. Thus, skin swabbing could produce erroneous data in some situations, but buccal swabbing is likely an effective substitute to toe clipping, even for small species. Our results can help future researchers select which genetic sampling method might best suit their research needs.

ANOTHER BRICK IN THE WALL: A STRANGE CASE OF A BIG HUG

Abstract Background Left ventricular pseudoaneurysm (LVP) is a rare complication of myocardial infarction MI (less than 0,1% of all patients with MI) and develops when cardiac rupture is contained by adherent pericardium or scar tissue, thus contains no endocardium or myocardium, unlike a true left ventricular aneurysm (LVA). Clinical Case A 41–year–old man without remote cardiac history was admitted to the Emergency Department with chest pain that had started 7 days before after a referred ‘big hug’ from a friend. Results of the physical examination were unremarkable. Electrocardiogram: T waves negative in the inferior and lateral leads. Blood exams: normal troponins, C–reactive protein and D–dimer values. Chest computed tomography: no sign of pulmonary embolism. Transthoracic echocardiography (TE): ejection fraction 45%, voluminous aneurismal chamber communicating with the infero–posterior wall of the LV, stratified thrombus and mild mitral valve regurgitation. Coronary angiography: three vessel coronary artery disease. The last diagnosis was established by cardiac magnetic resonance imaging (MRI) which revealed a voluminous pseudoaneurysm of the inferior wall (56 mm x 50 mm with a 51 mm neck) and transmural late gadolinium enhancement (LGE) of the wall adjacent to the pseudoaneurysm with fibroadipose replacement and calcific metaplasia. The patient was transferred to the Cardiac Surgery Department. Intraoperatively the LVP was resected and the defect of the LV was repaired with a patch in bovine pericardium. In addition, coronary artery bypass grafting and mitral valve repair were performed. Discussion LVP develops when pericardium, in combination with thrombus and inflammation, surrounds a cardiac rupture. Inferior and posterolateral myocardial infarction (MI), due to occlusion of the Circumflex artery, are responsible for 82% of the LVP. LVP can be also found in the apical region due to anterior MI. In conclusion symptoms, signs, electrocardiographic abnormalities and radiographic findings seen in patients with LVP can be indistinguishable from those in patients with coronary disease alone. TE is the first non–invasive method for early diagnosis of LVA, but MRI is the gold standard for differential diagnosis between true aneurysm vs pseudoaneurysm. LGE of the pericardium is a new specific marker of pseudoaneurysm as opposed to true aneurysm.

Radiographic evaluation of hard tissue changes in open flap technique versus flapless technique for implant placement

Open flap technique allows the clinician to directly visualize the alveolar bone and assess bone morphology of the ridge.However, this technique is relatively invasive and causes patient discomfort and marginal bone loss due to decreased supraperiosteal blood supply whereas the Flapless technique is one of the latest minimally invasive surgical methods of implant placement without the need to raise a mucoperiosteal flap to overcome the bone resorption process. The present study was designed to evaluate the hard tissue changes in open flap technique versus flapless ṭechnique for implant placement at the different time interval. Minimum thirty edentulous sites from Out Patient Department, Department of Periodontology (IDST) were randomly allocated to the following two groups by the flip of coin: Group I - Implant with open flap technique (fifteen sites) and Group II - Implant with flapless technique (fifteen sites). Patients were evaluated radiographically for crestal bone loss (mesial and distal) at Baseline (Immediately after implant placement), At the time of prosthetic loading and 3 months after prosthetic loading in both the groups. The result of the present study revealed that Sites where implants were placed with flapless technique showed lesser mean crestal bone loss scores as compared to sites where implants were placed with open flap technique, although the difference was insignificant. It can be concluded that flapless procedure may be considered as a better treatment option as compared to implant placed with open flap technique in terms of minimal pain, inflammation and less crestal bone loss associated with flapless technique than open flap technique.

Safe and genotyped. A non-invasive method for extraction of amphibian DNA from water baths and its application on Northern spectacled salamanders, Salamandrina perspicillata (Savi 1821)

AbstractThe global decline of amphibian populations, with 40.7% of species classified as threatened, calls for innovative and ethical approaches in conservation genetics. Molecular biology advancements have introduced environmental DNA (eDNA) analysis, primarily focusing on aquatic environments. However, the present study explores a novel non-invasive protocol using water samples to extract DNA from terrestrial and semi-terrestrial amphibians, specifically the endangered Italian endemic salamander, Salamandrina perspicillata (Savi, 1821). Unlike traditional invasive methods involving tissue sampling, this protocol immerses animals briefly, eliminating the need for digit or tail amputations or manipulation for buccal swabs. The study validated the protocol through DNA extraction, amplification, and sequencing, yielding results comparable to traditional methods. The non-invasive nature of the protocol aligns with the 3Rs principles (Replace, Reduce, Refine) and offers a streamlined, stress-minimizing alternative for studying protected and endangered species. Future experiments should also explore further refinements, including reduced soaking times and additional applications, such as skin microbiota analysis. This protocol represents a significant step towards ethical and effective research practices in amphibian conservation genetics, encouraging a paradigm shift in wildlife research ethics. Continued innovation in non-invasive methodologies is essential for comprehensive understanding and robust conservation strategies amid the ongoing biodiversity crisis.

Determination of anti-Müllerian hormone levels in blood and urine in fertile cats

In recent years, blood anti-Müllerian hormone (AMH) levels have been investigated in female animals to diagnose many conditions, such as the presence of ovarian tissue, follicle reserve, and granulosa cell tumors. Since blood collection is an invasive method, diagnosis with a non-invasive method is important in terms of practicality and animal welfare. This study aimed to investigate the presence of AMH in cat urine and determine whether a correlation exists between blood and urine AMH levels. In addition, it was aimed at revealing whether there was a change in blood and urine AMH levels according to ovarian follicle distribution. Twenty-seven healthy, fertile female cats in the follicular phase were included. Following blood and urine sample collection, a routine ovariohysterectomy was performed. Histological analysis of the removed ovarian tissue was used to determine ovarian follicle types. While both AMH and estrogen levels were determined in blood samples, only AMH levels were investigated in urine samples. Blood AMH levels averaged 10.61 ± 0.75 ng/mL (range: 5–16 ng/mL), while urine AMH levels averaged 5.67 ± 0.91 ng/mL (range: 0.2–13 ng/mL). While urinary AMH level was <1 ng/mL in 7 cats, urinary AMH was >1 ng/mL in all remaining cats. While the study demonstrated AMH excretion in urine, no correlation was found between blood and urine AMH values. However, a significant positive correlation was observed between blood AMH levels and serum estrogen levels (P < 0.001). These findings suggest that urinary AMH may be a product of proteolytic degradation, potentially leading to inaccurate estimations of ovarian activity based solely on urine AMH levels.

Comparing the advantages, disadvantages and diagnostic power of different non-invasive pre-implantation genetic testing: A literature review

To improve embryo transfer success and increase the chances of live birth in assisted reproductive methods, there is a growing demand for the use of pre-implantation genetic testing (PGT). However, the invasive approaches used in PGT have led to in vitro fertilization failure and abortions, increasing anxiety levels for parents. To address this, non-invasive PGT methods have been introduced, such as the detection of DNA in blastocoel fluid of blastocysts and spent culture media (SCM). These methods have proven to be minimally invasive and effective in detecting aneuploidy in the chromosomes of human embryos. This review aims to explore the different approaches to pre-implantation diagnosis, including invasive and non-invasive methods, with a particular focus on non-invasive PGT (niPGT). The search strategy involved gathering data from scientific databases such as PubMed, Google Scholar, and Science Direct using relevant keywords. The search was conducted until January 2023. In total, 22 studies have successfully reported the detection and amplification of cell-free DNA in the embryonic SCM. It is important to note that niPGT has some limitations, which include differences in indicators such as cell-free DNA amplification rate, concordance, level of maternal DNA contamination, sensitivity, and specificity between SCM samples and biopsied cells. Therefore, more extensive and detailed research is needed to fully understand niPGT’s potential for clinical applications. Key words: Spent culture media, Non-invasive pre-implantation genetic testing, Biopsy methods, Cell-free embryonic DNA.

Advancements in liquid chromatography‐mass spectrometry for amphetamine analysis in unconventional biological matrices: Focus on oral fluid and hair samples

AbstractAmphetamines (AMPHs) and their derivatives are potent central nervous system stimulants, in 2020 an astonishing 34 million regular users were reported worldwide. Consequently, there has been a critical need for the development of methods capable of detecting these compounds in alternative biological matrices. The review article discusses the analysis of amphetamines and their derivatives in alternative biological matrices, such as hair and oral fluid (OF), using liquid chromatography‐mass spectrometry. Compiles data from 28 articles published between 2012 and 2022, focusing on 13 articles on OFs and 15 on hair analysis. The article highlights the advantages of using these alternative matrices, including less invasive collection methods, greater sample stability, and simplified extraction processes. Additionally, prevalent analytical practices such as the use of C18 columns and the incorporation of formic acid and methanol into mobile phases are discussed. Furthermore, it demonstrates that the most used method for collecting OF is the Quantisal device, as well as solid phase extraction is also the most used for the same matrix. The review serves as a guide for researchers interested in analytical methods for identifying AMPHs, offering insights into advances, challenges, and the most used in the area.

CASE SERIES AND REVIEW ON THE MANAGEMENT OF BLADDER CALCULI CAUSED BY IUD MIGRATION

Objective: Comparing two cases of the management of bladder calculi caused by Intra Uterine Device (IUD) migration with other similar cases worldwide. Case(s) Presentation: A forty-eight-year-old woman diagnosed by Abdominal Non-contrast Computed Tomography (NCCT), already done IUD extraction through the bladder approach also hysteroscopy to evaluate the position from the womb side, and continued with the stone removal by vesicolithotripsy. The second case revealed a bladder stone with IUD tail presence based on Kidney Ureter Bladder (KUB), performed vesicolithotomy, and IUD was found attached to the stone. Both patients’ conditions improved after surgeries. IUD migration into the bladder causes perforation, stone formation, and Urinary Tract Infection (UTI). NCCT, KUB, and Ultrasonography can be used as imaging modalities for initial screening when IUD migration is suspected. Discussion: The managements consist of open cystolithotomy, transurethral grasping forceps, or minimally invasive laparoscopy. Open and laparoscopic surgery should be considered for the IUD removal with partial penetration due to vesicouterine fistula and high-risk stone removal, especially for the large stone with IUD embedded inside. Conclusion: Minimally invasive methods are efficient, safe, and frequently preferred for the bladder stone caused by IUD migration. Keywords: Bladder stone, IUD, migration.

Morphological Parameters of Gallbladder are Correlated with Age

Introduction: Gallbladder issues are prevalent globally, particularly in Bangladesh, and become more common with age. Diagnosis involves clinical assessment and confirmation through noninvasive and invasive methods. Understanding gallbladder features is crucial for effective investigation, diagnosis, and management. Objectives: To find out relation between morphological parameters of human gallbladder with age. Materials and Methods: This cross-sectional descriptive study was conducted in the Department of Anatomy in collaboration with the Department of Forensic Medicine, Sylhet MAG Osmani Medical College, Sylhet from January 2014 to December 2014. Fifty human postmortem gallbladders were selected. Dead bodies autopsied within 36 hours of death. Considerable signs of decomposition or decomposed dead body, presence of gross gallbladder disease and any history of poisoning cases were excluded. All the specimens were examined to detect the length, breadth, weight and thickness of the gallbladder; and length and diameter of cystic duct. Results: The study included cadavers ranging in age from 11 to 55 years, with a mean age of 35.02 ± 19.98 years. Of the total, 29 (58.0%) were male, and 21 (42.0%) were female. The length and thickness of the gallbladder increased significantly with age, as did the length and diameter of the cystic duct. But the weight and breadth also change with age, although not significantly. Conclusion: The length and thickness of the gallbladder; the length and diameter of the cystic duct were varied with age; but no variation in weight and breadth. Medicine Today 2023 Vol.36 (1): 31-35

Can linezolid be validly measured in endotracheal aspiration in critically ill patients? A proof-of-concept trial

BackgroundTherapeutic drug monitoring (TDM) of anti-infectives such as linezolid is routinely performed in blood of intensive care unit (ICU) patients to optimize target attainment. However, the concentration at the site of infection is considered more important for a successful therapy. Until now, bronchoalveolar lavage (BAL) is the gold standard to measure intrapulmonary concentrations of anti-infective agents. However, it is an invasive method and unsuitable for regular TDM. The aim of this proof-of-concept study was to investigate whether it is possible to reliably determine the intrapulmonary concentration of linezolid from endotracheal aspiration (ENTA).MethodsIntubated ICU patients receiving 600 mg intravenous linezolid twice daily were examined in steady state. First, preliminary experiments were performed in six patients to investigate which patients are suitable for linezolid measurement in ENTA. In a second step, trough and peak linezolid concentrations of plasma and ENTA were determined in nine suitable patients.ResultsLinezolid can validly be detected in ENTA with viscous texture and > 0.5 mL volume. The mean (SD) linezolid trough concentration was 2.02 (1.27) mg/L in plasma and 1.60 (1.36) mg/L in ENTA, resulting in a median lung penetration rate of 104%. The mean (SD) peak concentration in plasma and ENTA was 10.77 (5.93) and 4.74 (2.66) mg/L.ConclusionsLinezolid can validly be determined in ENTA with an adequate texture and volume. The penetration rate is comparable to already published BAL concentrations. This method might offer a simple and non-invasive method for TDM at the site of infection “lung”. Due to promising results of the feasibility study, comparison of ENTA and BAL in the same patient should be investigated in a further trial.

Transmalar Kirshner Wire Fixation Under Ultrasound Scanning is Useful for Unstable Zygomatic Arch Fracture Combined With Zygomatic Body Fracture.

Plate fixation to zygomatic arch fractures carries the risk of facial nerve palsy and scarring of the cheek; however, without plate fixation, bone deviation or displacement may reoccur after surgery. Furthermore, zygomatic arch fractures combined with zygomatic body fractures are more postoperatively unstable than single zygomatic arch fractures. Few reports have focused on this combined fracture type, and no consensus has been reached regarding treatment. Because plate fixation for slight deviation of the zygomatic body has little advantage for stabilization, the authors, usually opt for transmalar pinning alone instead of plate fixation at the hospital. This study is a retrospective case series of 7 patients, among 100 zygomatic fractures excluding isolated zygomatic arch fractures, treated using transmalar pinning under ultrasound scanning. The reduction was performed through the oral and temporal incision as a surgical procedure. Under ultrasound observation, a Kirshner wire was inserted into the zygomatic body from the unaffected side while maintaining the reduced position. The wire was removed at an outpatient visit 2 to 3 months following surgery. In all cases, the zygomatic body was of the laterally rotated type, and postoperative morphologic evaluation showed improvement without postoperative complications. Scores were higher in middle-aged and older than in young people. Correction of zygomatic rotation also scored higher than zygomatic arch morphology. Transmalar Kirshner wire fixation under ultrasound observation is a simple and minimally invasive method for zygomatic arch fractures, which avoids the possible complications related to plate fixation.

Long-term continuous monitoring of arrhythmias in pigs with insertable cardiac monitors.

Arrhythmia detection is essential when assessing the safety of novel drugs and therapies in preclinical studies. Many short-term arrhythmia monitoring methods exist, including non-invasive ECG and Holter. However, there are no reliable, long-term, non-invasive, or minimally invasive methods for cardiac arrhythmia follow-up in large animals that allows free movement with littermates. A long follow-up time is needed when estimating the impact of long-lasting drugs or therapies, such as gene therapy. We evaluated the feasibility and performance of insertable cardiac monitors (ICMs) in pigs for minimally invasive, long-term monitoring of cardiac arrhythmias that allows free movement and species-specific behavior. Multiple implantation sites were tested to assess signal quality. ICMs recognized reliably many different arrhythmias but failed to detect single extrasystoles. They also over-diagnosed T-waves, resulting in oversensing. Muscle activity and natural startles of the animals caused noise, leading to a heterogeneous signal requiring post-recording evaluation. In spite of these shortcomings, the ICMs showed to be very useful for minimally invasive long-term monitoring of cardiac rhythm in pigs.

Exoscopic Minimally Invasive Excision of Intradural Extramedullary Tumor

AbstractSpinal tumors extending up to two levels can be removed using minimally invasive techniques. A microscope is traditionally used as a visualization tool with the tubular-retractor system. An exoscope is a newer optical tool with improved digital resolution, panoramic view, and better ergonomics for surgery. A 36-year-old who presented with paraparesis was diagnosed with intradural extramedullary tumor in the T7-T8 region. A complete tumor resection was possible using tubular retractors and exoscope. The patient recovered clinically. We document our surgical experience and present an edited video of the surgery. The key steps and nuances are described in the audio timeline. The authors acknowledge the feasibility of performing this surgery via a minimally invasive method using an exoscope.

Clinical influencing factors of vital pulp therapy on pulpitis permanent teeth with 2 calcium silicate-based materials: A randomized clinical trial.

Compared with traditional root canal therapy (RCT), vital pulp therapy (VPT) is a personalized and minimally invasive method for the treatment of pulpitis caused by dental caries. However, there are still no clear guidelines for VPT because high-quality randomized clinical trials are scarce. This prospective cohort study evaluated the clinical efficacy of VPT with the light-curable calcium silicate-based material TheraCal LC (TH) and bioceramic material iRoot BP Plus (BP) in reversible and irreversible pulpitis permanent teeth with carious exposures. 115 teeth with reversible or irreversible pulpitis caused by deep care were randomly divided into 2 groups. TheraCal LC and iRoot BP Plus were used for the pulp capping. Direct pulp capping (DPC), partial pulpotomy (PP) and full pulpotomy (FP) were performed based on observation of the exposed pulp. Postoperative discomforts were enquired and recorded via follow-up phone calls. Clinical and radiographic evaluations were performed 3, 6, and 12 months postoperatively. The overall clinical success rate in the first year was 90.4% (47/52) in both groups. The TH group required less operating time, showed lower levels of pain, and had shorter pain duration post-operative (P < .001). According to the binary logistic regression model, preoperative pain duration was significantly correlated with the prognosis of VPT (P = .011). VPT with TheraCal LC and iRoot BP Plus in pulpitis permanent carious teeth both achieved good clinical outcomes, and TheraCal LC can be easily operated for clinical use. Preoperative pain duration of the affected tooth might have a significant correlation with the prognosis of VPT.

Abstract PO5-14-04: FTIR Spectroscopy Analysis of Lipid Region: Distinguishing Breast Cancer from Benign Breast Diseases Using PCA-SVM

Abstract Background: Breast cancer (BC) is the most diagnosed type worldwide, with 2.26 million new cases in 2020. Mammography is the preferred screening method, but it has limitations such as radiation exposure and low sensitivity in dense breasts. Therefore, there is a need for accurate diagnostic methods to detect breast cancer and distinguish benign conditions. Objective: This study aimed to develop an automated tool for the comparison of lipid spectral region in benign breast disease (BBD) and breast cancer (BC) to determine their potential diagnostic value using Fourier Transform Infrared Spectroscopy (ATR-FTIR). Methods: This study was conducted at a Clinical Hospital in Uberlandia, MG, Brazil, after approval by the Human Research Ethics Committee of the Federal University of Uberlandia, and all subjects provided written informed consent. Women who went to the Clinical Hospital for breast surgery were invited to participate in the study as volunteers. After surgery and histopathological analysis, the tumors and lesions found were classified according to histological type, staging, and the status of ER, PR, and HER2 receptors. A total of 60 women participated in the study, of whom 27 had BBD, and 33 had BC. Spectra were measured in the wavenumber range of 4000 cm-1 to 650 cm-1 using an Agilent Cary 600 Series FTIR spectrometer coupled to an MCT detector. The air spectrum was used as a background before each sample analysis. The sample spectra were obtained in triplicate, with a spectral resolution of 4 cm-1, and 128 scans were performed for each measurement. The infrared spectra were analyzed after undergoing preprocessing, which involved positive baseline rubberband normalization, normalization by minimum and maximum, and application of the second derivative. Results: The region of 3050-2800 cm-1 was able to differentiate BC from BBD using principal component analysis (PCA) followed by the support vector machine algorithm (PCA-SVM) with an accuracy of 80%, sensitivity of 88%, and specificity of 70%. This range corresponds to the vibration of lipids, and it is known that changes in the contents of biomolecules in the serum, an increase or decrease, can be related to the presence or absence of BC. The implementation of this approach in clinical practice may automate the diagnosis of BC, monitoring whether changes in therapy or interventions are necessary throughout the treatment. FTIR can potentially assist in clinical decision-making regarding follow-up or biopsy recommendations, avoiding unnecessary biopsies that are more invasive and expensive than blood collection, and which often cause significant anxiety to the patient even if the lesion is not highly suspicious. Conclusion: This study shows that it is possible to detect BC with good accuracy through a minimally invasive, fast, and cost-effective method analyzing the lipid spectral region using principal component analysis (PCA) followed by the support vector machine algorithm (PCA-SVM). Citation Format: Juliana Pereira, Alinne Faria, Izabella Ferreira, Letícia Santos, Donizeti Santos, Marcelo Maia, Ohanna Costa, Raul Freitas, Carlos Paiva, Yara Maia. FTIR Spectroscopy Analysis of Lipid Region: Distinguishing Breast Cancer from Benign Breast Diseases Using PCA-SVM [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-14-04.

C-29 | Utility of invasive bolus thermodilution method in diagnosis of coronary microvascular dysfunction (CMD): Real World data

C-29 | Utility of invasive bolus thermodilution method in diagnosis of coronary microvascular dysfunction (CMD): Real World data