Clinical Concept-Based Radiology Reports Classification Pipeline for Lung Carcinoma.

Rising incidence and mortality of cancer have led to an incremental amount of research in the field. To learn from preexisting data, it has become important to capture maximum information related to disease type, stage, treatment, and outcomes. Medical imaging reports are rich in this kind of information but are only present as free text. The extraction of information from such unstructured text reports is labor-intensive. The use of Natural Language Processing (NLP) tools to extract information from radiology reports can make it less time-consuming as well as more effective. In this study, we have developed and compared different models for the classification of lung carcinoma reports using clinical concepts. This study was approved by the institutional ethics committee as a retrospective study with a waiver of informed consent. A clinical concept-based classification pipeline for lung carcinoma radiology reports was developed using rule-based as well as machine learning models and compared. The machine learning models used were XGBoost and two more deep learning model architectures with bidirectional long short-term neural networks. A corpus consisting of 1700 radiology reports including computed tomography (CT) and positron emission tomography/computed tomography (PET/CT) reports were used for development and testing. Five hundred one radiology reports from MIMIC-III Clinical Database version 1.4 was used for external validation. The pipeline achieved an overall F1 score of 0.94 on the internal set and 0.74 on external validation with the rule-based algorithm using expert input giving the best performance. Among the machine learning models, the Bi-LSTM_dropout model performed better than the ML model using XGBoost and the Bi-LSTM_simple model on internal set, whereas on external validation, the Bi-LSTM_simple model performed relatively better than other 2. This pipeline can be used for clinical concept-based classification of radiology reports related to lung carcinoma from a huge corpus and also for automated annotation of these reports.

Brain SPECT scans in students with specific learning disability: Preliminary results.

Background and Objectives: Brain single-photon emission computed tomography (SPECT) assesses brain function through measurement of regional cerebral blood flow. This study was conducted to assess whether students with newly diagnosed specific learning disability (SpLD) show any abnormalities in cerebral cortex perfusion. Settings and Design: Cross-sectional single-arm pilot study in two tertiary care hospitals. Subjects and Methods: Nine students with SpLD were enrolled. Brain SPECT scan was done twice in each student. For the first or "baseline" scan, the student was first made to sit with eyes open in a quiet, dimly lit room for a period of 30-40 min and then injected intravenously with 20 mCi of 99mTc-ECD. An hour later, "baseline scan" was conducted. After a minimum gap of 4 days, a second or "test scan" was conducted, wherein the student performed an age-appropriate curriculum-based test for a period of 30-40 min to activate the areas in central nervous system related to learning before being injected with 20 mCi of 99mTc-ECD. Statistical Analysis Used: Cerebral cortex perfusion at rest and after activation in each student was compared qualitatively by visual analysis and quantitatively using NeuroGam™ software. Results: Visual analysis showed reduction in regional blood flow in temporoparietal areas in both "baseline" and "test" scans. However, when normalization was attempted and comparison done by Talairach analysis using NeuroGam software, no statistically significant change in regional perfusion in temporoparietal areas was appreciated. Conclusion: Brain SPECT scan may serve as a robust tool to identify changes in regional brain perfusion in students with SpLD.

Carcinoembryonic antigen directed PET-CECT scanning for postoperative surveillance of colorectal cancer.

AIM: During the follow-up of surgically resected colorectal cancer (CRC), positron emission tomography-contrast-enhanced computed tomography (PET-CECT) is indicated for asymptomatic elevation of carcinoembryonic antigen (CEA) > 5 ng/ml and no obvious site of recurrence on clinical examination and basic imaging. As an institutional policy, a PET-CECT scan was performed at our institute whenever (1) CEA levels rose above 5 ng/ml and (2) CEA values were doubled (even if the CEA level was < 5 ng/ml). Our aim was to correlate the range of CEA elevation with recurrence rates and to evaluate the diagnostic utility of PET-CECT scanning in this setting. METHOD: We retrospectively analysed all cases where a PET-CECT scan was performed for elevated CEA levels during surveillance visits after complete resection of the primary tumour followed by adjuvant therapy. This study was conducted from 1 January 2013 to 31 July 2015. RESULTS: In all, 104 patients underwent a PET-CECT scan for rising CEA values, and 62 patients (59.6%) were found to have recurrent disease. At CEA levels < 5, 5.1-10, 10.1-15, 15.1-50 and > 50 ng/ml, disease recurred in 10%, 45%, 70%, 94% and 100% patients, respectively. Sensitivity, specificity, positive predictive value and negative predictive value of the PET-CECT scan were 92.7%, 95.2%, 96.2% and 90.9%, respectively. Elevation of CEA levels during follow-up was indicative of recurrence in 68% of the secretors and 45% of the non-secretors (based on baseline CEA status). CONCLUSION: In the setting of rising CEA levels during follow-up of patients with CRC, a PET-CECT scan is a valuable tool to detect recurrence, irrespective of the baseline CEA secretor status. The likelihood of recurrence of disease was directly proportional to the value of the raised CEA level.

Concepts of occlusion in prosthodontics: A literature review, part II.

This series of articles describes about concepts of occlusion in the complete denture, fixed partial denture, and implants. This article discusses about the evolution of different concepts of nonbalanced occlusion and occlusal schemes in complete denture occlusion.

Concepts of occlusion in prosthodontics: A literature review, part I.

Occlusion and its relationship to the function of the stomatognathic system have been widely studied in dentistry since many decades. This series of articles describe about occlusion in the complete denture, fixed partial denture, and implants. Part I and II of this articles series describe concepts and philosophies of occlusion in complete denture. So far, available research has not concluded a superior tooth form or occlusal scheme to satisfy the requirements of completely edentulous patients with respect to comfort, mastication, phonetics, and esthetics. Since then, several balanced and nonbalanced articulation concepts were proposed in the literature. A balanced articulation appears to be most appropriate because of tooth contacts observed during nonfunctional activities of patients. This article discusses about evolution of different concepts of occlusion and occlusal schemes in complete denture occlusion.

Prospective observational study on diagnostic accuracy of whole-body MRI in solid small round cell tumours.

AIM: To assess the diagnostic accuracy of whole-body magnetic resonance imaging (WB-MRI) for metastatic disease in patients with solid small round cell tumours (SRCT) by comparing it with routine staging procedures (standard of care). MATERIALS AND METHODS: Eligible cases of neuroblastoma, primitive neuroectodermal tumour, and rhabdomyosarcoma were enrolled in the study after obtaining informed consent. WB-MRI was undertaken using overlapping coronal T1 and short-tau inversion recovery (STIR) sequences. Lesions were classified into skeletal, pulmonary, and soft-tissue types. Conventional staging, which consisted of combined positron-emission tomography & computed tomography (PET-CT), bone scintigraphy & bone marrow biopsy for bone metastases, CT thorax for lung metastases, combined PET-CT, metaiodobenzylguanidine (MIBG) scintigraphy (in neuroblastoma) for soft tissue metastases and clinical evaluation was used as the reference standard. Parameters for diagnostic accuracy were calculated. RESULTS: Thirty-four out of forty patients enrolled were included in final analysis, half of them having metastatic disease. The sensitivity, specificity, positive and negative predictive value, and the diagnostic accuracy of WB-MRI and PET-CT for skeletal metastases as compared to reference standard were 91.9%, 99.8%, 97.4%, 99.6%, and 95.5% and 99.1%, 99.9%, 99.1%, 99.9%, and 99.9%, respectively. The sensitivity of MRI, only PET and PET-CT with plain CT thorax was 30%, 40%, and 100%, respectively, for lung metastases. The sensitivity of MRI for soft-tissue lesions was 76.9%. CONCLUSION: WB-MRI is a radiation-free tool with high diagnostic accuracy for the evaluation of metastatic disease to the marrow. The rate of detection of soft-tissue metastases, such as nodal metastases, is less when WB-MRI is compared with conventional staging using coronal STIR images. CT thorax is essential for accurate evaluation of lung metastases.

Retraction Note to: Stem Cell Mediated Tooth Regeneration: New Vistas in Dentistry.

[This retracts the article DOI: 10.1007/s13191-011-0110-9.].

A Global Dataset of Potential Chloride Deposits on Mars as Identified by TGO CaSSIS.

Chloride deposits are markers for early Mars' aqueous past, with important implications for our understanding of the martian climate and habitability. The Colour and Stereo Surface Imaging System (CaSSIS) onboard ESA's Trace Gas Orbiter provides high-resolution color-infrared images, enabling a planet-wide search for (small) potentially chloride-bearing deposits. Here, we use a neural network to map potentially chloride-bearing deposits in CaSSIS images over a significant fraction of the planet. We identify 965 chloride deposit candidates with diameters ranging from <300 to >3000 m, including previously unknown deposits, 136 (~14%) of which are located in the highlands north of the equator, up to ~36°N. Northern chloride candidates tend to be smaller than in the south and are predominantly located in small-scale topographic depressions in low-albedo Noachian and Hesperian highland terranes. Our new dataset augments existing chloride deposit maps, informs current and future imaging campaigns, and enables future modelling work towards a better understanding of the distribution of near-surface water in Mars' distant past.

Impaired migration of IgA-secreting cells to colon adenocarcinomas.

Local inflammation is a strong risk factor for the development of gastrointestinal adenocarcinomas. Mucosal regulatory T cells and IgA-secreting cells both contribute to reduce inflammatory responses, and their recruitment to tissues is dependent on local production of chemokines. More specifically, IgA-secreting cells are recruited to mucosal tissues by CCL28 signalling through CCR10. Here, we examined the recruitment of IgA-secreting plasma cells to tumor-associated mucosa in patients suffering from colon adenocarcinoma. Flow cytometric analyses of single cell suspensions from tumor-associated and unaffected colon mucosa showed a marked decrease in CD19(+)CD38(high)IgA(+) plasmablasts in the tumor-associated mucosa, while the total frequencies of B and T cells were similar. This finding was confirmed in ELISPOT assays, demonstrating a 64 % reduction in the frequencies of IgA-secreting cells among cells from the tumor-associated mucosa. The few IgA(+) plasmablasts present in the tumor did not express CCR10, and functional migration assays demonstrated that IgA-secreting cells from tumor-associated mucosa did not migrate in response to CCL28. Taken together, our results show an impaired migration of IgA-secreting cells to colon tumors, presumably caused by a decreased production of CCL28 in the tumor. The lack of local IgA antibodies may lead to impaired barrier function and increased bacterial colonization, driving further inflammatory responses and promoting tumor growth.

Outcomes and prognostic factors of patients with Extranodal NK T cell lymphoma (ENKTL).

The staging, prognostication, and treatment of ENKTL has evolved over the years with better understanding of the disease biology. There is significant heterogeneity in the treatment followed across the world. Literature from India have been few with small number of patients. We studied the outcomes and prognostic factors of patients with ENKTL treated between May 2010 and December 2021 at our center. A total of 78 patients diagnosed with ENKTL were treated at our center. L-asparaginase based chemotherapy was administered in 84% of the patients. Close to 2/3rd patients received SMILE chemotherapy. After a median follow-up of 30 months (18.5-41.4 months), the median relapse free survival and overall survival for the overall population was 45 months (12-118 months) and 45 months (14-118 months) respectively. By multivariate analysis, PINK score of 2-4, non-receipt of RT and non-achievement of CR were associated with poor survival.

Stem cell mediated tooth regeneration: new vistas in dentistry.

The generation of dental structures and/or entire teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin and enamel. This review focuses on the different sources of stem cells that have been used for making teeth in vitro and their relative efficiency. Embryonic, post-natal and adult stem cells were assessed and proved to possess an enormous regenerative potential, but their application in dental practice is still limited due to various parameters that are not yet under control such as the high risk of rejection, cell behaviour, long tooth eruption period, appropriate crown morphology and suitable colour. Nevertheless, the development of biological approaches for dental reconstruction using stem cells is promising and remains one of the greatest challenges in the dental field.

A finite element analysis of stress distribution in the bone, around the implant supporting a mandibular overdenture with ball/o ring and magnetic attachment.

Today implant dentistry has made great inroads into the treatment modalities that are available in treating an edentulous patient. Popularity of a two implant retained overdenture has created a necessity to examine the various attachment systems being used and the stresses that are transmitted to the alveolar bone. Hence a Three dimensional Finite Element Analysis was done to analyze the stress distribution in the mandibular bone with implant-supported overdenture having Ball/O-ring and Magnet attachments of different diameters. A segment of the anterior region of the mandible was modeled with implant and the overdenture. Four different models were generated having Ball/O-Ring and Magnet Attachments. Forces of 10 N, 35 N and 70 N were applied from the horizontal, vertical and oblique directions respectively and the stress distribution studied. It was concluded that the greatest stress concentrations were seen at the crest of the cortical bone and could be reduced by using smaller sized attachments for implant supported-overdenture.

Radiotherapy for Post-Chemotherapy Residual Mass in Advanced Seminoma: A Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography-Based Risk-adapted Approach.

AIMS: There is a lack of consensus regarding the management of post-chemotherapy residual mass in classical seminoma. The use of fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) may aid the detection of residual masses harbouring viable disease and help to tailor therapy. The aim of this study was to evaluate if PET-CT could identify patients who will benefit from locoregional radiotherapy. MATERIALS AND METHODS: This ethics-approved study included patients with advanced classical seminoma primarily treated with standard platinum-based first-line chemotherapy. Patients were either observed or given adjuvant radiotherapy based on the clinician's preference and followed up. For this study, patients were stratified into two groups based on FDG PET-CT residual nodal maximum standardised uptake value (SUVmax): low risk (SUVmax <3) and high risk (SUVmax ≥3). Further subgroup analysis was carried out for patients with residual nodal size ≥3 cm and SUVmax ≥3, and this was considered as the very high risk group. The diagnostic accuracy of FDG PET-CT was assessed and survival was compared between the different groups. RESULTS: Sixty-nine patients were included in the study: 48 patients were observed and 21 received radiotherapy. The low and high risk groups contained 50.7% and 49.3% of the patients, respectively. The very high risk subgroup had 24 patients. At a median follow-up of 44 months, locoregional failures in the radiotherapy and observation cohorts were 0% and 30% (P = 0.059) in the very high risk subgroup and 5.8% and 29.4% (P = 0.078) in the high risk group. The positive predictive value for the very high risk and high risk groups was 30% and 17.1%, respectively. The benefit of locoregional control failed to translate into overall survival benefit. CONCLUSION: A tailored, FDG PET-based risk-adapted treatment approach can refine the management of post-chemotherapy residual masses in seminoma. In this study, with the largest cohort of advanced seminoma patients treated with radiotherapy reported to date, radiotherapy seems to benefit patients with post-chemotherapy residual mass SUVmax ≥3.

Repeatability and reproducibility study of radiomic features on a phantom and human cohort.

The repeatability and reproducibility of radiomic features extracted from CT scans need to be investigated to evaluate the temporal stability of imaging features with respect to a controlled scenario (test-retest), as well as their dependence on acquisition parameters such as slice thickness, or tube current. Only robust and stable features should be used in prognostication/prediction models to improve generalizability across multiple institutions. In this study, we investigated the repeatability and reproducibility of radiomic features with respect to three different scanners, variable slice thickness, tube current, and use of intravenous (IV) contrast medium, combining phantom studies and human subjects with non-small cell lung cancer. In all, half of the radiomic features showed good repeatability (ICC > 0.9) independent of scanner model. Within acquisition protocols, changes in slice thickness was associated with poorer reproducibility compared to the use of IV contrast. Broad feature classes exhibit different behaviors, with only few features appearing to be the most stable. 108 features presented both good repeatability and reproducibility in all the experiments, most of them being wavelet and Laplacian of Gaussian features.

PET-CT in oncology.

Diagnostic imaging plays a pivotal role in cancer management. Imaging has made rapid strides in the past few years with new modalities and new indications getting added all the time. Molecular and metabolic imaging with 18F Flurodeoxyglucose Positron Emission Tomography (FDG PET) and other non-FDG isotopes have revolutionized oncologic imaging and changed our approach towards cancer diagnosis, staging and imaging surveillance. The evidence for the use of FDG PET is mounting every day with newer indications getting added to the literature. The main focus of our discussion will be to understand the basic principles of FDG PET imaging and to study a few of its clinical applications in oncology.

PET-CT in recurrent head neck cancers: a study to evaluate impact on patient management.

BACKGROUND AND OBJECTIVES: PET-CT has shown promise in the management of head neck cancers. However, there have been only few studies evaluating its impact on management of patients with recurrent cancers in the presence of available clinicoradiologic methods of assessment. We conducted this study to assess the same in patients with suspected recurrent head and neck cancer. METHODS: Case histories were presented to two oncologists, who were blinded to PET-CT reports. Treatment plans were made by these oncologists based on clinical findings and other conventional imaging. These plans were then compared to the actual treatment received by patients after PET-CT. Any change was recorded as "change in management." RESULTS: Forty-nine patients with suspected recurrent head and neck cancer were evaluated in the study. Overall, there was a 38.7% change in management because of the addition of PET-CT to conventional methods of assessment. Eight patients (16.3%) had a major change in therapy while in 11 patients (22.4%), diagnostic procedures like endoscopies, biopsies and examination under anesthesia were avoided. CONCLUSION: In our study, PET-CT had a significant impact on the management of patients with suspected recurrent head neck cancer.

Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver.

Occurrence of primary Hodgkin's lymphoma (PHL) of the liver is extremely rare. We report on a case of a 60-year-old male who presented with liver mass and B-symptomatology. Hepatoma or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers like AFP, CEA, Total PSA, and CA-19.9 were within normal limits. Positron Emission Tomography / Computerized Tomography (PET/CT) revealed a large hepatic lesion and a nodal mass in the porta hepatis. A liver biopsy was consistent with Hodgkin's lymphoma. There was complete regression of the hepatic lesion and evidence of shrinkage of the nodal mass following four cycles of chemotherapy. 18F Fluro -de-oxy Glucose (FDG) PET / CT in this case helped in establishing a primary hepatic lymphoma by demonstrating the absence of pathologically hypermetabolic foci in any other nodes or organs. PET / CT scan is a useful adjunct to conventional imaging and histopathology, not only to establish the initial diagnosis, but also to monitor treatment response in PHL.