Computed microtomography of bone specimens for rapid analysis of bone changes associated with malignancy

The Value of Micro-CT in the Diagnosis of Lung Carcinoma: A Radio-Histopathological Perspective

Micro-computed tomography (micro-CT) is a relatively new imaging modality and the three-dimensional (3D) images obtained via micro-CT allow researchers to collect both quantitative and qualitative information on various types of samples. Micro-CT could potentially be used to examine human diseases and several studies have been published on this topic in the last decade. In this study, the potential uses of micro-CT in understanding and evaluating lung carcinoma and the relevant studies conducted on lung and other tumors are summarized. Currently, the resolution of benchtop laboratory micro-CT units has not reached the levels that can be obtained with light microscopy, and it is not possible to detect the histopathological features (e.g., tumor type, adenocarcinoma pattern, spread through air spaces) required for lung cancer management. However, its ability to provide 3D images in any plane of section, without disturbing the integrity of the specimen, suggests that it can be used as an auxiliary technique, especially in surgical margin examination, the evaluation of tumor invasion in the entire specimen, and calculation of primary and metastatic tumor volume. Along with future developments in micro-CT technology, it can be expected that the image resolution will gradually improve, the examination time will decrease, and the relevant software will be more user friendly. As a result of these developments, micro-CT may enter pathology laboratories as an auxiliary method in the pathological evaluation of lung tumors. However, the safety, performance, and cost effectiveness of micro-CT in the areas of possible clinical application should be investigated. If micro-CT passes all these tests, it may lead to the convergence of radiology and pathology applications performed independently in separate units today, and the birth of a new type of diagnostician who has equal knowledge of the histological and radiological features of tumors.

Bone lesions in systemic mastocytosis: Bone histomorphometry and histopathological mechanisms

Osteoporosis is considered the most frequent skeletal manifestation of systemic mastocytosis (SM). We performed a retrospective analysis of sixty patients (37 males and 23 females) who underwent a bone biopsy in the assessment of SM or in the assessment of unexplained bone fragility. Thirty-three had simultaneously a bone marrow biopsy with a Jamshidi's needle; this sample was used for immunohistochemical analysis (tryptase, c-KIT. CD20, VCAM-1). Bone biopsy was realized in 42 cases in the assessment of SM to provide histologic proof of the disease and in 18 cases in the assessment of unexplained bone fragility and surprisingly revealed a SM. An increased bone turnover was observed in patients with SM with elevated eroded surfaces, osteoclast number and bone formation rate. In addition to nodules of mast cells (MC), a high number of MC was directly apposed on the trabeculae, affixed on the osteoblasts or the lining cells. The VCAM-1 adhesion protein recognizing α4β7 and α4β1 integrins may be a candidate to explain this particular adherence. One third of the bone marrow biopsies did not exhibit MC nodules or MC infiltration and led to a false negative diagnosis for SM. SM can be discovered in the assessment of fracture or osteoporosis. Transiliac bone biopsy allows for the diagnosis of the disease more accurately than bone marrow biopsy; it also provides a histomorphometric analysis of bone remodeling.

The effects of varenicline on lumbar spinal fusion in a rat model

BACKGROUND CONTEXT

Smoking is detrimental to obtaining a solid spinal fusion mass with previous studies demonstrating its association with pseudoarthrosis in patients undergoing spinal fusion. Varenicline is a pharmacologic adjunct used in smoking cessation which acts as a partial agonist of the same nicotinic receptors activated during tobacco use. However, no clinical or basic science studies to date have characterized if varenicline has negative effects on spinal fusion and bone healing by itself.

PURPOSE

Our study's aim was to elucidate whether varenicline affects the frequency or quality of posterolateral spinal fusion in a rodent model at an endpoint of 12 weeks.

STUDY DESIGN

Randomized control trial.

PATIENT SAMPLE

Fourteen male Lewis rats randomly separated into two experimental groups.

OUTCOME MEASURES

Manual palpation of fusion segment, radiography, μCT imaging, and four-point bend.

METHODS

Fourteen male Lewis rats were randomly separated into two experimental groups undergoing L4-L5 posterior spinal fusion procedure followed by daily subcutaneous injections of human dose varenicline or saline (control) for 12 weeks postsurgery. Spine samples were explanted, and fusion was determined via manual palpation of segments by two independent observers. High-resolution radiographs were obtained to evaluate bridging fusion mass. μCT imaging was performed to characterize fusion mass and consolidation. Lumbar spinal fusion units were tested in four-point bending to evaluate stiffness and peak load. Study funding sources include $5000 OREF Grant. There were no applicable financial relationships or conflicts of interest.

RESULTS

At 3 months postsurgery, 12 out of 14 rats demonstrated lumbar spine fusion (86% fused) with no difference in fusion frequency between the varenicline and control groups as detected by manual palpation. High-resolution radiography revealed six out of seven rats (86%) having complete fusion in both groups. μCT showed no significant difference in bone mineral density or bone fraction volume between groups in the region of interest. Biomechanical testing demonstrated no significant different in the average stiffness or peak loads at the fusion site of the varenicline and control groups.

CONCLUSION

Based on the results of our rat study, there is no indication that varenicline itself has a detrimental effect on the frequency and quality of spinal fusion.

Nanocomposite Hydrogel with Tantalum Microparticles for Rapid Endovascular Hemostasis

Endovascular embolization to treat vascular hemorrhage involves pushing coil-shaped metal wires into the artery repeatedly until they are densely packed to slow the blood flow and clot. However, coil embolization is associated with high rebleeding rates, unpredictable economics and, most importantly, they rely on the patient's ability to make a clot. These issues are exacerbated when the patient is anticoagulated or coagulopathic. A novel bioengineered tantalum-loaded nanocomposite hydrogel for gel embolic material (Ta-GEM) that can be rapidly delivered using clinical catheters for instant hemostasis regardless of the coagulopathic state is reported. Ta-GEM formulation is visible by most of the clinically available imaging modalities including ultrasound, computed tomography, magnetic resonance imaging, and fluoroscopy without significant artifact. In addition, Ta-GEM can be retrieved, allowing temporary vascular occlusion, and it can be used to rescue cases of failed coil embolization. Ta-GEM occlusion of first-order arteries such as the renal artery and iliac artery in a swine model is found to be safe and durable; by 28 days, 75% of the injected Ta-GEM in the arterial lumen is replaced by dense connective tissue. Altogether, this study demonstrates that Ta-GEM has many advantages over the current technologies and has potential applications in clinical practice.

Earliest Known Hominin Calcar Femorale in Orrorin tugenensis Provides Further Internal Anatomical Evidence for Origin of Human Bipedal Locomotion

The calcar femorale (CF), a plate of dense bone internal to the lesser trochanter, is visible on computed tomographic images of the 6 million-year-old femoral fragment BAR 1003'00 (from the taxon Orrorin tugenensis), among the oldest specimens relevant to reconstructing the evolution of human bipedal locomotion. A strongly expressed CF has been used previously as an indicator of bipedality. If true, then there should be a quantifiable difference in the CF among hominoids. Absolute and normalized CF lengths were measured from computed tomographic images at five anatomical locations along the proximal portion of BAR 1003'00 in addition to samples of nine H. sapiens and ten P. troglodytes femora. The span of the CF superiorly to inferiorly within the proximal femur was measured by counting the number of cross-sections on which the CF occurred. A Bayesian approach was used to classify the BAR 1003'00 sample based on normalized lengths. The P. troglodytes femora were more variable both in the occurrence of the trait and, where present, its span in the proximal femur. The H. sapiens sample exhibited CF lengths that were consistently larger at each location than the P. troglodytes in absolute terms, but the normalized lengths overlap substantially. The Bayesian posterior probability test classifies the CF of BAR 1003'00 with H. sapiens. The BAR 1003'00's calcar femorale has a strong anatomical similarity to the H. sapiens sample, supporting the conclusion that O. tugenensis is an early bipedal hominin. Anat Rec, 301:1834-1839, 2018. © 2018 Wiley Periodicals, Inc.

Relationships between age and microarchitectural descriptors of iliac trabecular bone determined by microCT

AIM

Estimation of age at death is a major issue in anthropology. The main anthropological histological methods propose studying the architecture of cortical bone. In bone histomorphometry, researches on metabolic bone diseases have provided normative tables for trabecular bone volume (BV/TV) according to age and gender of individuals on trans-iliac bone biopsies. We have used microCT, a non-destructive tool for measuring bone volume and trabecular descriptors to compare the French tables to a series of forensic anthropological population and if the two iliac bones could be used interchangeably.

METHODOLOGY

Coxal bone of a personal forensic collection whose age and gender were known (DNA identification) were used. Bone samples, centered on the same area than bone biopsy. MicroCT (pixel size: 36μm) was used to measure BV/TV and morphometric trabecular parameters of microarchitecture. An adjusted Z-score was calculated for BV/TV to compare with normative tables and a right/left comparison of trabecular parameters was provided.

RESULTS

Twenty-seven iliac bones, which 20 forming 10 complete pelvises, aged between 24 and 73y.o. (average of 47.7 y.o.) were used. All adjusted Z-score were within normal values. There was a strong positive correlation between right and left sides for Tb.Th, Tb.N and Tb.Sp, but an insignificant correlation was obtained for BV/TV.

CONCLUSION

Normative tables between age and BV/TV are valid and therefore usable in anthropology. They may represent an alternative to determine the age at death. Nevertheless, it requires a precise technique that could be a drawback in current practice.

A case of polyostotic osteosarcoma with kidney metastases in a dog: histopathology and microcomputed tomographic analysis

A 7-year- old sexually intact female Leonberg dog was evaluated for chronic lameness of the right forelimb. The bitch showed mild hyperthermia (39.3°C), a decrease in its activity, a capricious appetite, a high weight loss (4 kg in 15 days) and a right foreleg lameness. A careful clinical examination revealed a deformation of the right proximal humerus and right tibia. Radiographic examination of the right tibia, right humerus showed osteolysis of both cortical and trabecular bone with a periosteal bone proliferation in the vicinal soft tissues. The owner having refused a bone biopsy, a treatment with NSAIDs and antibiotics was prescribed. After a marked improvement during the first two weeks, an increase in lameness and activity was observed. At that time, the owner accepted the bone biopsy. Histopathologic examination evidenced an osteosarcoma but the amount of available tissue was limited. Due to the poor prognosis, he declined treatment and decided to euthanize the dog. An osteosarcoma with a large chondroid component was observed at autopsy together with ossifying kidney metastases. Histological findings revealed a grade III osteosarcoma. Conventional and undecalcified histology and X-ray microcomputed tomography findings evidenced a large and partially mineralized osteoid part with a sunburst extension in the soft tissues. This is the first time that microCT and undecalcified analyses of an osteosarcoma are presented. The osteolytic and metaplastic bone foci were easily demonstrated by this method.

Walker 256/B malignant breast cancer cells improve femur angioarchitecture and disrupt hematological parameters in a rat model of tumor osteolysis

This study was designed to assess femur angioarchitecture and hematological effects of Walker 256/B cells in a rat model of tumor osteolysis. Tumor osteolysis was induced by in situ inoculation of Walker 256/B malignant cells. Six other rats were sham operated and served as control. Twenty days later, rats were euthanized, and femurs were collected than radiographed. Angioarchitecture [mean lumen diameter (MLD), wall thickness (WTh), Vessel number, volume, and separation (VNb, VV, and VSp respectively)] was studied by histomorphometry at 2 different positions (P1: diaphysis, and P2: metaphysis) of the operated femora. Some hematological parameters were also assessed. Walker 256/B induced marked tumor osteolysis, with cortical perforation and trabecular destruction, associated increase in bone vascularization (increases of VNb and VV and decrease of VSp). Angioarchitecture of W256/B rats was disorganized and showed large MLD and lower WTh. These effects were more prominent in P2. When compared to Sham group, significantly decreases at levels of red blood cell (RBC), hemoglobin (Hb), hematocrit (Ht), and white blood cell (WBC) were observed in W256/B rats. These results suggest that Walker 256/B cells induced tumor osteolysis, improve hypervasculature especially near the tumoral foci (P2) associated hematological disruption. Besides, tumor vessels showed abnormal (enlarged and thinner) and disorganized morphology.

Cancer-associated bone disease

Bone is commonly affected in cancer. Cancer-induced bone disease results from the primary disease, or from therapies against the primary condition, causing bone fragility. Bone-modifying agents, such as bisphosphonates and denosumab, are efficacious in preventing and delaying cancer-related bone disease. With evidence-based care pathways, guidelines assist physicians in clinical decision-making. Of the 57 million deaths in 2008 worldwide, almost two thirds were due to non-communicable diseases, led by cardiovascular diseases and cancers. Bone is a commonly affected organ in cancer, and although the incidence of metastatic bone disease is not well defined, it is estimated that around half of patients who die from cancer in the USA each year have bone involvement. Furthermore, cancer-induced bone disease can result from the primary disease itself, either due to circulating bone resorbing substances or metastatic bone disease, such as commonly occurs with breast, lung and prostate cancer, or from therapies administered to treat the primary condition thus causing bone loss and fractures. Treatment-induced osteoporosis may occur in the setting of glucocorticoid therapy or oestrogen deprivation therapy, chemotherapy-induced ovarian failure and androgen deprivation therapy. Tumour skeletal-related events include pathologic fractures, spinal cord compression, surgery and radiotherapy to bone and may or may not include hypercalcaemia of malignancy while skeletal complication refers to pain and other symptoms. Some evidence demonstrates the efficacy of various interventions including bone-modifying agents, such as bisphosphonates and denosumab, in preventing or delaying cancer-related bone disease. The latter includes treatment of patients with metastatic skeletal lesions in general, adjuvant treatment of breast and prostate cancer in particular, and the prevention of cancer-associated bone disease. This has led to the development of guidelines by several societies and working groups to assist physicians in clinical decision making, providing them with evidence-based care pathways to prevent skeletal-related events and bone loss. The goal of this paper is to put forth an IOF position paper addressing bone diseases and cancer and summarizing the position papers of other organizations.

Bone metastasis: histological changes and pathophysiological mechanisms in osteolytic or osteosclerotic localizations. A review

The development of a bone metastasis involves interactions between the tumor cells, the bone marrow microenvironment and the bone cells themselves. A better understanding of the pathophysiological changes occurring in bone metastasis can be obtained from histopathological examination of invaded specimens. This review focuses on the main molecular mechanisms implied in the localization and growth of malignant cells in the bone marrow. The corresponding histologic developmental stages are illustrated both in osteolytic (or mixed metastasis) or in the osteosclerotic forms by histological analysis, immunohistochemistry and microcomputed tomographic analysis of bone samples. In both cases, the malignant cells find a "fertile soil" in the bone marrow microenvironment. They use the growth factors released by bone cells for the coupling between osteoclasts/osteoblasts to promote their own development. In turn, they elaborate a variety of cytokines that can promote osteoclastogenesis (PTHrP, IL-1, IL-6…) or on the contrary, other growth factors that can boost the osteoblastic activity (ET1, IGFs). A "vicious circle" occurs between the malignant cells and the bone cells leading to the radiological expression of the metastasis.