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Background: Non-invasive biomarkers for early chemotherapeutic response in Ewing sarcoma family of tumors (ESFT) are useful for optimizing existing treatment protocol. Purpose: To assess the role of diffusion-weighted magnetic resonance imaging (MRI) in the early evaluation of chemotherapeutic response in ESFT. Material and Methods: A total of 28 patients (mean age = 17.2 ± 5.6 years) with biopsy proven ESFT were analyzed prospectively. Patients underwent MRI acquisition on a 1.5-T scanner at three time points: before starting neoadjuvant chemotherapy (baseline), after first cycle chemotherapy (early time point), and after completion of chemotherapy (last time point). RECIST 1.1 criteria was used to evaluate the response to chemotherapy and patients were categorized as responders (complete and partial response) and non-responders (stable and progressive disease). Tumor diameter, absolute apparent diffusion coefficient (ADC), and normalized ADC (nADC) values in the tumor were measured. Baseline parameters and relative percentage change of parameters after first cycle chemotherapy were assessed for early detection of chemotherapy response. Results: The responder:non-responder ratio was 21:7. At baseline, ADC ([0.864 ± 0.266 vs. 0.977 ± 0.246]) × 10−3mm2/s; P = 0.205) and nADC ([0.740 ± 0.254 vs. 0.925 ± 0.262] × 10−3mm2/s; P = 0.033) among responders was lower than the non-responders and predicted response to chemotherapy with AUCs of 0.6 and 0.735, respectively. At the early time point, tumor diameter (27% ± 14% vs. 4.6% ± 10%; P = 0.002) showed a higher reduction and ADC (75% ± 44% vs. 52% ± 72%; P = 0.039) and nADC (81% ± 44% vs. 48% ± 67%; P = 0.008) showed a higher increase in mean values among responders than the non-responders and identified chemotherapy response with AUC of 0.890, 0.723, and 0.756, respectively. Conclusion: Baseline nADC and its change after the first cycle of chemotherapy can be used as non-invasive surrogate markers of early chemotherapeutic response in patients with ESFT. [ABSTRACT FROM AUTHOR]

Multinucleated giant cells are commonly encountered in histopathology and are mostly a clue to diagnosis but sometimes pose a diagnostic confusion. The present study elucidates a case series of giant cell lesions (GCL) with emphasis on differential diagnosis and other investigations that contribute towards arriving at a final diagnosis. We also intended to devise an algorithmic approach for the accurate pathological characterization of these lesions. All the cases reported in the department from January 2018 to June 2019 were reviewed by pathologists and the total number of lesions where giant cells were diagnostic or an additional finding were included in this study. Twenty-five cases out of 1000 biopsies were diagnosed based on giant cell morphology. The most frequent lesions were central giant cell granuloma, followed by cherubism, hyperparathyroidism, peripheral giant cell granuloma, tuberculosis, and hybrid lesion. A systematic approach towards differential diagnosis for such cases and a diagnostic algorithm was devised which is being followed as per the reported spectrum of GCL. Radiological, serology, and sometimes ancillary staining techniques are essential for the accurate histopathological diagnosis of giant cell lesions. Our diagnostic algorithm helps narrow down the spectrum of investigations necessary to characterize these lesions, enabling for a swifter and more confident identification of the pathologies. [ABSTRACT FROM AUTHOR]

Undue heat production in surgical bone drilling leads to osteonecrosis and can be an important cause of failure of osteosynthesis, impaired healing, and loosening of implants following orthopedic surgery. The present work aims to minimize heat production below the critical temperature for thermal osteonecrosis (i.e., 47°C) and obviate thermal bone damage due to drilling. A total of 20 samples from the shaft of the human femur were obtained at autopsies and drilling was performed at room temperature by an operation theater (OT) compatible rotary ultrasonic bone drilling (RUBD) machine. K‐type thermocouples were used to measure the temperature rise during drilling and the physical changes of the bone samples were observed by infrared gama camera. Light microscopic and transmission electron microscopic studies were performed to evaluate the bone cell damage. The maximum temperature recorded in RUBD (40.6 ± 1.3°C) was much below the critical temperature for thermal osteonecrosis (p <.05) at the rotational speed of 2000 rpm. Light microscopic and ultrastructural studies also revealed that there was no appreciable damage to the bone cells. Conventional bone drilling (CD) on the other hand recorded much higher temperature (66.6 ± 3.2°C), tissue burn and bone cell necrosis. Hence, RUBD machine has a potentiality for its use in orthopedic surgery and may provide better results. [ABSTRACT FROM AUTHOR]