Three dimensional modeling and quantitative analysis of long bone parameters of rabbit using micro-computed tomography.

BACKGROUND: Micro-computed tomography (µCT), a modern imaging technique, provides detailed information on the bone morphology of small animal models. AIMS: The objectives are 1) to produce three dimensional (3D) models from µCT images of femoral and tibial bones of New Zealand rabbits, and 2) to estimate and compare morphometric and volumetric results among genders as well as left and right sides. METHODS: A total of twenty adult New Zealand rabbits (10 females, 10 males, aged 12-18 weeks, weight= 2.5-3 kg) were used for this study. Three dimensional reconstructed models of the femoral and tibial bones of rabbits were created from cross-sectional images of µCT using the 3D Slicer program. Anatomical structures were determined on these 3D bone models. Afterward, morphometric parameters such as length, thickness, and width of various parts of the bones were calculated with volume and volume ratio values of cortical bone, trabecular bone, and medullary cavity. RESULTS: The gender*laterality interaction term was found statistically significant in measurements of femoral diaphysis diameter (FDD), internal femoral diaphysis diameter (IFDD), femoral head diameter (FHD), tibial diaphysis diameter (TDD), tibial distal width (TDH), and tibial proximal width (TPW) (P<0.001). The gender*laterality interaction term was not significant in volume and volume fraction values of cortical bone, trabecular bone, and medullary cavity (P>0.05). CONCLUSION: It is thought that the study will contribute to the orthopedic experimental studies of rabbits for femoral and tibial bones and will bring a modern perspective to the field of veterinary anatomy.

Volumetric analysis of the cranial and nasal cavity from micro-computed tomography scans in the rabbit.

BACKGROUND: The aim of the study was to estimate the volume values of the cranial cavity and nasal cavity structures and to compare the efficiency of manual segmentation of three-dimensional reconstruction and Cavalieri's principle (CP) methodologies. MATERIALS AND METHODS: Volume values of the cranial cavity, maxillary sinus (MS), dorsal conchal sinus (DCS), dorsal nasal meatus (DNM), middle nasal meatus (MNM), ventral nasal meatus (VNM), ventral nasal concha (VNC), middle nasal concha (MNC) and nasal vestibule (NV) were estimated with manual segmentation and CP from micro-computed tomography images in 5 male New Zealand white rabbits. Volume measurements and elapsed time were compared with each other. Three-dimensional reconstruction models of nasal and cranial cavity structures were created. RESULTS: There was a statistically significant difference between methods of the MS, DCS, DNM, MNM, VNM, VNC, and MNC volume measurements. Additionally, there was a statistically significant difference between the volumetric analysis time period of the methods and CP was found much shorter than manual segmentation. CONCLUSIONS: Realistic results were achieved in a short time with the CP among the stereology methods. It is thought that these image and quantitative data results can be used for modelling, toxicology and pathology studies such as acute and chronic rhinitis or rhino sinusitis as well as a good understanding of the relationship of the anatomical structures in the nasal cavity.

Introducing FDG PET/CT-guided chemoradiotherapy for stage III NSCLC in low- and middle-income countries: preliminary results from the IAEA PERTAIN trial.

PURPOSE: Patients with stage III non-small-cell lung cancer (NSCLC) treated with chemoradiotherapy (CRT) in low- and middle-income countries (LMIC) continue to have a poor prognosis. It is known that FDG PET/CT improves staging, treatment selection and target volume delineation (TVD), and although its use has grown rapidly, it is still not widely available in LMIC. CRT is often used as sequential treatment, but is known to be more effective when given concurrently. The aim of the PERTAIN study was to assess the impact of introducing FDG PET/CT-guided concurrent CRT, supported by training and quality control (QC), on the overall survival (OS) and progression-free survival (PFS) of patients with stage III NSCLC. METHODS: The study included patients with stage III NSCLC from nine medical centres in seven countries. A retrospective cohort was managed according to local practices between January 2010 and July 2014, which involved only optional diagnostic FDG PET/CT for staging (not for TVD), followed by sequential or concurrent CRT. A prospective cohort between August 2015 and October 2018 was treated according to the study protocol including FDG PET/CT in treatment position for staging and multimodal TVD followed by concurrent CRT by specialists trained in protocol-specific TVD and with TVD QC. Kaplan-Meier analysis was used to assess OS and PFS in the retrospective and prospective cohorts. RESULTS: Guidelines for FDG PET/CT image acquisition and TVD were developed and published. All specialists involved in the PERTAIN study received training between June 2014 and May 2016. The PET/CT scanners used received EARL accreditation. In November 2018 a planned interim analysis was performed including 230 patients in the retrospective cohort with a median follow-up of 14 months and 128 patients in the prospective cohort, of whom 69 had a follow-up of at least 1 year. Using the Kaplan-Meier method, OS was significantly longer in the prospective cohort than in the retrospective cohort (23 vs. 14 months, p = 0.012). In addition, median PFS was significantly longer in the prospective cohort than in the retrospective cohort (17 vs. 11 months, p = 0.012). CONCLUSION: In the PERTAIN study, the preliminary results indicate that introducing FDG PET/CT-guided concurrent CRT for patients with stage III NSCLC in LMIC resulted in a significant improvement in OS and PFS. The final study results based on complete data are expected in 2020.