GATE Monte Carlo approach to heterogeneity dose distribution in small fields used in radiation therapy

The Accurate dosage prediction in Radiation Therapy is challenging, prompting a need for precision beyond conventional clinical Treatment Planning Systems (TPS). Monte Carlo-based methods are sought for their superior accuracy. The aim of this study is to compare dose distributions between the ACUROS algorithm and the GATE platform in various tissue densities and field sizes, focusing on smaller fields. This study was initiated with a homogeneous validation of the TrueBeam STX system, using measurements obtained from the Centre Hospitalier Interregional Edith Cavell (CHIREC) in Brussels. The validation compared dosimetric functions (Percentage Depth Dose (PDD), Dose profile (DP) and Collimator scatter fraction (CSF)) employing the GAMMA index with a 2% / 2 mm criterion tolerance. Following this, heterogeneous studies examined dose distributions between the ACUROS algorithm and the GATE platform in various tissue densities and field sizes, with a specific focus on smaller fields. Simulations were conducted using both platforms on chest phantoms with heterogeneous slabs representing bone, lung, and heart, each housing a central tumor. The impact of electronic equilibrium on tumors for different small field sizes was evaluated. Results showed a remarkable 99% agreement between measurements and GATE calculations in the homogeneous validation of the TrueBeam STX system. However, in heterogeneous studies, ACUROS consistently overestimated lung doses by up to 8% compared to GATE simulation, especially evident with a flattening filter and smaller beam sizes at density interfaces. This highlights significant dose estimation discrepancies between ACUROS and GATE, emphasizing the need for precise calculations. The findings support exploring Monte Carlo-based methods for enhanced accuracy in Radiation Therapy treatment planning.

Ensembl 2023

Ensembl (https://www.ensembl.org) has produced high-quality genomic resources for vertebrates and model organisms for more than twenty years. During that time, our resources, services and tools have continually evolved in line with both the publicly available genome data and the downstream research and applications that utilise the Ensembl platform. In recent years we have witnessed a dramatic shift in the genomic landscape. There has been a large increase in the number of high-quality reference genomes through global biodiversity initiatives. In parallel, there have been major advances towards pangenome representations of higher species, where many alternative genome assemblies representing different breeds, cultivars, strains and haplotypes are now available. In order to support these efforts and accelerate downstream research, it is our goal at Ensembl to create high-quality annotations, tools and services for species across the tree of life. Here, we report our resources for popular reference genomes, the dramatic growth of our annotations (including haplotypes from the first human pangenome graphs), updates to the Ensembl Variant Effect Predictor (VEP), interactive protein structure predictions from AlphaFold DB, and the beta release of our new website.

Ensembl 2022

Ensembl (https://www.ensembl.org) is unique in its flexible infrastructure for access to genomic data and annotation. It has been designed to efficiently deliver annotation at scale for all eukaryotic life, and it also provides deep comprehensive annotation for key species. Genomes representing a greater diversity of species are increasingly being sequenced. In response, we have focussed our recent efforts on expediting the annotation of new assemblies. Here, we report the release of the greatest annual number of newly annotated genomes in the history of Ensembl via our dedicated Ensembl Rapid Release platform (http://rapid.ensembl.org). We have also developed a new method to generate comparative analyses at scale for these assemblies and, for the first time, we have annotated non-vertebrate eukaryotes. Meanwhile, we continually improve, extend and update the annotation for our high-value reference vertebrate genomes and report the details here. We have a range of specific software tools for specific tasks, such as the Ensembl Variant Effect Predictor (VEP) and the newly developed interface for the Variant Recoder. All Ensembl data, software and tools are freely available for download and are accessible programmatically.

Composite lymphomas: Experience from a tertiary cancer center in Kerala, South India

OBJECTIVES

Composite tumors are defined as tumors in which there are two different intermixed histologic types. Our objective was to study the clinical and pathologic features of five cases of composite lymphoma.

MATERIALS AND METHODS

Our study included five patients of composite lymphoma diagnosed over a period of 5 years. Clinical presentation, hematological parameters including peripheral smear, bone marrow aspirate, and histopathological examination of lymph node including immunohistochemistry (IHC) were studied. Treatment and follow-up details were also noted.

RESULTS

All the five cases were in the adult age group ranging from 44 to 72 years. All the cases were composite follicular lymphoma (FL) and mixed cellularity classical Hodgkin lymphoma (CHL). Diagnosis in all cases was suspected on morphology by identification of distinct neoplastic follicles in FL and classic Reed-Sternberg cells in CHL and confirmed by IHC.

CONCLUSION

Although rare, composite lymphomas should be kept in mind. Careful histopathological examination of lymph node with identification of distinct morphological features along with IHC helps to arrive at the definitive diagnosis.

Schwannoma base tongue: Case report and review of literature

Schwannomas are benign peripheral nerve sheath tumors. These are rare in the oral cavity (1%). The most common site of involvement in oral cavity is the tongue. Posterior third of tongue is not frequently involved. The aim of this paper is to present a case report of base tongue schwannoma and review literature of this rare tumor. Data from literature were analyzed for age, gender, presenting symptom, size at presentation, and surgical approach. We report a case of 26 year-old male who presented with swelling posterior 1/3rd tongue and change in quality of voice. He was evaluated for the same with MR and incision biopsy and was planned for surgery. Surgery was abandoned at a district hospital due to difficulty in intubation. At our center he underwent fibro optic bronchoscopy guided intubation followed by general anesthesia. He underwent excision of mass using left paramedian lip spitting approach with mandibulotomy and mandibular swing. Tumor was excised in toto. His postoperative recovery was uneventful. Literature review between 2001 and 2012 was done. 15 cases of base tongue schwannoma were identified. The most common age group involved was between 30-40 years. There was a slightly higher incidence in females. All patients were symptomatic at presentation. Most common complaints were related to swallowing and throat pain. Most patients underwent transoral excision of the tumor.