Evaluation of the accuracy of an enhanced MLC leaf model for Linac-based stereotactic radiosurgery.

Purpose: For LINAC-based stereotactic radiosurgery (SRS) treatments, the binary MLC models utilizing single dosimetric leaf gap (DLG) parameters in Eclipse versions prior to v18 can result in imperfect agreement between measured and calculated doses, increased commissioning complexity, and user-dependent variability. This study aims to evaluate the efficiency and accuracy of the enhanced leaf model (ELM) in Eclipse version 18.0, which incorporates the actual rounded-end MLC design in dose calculations.

A multi-institutional meningioma MRI dataset for automated multi-sequence image segmentation.

Meningiomas are the most common primary intracranial tumors and can be associated with significant morbidity and mortality. Radiologists, neurosurgeons, neuro-oncologists, and radiation oncologists rely on brain MRI for diagnosis, treatment planning, and longitudinal treatment monitoring. However, automated, objective, and quantitative tools for non-invasive assessment of meningiomas on multi-sequence MR images are not available.

Head and Neck Paragangliomas: Overview of Institutional Experience.

Head and neck paragangliomas (HNPGLs) are rare and have high rates of genetic mutations. We conducted a retrospective review of 187 patients with 296 PGLs diagnosed between 1974 and 2023. The mean age of diagnosis was 48.

A Prospective Phase I/II Clinical Trial of High-Dose Proton Therapy for Chordomas and Chondrosarcomas.

Purpose: The purpose of this study was to evaluate the feasibility and safety of dose-escalated proton beam therapy for treating chordomas and chondrosarcomas of the skull base and spine. Methods: A prospective cohort of 54 patients (42 with chordomas and 12 with chondrosarcomas) was enrolled between 2010 and 2018. The primary endpoints were feasibility and <20% rate of acute grade ≥3 toxicity, and secondary endpoints included cancer-specific outcomes and toxicities.

ACR benchmark testing of a novel high-speed ring-gantry linac kV-CBCT system.

A new generation cone-beam computed tomography (CBCT) system with new hardware design and advanced image reconstruction algorithms is available for radiation treatment simulation or adaptive radiotherapy (HyperSight CBCT imaging solution, Varian Medical Systems-a Siemens Healthineers company). This study assesses the CBCT image quality metrics using the criteria routinely used for diagnostic CT scanner accreditation as a first step towards the future use of HyperSight CBCT images for treatment planning and target/organ delineations. Image performance was evaluated using American College of Radiology (ACR) Program accreditation phantom tests for diagnostic computed tomography systems (CTs) and compared HyperSight images with a standard treatment planning diagnostic CT scanner (Siemens SOMATOM Edge) and with existing CBCT systems (Varian TrueBeam version 2.

Repeated peripheral infusions of anti-EGFRvIII CAR T cells in combination with pembrolizumab show no efficacy in glioblastoma: a phase 1 trial.

We previously showed that chimeric antigen receptor (CAR) T-cell therapy targeting epidermal growth factor receptor variant III (EGFRvIII) produces upregulation of programmed death-ligand 1 (PD-L1) in the tumor microenvironment (TME). Here we conducted a phase 1 trial (NCT03726515) of CAR T-EGFRvIII cells administered concomitantly with the anti-PD1 (aPD1) monoclonal antibody pembrolizumab in patients with newly diagnosed, EGFRvIII glioblastoma (GBM) (n = 7). The primary outcome was safety, and no dose-limiting toxicity was observed.

Hypofractionation in Glioblastoma: An Overview of Palliative, Definitive, and Exploratory Uses.

Glioblastoma (GBM) is the most common primary brain malignancy in adults, and its incidence is increasing worldwide. Its prognosis remains limited despite recent imaging and therapeutic advances. The current standard of care is maximal safe resection followed by conventionally fractionated radiotherapy with concurrent and adjuvant temozolomide (TMZ), with or without tumor-treating fields (TTF).

One-year outcomes after stereotactic body radiotherapy for refractory ventricular tachycardia.

Background: Cardiac stereotactic body radiotherapy (SBRT) has emerged as a promising noninvasive treatment for refractory ventricular tachycardia (VT).

Objective: The purpose of this study was to describe the safety and effectiveness of SBRT for VT in refractory to extensive ablation.

Methods: After maximal medical and ablation therapy, patients were enrolled in a prospective registry.

The ASNR-MICCAI Brain Tumor Segmentation (BraTS) Challenge 2023: Intracranial Meningioma.

Meningiomas are the most common primary intracranial tumor in adults and can be associated with significant morbidity and mortality. Radiologists, neurosurgeons, neuro-oncologists, and radiation oncologists rely on multiparametric MRI (mpMRI) for diagnosis, treatment planning, and longitudinal treatment monitoring; yet automated, objective, and quantitative tools for non-invasive assessment of meningiomas on mpMRI are lacking. The BraTS meningioma 2023 challenge will provide a community standard and benchmark for state-of-the-art automated intracranial meningioma segmentation models based on the largest expert annotated multilabel meningioma mpMRI dataset to date.

Proton radiotherapy for glioma and glioblastoma.

Radiotherapy (RT) continues to be an important component of treatment of glioma, particularly high-grade glioma and glioblastoma multiforme (GBM). GBM is one of the most aggressive central nervous system (CNS) tumors, with high rates of recurrence and very low rates of long-term survival. However, outcomes in these patients are improving with modern genetic profiling and multimodal therapy, which leads to more consideration for the risk for toxicities associated with traditional photon-based RT.

Prognostication of overall survival in patients with brain metastases using diffusion tensor imaging and dynamic susceptibility contrast-enhanced MRI.

Objectives: To investigate the prognostic utility of DTI and DSC-PWI perfusion-derived parameters in brain metastases patients.

Methods: Retrospective analyses of DTI-derived parameters (MD, FA, CL, CP, and CS) and DSC-perfusion PWI-derived rCBV from 101 patients diagnosed with brain metastases prior to treatment were performed. Using semi-automated segmentation, DTI metrics and rCBV were quantified from enhancing areas of the dominant metastatic lesion.

Gamma Knife radiosurgery for trigeminal neuralgia provides greater pain relief at higher dose rates.

In Gamma Knife (GK) radiosurgery, dose rate decreases during the life cycle of its radiation source, extending treatment times. Prolonged treatments influence the amount of sublethal radiation injury that is repaired during exposure, and is associated with decreased biologically-equivalent dose (BED). We assessed the impact of treatment times on clinical outcomes following GK of the trigeminal nerve - a rare clinical model to isolate the effects of treatment times.

Cerebral hemodynamic and metabolic dysregulation in the postradiation brain.

Technological advances in the delivery of radiation and other novel cancer therapies have significantly improved the 5-year survival rates over the last few decades. Although recent developments have helped to better manage the acute effects of radiation, the late effects such as impairment in cognition continue to remain of concern. Accruing data in the literature have implicated derangements in hemodynamic parameters and metabolic activity of the irradiated normal brain as predictive of cognitive impairment.

Multi-institutional review of sinonasal and skull base chondrosarcoma: 20-year experience.

Background: Chondrosarcomas of the sinonasal cavity and skull base are uncommon malignancies. We sought to provide long-term outcomes at two tertiary care centers.

Methods: Patients with chondrosarcoma treated between 2000 and 2021 were included.

Correlation of LET With MRI Changes in Brain and Potential Implications for Normal Tissue Complication Probability for Patients With Meningioma Treated With Pencil Beam Scanning Proton Therapy.

Purpose: This study aimed to investigate the correlation between imaging changes in brain normal tissue and the spatial distribution of linear energy transfer (LET) for a cohort of patients with meningioma treated with scanned proton beams. Then, assuming imaging changes are induced by cell lethality, we studied the correlation between normal tissue complication probability and LET.

Methods And Materials: Magnetic resonance imaging T2/fluid attenuated inversion recovery acquired at different intervals after proton radiation were coregistered with the planning computed tomography (CT) images from 26 patients with meningioma with abnormalities after proton radiation therapy.

Factors Associated with and Temporal Trends in the Use of Radiation Therapy for the Treatment of Pituitary Adenoma in the National Cancer Database.

 Radiation therapy represents an uncommon but important component of treatment plans for some pituitary adenomas (PAs). Although radiation therapy has been used to treat pituitary adenomas for over a century, general trends in the usage of radiation therapy for this purpose have not been reviewed. Additionally, there are few large studies evaluating how radiation therapy is used for the treatment of these benign tumors.

A Probability-Based Investigation on the Setup Robustness of Pencil-beam Proton Radiation Therapy for Skull-Base Meningioma.

Introduction: The intracranial skull-base meningioma is in proximity to multiple critical organs and heterogeneous tissues. Steep dose gradients often result from avoiding critical organs in proton treatment plans. Dose uncertainties arising from setup errors under image-guided radiation therapy are worthy of evaluation.

Initial Evaluation of a Novel Cone-Beam CT-Based Semi-Automated Online Adaptive Radiotherapy System for Head and Neck Cancer Treatment - A Timing and Automation Quality Study.

Introduction A novel on-line adaptive radiotherapy (ART) system based on O-ring linear accelerator (LINAC) and cone-beam CT (CBCT) was evaluated for treatment and management of head & neck (H&N) cancer in an emulated environment accessed via remote desktop connection. In this on-line ART system, organs-at-risk (OARs) and target contours and radiotherapy (RT) plans are semi-automatically generated based on the patient CBCT, expediting a typically hours-long RT planning session to under half an hour. In this paper, we describe our initial experiences with the system and explore optimization strategies to expedite the process further.

Multi-institutional retrospective review of stereotactic radiosurgery for brain metastasis in patients with small cell lung cancer without prior brain-directed radiotherapy.

Patients with small cell lung cancer (SCLC) brain metastasis (BM) typically receive whole brain radiotherapy (WBRT) as data regarding upfront radiosurgery (SRS) in this setting are sparse. Patients receiving SRS for SCLC BM without prior brain radiation were identified at three U.S.

Rapid and ultrasensitive digital PCR (dPCR) profiling of EGFRvIII in tumor cells and tissues.

Background: Amplification of the epidermal growth factor receptor () gene is commonly found in glioblastoma (GBM). About 57% GBM overexpresses EGFR and are associated with tumor progression, poor prognosis, and shorter life expectancy. Molecular profiling of solid tumors usually takes several weeks and may be biased by intrinsic tumor heterogeneity.

Factors Associated With Facial Nerve Paresis Following Gamma Knife for Vestibular Schwannoma.

Objective: Evaluate the incidence of and potential contributory factors to facial nerve paresis and other cranial neuropathies (CN) following stereotactic radiosurgery with Gamma Knife (GK) for primary treatment of vestibular schwannoma (VS).

Study Design: Retrospective chart review.

Setting: Tertiary referral center.