Dosimetric Impact of Source Displacement in GammaTile Surgically Targeted Radiation Therapy for Gliomas.

Background This study aims to evaluate dosimetric changes that happened during the first month after GammaTile surgically targeted radiation therapy (STaRT) for gliomas due to Cesium-131 (Cs-131) seed displacement caused by cavity shrinkage in brain brachytherapy. Methodology In this study, 10 glioma patients had 4-11 GammaTiles placed along the resection bed after maximal safe resection during craniotomy. Each GammaTile is composed of four Cs-131 seeds embedded in a biodegradable collagen sponge to minimize seed movement and maintain seed-to-cavity surface distance.

A phantom-based analysis for tracking intra-fraction pancreatic tumor motion by ultrasound imaging during radiation therapy.

Purpose: In this study, we aim to further evaluate the accuracy of ultrasound tracking for intra-fraction pancreatic tumor motion during radiotherapy by a phantom-based study.

Methods: Twelve patients with pancreatic cancer who were treated with stereotactic body radiation therapy were enrolled in this study. The displacement points of the respiratory cycle were acquired from 4DCT and transferred to a motion platform to mimic realistic breathing movements in our phantom study.

GammaTile for Gliomas: A Single-Center Case Series.

GammaTile® (GT Medical Technologies, Tempe, Arizona) is a surgically targeted radiation source, approved by FDA for brachytherapy in primary and secondary brain neoplasms. Each GammaTile is composed of a collagen sponge with four seeds of cesium 131 and is particularly useful in recurrent tumors. We report our early experience in seven patients with recurrent gliomas to assess this type of brachytherapy with particular attention to ease of use, complication, and surgical planning.

Safety and efficacy of GammaTile intracranial brachytherapy implanted during awake craniotomy.

Introduction: GammaTile intracranial brachytherapy (cesium-131 seeds) has demonstrated encouraging safety and local control results, and recently received Food and Drug Administration clearance for newly diagnosed and recurrent brain tumors. The authors present the first reported case of GammaTile intraoperative brachytherapy performed during an awake craniotomy.

Methods: A 50-year-old man had a biopsy-proven, 2.

Phase II study of intraoperative dosimetry for prostate brachytherapy using registered ultrasound and fluoroscopy.

Purpose: To assess the performance of a system of intraoperative dosimetry and obtain estimates of dosimetry outcomes achieved when utilizing the system in a Phase II clinical trial.

Methods And Materials: Forty-five patients undergoing permanent Pd-103 seed implantation for prostate cancer were prospectively enrolled. Seed implantation was performed and dose was tracked intraoperatively using intraoperative registered ultrasound and fluoroscopy (iRUF).

Interventional Radiation Oncology (IRO): Transition of a magnetic resonance simulator to a brachytherapy suite.

Purpose: As a core component of a new gynecologic cancer radiation program, we envisioned, structured, and implemented a novel Interventional Radiation Oncology (IRO) unit and magnetic resonance (MR)-brachytherapy environment in an existing MR simulator.

Methods And Materials: We describe the external and internal processes required over a 6-8 month time frame to develop a clinical and research program for gynecologic brachytherapy and to successfully convert an MR simulator into an IRO unit.

Results: Support of the institution and department resulted in conversion of an MR simulator to a procedural suite.

Feasibility study of ultrasound imaging for stereotactic body radiation therapy with active breathing coordinator in pancreatic cancer.

Purpose: Stereotactic body radiation therapy (SBRT) allows for high radiation doses to be delivered to the pancreatic tumors with limited toxicity. Nevertheless, the respiratory motion of the pancreas introduces major uncertainty during SBRT. Ultrasound imaging is a non-ionizing, non-invasive, and real-time technique for intrafraction monitoring.

Stereotactic body radiation therapy in pancreatic cancer: the new frontier.

Pancreatic cancer (PCA) remains a disease with a poor prognosis. The majority of PCA patients are unable to undergo surgical resection, which is the only potentially curative option at this time. A combination of chemotherapy and chemoradiation (CRT) are standard options for patients with locally advanced, unresectable disease, however, local control and patient outcomes remains poor.

Optimal parameters for clinical implementation of breast cancer patient setup using Varian DTS software.

Digital tomosynthesis (DTS) was evaluated as an alternative to cone-beam computed tomography (CBCT) for patient setup. DTS is preferable when there are constraints with setup time, gantry-couch clearance, and imaging dose using CBCT. This study characterizes DTS data acquisition and registration parameters for the setup of breast cancer patients using nonclinical Varian DTS software.

Localization of a portion of an endorectal balloon for prostate image-guided radiation therapy using cone-beam tomosynthesis: a feasibility study.

Purpose: To assess the feasibility of using cone-beam tomosynthesis (CBTS) to localize the air-tissue interface for the application of prostate image-guided radiation therapy using an endorectal balloon for immobilization and localization.

Methods And Materials: A Feldkamp-David-Kress-based CBTS reconstruction was applied to selected sets of cone-beam computed tomography (CBCT) projection data to simulate volumetric imaging achievable from tomosynthesis for a limited range of scan angles. Projection data were calculated from planning CT images of 10 prostate cancer patients treated with an endorectal balloon, as were experimental CBCT projections for a pelvic phantom in two patients.

Automation of clip localization in Digital Tomosynthesis for setup of breast cancer patients.

The objective of this study is to develop an automatic clip localization procedure for breast cancer patient setup based on Digital Tomosynthesis (DTS) and to characterize its performance with respect to the overall registration accuracy and robustness. The study was performed under an IRB-approved protocol for 12 breast cancer patients with surgical clips implanted around the tumor cavity. The registration of DTS images to planning CTs was performed using an automatic algorithm developed to overcome specific challenges of localization and registration of clips in the breast setup images.

Evaluation of MatriXX for IMRT and VMAT dose verifications in peripheral dose regions.

Purpose: MatriXX is a two-dimensional ion chamber array designed for IMRT/VMAT (RapidArc, IMAT, etc.) dose verifications. Its dosimetric properties have been characterized for megavoltage beams in a number of studies; however, to the best of the authors' knowledge, there is still a lack of an investigation into its performance in the peripheral or low dose regions.

An oscillating sweeping gap test for VMAT quality assurance.

The objective of this study was to develop an oscillating sweeping gap test for volumetric modulated arc therapy (VMAT) quality assurance (QA). A novel test was designed and used to simultaneously determine uncertainties associated with linac performance, dose calculation and dosimetric MLC parameters during VMAT delivery. Delivered doses were measured with Matrixx, ionization chamber A12 and EDR2 films, and compared to calculations from the treatment planning system (TPS) Eclipse.