98%
921
2 minutes
20
A Helical Tomotherapy (HT) Hi-Art II machine, Hi ART (TomoTherapy, Inc., Madison, WI, USA) was installed at our center in July 2007, and was the first machine in India. Image-guided HT is a new modality for delivering intensity modulated radiotherapy (IMRT). Dosimetric tests done include (a) primary beam alignment (b) secondary beam alignment (c) water tank measurements (profiles and depth doses) (d) dose rate measurements (e) IMRT verification, and (f) Mega voltage Computed Tomography (MVCT) dose. Primary and secondary beam alignment revealed an acceptable linear accelerator (linac) alignment in both X and Y axes. In addition, it was observed that the beam was aligned in the same plane as gantry and the jaws were not twisted with respect to gantry. The rotational beam stability was acceptable. Multi-leaf collimators (MLC) were found to be stable and properly aligned with the radiation plane. The jaw alignment during gantry rotation was satisfactory. Transverse and longitudinal profiles were in good agreement with the "Gold" standard. During IMRT verification, the variation between the measured and calculated dose for a particular plan at the central and off-axis was found to be within 2% and 1mm in position, respectively. The dose delivered during the TomoImage scan was found to be 2.57 cGy. The Helical Tomotherapy system is mechanically stable and found to be acceptable for clinical treatment. It is recommended that the output of the machine should be measured on a daily basis to monitor the fluctuations in output.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804144 | PMC |
http://dx.doi.org/10.4103/0971-6203.48717 | DOI Listing |
Med Phys
September 2025
Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
Background: Radiotherapy workflows conventionally deliver one treatment plan multiple times throughout the treatment course. Non-coplanar techniques with beam angle optimization or dosimetrically optimized pathfinding (DOP) exploit additional degrees of freedom to improve spatial conformality of the dose distribution compared to widely used techniques like volumetric-modulated arc therapy (VMAT). The temporal dimension of dose delivery can be exploited using multiple plans (sub-plans) within one treatment course.
View Article and Find Full Text PDFJ Appl Clin Med Phys
September 2025
Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Clinical Research Center for Radiation Oncology, Shanghai Key Laboratory of Radiation Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Purpose: This study aims to assess percentage of automated AIO plans that met clinical treatment standards of radiotherapy plans generated by the fully automated All-in-one (AIO) process.
Methods: The study involved 117 rectal cancer patients who underwent AIO treatment. Fully automated regions of interest (ROI) and treatment plans were developed without manual intervention, comparing them to manually generated plans used in clinical practice.
J Appl Clin Med Phys
September 2025
Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia, USA.
Purpose: Real‑time magnetic resonance-guided radiation therapy (MRgRT) integrates MRI with a linear accelerator (Linac) for gating and adaptive radiotherapy, which requires robust image‑quality assurance over a large field of view (FOV). Specialized phantoms capable of accommodating this extensive FOV are therefore essential. This study compares the performance of four commercial MRI phantoms on a 0.
View Article and Find Full Text PDFJ Appl Clin Med Phys
September 2025
Icon Cancer Centre Toowoomba, Toowoomba, Queensland, Australia.
Introduction: The role of imaging in radiotherapy is becoming increasingly important. Verification of imaging parameters prior to treatment planning is essential for safe and effective clinical practice.
Methods: This study described the development and clinical implementation of ImageCompliance, an automated, GUI-based script designed to verify and enforce correct CT and MRI parameters during radiotherapy planning.
J Appl Clin Med Phys
September 2025
Department of Radiation Oncology, University of Utah, Salt Lake City, Utah, USA.
Purpose: The development of on-board cone-beam computed tomography (CBCT) has led to improved target localization and evaluation of patient anatomical change throughout the course of radiation therapy. HyperSight, a newly developed on-board CBCT platform by Varian, has been shown to improve image quality and HU fidelity relative to conventional CBCT. The purpose of this study is to benchmark the dose calculation accuracy of Varian's HyperSight cone-beam computed tomography (CBCT) on the Halcyon platform relative to fan-beam CT-based dose calculations and to perform end-to-end testing of HyperSight CBCT-only based treatment planning.
View Article and Find Full Text PDF