Commissioning and quality assurance of HalcyonTM 2.0 linear accelerator

Pathak, Pushpraj; Vashisht, S K; Baby, Sony; Jithin, P K; Jain, Y; Mahawar, R; Sharan, V G G K

doi:10.5603/rpor.a2021.0065

Cited by 8 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dosimeters were irradiated on the CAX in a MP3-T water tank phantom (PTW, Freiburg, Germany). Since optical SSD indicators or a light field are not provided by the closed gantry system of the Halcyon, [17][18][19][20] MV imaging was applied to verify the vertical setup of the water tank. Depth dose curves and lateral dose profiles were measured with the Tandem electrometer T10011, the TBA control unit T41013 and the Mephysto mc 2 software package (PTW, Freiburg, Germany).…”

Section: General Methodsmentioning

confidence: 99%

Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine

Höfel,

Liebig,

Fix

et al. 2023

J Applied Clin Med Phys

View full text Add to dashboard Cite

PurposeModern radiotherapy techniques often deliver small radiation fields. In this work, a practical Electron Paramagnetic Resonance (EPR) dosimetry protocol is adapted and applied to measure output factors (OF) in small fields of a 6 MV radiotherapy system. Correction factors and uncertainties are presented and OFs are compared to the values obtained by following TRS‐483 using an ionization chamber (IC).MethodsIrradiations were performed at 10 cm depth inside a water phantom positioned at 90 cm source to surface distance with a 6 MV flattening filter free photon beam of a Halcyon radiotherapy system. OFs for different nominal field sizes (1 × 1, 2 × 2, 3 × 3, 4 × 4, normalized to 10 × 10 cm2) were determined with a PinPoint 3D (PTW 31022) IC following TRS‐483 as well as with alanine pellets with a diameter of 4 mm and a height of 2.4 mm. EPR readout was performed with a benchtop X‐band spectrometer. Correction factors due to volume averaging and due to positional uncertainties were derived from 2D film measurements.ResultsOFs obtained from both dosimeter types agreed within 0.7% after applying corrections for the volume averaging effect. For the used alanine pellets, volume averaging correction factors of 1.030(2) for the 1 × 1 cm2 field and <1.002 for the larger field sizes were determined. The correction factor for positional uncertainties of 1 mm was in the order of 1.018 for the 1 × 1 cm2 field. Combined relative standard uncertainties uc for the OFs resulting from alanine measurements were estimated to be below 1.5% for all field sizes. For IC measurements, uc was estimated to be below 1.0%.ConclusionsA practical EPR dosimetry protocol is adaptable for precisely measuring OFs in small fields down to 1 × 1 cm2. It is recommended to consider the effect of positional uncertainties for field sizes <2 × 2 cm2.

show abstract

Section: General Methodsmentioning

confidence: 99%

Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine

Höfel,

Liebig,

Fix

et al. 2023

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…The Varian Ethos (Varian Medical Systems, Palo Alto, CA), introduced in 2019, pairs the closed bore Halcyon linac with dedicated treatment planning and record and verify systems. The Halcyon linac provides a 6 MV flattening filter free (FFF) beam and kV iterative cone-beam CT (iCBCT) imaging, with a minimum CBCT acquisition time of 17 s (Netherton et al 2019, Pathak et al 2021. A streamlined adaptive workflow is enabled in part through artificial intelligence (AI)-based auto-contouring of relevant organs at risk (OARs) and rapid plan re-optimization capabilities.…”

Section: Varian Ethosmentioning

confidence: 99%

Online adaptive planning methods for intensity-modulated radiotherapy

et al. 2023

View full text Add to dashboard Cite

Online adaptive radiation therapy aims at adapting a patient’s treatment plan to their current anatomy to account for inter-fraction variations before daily treatment delivery. As this process needs to be accomplished while the patient is immobilized on the treatment couch, it requires time-efficient adaptive planning methods to generate a quality daily treatment plan rapidly. The conventional planning methods do not meet the time requirement of online adaptive radiation therapy because they often involve excessive human intervention, significantly prolonging the planning phase. This article reviews the planning strategies employed by current commercial online adaptive radiation therapy systems, research on online adaptive planning, and artificial intelligence’s potential application to online adaptive planning.

show abstract

“…Halcyon 2.0 imaging no longer requires MV-X rays but adds a dedicated kV imaging system with greatly improved soft tissue resolution. [2] It has a gantry speed of up to 4 rotations a minute. Since there is no field light, optical distance indicator or source-skin distance (SSD) measuring device, only the laser on the machine shell is used for patient positioning.…”

Section: Introductionmentioning

confidence: 99%

Dosimetric performance evaluation of the Halcyon treatment platform for stereotactic radiotherapy: A pooled study

Huang,

Liu

2023

Medicine

View full text Add to dashboard Cite

With the advancement of radiotherapy equipment, stereotactic radiotherapy (SRT) has been increasingly used. Among the many radiotherapy devices, Halcyon shows promising applications. This article reviews the dosimetric performance such as plan quality, plan complexity, and gamma passing rates of SRT plans with Halcyon to determine the effectiveness and safety of Halcyon SRT plans. This article retrieved the last 5 years of PubMed studies on the effectiveness and safety of the Halcyon SRT plans. Two authors independently reviewed the titles and abstracts to decide whether to include the studies. A search was conducted to identify publications relevant to evaluating the dosimetric performance of SRT plans on Halcyon using the key strings Halcyon, stereotactic radiosurgery, SRT, stereotactic body radiotherapy, and stereotactic ablative radiotherapy. A total of 18 eligible publications were retrieved. Compared to SRT plans on the TrueBeam, the Halcyon has advantages in terms of plan quality, plan complexity, and gamma passing rates. The high treatment speed of SRT plans on the Halcyon is impressive, while the results of its plan evaluation are also encouraging. As a result, Halcyon offers a new option for busy radiotherapy units while significantly improving patient comfort in treatment. For more accurate results, additional relevant publications will need to be followed up in subsequent studies.

show abstract

Commissioning and quality assurance of HalcyonTM 2.0 linear accelerator

Cited by 8 publications

References 26 publications

Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine

Adapting a practical EPR dosimetry protocol to measure output factors in small fields with alanine

Online adaptive planning methods for intensity-modulated radiotherapy

Dosimetric performance evaluation of the Halcyon treatment platform for stereotactic radiotherapy: A pooled study

Contact Info

Product

Resources

About