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Record W2186727038

Impact of energy variation on Cone Ratio, PDD10, TMR20/10 and IMRT doses for flattening filter free (FFF) beam of TomoTherapy Hi-Art(TM)machines.

2018· article· en· W2186727038 on OpenAlexaff
Ranjini Tolakanahalli, D Tewatia

Bibliographic record

VenuePubMed · 2018
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAdvanced Radiotherapy Techniques
Canadian institutionsCanadian Sleep SocietyNiagara Health System
Fundersnot available
KeywordsTomotherapyNuclear medicineBeam energyBeam (structure)Imaging phantomMaterials scienceIonization chamberField sizeEnergy (signal processing)Coefficient of variationDetectorOpticsPhysicsMedicineRadiation therapyMathematicsIonStatisticsRadiology
DOInot available

Abstract

fetched live from OpenAlex

PURPOSE: The beam energy (PDD10: Percent depth dose) of a Tomotherapy Hi-ArtTM machine was varied in a controlled experiment from -1.64 to +1.66%, while keeping the output at 100% and the effect of this on IMRT output, MU chamber ratio (MUR), cone ratio (CR) and Tissue Maximum Ratio (TMR20/10) was studied METHODS: In this study, Injector Current Voltage (VIC) and Pulse Forming Network Voltage (VPFN) were changed in steps such that the PDD10 was varied from golden beam value incrementally between -1.64 to +1.66%. The effect of this on other energy indicators was studied to verify the sensitivity of TMR20/10, MUR, and detector data-based-CR. To quantify the effect of energy variation on Intensity Modulated Radiation Therapy (IMRT) dose, multiple ion-chamber based dose measurements were recorded by irradiating a cylindrical phantom with standard IMRT plans. Dose variation across each commissioned Field width (FW) was tabulated against energy variation. RESULTS: Good agreement between PDD10 and TMR20/10, MUR, CR was observed. CR was more sensitive to energy change than PDD10. More variation was observed across standard IMRT plan with increasing energy. CONCLUSION: CR is more sensitive to energy changes compared to PDD10, and CR with MUR can definitely be used as surrogates for checks on a daily/weekly basis. Variation in output across the 6 standard IMRT plans can vary up to 2.8% for a 1.6% increase in energy. Hence, it is of utmost importance to manage the PDD10 tightly around +0.5% in order to regulate standard IMRT QA agreement to within 1% and patient IMRT QA within ±3%.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.001
Threshold uncertainty score0.004

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.011
GPT teacher head0.265
Teacher spread0.254 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2018
Admission routes1
Has abstractyes

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