Verification of junction dose between <scp>VMAT</scp> arcs of total body irradiation using a Sun Nuclear Arc<scp>CHECK</scp> phantom

Morrison, Colm; Symons, Kirsty Louise; Woodings, S.; House, Michael J.

doi:10.1002/acm2.12208

Cited by 9 publications

(9 citation statements)

References 24 publications

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“…ArcCHECK allows measurement of treatment eld length ≤20 cm in a single irradiation. Our protocol is in alignment with other studies wherein several authors have reported veri cation of absolute dose and uence either section by section or in the junction of two consecutive arcs using various detectors and methods [7,11]. In addition, for each patient we also carried out in-vivo EBT3 lm dosimetry a) at eleven pre-de ned locations across the whole body and b) in the junction region of upper and lower body treatment plans to ensure delivery of homogeneous dose.…”

Section: Discussionmentioning

confidence: 99%

“…All the commercially available active or passive detectors for patient speci c quality assurance (PSQA) have limited longitudinal and lateral dimensions of 20-25 cm to verify highly modulated mega treatment elds from TMI/TMLI especially for HT delivery. The feasibility of different detector arrays (2D or 3D) arranged in planar, hexagonal, circular and helical have been investigated for section by section dose veri cation of TBI/TMI plans [7,10,11]. Takahashi Y and Hui K S [12] developed a simple inhouse whole body phantom to verify TMI treatment plan of up to 110 cm in HT using three ionization chambers and three radiochromic lms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Leaf Open Time Sinogram (LOTS): A novel approach for Patient specific quality assurance of Total marrow irradiation

Thiyagarajan

Sharma

Kaushik

et al. 2020

Preprint

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There is no ideal detector-phantom combination to perform patient specific quality assurance (PSQA) for total marrow (TMI) and Lymphoid (TMLI) irradiation plan. In this study, 3D dose reconstruction using mega voltage computed tomography detectors measured leaf open time sinogram (LOTS) was investigated for PSQA of TMI/TMLI patients in helical tomotherapy. The feasibility of this method was first validated for ten non-TMI/TMLI patients, by comparing reconstructed dose with a) ion-chamber (IC) and helical detector array (ArcCheck) measurement and b) planned dose distribution using 3Dγ analysis for 3%@3mm and dose to 98%(D98%) and 2%(D2%) of PTVs. Same comparison was extended for ten treatment plans from five TMI/TMLI patients. In all non-TMI/TMLI patients, reconstructed absolute dose was within ±1.8% of planned and IC measurement. The planned dose distribution agrees with reconstructed and ArcCheck measured dose with mean(SD) 3Dγ of 98.7%(1.57%) and 2Dγ of 99.48%(0.81%). The deviation in D98% and D2% were within 1.71% and 4.1% respectively. In all 25 measurement locations from TMI/TMLI patients, planned and IC measured absolute dose agrees within ±1.2%. Although sectorial fluence verification using ArcCHECK measurement for PTVs chest from five upper body TMI/TMLI plans showed mean±SD 2Dγ of 97.82%±1.27%, the reconstruction method resulted poor mean(SD) 3Dγ of 92.00%(±5.83%), 64.80%(±28.28%), 69.20%(±30.46%), 60.80%(±19.37%) and 73.2% (±20.36%) for PTVs brain, chest, torso, limb and upper body respectively. The corresponding deviation in median D98% and D2% of all PTVs were <3.8% and 9.5%. Re-optimization of all upper body TMI/TMLI plans with new pitch and modulation factor of 0.3 and 3 leads significant improvement with 3Dγ of 100% for all PTVs and median D98% and D2% <1.6%. LOTS based PSQA for TMI/TMLI is accurate, robust and efficient. A field width, pitch and modulation factor of 5cm, 0.3 and 3 for upper body TMI/TMLI plan is suggested for better dosimetric outcome and PSQA results.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Leaf Open Time Sinogram (LOTS): A novel approach for Patient specific quality assurance of Total marrow irradiation

Thiyagarajan

Sharma

Kaushik

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…ArcCHECK allows measurement of treatment field length ≤ 20 cm in a single irradiation. Our protocol is in alignment with other studies wherein several authors have reported verification of absolute dose and fluence either section by section or in the junction of two consecutive arcs using various detectors and methods [7,11]. In addition, for each patient we also carried out in-vivo EBT3 film dosimetry (a) at eleven pre-defined locations across the whole body and (b) in the junction region of upper and lower body treatment plans to ensure delivery of homogeneous dose.…”

Section: Discussionmentioning

confidence: 99%

“…All the commercially available active or passive detectors for patient specific quality assurance (PSQA) have limited longitudinal and lateral dimensions of 20-25 cm to verify highly modulated mega treatment fields from TMI/TMLI especially for HT delivery. The feasibility of different detector arrays (2D or 3D) arranged in planar, hexagonal, circular and helical have been investigated for section by section dose verification of TBI/TMI plans [7,10,11]. Takahashi and Hui [12] developed a simple in-house whole body phantom to verify TMI treatment plan of up to 110 cm in HT using three ionization chambers and three radiochromic films.…”

Section: Introductionmentioning

confidence: 99%

Leaf open time sinogram (LOTS): a novel approach for patient specific quality assurance of total marrow irradiation

et al. 2020

View full text Add to dashboard Cite

There is no ideal detector-phantom combination to perform patient specific quality assurance (PSQA) for Total Marrow (TMI) and Lymphoid (TMLI) Irradiation plan. In this study, 3D dose reconstruction using mega voltage computed tomography detectors measured Leaf Open Time Sinogram (LOTS) was investigated for PSQA of TMI/TMLI patients in helical tomotherapy. The feasibility of this method was first validated for ten non-TMI/TMLI patients, by comparing reconstructed dose with (a) ion-chamber (IC) and helical detector array (ArcCheck) measurement and (b) planned dose distribution using 3Dγ analysis for 3%@3mm and dose to 98% (D98%) and 2% (D2%) of PTVs. Same comparison was extended for ten treatment plans from five TMI/TMLI patients. In all non-TMI/TMLI patients, reconstructed absolute dose was within ± 1.80% of planned and IC measurement. The planned dose distribution agreed with reconstructed and ArcCheck measured dose with mean (SD) 3Dγ of 98.70% (1.57%) and 2Dγ of 99.48% (0.81%). The deviation in D98% and D2% were within 1.71% and 4.10% respectively. In all 25 measurement locations from TMI/TMLI patients, planned and IC measured absolute dose agreed within ± 1.20%. Although sectorial fluence verification using ArcCHECK measurement for PTVs chest from the five upper body TMI/TMLI plans showed mean ± SD 2Dγ of 97.82% ± 1.27%, the reconstruction method resulted poor mean (SD) 3Dγ of 92.00% (± 5.83%), 64.80% (± 28.28%), 69.20% (± 30.46%), 60.80% (± 19.37%) and 73.2% (± 20.36%) for PTVs brain, chest, torso, limb and upper body respectively. The corresponding deviation in median D98% and D2% of all PTVs were < 3.80% and 9.50%. Re-optimization of all upper body TMI/TMLI plans with new pitch and modulation factor of 0.3 and 3 leads significant improvement with 3Dγ of 100% for all PTVs and median D98% and D2% < 1.6%. LOTS based PSQA for TMI/TMLI is accurate, robust and efficient. A field width, pitch and modulation factor of 5 cm, 0.3 and 3 for upper body TMI/TMLI plan is suggested for better dosimetric outcome and PSQA results.

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“…So, Delta 4, ArcCheck and Octavius 4D for dose veri cation of VMAT are more common in daily work [23][24][25].…”

Section: D Gamma Standard and Passing Ratementioning

confidence: 99%

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

Bai¹,

Zhu²,

Wu³

et al. 2020

Preprint

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Objective: To explore the efficacy and sensitivity of 3D gamma analysis and bio-mathematical model for cervical cancer in detecting dose changes caused by dose-calculation-grid-size (DCGS).Methods：17 patients’ plans for cervical cancer were enrolled (Pinnacle TPS，VMAT), and the DCGS was changed from 2.0mm to 5.0mm to calculate the planned dose respectively. The dose distribution calculated by DCGS = 2.0mm as the “reference” data set (RDS), the dose distribution calculated by the rest DCGS as the“measurement”data set (MDS), the 3D gamma passing rates and the (N)TCPs of the all structures under different DCGS were obtained, and then analyze the ability of 3D gamma analysis and (N)TCP model in detecting dose changes and what factors affect this ability.Results: The effect of DCGS on planned dose was obvious. When the gamma standard was 1.0mm, 1.0% and 10.0%, the difference of the results of the DCGS on dose-effect could be detected by 3D gamma analysis (all p value < 0.05). With the decline of the standard, 3D gamma analysis’ ability to detect this difference shows weaker. When the standard was 1.0mm, 3.0% and 10.0%, the p value of > 0.05 accounted for the majority. With DCGS=2.0mm being RDS, ∆gamma-passing-rate presented the same trend with ∆(N)TCPs of all structures except for the femurs only when the 1.0mm, 1.0% and 10.0% standards were adopted for the 3D gamma analysis.Conclusions: The 3D gamma analysis and bio-mathematical model can be used to analyze the effect of DCGS on the planned dose. For comparison, the former’s detection ability has a lot to do with the designed standard, and the latter’s capability is related to the parameters and calculated accuracy instrinsically.

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Verification of junction dose between VMAT arcs of total body irradiation using a Sun Nuclear ArcCHECK phantom

Cited by 9 publications

References 24 publications

Leaf Open Time Sinogram (LOTS): A novel approach for Patient specific quality assurance of Total marrow irradiation

Leaf Open Time Sinogram (LOTS): A novel approach for Patient specific quality assurance of Total marrow irradiation

Leaf open time sinogram (LOTS): a novel approach for patient specific quality assurance of total marrow irradiation

Study on the ability of 3D gamma analysis and bio-mathematical model in detecting dose changes caused by dose-calculation-grid-size (DCGS)

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