scholarly journals A Mathematic Method to Adjust MLC Leaf End Position for Accuracy Dose Calculation in Carbon Ion Beam Radiation Therapy Treatment Planning System

2021 ◽  
Author(s):  
Yan-Shan Zhang ◽  
Yan-Cheng Ye ◽  
Jia-Ming Wu
Keyword(s):  
Treatment Planning ◽  
Ion Beam ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Carbon Ion ◽  
Radiation Therapy Treatment Planning ◽  
Offset Correction ◽  
Carbon Ion Beam ◽  
Ion Treatment

Abstract IntroductionWe present a mathematic method to adjust the leaf end position for dose calculation correction in carbon ion radiation therapy treatment planning system. Methods and MaterialsA struggling range algorism of 400 MeV/n carbon ion beam in nine different multi-leaf collimator (MLC) materials was conducted to calculate the dose 50% point in order to derive the offset corrections in carbon ion treatment planning system (ciPlan). The visualized light field edge position in treatment planning system is denoted as Xtang.p and MLC position (Xmlc.p) is defined as the source to leaf end mid-point projection on axis for monitor unit calculation. The virtual source position of an energy at 400 MeV/n and struggling range in MLC at different field sizes were used to calculate the dose 50% position on axis. On-axis MLC offset (correction) could then be obtained from the position corresponding to 50% of the central axis dose minus the Xmlc.p MLC position. ResultsThe precise MLC position in carbon ion treatment planning system can be used an offset to do the correction. The offset correction of pure tungsten is the smallest among the others due to its shortest struggling range of carbon ion beam in MLC. The positions of 50% dose of all MLC materials are always located in between Xtang.p and Xmlc.p under the largest field of 12 cm by 12 cm. ConclusionsMLC offset should be adjusted carefully at different field size in treatment planning system especially of its small penumbra characteristic in carbon ion beam. It is necessary to find out the dose 50% position for adjusting MLC leaf edge on-axis location in the treatment planning system to reduce dose calculation error.

scholarly journals A Light-Field-Based Method to Adjust On-Axis Rounded Leaf End MLC Position to Predict Off-Axis MLC Penumbra Region Dosimetric Performance in a Radiation Therapy Planning System

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jia-Ming Wu ◽  
Tsair-Fwu Lee ◽  
Shyh-An Yeh ◽  
Kuan-Yin Hsiao ◽  
Hsin-Hsiung Chen ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Treatment Planning ◽  
Light Field ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Monitor Unit ◽  
Offset Correction ◽  
Axis Offset ◽  
Penumbra Region

Purpose. An analytical and experimental study of split shape dose calculation correction by adjusting the position of the on-axis round leaf end position is presented. We use on-axis corrected results to predict off-axis penumbra region dosimetric performance in an intensity-modulated radiation therapy treatment planning system.Materials and Methods. The precise light-field edge position (Xtang.p) was derived from the on-axis 50% dose position created by using the nominal light field for geometric and mathematical manipulation. Leaf position (Xmlc.p) could be derived fromXtang.pby defining in the treatment planning system for monitor unit calculation. On-axis offset (correction) could be obtained from the position corresponding to 50% of the central axis dose minus theXmlc.pposition. The off-axis 50% dose position can then be derived from the on-axis 50% dose position.Results. The monitor unit calculation of the split shape using the on-axis rounded leaf end MLC penumbra region could provide an under-or overdose of 7.5% per millimeter without an offset correction. When using the on-axis rounded leaf end offset correction to predict the off-axis dose, the difference between the off- and on-axis 50% dose position is within ±1.5 mm.Conclusions. It is possible to achieve a dose calculation within 0.5% error for an adjusted MLC leaf edge location in the treatment planning system with careful measurement and an accurate on-axis offset correction. Dose calculations located at an off-axis spilt shape region should be used carefully due to noncorrectable errors which were found to be up to 10%.

scholarly journals Evaluation of a treatment planning system developed for clinical boron neutron capture therapy and validation against an independent Monte Carlo dose calculation system

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Naonori Hu ◽  
Hiroki Tanaka ◽  
Ryo Kakino ◽  
Syuushi Yoshikawa ◽  
Mamoru Miyao ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Treatment Planning ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Neutron Capture Therapy ◽  
Boron Neutron Capture ◽  
Monte Carlo Dose Calculation

AbstractBoron neutron capture therapy (BNCT) for the treatment of unresectable, locally advanced, and recurrent carcinoma of the head and neck cancer has been approved by the Japanese government for reimbursement under the national health insurance as of June 2020. A new treatment planning system for clinical BNCT has been developed by Sumitomo Heavy Industries, Ltd. (Sumitomo), NeuCure® Dose Engine. To safely implement this system for clinical use, the simulated neutron flux and gamma ray dose rate inside a water phantom was compared against experimental measurements. Furthermore, to validate and verify the new planning system, the dose distribution inside an anthropomorphic head phantom was compared against a BNCT treatment planning system SERA and an in-house developed Monte Carlo dose calculation program. The simulated results closely matched the experimental results, within 5% for the thermal neutron flux and 10% for the gamma ray dose rate. The dose distribution inside the head phantom closely matched with SERA and the in-house developed dose calculation program, within 3% for the tumour and a difference of 0.3 Gyw for the brain.

scholarly journals A treatment planning study of combined carbon ion-beam plus photon intensity-modulated radiotherapy

2020 ◽  
Vol 15 ◽  
pp. 16-22
Author(s):  
Christopher Schuppert ◽  
Angela Paul ◽  
Simeon Nill ◽  
Andrea Schwahofer ◽  
Jürgen Debus ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Ion Beam ◽  
Intensity Modulated Radiotherapy ◽  
Planning Study ◽  
Carbon Ion ◽  
Intensity Modulated ◽  
Photon Intensity ◽  
Carbon Ion Beam
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