ePoster Forums
Purpose: Development of a 4-Dimensional planning and verification system for treatment of patients with moving lesions due to respiratory movement.
Methods: A modular device composed of hardware + software that allows 4D-CT imaging data analysis, treatment, and subsequent assurence and verification. MATLAB-based, in-house developed software that allows video and point-to-point navigation through every respiratory phase.Use of 4D region growing software, to “plant” a single “seed”, in any respiratory phase, within the lesion, the software propagates the search throughout all phases, delivering the corresponding lesion volumes in each phase. These will feed an array of optimizing modules that calculate, based on LINAC and MLC specs, an assorted PTV sequence and identify the optimal starting points that allow the gantry and MLC to follow the lesion and continuously adapt to it’s changing morphology and position.Time, and spatial coordinates from the region growing, will allow a radiation detector, assisted by the hardware, to simulate with precision the movement of the lesion.The data gathered from irradiating the detector is then compared with a full Monte Carlo simulation verification purposes.
Results: The segmented volumes, when compared with clinical hand-drawn volumes showed a remarkable resemblance. After optimization, the PTV sequence usually covers multiple phases which contributes to an homogenious dose distribution.By moving the part that accomodates the detector (ion chamber, pin point, diode, etc), the device is able to move the detector faultlessly, replicating the lesion movement through a phantom. Any double open end phantom can be used with the device.
Conclusion: The developed system can help to a safe and efficient clinical implementation of MLC tracking in radiotherapy by means of a flexible dynamic dose measurement able to follow the lesion movement recorded in the clinical image and also any other control point tracking for 4D dose distribution verification.
Funding Support, Disclosures, and Conflict of Interest: Funding Support: Ministerio de Ciencia e Innovacion and Agencia Estatal de Investigacion of Spain: RTI2018-098656-B-I00; European Regional Development Fund (FEDER): RTI2018-098656-B-I00
Not Applicable / None Entered.