Premium
Compton scatter imaging: A promising modality for image guidance in lung stereotactic body radiation therapy
Author(s) -
Redler Gage,
Jones Kevin C.,
Templeton Alistair,
Bernard Damian,
Turian Julius,
Chu James C. H.
Publication year - 2018
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1002/mp.12755
Subject(s) - imaging phantom , pinhole (optics) , monte carlo method , collimator , medical imaging , radiosurgery , contrast to noise ratio , physics , nuclear medicine , medical physics , optics , radiation therapy , medicine , radiology , computer science , image quality , artificial intelligence , image (mathematics) , mathematics , statistics
Purpose Lung stereotactic body radiation therapy ( SBRT ) requires delivering large radiation doses with millimeter accuracy, making image guidance essential. An approach to forming images of patient anatomy from Compton‐scattered photons during lung SBRT is presented. Methods To investigate the potential of scatter imaging, a pinhole collimator and flat‐panel detector are used for spatial localization and detection of photons scattered during external beam therapy using lung SBRT treatment conditions (6 MV FFF beam). MCNP Monte Carlo software is used to develop a model to simulate scatter images. This model is validated by comparing experimental and simulated phantom images. Patient scatter images are then simulated from 4 DCT data. Results Experimental lung tumor phantom images have sufficient contrast‐to‐noise to visualize the tumor with as few as 10 MU (0.5 s temporal resolution). The relative signal intensity from objects of different composition as well as lung tumor contrast for simulated phantom images agree quantitatively with experimental images, thus validating the Monte Carlo model. Scatter images are shown to display high contrast between different materials (lung, water, bone). Simulated patient images show superior (~double) tumor contrast compared to MV transmission images. Conclusions Compton scatter imaging is a promising modality for directly imaging patient anatomy during treatment without additional radiation, and it has the potential to complement existing technologies and aid tumor tracking and lung SBRT image guidance.