Evaluation of a multi-atlas CT synthesis approach for MRI-only radiotherapy treatment planning
Year: 2017
Type: article
Abstract: Background and purpose Computed tomography (CT) imaging is the current gold standard for radiotherapy treatment planning (RTP). The establishment of a magnetic resonance imaging (MRI) only RTP workflow requires the generation of a synthetic CT (sCT) for dose calculation. This study evaluates the feasibility of using a multi-atlas sCT synthesis approach (sCT a ) for head and neck and prostate patients. Material and methods The multi-atlas method was based on pairs of non-rigidly aligned MR and CT images. The sCT a was obtained by registering the MRI atlases to the patient's MRI and by fusing the mapped atlases according to morphological similarity to the patient. For comparison, a bulk density assignment approach (sCT bda ) was also evaluated. The sCT bda was obtained by assigning density values to MRI tissue classes (air, bone and soft-tissue). After evaluating the synthesis accuracy of the sCTs (mean absolute error), sCT-based delineations were geometrically compared to the CT-based delineations. Clinical plans were re-calculated on both sCTs and a dose-volume histogram and a gamma analysis was performed using the CT dose as ground truth. Results Results showed that both sCTs were suitable to perform clinical dose calculations with mean dose differences less than 1% for both the planning target volume and the organs at risk. However, only the sCT a provided an accurate and automatic delineation of bone. Conclusions Combining MR delineations with our multi-atlas CT synthesis method could enable MRI-only treatment planning and thus improve the dosimetric and geometric accuracy of the treatment, and reduce the number of imaging procedures.
Source: Physica Medica
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,004
Awards: G1000277579, G1220899931, G1238216143, G1289590720, G1348610338, G150562299, G1737639950, G1775974636, NIHR Senior Investigator Award, G2016760218, G2630917288, Medical image computing for next-generation healthcare technology, G3302706239, Development of MRI-guided radiation therapy, Intelligent Imaging: Motion, Form and Function Across Scale, G4266322423, G5919881315, G601834287, G630566656, G637517385, G7045805191, G7159919620, G7162635584, G7528670117, G7768537329, G8086000308, G844244329, NIHR Senior Investigator Award, G8801512839
OpenAlex ID: W2591855782