An interventional study of CBCT Imaging in Lung Cancer, Liver Cancer and Breast Cancer, sponsored by Varian, a Siemens Healthineers Company. Completed at 1 site in Canada. Open to participants aged 19 Years and older. Per ClinicalTrials.gov, last updated 2026-08-26.
Sponsored by Varian, a Siemens Healthineers Company · Not applicable, Interventional, and Other
This is a feasibility study investigating the image quality of a new, high-performance cone beam CT (CBCT) used for on-couch imaging during radiotherapy treatments.
This study focuses on potential benefits of a high performance cone beam CT (CBCT) image guidance system for improved precision in the delivery of radiotherapy. CBCT is currently used during radiation therapy to align the patient to their original treatment plan to increase the precision of radiation delivery. Current CBCT imaging technology requires approximately a minute to acquire an image. In order to acquire images with sufficient quality to allow accurate targeting, the patient may need to perform multiple breath hold maneuvers to "freeze" the motion of tumors that move with the breathing cycle (e.g. lung, liver, and breast tumors). The new high-performance CBCT can acquire an image in approximately 6 seconds, potentially enabling acquisition of images with a single breath hold. Improved motion compensation algorithms used in image reconstruction may allow acquisition of good quality images even while a patient is not holding their breath.
The methodology for the subject's treatment setup, CT simulation, treatment planning, image guidance and treatment delivery will be determined by the subject's treatment team and is not specified by this study. Enrollment in the study may occur after treatment delivery has started but must be prior to the fifth fraction.
Following completion of informed consent to participate in this study, high-performance CBCT imaging will be scheduled immediately before or after one of the subject's first five scheduled radiation treatment fractions. Two research CBCT images will be acquired, one with breath hold, the other with free breathing.
With minimal disruption for participating patients, this study will enable a comparison of (i) the subject's treatment planning fan-beam CT and (ii) the conventional CBCT acquired on an existing treatment unit with (iii) the high-performance CBCT. Image quality of the high performance CBCT image data will thereby be compared to both a best-case standard (fan-beam) and the status-quo for on-couch imaging to isolate and identify improvements.
7,243 studies on the registry are indexed under Lung Neoplasms; 1,557 are open to participants now.
This study's enrollment of 31 is below the median of 60 across 5,295 interventional studies indexed under Lung Neoplasms.
Browse Lung Neoplasms studies →Varian, a Siemens Healthineers Company is the lead sponsor of 27 studies on the registry; 6 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 4 (50%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Two additional study imaging sets are acquired.
Device: CBCT Imaging
Two research CBCT images will be acquired per subject.
CBCT Image Quality - Artifact Index
Artifact Index (AI) is a measurement of the strength of imaging artifact and the degree to which is affects visibility of anatomical structures in the vicinity of the artifact. Artifacts can be produced in CT and CBCT images by a number of factors, such as metal implants, gas, or breathing motion. AI = sqrt((STD\_VOI)\^2 - (STD\_background)\^2), where STD\_VOI is the standard deviation of the image Hounsfield Units in a region of interest at the location of an artifact, and STD\_background is the standard deviation of the Hounsfield Unit values in the background (i.e. in similar tissue but away from the artifact. A lower AI value indicates that the artifact has a lower impact on image quality. Artifacts were identified in all study participants. The median AI across the study population is presented for four imaging modalities.
Time frame: 1 day
CBCT Image Quality - Image Nonuniformity
Nonuniformity (NU) is a measure of the variation of CT image intensity in uniform tissue. NU = (HU\_max - HU\_min)/(HU\_max + HU\_min), where HU\_max and HU\_min are the maximum and minimum Hounsfield Unit values among multiple locations sampled within regions of uniform tissue that were relevant to the anatomy of interest (e.g., a uniform region of breast tissue for patients undergoing breast treatments). A lower NU represents greater uniformity of CT image intensity within a region of interest. Median NU across the study population is presented for four imaging modalities.
Time frame: 1 day
CBCT Image Quality - Contrast
Contrast represents the ability to distinguish between two different regions in a CT image (e.g. to distinguish between two adjacent organs). Contrast = \|HU1 - HU2\| where HU1 and HU2 are the mean HU values in two different 100 mm\^2 ROIs, where the ROIs were located in two different tissue types that were relevant to the site being treated (e.g., in the liver and in perihepatic fat for liver treatments). Higher contrast values indicate that it is easier to distinguish between regions (anatomical structures) in a CT image. Median contrast across the study population is presented for four imaging modalities.
Time frame: 1 week
CBCT Image Quality - Contrast to Noise Ratio
Contrast to Noise Ratio (CNR) measures the ability to distinguish an object or lesion from its background. CNR = \|HU1 - HU2\|/\[0.5 (STD1 + STD2)\] where HU1 and HU2 are the mean Hounsfield Unit values in two different 100 mm\^2 ROIs, where the ROIs were located in two different tissue types that were relevant to the site being treated (e.g., in the liver and in perihepatic fat for liver treatments), and STD1 and STD2 are the standard deviations of the HU values in those same ROIs. A higher CNR makes it easier to distinguish an object from its background. CNR analysis was limited to images with similar imaging dose. Median CNR across all study participants treated for lung cancer are presented for three CBCT modalities.
Time frame: 1 week
CBCT Image Quality - HU Similarity to CT Simulation
The intensity of a pixel in a CT image is a function of its Hounsfield Unit (HU) value. HU is also directly related to the underlying electron density, which means that the pixel value of a CT image can be used directly in the calculation of dose for a prescribed radiation treatment plan. CT simulation scanners produce images with high HU accuracy and are regularly used for radiation treatment planning. Here, we present the difference in HU between CT simulation images and different CBCT images. ΔHU = HU\_CBCT - HU\_CTSim, where HU\_CBCT and HU\_CTSim are mean values among HU averages at 4 reference points in a CBCT image and the corresponding CT simulation image, respectively. The lower the ΔHU, the greater the HU accuracy of the CBCT image, and the greater the likelihood that CBCT imaging can be used for radiation treatment planning. Median ΔHU across the study population are presented for three different tissue types for three CBCT imaging modalities.
Time frame: 1 week
Dosimetry Calculations - Gamma Pass Rate
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. The overall difference between calculated radiation distributions was evaluated using three different gamma pass criteria: 3% dose difference / 3 mm distance to agreement, 2%/2mm, and 1%/1mm. The gamma pass rate is expressed as a percentage of data points that meet the pass criteria. A gamma pass rate of \> 95% is typically considered acceptable for 3%/3mm. As the gamma pass criteria become stricter, the pass rates decrease. Gamma pass rates were calculated to compare the CT simulation-based dose calculation and the high performance CBCT-based dose calculation. Gamma pass rates were also calculated to compare the CT simulation-based dose calculation and the conventional CBCT-based dose calculation. The median gamma pass rates across the entire study population are presented.
Time frame: 1 day
Dosimetry Calculations - Target DVH Volume Metrics
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual target structures from all three dose distributions. Individual DVH metrics, such as V90(%) (the percentage of the structure volume receiving 90% of the prescribed radiation dose) were extracted for individual target structures from their DVH. The difference between a DVH metric derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median target DVH metric differences across the study population are presented.
Time frame: 1 day
Dosimetry Calculations - Target DVH Dose Metrics
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual target structures from all three dose distributions. Individual DVH dose metrics, such as D95(%) (the minimum dose covering 95% of the structure, expressed as a % of the prescription dose) were extracted for individual target structures from their DVH. The difference between a DVH metric derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median target DVH metric differences across the study population are presented.
Time frame: 1 day
Dosimetry Calculations - Breast OAR DVH Metrics
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for breast cancer are the heart, ipsilateral lung, and contralateral breast. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for breast cancer are presented.
Time frame: 1 day
Dosimetry Calculations - Lung OAR DVH Metrics
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for lung cancer are the heart, esophagus and spinal cord. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for lung cancer are presented.
Time frame: 1 day
Dosimetry Calculations - Abdomen OAR DVH Metrics
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for abdominal cancer are the heart, bowel and kidneys. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for abdominal cancer are presented.
Time frame: 1 day
Patient Experience - General Ease of Breath Hold
Study participants were asked to respond to the statement, "I find it easy to hold my breath", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
Time frame: 1 Day
Patient Experience - Ease of Breath Hold on TrueBeam
Study participants were asked to respond to the statement, "It was easy for me to perform the breath holds that were needed for imaging on the TrueBeam radiation machine", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
Time frame: 1 Day
Patient Experience - Ease of Breath Hold on Ethos
Study participants were asked to respond to the statement, "It was easy for me to perform the breath holds needed for imaging on the Ethos radiation machine", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
Time frame: 1 Day
Patient Experience - Relative Ease of Breath Hold Between Machines
Study participants were asked to respond to the statement, "It was easier for me to perform the breath holds needed for imaging on one radiation machine compared to the other", on a 5-point scale, where 1 represents "TrueBeam much easier", 3 represents "Both machines equally easy", and 5 represents "Ethos much easier".
Time frame: 1 Day
Patient Experience - Overall TrueBeam Experience
Study participants were asked to respond to the statement, "My overall experience during imaging on the TrueBeam was good", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
Time frame: 1 Day
Patient Experience - Overall Ethos Experience
Study participants were asked to respond to the statement, "My overall experience during imaging on the Ethos platform was good", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
Time frame: 1 Day
| Milestone | High-performance CBCT Imaging |
|---|---|
| Started | 31 |
| Completed | 30 |
| Not completed | 1 |
| Withdrew: Physician decision | 1 |
Artifact Index (AI) is a measurement of the strength of imaging artifact and the degree to which is affects visibility of anatomical structures in the vicinity of the artifact. Artifacts can be produced in CT and CBCT images by a number of factors, such as metal implants, gas, or breathing motion. AI = sqrt((STD\_VOI)\^2 - (STD\_background)\^2), where STD\_VOI is the standard deviation of the image Hounsfield Units in a region of interest at the location of an artifact, and STD\_background is the standard deviation of the Hounsfield Unit values in the background (i.e. in similar tissue but away from the artifact. A lower AI value indicates that the artifact has a lower impact on image quality. Artifacts were identified in all study participants. The median AI across the study population is presented for four imaging modalities.
| HU | Breath Hold High Performance CBCT | Free Breathing High Performance CBCT | Conventional CBCT | CT Simulation |
|---|---|---|---|---|
| CBCT Image Quality - Artifact Index | 20.2 (13.9 to 31.0) | 32.9 (14.7 to 50.2) | 59.2 (30.5 to 89.4) | 17.3 (8.2 to 24.3) |
Nonuniformity (NU) is a measure of the variation of CT image intensity in uniform tissue. NU = (HU\_max - HU\_min)/(HU\_max + HU\_min), where HU\_max and HU\_min are the maximum and minimum Hounsfield Unit values among multiple locations sampled within regions of uniform tissue that were relevant to the anatomy of interest (e.g., a uniform region of breast tissue for patients undergoing breast treatments). A lower NU represents greater uniformity of CT image intensity within a region of interest. Median NU across the study population is presented for four imaging modalities.
| ratio | Breath Hold High Performance CBCT | Free Breathing High Performance CBCT | Conventional CBCT | CT Simulation |
|---|---|---|---|---|
| CBCT Image Quality - Image Nonuniformity | 0.1 (0.07 to 0.19) | 0.25 (0.15 to 0.40) | 0.25 (0.16 to 0.51) | 0.05 (0.03 to 0.09) |
Contrast represents the ability to distinguish between two different regions in a CT image (e.g. to distinguish between two adjacent organs). Contrast = \|HU1 - HU2\| where HU1 and HU2 are the mean HU values in two different 100 mm\^2 ROIs, where the ROIs were located in two different tissue types that were relevant to the site being treated (e.g., in the liver and in perihepatic fat for liver treatments). Higher contrast values indicate that it is easier to distinguish between regions (anatomical structures) in a CT image. Median contrast across the study population is presented for four imaging modalities.
| HU | Breath Hold High Performance CBCT | Free Breathing High Performance CBCT | Conventional CBCT | CT Simulation |
|---|---|---|---|---|
| CBCT Image Quality - Contrast | 134.1 (119.0 to 145.9) | 129.7 (109.2 to 138.0) | 126.8 (101.8 to 151.1) | 142.3 (133.7 to 154.6) |
Contrast to Noise Ratio (CNR) measures the ability to distinguish an object or lesion from its background. CNR = \|HU1 - HU2\|/\[0.5 (STD1 + STD2)\] where HU1 and HU2 are the mean Hounsfield Unit values in two different 100 mm\^2 ROIs, where the ROIs were located in two different tissue types that were relevant to the site being treated (e.g., in the liver and in perihepatic fat for liver treatments), and STD1 and STD2 are the standard deviations of the HU values in those same ROIs. A higher CNR makes it easier to distinguish an object from its background. CNR analysis was limited to images with similar imaging dose. Median CNR across all study participants treated for lung cancer are presented for three CBCT modalities.
| ratio | Breath Hold High Performance CBCT | Free Breathing High Performance CBCT | Conventional CBCT |
|---|---|---|---|
| CBCT Image Quality - Contrast to Noise Ratio | 6.64 (2.99 to 9.37) | 4.13 (3.31 to 5.41) | 5.10 (2.44 to 6.99) |
The intensity of a pixel in a CT image is a function of its Hounsfield Unit (HU) value. HU is also directly related to the underlying electron density, which means that the pixel value of a CT image can be used directly in the calculation of dose for a prescribed radiation treatment plan. CT simulation scanners produce images with high HU accuracy and are regularly used for radiation treatment planning. Here, we present the difference in HU between CT simulation images and different CBCT images. ΔHU = HU\_CBCT - HU\_CTSim, where HU\_CBCT and HU\_CTSim are mean values among HU averages at 4 reference points in a CBCT image and the corresponding CT simulation image, respectively. The lower the ΔHU, the greater the HU accuracy of the CBCT image, and the greater the likelihood that CBCT imaging can be used for radiation treatment planning. Median ΔHU across the study population are presented for three different tissue types for three CBCT imaging modalities.
| HU | Breath Hold High Performance CBCT | Free Breathing High Performance CBCT | Conventional CBCT |
|---|---|---|---|
| Bone | -12.1 (-25.8 to 9.9) | -31.4 (-58.6 to -11.7) | 6.7 (-33.0 to 39.5) |
| Lung | -14.0 (-32.3 to 2.5) | 85.0 (12.6 to 111.3) | -33.0 (-69.0 to -9.5) |
| Tissue | -0.8 (-12.1 to 6.9) | -11.3 (-30.6 to 4.9) | -18.7 (-30.3 to -6.7) |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. The overall difference between calculated radiation distributions was evaluated using three different gamma pass criteria: 3% dose difference / 3 mm distance to agreement, 2%/2mm, and 1%/1mm. The gamma pass rate is expressed as a percentage of data points that meet the pass criteria. A gamma pass rate of \> 95% is typically considered acceptable for 3%/3mm. As the gamma pass criteria become stricter, the pass rates decrease. Gamma pass rates were calculated to compare the CT simulation-based dose calculation and the high performance CBCT-based dose calculation. Gamma pass rates were also calculated to compare the CT simulation-based dose calculation and the conventional CBCT-based dose calculation. The median gamma pass rates across the entire study population are presented.
| percentage | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| 3%/3mm | 96.7 ± 3.1 | 93.3 ± 14 |
| 2%/2mm | 89.9 ± 6.0 | 85.4 ± 18.4 |
| 1%/1mm | 70.2 ± 11.8 | 61.6 ± 22.4 |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual target structures from all three dose distributions. Individual DVH metrics, such as V90(%) (the percentage of the structure volume receiving 90% of the prescribed radiation dose) were extracted for individual target structures from their DVH. The difference between a DVH metric derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median target DVH metric differences across the study population are presented.
| % target volume (Vxx) | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| V90(%) | 0.1 (-0.7 to 0.9) | 0.0 (-1.0 to 1.0) |
| V95(%) | 0.3 (-3.4 to 4.0) | 0.0 (-2.9 to 2.9) |
| V100(%) | 1.5 (-8.2 to 11.2) | 0.2 (-10.7 to 11.1) |
| V105(%) | -0.9 (-4.0 to 5.8) | -2.7 (-13 to 7.6) |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual target structures from all three dose distributions. Individual DVH dose metrics, such as D95(%) (the minimum dose covering 95% of the structure, expressed as a % of the prescription dose) were extracted for individual target structures from their DVH. The difference between a DVH metric derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median target DVH metric differences across the study population are presented.
| % prescription dose (Dxx) | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| D90(%) | 0.5 (-2.2 to 3.2) | 0.0 (-3.1 to 3.1) |
| D95(%) | 1.0 (-3.5 to 5.5) | 0.5 (-3.2 to 4.2) |
| D99(%) | 2.2 (-3.7 to 8.1) | 1.5 (-10.2 to 13.2) |
| Dmax(%) | -2.3 (-5.4 to 0.8) | -2.4 (-7.6 to 2.8) |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for breast cancer are the heart, ipsilateral lung, and contralateral breast. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for breast cancer are presented.
| % dose | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| Heart D2%(%) | -1.4 (-4.4 to 2.6) | -2.7 (-9.3 to 3.9) |
| Ipsilateral lung D2%(%) | 1.1 (-1.6 to 3.8) | 2.9 (-0.2 to 6.0) |
| Contralateral breast D2%(%) | 0.1 (-1.2 to 1.4) | 0.5 (-0.5 to 1.5) |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for lung cancer are the heart, esophagus and spinal cord. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for lung cancer are presented.
| % dose | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| Heart D2%(%) | -0.3 (-1.2 to 0.6) | -0.1 (-1.3 to 1.1) |
| Esophagus D2%(%) | 0.1 (-1.3 to 1.5) | -0.2 (-1.1 to 0.7) |
| Spinal cord D2%(%) | -0.4 (-1.0 to 0.2) | -0.1 (-0.9 to 0.7) |
Every trial participant had a radiation treatment plan calculated on their CT simulation image series. That same plan was then re-calculated on both the breath hold high-performance CBCT and conventional CBCT. Dose-volume histograms (DVH) were calculated for individual organs at risk (OAR) from all three dose distributions. The key organs at risk for patients being treated for abdominal cancer are the heart, bowel and kidneys. The differences between the D2%(%) (minimum dose received by the "hottest" 2% of the OAR, expressed as a % of the prescription dose) derived from CT simulation-based dose calculation and the same metric derived from a CBCT-based dose calculation are reported. The smaller the difference, the greater the accuracy of the CBCT-based dose calculation. Median differences in OAR D2%(%) across study participants treated for abdominal cancer are presented.
| % dose | Breath Hold High Performance CBCT | Conventional CBCT |
|---|---|---|
| Heart D2%(%) | 0.7 (-0.5 to 1.9) | -0.8 (-3.1 to 1.5) |
| Bowel D2%(%) | -0.2 (-1.7 to 1.3) | -0.6 (-1.8 to 0.6) |
| Kidneys D2%(%) | -0.1 (-2.3 to 2.1) | 0.0 (-0.9 to 0.9) |
Study participants were asked to respond to the statement, "I find it easy to hold my breath", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - General Ease of Breath Hold | 4.3 ± 0.47 |
Study participants were asked to respond to the statement, "It was easy for me to perform the breath holds that were needed for imaging on the TrueBeam radiation machine", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - Ease of Breath Hold on TrueBeam | 4.3 ± 0.48 |
Study participants were asked to respond to the statement, "It was easy for me to perform the breath holds needed for imaging on the Ethos radiation machine", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - Ease of Breath Hold on Ethos | 4.5 ± 0.51 |
Study participants were asked to respond to the statement, "It was easier for me to perform the breath holds needed for imaging on one radiation machine compared to the other", on a 5-point scale, where 1 represents "TrueBeam much easier", 3 represents "Both machines equally easy", and 5 represents "Ethos much easier".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - Relative Ease of Breath Hold Between Machines | 4.2 ± 0.99 |
Study participants were asked to respond to the statement, "My overall experience during imaging on the TrueBeam was good", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - Overall TrueBeam Experience | 4.4 ± 0.68 |
Study participants were asked to respond to the statement, "My overall experience during imaging on the Ethos platform was good", on a 5-point scale, where 1 represents "Strongly Disagree", 3 represents "Neutral", and 5 represents "Strongly Agree".
| Units on a Likert scale | High-performance CBCT Imaging |
|---|---|
| Patient Experience - Overall Ethos Experience | 4.5 ± 0.51 |
Collected over 1 week. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| High-performance CBCT Imaging | 0/30 (0%) | 0/30 (0%) | 0/30 (0%) |
| Age, Continuous(years) | High-performance CBCT Imaging |
|---|---|
| Median | 66 ± 8.2 |
| Sex: Female, Male(Participants) | High-performance CBCT Imaging |
|---|---|
| Female | 18 |
| Male | 12 |
| Race and Ethnicity Not Collected(Participants) | High-performance CBCT Imaging |
|---|
| BMI(kg/m^2) | High-performance CBCT Imaging |
|---|---|
| Mean | 29.2 (19.2 to 38.1) |
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