TriangleNCT01843673 · OUTCOME
Differences of Calculated Set up Errors of 2 mm Between the Different Imaging Technologies
Results reported by the registry submitting party. Population, time horizon, units and missing values must be read together.
- Measure
- MEAN
- Unit
- mm
- Interval / dispersion
- Standard Deviation
- Time frame
- up to 7 weeks
What was measured
The automated patient setup procedure varies between 'OBI', 'CBCT' or 'Exactrac' imaging technologies. Each procedure gives two shifts: 'vertical' and 'lateral'. In the absence of a gold standard, our goal is to compare the shifts recommended by each pair of automated patient setup procedures. Average and Std deviation of vertical and lateral motion from the three systems were computed. P value, 1.00, refers to the test of difference of each system with OBI being more than 2 mm. Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. The reported mean value represents the shift from planned treatment position averaged over all daily treatment setups. A negative mean vertical value indicates the patient was consistently set up posterior to plan; a negative mean lateral value indicates a set up consistently right of plan.
Analysis population: Ten evaluable head and neck patients treated with external beam radiation therapy received 19 to 32 fractions with all three imaging techniques. The mean daily shift of these 19 to 32 fractions were recorded for each technique. Statistical significance is determined based on 5% level of significance.
Groups in this outcome
Orthogonal Varian kV OBI Image
Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure OBI gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
Varian CBCT (Cone Beam CT) Imaging
Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure CBCT gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
Oblique Brainlab ExacTrac Images
Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure ExacTrac gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
| Group | Source count |
|---|---|
| Orthogonal Varian kV OBI Image | 10 |
| Varian CBCT (Cone Beam CT) Imaging | 10 |
| Oblique Brainlab ExacTrac Images | 10 |
Reported measurements
Vertical shift
| Group | Value | Spread | Lower | Upper | Comment |
|---|---|---|---|---|---|
| Orthogonal Varian kV OBI Image | -1.2 | 3.1 | Not reported | Not reported | Not reported |
| Varian CBCT (Cone Beam CT) Imaging | -0.8 | 3.4 | Not reported | Not reported | Not reported |
| Oblique Brainlab ExacTrac Images | -1.8 | 3.2 | Not reported | Not reported | Not reported |
Lateral shift
| Group | Value | Spread | Lower | Upper | Comment |
|---|---|---|---|---|---|
| Orthogonal Varian kV OBI Image | -1.5 | 3.3 | Not reported | Not reported | Not reported |
| Varian CBCT (Cone Beam CT) Imaging | -1.1 | 3.3 | Not reported | Not reported | Not reported |
| Oblique Brainlab ExacTrac Images | 1.3 | 3.9 | Not reported | Not reported | Not reported |
Source statistical analyses
- group Description
- Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. Clinical significance is based on a 2 mm difference. Statistical significance is determined based on 5% level of significance.
- group Ids
- OG000
- OG001
- non Inferiority Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05 . The p-values for pairwise comparison.
- non Inferiority Type
- NON_INFERIORITY_OR_EQUIVALENCE
- p Value
- 1.00
- p Value Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. The p-values for pairwise comparison lateral and vertical, for OBI and CBCT was 1.00.
- statistical Method
- t-test, 2 sided
- tested Non Inferiority
- true
- group Description
- Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. Clinical significance is based on a 2 mm difference. Statistical significance is determined based on 5% level of significance.
- group Ids
- OG000
- OG002
- non Inferiority Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. Those are the p-values for pairwise comparison.
- non Inferiority Type
- NON_INFERIORITY_OR_EQUIVALENCE
- p Value
- 1.00
- p Value Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. The p-values for pairwise comparison lateral and vertical, for OBI and ExacTrac was 1.00.
- statistical Method
- t-test, 2 sided
- tested Non Inferiority
- true
Complete source fields
- analyses
- group Description
- Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. Clinical significance is based on a 2 mm difference. Statistical significance is determined based on 5% level of significance.
- group Ids
- OG000
- OG001
- non Inferiority Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05 . The p-values for pairwise comparison.
- non Inferiority Type
- NON_INFERIORITY_OR_EQUIVALENCE
- p Value
- 1.00
- p Value Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. The p-values for pairwise comparison lateral and vertical, for OBI and CBCT was 1.00.
- statistical Method
- t-test, 2 sided
- tested Non Inferiority
- true
- group Description
- Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. Clinical significance is based on a 2 mm difference. Statistical significance is determined based on 5% level of significance.
- group Ids
- OG000
- OG002
- non Inferiority Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. Those are the p-values for pairwise comparison.
- non Inferiority Type
- NON_INFERIORITY_OR_EQUIVALENCE
- p Value
- 1.00
- p Value Comment
- Statistical significance testing at 5% level of significance, p-value being larger than 0.05. The p-values for pairwise comparison lateral and vertical, for OBI and ExacTrac was 1.00.
- statistical Method
- t-test, 2 sided
- tested Non Inferiority
- true
- classes
- categories
- measurements
- group Id
- OG000
- spread
- 3.1
- value
- -1.2
- group Id
- OG001
- spread
- 3.4
- value
- -0.8
- group Id
- OG002
- spread
- 3.2
- value
- -1.8
- title
- Vertical shift
- categories
- measurements
- group Id
- OG000
- spread
- 3.3
- value
- -1.5
- group Id
- OG001
- spread
- 3.3
- value
- -1.1
- group Id
- OG002
- spread
- 3.9
- value
- 1.3
- title
- Lateral shift
- denoms
- counts
- group Id
- OG000
- value
- 10
- group Id
- OG001
- value
- 10
- group Id
- OG002
- value
- 10
- units
- Participants
- description
- The automated patient setup procedure varies between 'OBI', 'CBCT' or 'Exactrac' imaging technologies. Each procedure gives two shifts: 'vertical' and 'lateral'. In the absence of a gold standard, our goal is to compare the shifts recommended by each pair of automated patient setup procedures. Average and Std deviation of vertical and lateral motion from the three systems were computed. P value, 1.00, refers to the test of difference of each system with OBI being more than 2 mm. Pairwise comparison for each direction between each pair of technologies were done using a t test to check if the difference in the recommended shift is more than 2 mm. The reported mean value represents the shift from planned treatment position averaged over all daily treatment setups. A negative mean vertical value indicates the patient was consistently set up posterior to plan; a negative mean lateral value indicates a set up consistently right of plan.
- dispersion Type
- Standard Deviation
- groups
- description
- Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure OBI gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
- id
- OG000
- title
- Orthogonal Varian kV OBI Image
- description
- Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure CBCT gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
- id
- OG001
- title
- Varian CBCT (Cone Beam CT) Imaging
- description
- Patients are first set up for treatment with surface fiducial marks and followed by an automated image guided alignment procedure to achieve better alignment with the planning image. The automated procedure ExacTrac gives two shifts: vertical and lateral. In the absence of a gold standard, our goal is to compare the vertical and lateral shifts recommended by each pair of automated procedures.
- id
- OG002
- title
- Oblique Brainlab ExacTrac Images
- param Type
- MEAN
- population Description
- Ten evaluable head and neck patients treated with external beam radiation therapy received 19 to 32 fractions with all three imaging techniques. The mean daily shift of these 19 to 32 fractions were recorded for each technique. Statistical significance is determined based on 5% level of significance.
- reporting Status
- POSTED
- time Frame
- up to 7 weeks
- title
- Differences of Calculated Set up Errors of 2 mm Between the Different Imaging Technologies
- type
- PRIMARY
- unit Of Measure
- mm
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Preserved source evidence · Not medical advice