QXRay Consulting

Introducing ScanDoseMatch software

Opening a reference profile or pdd

1. Click on the file opening icon in the reference section

2. Select proper file type from file selector.

3. If selected file has a multi-scan format the dropdown box in the reference section will turn yellow. The user can then proceed with selection of the appropriate field size or depth.

4. The program will show two data series at the end of the import process. A data series in green color will be the reference dataset. The second data series in blue color will be the fitting curve calculated with spline interpolation.

5. The “quality” of the fitness can be adjusted by selecting the appropriate spline smooth factor "Spline SF" The fitting curve goes from a simple line when SF equals 1 to a complex curve virtually crossing all points when SF equals 10.

6. Visualization of data series can be turned on and off by clicking on the magnifying lens icon The green icon will affect reference data visualization and the blue icon will affect fitting curve visualization.

Rotate profile

1. Profiles can be vertically flipped by checking the "Rotate Profile" box. This is a data manipulation that has to be performed with certain cautious. The operation will flip profile across central axis (zero X coordinate). This situation can induce some errors in the analysis if the reference data have some misalignment or have been intentionally taken with some off-axis shift.

2. This option only affects profiles. It won't flip PDDs

Opening a measured profile or pdd

1. Click on the file opening icon in the measurement section.

2. Select the proper file type from file selector.

3. If selected file has a multi-scan format the dropdown box in the measurement section will turn yellow. The user can then proceed with selection of the appropriate field size or depth.

Shift and Auto Shift functions

1. The program will superimpose both datasets in the chart after the import process.

2. If needed a shift of the measurement dataset can be applied by typing a decimal number in the edit box and then pressing the "Shift" button .

3. A negative value means moving measurement dataset to the surface for pdds or to the left for profiles

4. The Auto shift function attempts to align measurement profile/pdd against the reference dataset. The program will try to find the minimum square relative difference between both datasets. The search area for the minimum is between 80 and 30% of the profile/pdd.

5. Result of the Auto shift process will be displayed in the edit box on the top right of the measurement section

6. The user should be very careful when attempts to apply the auto shift function to pdd scans. The present algorithm will definitely shift location of dmax.

Profile normalization

1. By default all profiles are normalized to 100% at central axis (CAX) during the import process. If the user prefers to display original data instead, "Norm. CAX 100%" option has to be unchecked.

2. This option is available only for profiles and certain scanners

Gamma calculations

1. There are two types of gamma calculations that can be performed with the program. The first one is a gamma calculation of the reference dataset against fitting curve. This is specified when the user checks "Fit-Ref" box. The second gamma calculation can be performed between measurements and fitting curve. This is specified by checking “Measurement-Ref” box. The user needs to select first the type of calculation in order to enable the “Get Gamma” button . Then by pressing Get Gamma button the gamma result for each tested point is calculated and displayed in the chart.

2. Gamma calculation between reference and fitted datasets is useful for testing the level of “noise” introduced by the fitting curve. The program by default starts with a spline smooth factor “Spline SF” of 8. This value is usually sufficient for a good fit but sometimes a higher value could be needed.

3. In the present implementation gamma expression is calculated as the minimum of the gamma index as defined by Low et al within a fixed search distance of twice the DTA around the tested point. Dose difference (difference in profile or pdd values) can be normalized to the maximum profile or pdd value. In this case the option has to be checked.

4. Defaults for the gamma calculation are 2%/2mm for the whole data range. Dose tolerance and DTA can be changed to any value except zero for Dose tolerance. After changing Dose tolerance and DTA you need to click on the Get Gamma button to generate new results.

5. When DTA is set to zero gamma calculation becomes the special case of a relative percentage difference. The analysis of the distance component in the gamma expression is omitted.

6. The From(cm) and To(cm) values can be modified to define the range where the user wants to calculate the gammas. The TH(%) value which stands for threshold will limit the gamma calculation for profiles or pdd values above the preset value.

7. The red lens button turns display of gamma series on and off.

Chart Options

1. The user can set X and Y axis labels as well as main title and subtitle by just typing the appropriate text in the corresponding edit box. Left Y axis will show profile or pdd values depending on the type of data imported. Right axis will show gamma index or relative percentage difference depending on selected DTA value.

2. Any area of the chart can be magnified by dragging a rectangle from top left (1) to bottom right (2) as indicated in the following illustration. To go back to original chart layout just drag in any place of the chart from bottom right (2) to top left (1).

3. Chart can be copied to clipboard with right click and selecting the image type. Depending on user’s preference a BMP or Windows metafile image will be saved in the clipboard and there will be available for future pasting in any document.

4. The Save icon on the left of the chart allows saving a BMP copy of the chart in any accessible folder.

5. The Print icon will send the job to Windows’s default printer.

6. The Report icon will preview the document in pdf format. This report will present a more comprehensive information about gamma analysis and calculation conditions.

7. The top labels of the report can be configured by clicking the tool icon and completing Report Title, Institution name, Machine Model and Machine Serial Number. This information will be saved in a text file named “config.scn” located in the same folder from where the application is launched.

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