Dose Histogram Options

Histogram Options Menus

The Histogram Options menus control the resolution and appearance of dose-histogram calculations.

By default, histogram #1 is configured as a Retinal Dose Area Histogram (RDAH) and histogram #2 is configured as a Dose Volume Histogram (DVH).

Note: the submenus for histograms #1 and #2 are identical so only histogram #1 is illustrated above.

Low Resolution - fastest to calculate, 256 pixel diameter retinal diagram (≈ 0.05 mm² per pix) or voxels of 1.00 x 1.00 x 1.00 mm (1E-3 cc).
Medium Resolution - a good compromise for routine use, 512 pixel diameter retinal diagram (≈ 0.01 mm² per pix) or voxels of 0.50 x 0.50 x 0.50 mm (1.25E-4 cc).
High Resolution - slowest to calculate, 1024 pixel diameter retinal diagram (≈ 0.003 mm² per pix) or voxels of 0.25 x 0.25 x 0.25 mm (1.56E-5 cc).
Custom Resolution - uses the custom preference setting for the diameter of the retinal diagram in pixels.

Eye Dose-Volume - select to change to dose-volume histogram mode. Optional, but not very useful, because most of the eye volume is radiobiologically inert vitreous humour. For the dose-volume calculation, the volume of the eye and tumor are subdivided into voxels. The average dose per voxel is estimated as the dose delivered to a point at the center of each voxel. Calculation time is inversely proportional to voxel size.
Retina Dose-Area - select to change to dose-area histogram mode. Selected by default, this is the most useful dose histogram because the retina is the most radiobiologically important region of the eye. To calculate the retina dose-area calculation (RDAH), a retinal diagram is imagined to be subdivided into pixels. The average dose per pixel is estimated as the dose delivered to a point at the center of each pixel. Calculation time is proportional to the number of pixels.

Histogram Preference Settings... - The RDAH calculation and plotting parameters are set in the histogram pane of the Preferences window.

More Histogram Options

All Included Tumors - the RDAH tumor region includes the active tumor, or, in the case of multiple tumors, all included tumors.
Tumor 1 - the RDAH tumor region is the base of tumor #1, even if it is not active or included. This enables unused tumors to be repurposed as retinal regions of interest. Note: If you customize the name of a tumor in the Multiple Tumors dialog, that name will appear here rather than 'Tumor 1'.
Tumor 2 - the RDAH tumor region is the base of tumor #2, even if it is not active or included. This enables unused tumors to be repurposed as retinal regions of interest.
Tumor 3 - the RDAH tumor region is the base of tumor #3, even if it is not active or included. This enables unused tumors to be repurposed as retinal regions of interest.
Tumor 4 - the RDAH tumor region is the base of tumor #4, even if it is not active or included. This enables unused tumors to be repurposed as retinal regions of interest.