Users Manual Part 4

IBA | 30-18 | Clinical User’s Guide
Volume 1 - Treatment Session
|Part IV - Using ada PT prescribe Using QA Features of adaPT prescribe |
 The blue number is the number of elements contained in the layer. There
are 2 elements per spot, so this third number is 2 times the number of spots
to be irradiated.
 The last number (green) is the number of paintings, meaning the number of
times that the layer will be irradiated. The total number of MUs to be
delivered on a spot is then divided by the number of paintings in order to
keep the total number of MUs the same. Changing the number of paintings
will not have any impact on the number of delivered MUs. Repainting
techniques are used for proton therapy to be less sensitive to organ motion.
 After this line, there is a list of all the spots contained in the layer. Each line starts
with the word ‘Element’, then in red the position expected in X (IEC coordinate
system) in the isocenter plane and in blue the Y coordinate in the isocenter
plane.
The green number is the meterset weight of this spot. Each spot requires two
elements, the first one with a meter set weight equal to 0 and a second one with
the requested meterset weight.
The last parameter of the line is the meterset rate and is set at 0 in case of Spot
scanning (meaning that the spot is not moving during the irradiation). In case of
active scanning (beam moved during the irradiation), this parameter represents
the speed at which the meterset weight needs to be delivered on this element.
When loading a PLD file into the PTS database, the BMS performs a translation on
this data to check that the final cumulative meterset weight is equal to the sum of all
the meterset weights, that the number of layers in the map is equal to the number
of layers defined in the header, etc.