IMRT SX2

This international plan competition, sponsored by the AAMD, was designed to compare photon treatment to proton treatment of a 59 year old patient with Stage III, cT2bN3M0 adenocarcinoma of the left-lower lobe of the lung. The plan is designed using 1.8 Gy/fraction for a total of 34 fractions. Total dose to be 61.2 Gy.

The following are special notes of the plan study:

• There are 7 targets all to receive a total dose of 61.2 Gy
• CT Sim was done with 4D Sim CT to evaluate ITV of target
• Any contrast in vessels from Sim CT are overridden to water

The plan was created using 18 IMRT fields with alternating collimator angles of 0 degrees and 90 degrees and evenly distributed gantry angles with 20 degrees of separation. Isocenter placement was manually set to allow for field symmetry above and below the largest target PTV.  IGRT chosen was kV CBCT and the total treatment time, including IGRT, was less than 10 minutes.

The largest challenge of this case was delivering effective treatment dose while minimizing the dose to the surrounding healthy lungs below 5 GY, 10 Gy and 20 Gy. Keeping the maximum dose to 0.03cc of the pericardium below 67 Gy was also very challenging.

_{Any reference to a "plan study" are simply what the organizers call each case and may not be a "study" in the FDA sense as they may not have been published in a peer reviewed journal.
Varian does not provide medical advice and these are illustrative examples only.
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