IMRT SX1+brachy

A Halcyon plan was created for this plan study even though Halcyon doesn’t include an electron beam. A six field IMRT Halcyon plan was created for the external beam portion (ear/neck) and a HDR treatment for the two skin targets on the chest with a GammaMed HDR afterloader.

No Bolus was used on the ear due to the irregular surface. The Halcyon 6XFFF beam covered the target well.

Since we used catheters on the patient's bolus surface for 6 fractions of HDR the patient's in-room or total treatment time for this plan is likely the shortest of any submitted for this study.  The estimated treatment time for a fraction of the external bean portion is approximately two minutes.

The Halcyon plan was created with the proven AAA algorithm. The final brachy HDR plan was calculated using the AcurosBV algorithm (monte carlo accuracy).  All plans and the plan sum (seen above) were created in Eclipse.

Homogeneity in the external beam photon portion was within the norm with a max point dose near ~110%. Heterogeneity with a point source for Brachy is as expected.

The chest targets were prescribed differently to accommodate the HDR delivery method. We used 7.55Gy x6 fx (45.3Gy actual total) and using a skin alpha/beta ratio of 10 to achieve EQD2 of 66.3 to match the requested Rx of 66Gy standard fractionation. If accounting for that fractionation difference, all PQM/metric goals are/would be achieved.

We used the .5cm bolus structure provided on the chest and no bolus on the ear. For the external beam portion standard vac-lock bags would likely be used and registered to the table. No immobilization needed for HDR to the chest.

_{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.
Leading plans by expert planner. Your results may vary.}