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An Evaluation of IMRT/VMAT Plans Between Halcyon and Conventional Linacs

A Dimofte*, W Ingram , O Dolney , S Anamalayil , C Kennedy , R Scheuermann , T Zhu , university Pennsylvania, Philadelphia, PA


(Sunday, 7/29/2018) 3:00 PM - 6:00 PM

Room: Exhibit Hall

Purpose: To compare the quality of treatment plans delivered with IMRT/RA technique on Halcyon accelerator to those delivered on TrueBeam, for commonly treated sites.

Methods: Patients with commonly treated sites (H&N, breast, pelvis and brain) were planned via IMRT and VMAT on a Halcyon and the resulting plans were compared to those on a TB. Dose distribution and DVHs were used to evaluate the plans. The DVH for Target and OAR for all patients were analyzed to compare the dosimetric characteristics of the two delivery methods. Total delivery time and homogeneity index (HI), HI= (D2-D98)/D50, were also compared.

Results: Overall, the plan qualities of the two systems are comparable, with comparable dosimetric characteristics. The total MU is higher for Halcyon than that for TB, while the total delivery time is shorter. We compared max dose, D100, D98, D95, D50 and D2 and they were similar for the two systems.

Conclusion: The plan qualities of commonly sites (H&N, breast, pelvis, and Brain) examined are comparable between Halcyon and conventional Linacs while the treatment time is decreased.


Not Applicable / None Entered.


TH- External beam- photons: treatment planning/virtual clinical studies

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