TY  - JOUR
A1  - Richter, Anne
A1  - Wegener, Sonja
A1  - Breuer, Kathrin
A1  - Razinskas, Gary
A1  - Weick, Stefan
A1  - Exner, Florian
A1  - Bratengeier, Klaus
A1  - Flentje, Michael
A1  - Sauer, Otto
A1  - Polat, Bülent
T1  - Comparison of sliding window and field-in-field techniques for tangential whole breast irradiation using the Halcyon and Synergy Agility systems
T2  - Radiation Oncology
N2  - Background
To implement a tangential treatment technique for whole breast irradiation using the Varian Halcyon and to compare it with Elekta Synergy Agility plans.

Methods
For 20 patients two comparable treatment plans with respect to dose coverage and normal tissue sparing were generated. Tangential field-in-field treatment plans (Pinnacle/Synergy) were replanned using the sliding window technique (Eclipse/Halcyon). Plan specific QA was performed using the portal Dosimetry and the ArcCHECK phantom. Imaging and treatment dose were evaluated for treatment delivery on both systems using a modified CIRS Phantom.

Results
The mean number of monitor units for a fraction dose of 2.67 Gy was 515 MUs and 260 MUs for Halcyon and Synergy Agility plans, respectively. The homogeneity index and dose coverage were similar for both treatment units. The plan specific QA showed good agreement between measured and calculated plans. All Halcyon plans passed portal dosimetry QA (3%/2 mm) with 100% points passing and ArcCheck QA (3%/2 mm) with 99.5%. Measurement of the cumulated treatment and imaging dose with the CIRS phantom resulted in lower dose to the contralateral breast for the Halcyon plans.

Conclusions
For the Varian Halcyon a plan quality similar to the Elekta Synergy device was achieved. For the Halcyon plans the dose contribution from the treatment fields to the contralateral breast was even lower due to less interleaf transmission of the Halcyon MLC and a lower contribution of scattered dose from the collimator system.
KW  - whole breast irradiation
KW  - Halcyon
KW  - IGRT
KW  - dose to OARs
Y1  - 2021
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/26570
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-265704
VL  - 16
ER  -