Premium
SU‐GG‐T‐130: Rotational IMRT Delivery Using a Siemens Artiste in Flattening‐Filter‐Free, High Dose‐Rate Mode
Author(s) -
Sarkar V,
RassiahSzegedi P,
Szegedi M,
Wang B,
Zhao H,
Huang Y,
Shukla H,
Salter B
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3468519
Subject(s) - linear particle accelerator , siemens , nuclear medicine , ionization chamber , radiation treatment planning , dosimetry , dicom , imaging phantom , dose rate , computer science , medical physics , physics , medicine , radiation therapy , optics , surgery , beam (structure) , ion , operating system , quantum mechanics , ionization
Purpose : To demonstrate the ability to deliver unflattened (high dose rate), modulated arc plans using the Siemens Artiste linear accelerator using prototype linac firmware developed by Siemens and prototype TPS software developed by Prowess. Method and Materials : Prototype Prowess treatment planning software was used to develop a set of high dose rate (1,000 mu/min) modulated arc plans for four treatment sites ‐ head/neck, lung, prostate and breast. A step‐and‐shoot plan (SS) was also created for delivery efficiency comparison to arc‐based plans. The same planning criteria were used for all plans to ensure their ‘equivalence’. With the linear accelerator converted to the experimental state, all plans were delivered to a solid water phantom. Dose was measured using an ion chamber for point dose measurements and film for evaluation of relative dose distribution with a gamma criteria of 3%/3mm. Delivery times were collected to assess delivery efficiency. Results : Plans developed using all arc modalities were successfully delivered for all cases. The maximum difference between measured and calculated doses was 3.08% for ion chamber measurements and the minimum 3%/3mm gamma agreement was 87% of pixels. All arc treatments were delivered in less time than the corresponding SS plans, with the lung SBRT plans being delivered in 5 minutes for a 20 Gy prescription. Conclusion : Unflattened, modulated arc delivery is possible using prototype firmware on a Siemens Artiste machine and the Prowess treatment planning system accurately predicted doses for such deliveries. Modulated arc delivery in combination with unflat (high dose rate i.e. 1,000+ mu/min) mode may allow for very efficient delivery of highly conformai isodose distributions. Conflict of Interest : This work is funded by a grant from Siemens Oncology.