Premium
Technical note: Patient‐specific quality assurance methods for TomoDirect TM whole breast treatment delivery
Author(s) -
Catuzzo P.,
Ze F.,
Aimonetto S.,
Peruzzo A.,
Casanova Borca V.,
Pasquino M.,
Franco P.,
La Porta M. R.,
Ricardi U.,
Tofani S.
Publication year - 2012
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 - 10.1118/1.4722967
Subject(s) - tomotherapy , imaging phantom , quality assurance , dosimetry , nuclear medicine , materials science , diode , detector , sensitivity (control systems) , medical physics , optics , medicine , radiation therapy , physics , radiology , optoelectronics , external quality assessment , engineering , pathology , electronic engineering
Purpose: To investigate the feasibility of implementing a novel approach for patient‐specific QA of TomoDirect TM whole breast treatment. Methods: The most currently used TomoTherapy DQA method, consisting in the verification of the 2D dose distribution in a coronal or sagittal plane of the Cheese Phantom by means of gafchromic films, was compared with an alternative approach based on the use of two commercially available diode arrays, MapCHECK2 TM and ArcCHECK TM . The TomoDirect TM plans of twenty patients with a primary unilateral breast cancer were applied to a CT scan of the Cheese Phantom and a MVCT dataset of the diode arrays. Then measurements of 2D dose distribution were performed and compared with the calculated ones using the gamma analysis method with different sets of DTA and DD criteria (3%‐3 mm, 3%‐2 mm). The sensitivity of the diode arrays to detect delivery and setup errors was also investigated. Results: The measured dose distributions showed excellent agreement with the TPS calculations for each detector, with averaged fractions of passed Γ values greater than 95%. The percentage of points satisfying the constraint Γ < 1 was significantly higher for MapCHECK2 TM than for ArcCHECK TM and gafchromic films using both the 3%‐3 mm and 3%‐2 mm gamma criteria. Both the diode arrays show a good sensitivity to delivery and setup errors using a 3%‐2 mm gamma criteria. Conclusions: MapCHECK2™ and ArcCHECK TM may fulfill the demands of an adequate system for TomoDirect TM patient‐specific QA.