title: Technical note: patient-specific quality assurance methods for TomoDirect(TM) whole breast treatment delivery.
abstract: OBJECTIVE
  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.
authors: Medical Physics Department, Ospedale Regionale U. Parini, AUSL Valle d'Aosta, Aosta, Italy.
authors: P
authors: P
authors: Catuzzo
authors: F
authors: F
authors: Zenone
authors: S
authors: S
authors: Aimonetto
authors: A
authors: A
authors: Peruzzo
authors: V
authors: V
authors: Casanova Borca
authors: M
authors: M
authors: Pasquino
authors: P
authors: P
authors: Franco
authors: M R
authors: MR
authors: La Porta
authors: U
authors: U
authors: Ricardi
authors: S
authors: S
authors: Tofani
mesh_terms: D000465:Algorithms; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007558:Italy; D011785:Quality Assurance, Health Care / Q000379:methods*; D011874:Radiometry / Q000379:methods* / Q000592:standards*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000592:standards*