A versatile phantom for quality assurance in the UK Medical Research Council (MRC) RT01 trial (ISRCTN47772397) in conformal radiotherapy for prostate cancer.
Within the UK RT01 trial the MRC also funded a quality assurance (QA) programme. This included a planning and dosimetry audit at participating centres using a purpose built phantom. Geometrical setup was visually assessed via field shaping around the phantom GTV (to within the order of 1 mm). Within the phantom, ion chamber positional uncertainties were estimated as 0.6 mm (95% CL, k=2). This was the basis for ion chamber measurements in a variety of dose gradients around the PTV closely simulating a patient case. The design provides a representative but reproducible system for QA in the prostate radiotherapy process, from CT scan to treatment. Setup errors are not eliminated, but minimised and estimated.
Moore
A Rollo
AR
Medical Physics, Royal Marsden NHS Foundation Trust, London, UK. rollo.moore@nhs.net
Warrington
A P Jim
AP
Aird
Edwin G A
EG
Bidmead
A Margaret
AM
Dearnaley
David P
DP
D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D011786:Quality Control; D011874:Radiometry; D011878:Radiotherapy / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal / Q000295:instrumentation* / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation