Development of a novel treatment planning test for credentialing rotational intensity-modulated radiotherapy techniques in the UK

Abstract

The increasing use of tomotherapy and volumetric-modulated arc therapy in UK centres will result in more centres choosing to use this technology in a clinical trial setting. The Radiotherapy Trials Quality Assurance (RTTQA) group has developed a new procedure to integrate into the UK intensity-modulated radiotherapy (IMRT) credentialing programme to cover rotational IMRT delivery techniques. A planning test [three-dimensional treatment planning system (3DTPS)] was designed specifically for rotational IMRT techniques. The feasibility of using this test in the credentialing programme for rotational IMRT was validated by 10 experienced UK centres. The study included five centres using Varian RapidArc™ (RA) (Varian Medical Systems, Milpitas, CA), two using Elekta VMAT™ (VMAT) (Elekta Inc., Norcross, GA) and three using helical tomotherapy (HT) plans. Centres were asked to carry out their own in-house quality assurance (QA) for the plans submitted for this study. A survey was sent out to centres aiming to gather information on their experience in undertaking the exercise and their QA results. All centres fulfilled the primary goal by achieving the dose constraints of the primary planning target volume and organ at risk. Seven centres (three RA, one VMAT and three HT plans) were able to fulfil the secondary goal. Among those seven centres, three centres (two RA and one VMAT plans) achieved the tertiary goal. The results of the survey indicated that the 3DTPS test is a clinically relevant and practical planning test to be used. A planning test for rotational therapy techniques was developed for the RTTQA IMRT credentialing programme. This study validated the feasibility of a 3DTPS test to be used as part of a credentialing programme for rotational IMRT techniques in the UK.