Provision of Organ at Risk Contouring Guidance in UK Radiotherapy Clinical Trials.

AIMS: Accurate delineation of organs at risk (OAR) is vital to the radiotherapy planning process. Inaccuracies in OAR delineation arising from imprecise anatomical definitions may affect plan optimisation and risk inappropriate dose delivery to normal tissues. The aim of this study was to review the provision of OAR contouring guidance in National Institute of Health Research Clinical Research Network (NIHR CRN) portfolio clinical trials. MATERIALS AND METHODS: The National Radiotherapy Quality Trials Assurance (RTTQA) Group carried out a two-round Delphi assessment to determine which OAR descriptions provided optimal guidance. RESULTS: Eighty-four clinical trials involving radiotherapy quality assurance were identified as either in recruitment or in setup within the NIHR CRN portfolio. Fifty-nine trials mandated OAR contouring. In total there were 412 OAR; 171 were uniquely named; 159 OAR had more than one name associated with a single structure, with the greatest nomenclature variation seen for the femoral head ± neck, the parotid gland, and bowel. The two-round Delphi assessment determined 42 OAR descriptions as providing optimal contouring guidance. CONCLUSIONS: This study identified the need for OAR nomenclature and contouring guidance consistency across clinical trials. In response to this study and in conjunction with the Global Quality Assurance of Radiation Therapy Clinical Trials Harmonisation Group, the RTTQA Group is in collaboration with international partners to provide consensus recommendations for OAR delineation in clinical trials.

Technical note: the development of quality assurance for Sheffield's radiotherapy treatment planning systems.

Quality assurance procedures have been defined and implemented for the treatment planning systems at Weston Park Hospital. The programme of tests and checks covers both hardware and software: hardware checks are concerned with the input and output performance of the system's peripheral devices; the software checks involve testing system data integrity, and testing the algorithms used for planning external photon and electron beams. Beam measurements from an ionization chamber scanned in water and air were compared with calculations from two independent treatment planning systems. Following the implementation of these quality assurance procedures, some improvements have been made to the system data used and changes have been introduced to planning practice.