ABSTRACT
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.
Subject(s)
Phantoms, Imaging , Prostatic Neoplasms/pathology , Prostatic Neoplasms/radiotherapy , Radiotherapy, Conformal/instrumentation , Radiotherapy, Conformal/methods , Radiotherapy/instrumentation , Radiotherapy/methods , Humans , Male , Quality Control , Radiometry , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Tomography, X-Ray Computed/instrumentationABSTRACT
BACKGROUND AND PURPOSE: In order to ensure the validity of the outcome of the Medical Research Council's 'RTO1 trial' of dose escalation in conformal radiotherapy for prostate cancer it was considered important that the quality of treatment delivery should meet an adequate standard across all contributing centres. A questionnaire was therefore devised to ensure that all aspects of the planning and delivery process were adequately covered. PATIENTS AND METHODS: The questionnaire considered each step in the planning and delivery process and drew the attention of the participants to the specific requirements of the trial. Before entering patients into the trial each participating centre had to complete the questionnaire and an outlining exercise (reported elsewhere). RESULTS: It was not practicable to define a detailed universally acceptable protocol for the whole process of delivery of conformal radiotherapy, not least because of the different equipment available for planning and treatment in different centres. The questionnaire identified some areas of difference in practice between centres where there may be a need for the development of a consensus as to best practice, particularly in the area of patient set-up. Occasionally it was necessary to follow up responses to questions that had been misunderstood or inadequately answered, but in most cases these issues proved to be easily resolved. CONCLUSIONS: The questionnaire proved to be a useful self-assessment tool as well as enabling the quality assurance group to ensure that the standards of the trial were being met. Subsequent follow-up visits confirmed the usefulness and validity of this self assessment process.
Subject(s)
Prostatic Neoplasms/radiotherapy , Quality Assurance, Health Care , Radiation Injuries/prevention & control , Radiotherapy, Conformal/methods , Adult , Aged , Clinical Trials as Topic , Dose-Response Relationship, Radiation , Humans , Male , Maximum Tolerated Dose , Middle Aged , Prostatic Neoplasms/mortality , Prostatic Neoplasms/pathology , Radiotherapy Dosage , Risk Assessment , Sensitivity and Specificity , Surveys and Questionnaires , Survival Analysis , Treatment OutcomeABSTRACT
BACKGROUND AND PURPOSE: Radiotherapy is the most frequently used treatment for men with localised prostate cancer. Conformal radiotherapy (CFRT) is a relatively new development. MRC RT01 was set-up to explore optimum CFRT dose. PATIENTS AND METHODS: RT01 was an international multi-centre randomised controlled trial for men with T1b-T3a, N0, M0 prostate cancer that evolved from a single-centre pilot trial of similar design. All men received at least 3 months of pre-radiotherapy hormone treatment, before randomisation to standard (64 Gy) or high dose (74 Gy) radical CFRT. Accrual was completed in December 2001 with 843 men randomised from 25 centres in less than 4 years. RT01 has been a catalyst for implementing CFRT across UK. In addition to the Trial Management Group, independent Data Monitoring and Ethics Committee and independent Trial Steering Committee, a Quality of Life and Health Economics (QL/HE) group, a radiotherapy Quality Assurance (QA) Group and a Radiography Trial Implementation Group were set up. The QL/HE group ensured implementation, compliance, analysis and interpretation of the QL and HE data in the trial. The inauguration of QA and Radiography groups facilitated inter-centre collaboration. The QA Group ensured procedures were in place before and during trial participation, and monitored quality and consistency with systems including a physics questionnaire, a clinical examples exercise, a standard operating procedure document, designing and building a phantom, and convening a complications modelling subgroup. The Radiography group agreed and implemented technique improvements. RESULTS: More centres participated than initially predicted, enabling recruitment better than scheduled. The trial expedited the implementation of CFRT in many UK radiotherapy centres. Additionally, the QA and Radiography groups helped ensure smooth initiation and established consistency in planning, dosimetry and delivery of prostate CFRT services at participating UK centres. Considerable data has been collected; a series of papers will be produced, although mature clinical trial results are not anticipated until 2006-2008.
