Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials.

Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment.

A multicentre 'end to end' dosimetry audit for cervix HDR brachytherapy treatment.

Purpose: To undertake the first multicentre fully 'end to end' dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures.

Materials And Methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems.

Global harmonization of quality assurance naming conventions in radiation therapy clinical trials.

Purpose: To review the various radiation therapy quality assurance (RTQA) procedures used by the Global Clinical Trials RTQA Harmonization Group (GHG) steering committee members and present the harmonized RTQA naming conventions by amalgamating procedures with similar objectives.

Methods And Materials: A survey of the GHG steering committee members' RTQA procedures, their goals, and naming conventions was conducted. The RTQA procedures were classified as baseline, preaccrual, and prospective/retrospective data capture and analysis.

Escalated-dose versus control-dose conformal radiotherapy for prostate cancer: long-term results from the MRC RT01 randomised controlled trial.

Background: The aim of this trial was to compare dose-escalated conformal radiotherapy with control-dose conformal radiotherapy in patients with localised prostate cancer. Preliminary findings reported after 5 years of follow-up showed that escalated-dose conformal radiotherapy improved biochemical progression-free survival. Based on the sample size calculation, we planned to analyse overall survival when 190 deaths occurred; this target has now been reached, after a median 10 years of follow-up.

Contribution to normal tissue dose from concomitant radiation for two common kV-CBCT systems and one MVCT system used in radiotherapy.

Background And Purpose: This study outlines the measured doses for three concomitant imaging modalities used in radiotherapy.

Material And Methods: Doses were measured using thermo luminescent dosemeters within pelvis and thorax anthropomorphic phantoms for the Varian On Board Imager (OBI), Elekta X-ray Volume Imager (XVI) and Tomotherapy HiArt II systems. Organ sites were selected to include those organs which would be irradiated by the treatment beam during the therapy exposure.

EORTC Radiation Oncology Group quality assurance platform: establishment of a digital central review facility.

Objective: Quality assurance (QA) in clinical trials is essential to ensure treatment is safely and effectively delivered. As QA requirements have increased in complexity in parallel with evolution of radiation therapy (RT) delivery, a need to facilitate digital data exchange emerged. Our objective is to present the platform developed for the integration and standardization of QART activities across all EORTC trials involving RT.

Quality assurance for prospective EORTC radiation oncology trials: the challenges of advanced technology in a multicenter international setting.

The European Organization for the Research and Treatment of Cancer (EORTC) is a pan-European structure charged with improving cancer treatment through the testing of new therapeutic strategies in phases I-III clinical studies. Properly conducted trials in radiation oncology are required to demonstrate superiority of a new treatment over the current standard. The Radiation Oncology Group (ROG) has initiated a complex quality assurance (QA) program to ensure safe and effective treatment delivery.

Radiation dose from volumetric helical perfusion CT of the thorax, abdomen or pelvis.

Purpose: To evaluate the radiation doses delivered during volumetric helical perfusion CT of the thorax, abdomen or pelvis.

Materials And Methods: The dose-length product (DLP) and CT dose index (CTDIvol) were recorded and effective dose (E) determined for patients undergoing CT (4D adaptive spiral) for tumour evaluation. Image noise and contrast to noise (CNR) at peak enhancement were also assessed for quality.

Dummy run and conformity indices in the ongoing EORTC low-grade glioma trial 22033-26033: First evaluation of quality of radiotherapy planning.

Purpose: Early assessment of radiotherapy (RT) quality in the ongoing EORTC trial comparing primary temozolomide versus RT in low-grade gliomas.

Materials And Methods: RT plans provided for dummy cases were evaluated and compared against expert plans. We analysed: (1) tumour and organs-at-risk delineation, (2) geometric and dosimetric characteristics, (3) planning parameters, compliance with dose prescription and Dmax for OAR (4) indices: RTOG conformity index (CI), coverage factor (CF), tissue protection factor (PF); conformity number (CN = PF x CF); dose homogeneity in PTV (U).

Dose-volume constraints to reduce rectal side effects from prostate radiotherapy: evidence from MRC RT01 Trial ISRCTN 47772397.

Purpose: Radical radiotherapy for prostate cancer is effective but dose limited because of the proximity of normal tissues. Comprehensive dose-volume analysis of the incidence of clinically relevant late rectal toxicities could indicate how the dose to the rectum should be constrained. Previous emphasis has been on constraining the mid-to-high dose range (>/=50 Gy).

Dosimetry and field matching for radiotherapy to the breast and supraclavicular fossa.

Purpose: Early breast cancer radiotherapy aims for local disease control and reduced recurrence. Treatment is directed to breast or chest wall alone using tangential fields, or includes regional lymph nodes with a separate anterior field. The complex geometry of this region necessitates matching adjacent radiation fields in three-dimensions.

Profile of European radiotherapy departments contributing to the EORTC Radiation Oncology Group (ROG) in the 21st century.

Purpose: Since 1982, the Radiation Oncology Group of the EORTC (EORTC ROG) has pursued an extensive Quality Assurance (QA) program involving all centres actively participating in its clinical research. The first step is the evaluation of the structure and of the human, technical and organisational resources of the centres, to assess their ability to comply with the current requirements for high-tech radiotherapy (RT).

Materials And Methods: A facility questionnaire (FQ) was developed in 1989 and adapted over the years to match the evolution of RT techniques.

Quality assurance of dosimetry and the impact on sample size in randomized clinical trials.

Background And Purpose: The aim of this study was to investigate the impact of appropriate dosimetry quality assurance (QA) on patient number required in radiotherapy randomized control trials (RCT).

Materials And Methods: The steepness of clinical dose-response curves, gamma(clin.), was calculated by a convoluting a biological dose-response distribution and the distribution of technical and dosimetrical factors.

Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial.

Background: In men with localised prostate cancer, conformal radiotherapy (CFRT) could deliver higher doses of radiation than does standard-dose conventional radical external-beam radiotherapy, and could improve long-term efficacy, potentially at the cost of increased toxicity. We aimed to present the first analyses of effectiveness from the MRC RT01 randomised controlled trial.

Methods: The MRC RT01 trial included 843 men with localised prostate cancer who were randomly assigned to standard-dose CFRT or escalated-dose CFRT, both administered with neoadjuvant androgen suppression.

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).

Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less.

Background And Purpose: Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods.

Patients And Methods: Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated.

Questionnaire based quality assurance for the RT01 trial of dose escalation in conformal radiotherapy for prostate cancer (ISRCTN 47772397).

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.

Implementing the UK Medical Research Council (MRC) RT01 trial (ISRCTN 47772397): methods and practicalities of a randomised controlled trial of conformal radiotherapy in men with localised prostate cancer.

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.

The use of in vivo thermoluminescent dosimeters in the quality assurance programme for the START breast fractionation trial.

Background And Purpose: The use of in vivo dosimetry for patient measurement is recommended in many publications. It provides an additional check to verify that the dose delivered to the patient corresponds to the prescribed dose. In the context of a clinical trial investigating the effects of different fractionation regimens, it is imperative that the dose given is that prescribed to ensure that noise in the data between centres does not mask the results of the trial.

Validation of active breathing control in patients with non-small-cell lung cancer to be treated with CHARTWEL.

Purpose: Active breathing control (ABC) was validated using patients with non-small-cell lung cancer (NSCLC) to be treated with continuous hyperfractionated accelerated radiotherapy weekend-less (CHARTWEL). Effects of breath hold (BH) on accuracy and normal tissue doses were evaluated.

Methods And Materials: Eleven patients were studied.

Three-dimensional distribution of radiation within the breast: an intercomparison of departments participating in the START trial of breast radiotherapy fractionation.

Purpose: To examine the ability of computer planning systems to calculate the dose to the breast correctly in three dimensions. Both the absolute dose at the center of the breast and the accuracy of the isodose distributions were investigated.

Methods And Materials: Measurements were performed in a water-filled breast phantom using an ionization chamber.