Quality assurance control in the EORTC cooperative group of radiotherapy. 3. Intercomparison in an anatomical phantom

[Quality criteria in radiotherapy for head and neck cancers under the aegis of Head and Neck Intergroup]

The aim of radiotherapy is to deliver enough radiation to the tumor in order to achieve maximum tumour control in the irradiated volume with as few serious complications as possible with an irradiation dose as low as possible to normal tissue. The quality of radiotherapy is essential for optimal treatment and quality control is to reduce the bias in clinical trials avoiding possible major deviations. The assurance and quality control programs have been developed in large european (EORTC, GORTEC) and american cooperative groups (RTOG) of radiation oncology since the 1980s. We insist here on the importance of quality assurance in radiotherapy and the current status in this domain and the criteria for quality control especially for current clinical trials within GORTEC are discussed here.

What accuracy is required and can be achieved in radiation therapy (review of radiobiological and clinical data)

An attempt is made to formulate the requirements for the accuracy in the delivery of absorbed dose to a patient during radiation therapy. These requirements are mainly based on the relative steepness and separation of the dose-effect curves for local tumour control and normal tissue damage. The curves for normal tissue complications in general may be steeper than those for local tumour control. From these data, a standard requirement of 3.5% is proposed for the combined uncertainty of type A (random) and type B (systematic), given as one relative standard deviation in the absorbed dose delivery. However, it is recognized that, in many cases, larger uncertainties are acceptable palliative treatments). This value of 3.5% applies to the absorbed dose at the specification point for curative treatments. As far as the dose accuracy requirements at other points in the planning target volume are concerned, a value of 5% (one standard deviation) seems more appropriate. This required accuracy in the delivery of the absorbed dose cannot always be completely achieved in photon therapy even for simple treatment conditions. All the clinical data which were reviewed, including some results from the ldquo;Patterns of Care Study”, indicate a close correlation between the outcomes of therapy (control rates, complications) and dose level, inaccuracy or errors in dosimetry and patient-machine positioning. This has been reported for external beam therapy as well as for brachytherapy. Only the clinical results will allow us to select the optimal treatment conditions (e.g. selection and definition of the planning target volumes, dose levels and beam arrangement), but they could be interpreted correctly only to the extent that the treatment execution would be correct. This result strongly endorses the Quality Assurance Programmes, in which the clinicians and physicists should be fully involved. Lastly, the outcome of a treatment can only be interpreted meaningfully if the parameters of the irradiation, in particular, the distribution of dose in space and time can be accurately correlated with the type and extent of the disease. It is essential that clear, well defined and unambiguous concepts and parameters be used for reporting purposes to ensure a common language between collaborating centres. This is one of the major tasks that the ICRU undertook several years ago.

EORTC 22972-26991/MRC BR10 trial: fractionated stereotactic boost following conventional radiotherapy of high grade gliomas. Clinical and quality-assurance results of the stereotactic boost arm

BACKGROUND AND PURPOSE

The EORTC trial No. 22972 investigated the role of an additional fractionated stereotactic boost (fSRT) to conventional radiotherapy for patients with high grade gliomas. A quality-assurance (QA) programme was run in conjunction with the study and was the first within the EORTC addressing the quality of a supposedly highly accurate treatment technique such as stereotactic radiotherapy. A second aim was to investigate a possible relation between the clinical results of the stereotactic boost arm and the results of the QA.

MATERIALS AND METHODS

The trial was closed in 2001 due to low accrual. In total, 25 patients were randomized: 14 into the experimental arm and 11 into the control arm. Six centres randomized patients, 8 centres had completed the dummy run (DR) for the stereotactic boost part. All participating centres (9) were asked to complete a quality-assurance questionnaire. The DR consisted of treatment planning according to the guidelines of the protocol on 3 different tumour volumes drawn on CT images of a humanized phantom. The SRT technique to be used was evaluated by the questionnaire. Clinical data from patients recruited to the boost arm from 6 participating centres were analysed.

RESULTS

There was a full compliance to the protocol requirements for 5 centres. Major and minor deviations in conformality were observed for 2 and 3 centres, respectively. Of the 8 centres which completed the DR, one centre did not comply with the requirements of stereotactic radiotherapy concerning accuracy, dosimetry and planning. Median follow-up and median overall survival were 39.2 and 21.4 months, respectively. Acute and late toxicities of the stereotactic boost were low. One radiation necrosis was seen for a patient who has not received the SRT boost. Three reported serious adverse events were all seizures and probably therapy-related.

CONCLUSIONS

Overall compliance was good but not ideal from the point of view of this highly precise radiation technique. Survival in the subgroup of patients with small volume disease was encouraging, but the study does not provide sufficient information about the potential value of fSRT boost in patients with malignant glioma.Toxicity due to an additional stereotactic boost of 20 Gy in 4 fractions was low and may be considered as a safe treatment option for patients with small tumours.

Quality assurance in the EORTC phase III randomised 'boost vs. no boost' trial for breast conserving therapy: comparison of the results of two individual case reviews performed early and late during the accrual period

BACKGROUND AND PURPOSE

To evaluate the impact of quality assurance on treatment compliance, we compared the outcome of the two individual case reviews (ICR) conducted early and late during the accrual period of a large prospective multi-centre trial.

PATIENTS AND METHODS

At the onset of the trial, medical files of five patients from each participating centre were evaluated for the compliance to the protocol for eligibility, surgery, pathology and radiotherapy and for the quality of reporting of the data on the case report forms. In nine major centres, this procedure was repeated near the end of the trial.

RESULTS

Both in the early and the late ICR, we found a very limited number of deviations from the guidelines for eligibility, staging, surgery, and pathology. Compliance to radiotherapy requirements was good with the exception of a too low minimal dose in 30% and the lack of target volume delineation in the majority of the evaluated patients. The comparison of the late with the early ICR demonstrated an improvement of the quality of data reporting by 6% and of target volume delineation from 33 to 53%.

CONCLUSIONS

The initial ICR has lead to the identification of a number of parameters, which needed a clarification in the protocol. These items have been corrected and the individual institutions have been made aware of the necessary adaptations. The evaluation at the end of the trial period showed that there was an improvement but also showed that continuous monitoring is necessary, especially for institutions which have the most deviations in the first ICR.

The quality assurance programme of the Radiotherapy Group of the European Organisation for Research and Treatment of Cancer: past, present and future

As early as in 1982, the European Organisation for Research and Treatment of Cancer Radiotherapy Group established a quality assurance programme. In the course of 20 years, quality assurance procedures have become a vast and important part of the activities of the group. Today, the membership committee uses standard procedures based on minimal requirements to evaluate current members and new membership applications. Moreover, for every new trial, specific quality assurance procedures are an integral part of the preparation of the protocol and executed under the responsibility of the study coordinator. With the growing complexity of the radiotherapy techniques used in the framework of the more recent trials, quality assurance procedures have also become more complex including trial specific phantom based measurements. Future ways to evaluate all steps of the radiotherapy process using a common platform connecting all users with the internet are currently under development.

The radiotherapy reference panel--experiences and results of the German Hodgkin Study Group (GHSG)

OBJECTIVE

The German Hodgkin Study Group (GHSG) including more than 500 participating centers established a central radiotherapy (RT) reference center to improve quality of treatment. The purpose of the present article is to summarize the experiences and results of the performed and ongoing quality assurance programs (QAP) of RT.

METHODS

A panel of expert radiation oncologists evaluated retrospectively the adequacy of treatment fields, applied radiation doses, treatment time and technical parameters. For the fourth study generation (HD10-12, 1998-2003), the RT reference center moved from Munich to Cologne. New RT QAP were initiated according to the demands of the new trials and former programs were enhanced.

RESULTS

A strong achievement in the era of extended field RT was to show that major deviations of radiation treatment portals and radiation dose from prospective treatment prescriptions were unfavorable prognostic factors for patients with early-stage Hodgkin's lymphoma (HL). The central prospective radiation oncological review of all diagnostic imaging showed that corrections of disease involvement in 49% of patients with early stages (HD10) and in 67% for patients with intermediate stages (HD11) were necessary. The introduction of electronic image transfer optimized and simplified the workflow of the QAP.

CONCLUSION

Today radiation oncologists in the GHSG perform efficient QAP to improve treatment quality of study patients. For early-stage HL a central prospective review of all diagnostic imaging is performed to control the disease extension and to define the IF treatment volume. Retrospective analysis of RT portals detects faults in the applied irradiation.

Centralized radiation oncologic review of cross-sectional imaging of Hodgkin's disease leads to significant changes in required involved field-results of a quality assurance program of the German Hodgkin Study Group

PURPOSE

To guarantee the treatment quality of involved-field radiotherapy (IF-RT) of patients in the Hodgkin's disease (HD)10 and HD11 trials of the German Hodgkin Study Group, with 460 participating study centers, a quality assurance program was conducted. It was based on a central prospective radiation oncologic review of all patients' entire diagnostic imaging and clinical findings. An individual RT prescription was provided for every study patient. The purpose of the present investigation was to assess the feasibility of such a procedure and its impact on the final definition of disease extension and patient treatment.

METHODS AND MATERIALS

Between 1998 and 2002, 1371 patients were enrolled into the HD10 trial (early-stage disease) and 1570 patients into the HD11 trial (intermediate-stage disease). The HD10 trial tested four cycles of Adriamycin (doxorubicin), bleomycin, vinblastine, and dacarbazine (ABVD) against two cycles of ABVD followed by 20 Gy of IF-RT vs. 30 Gy of IF-RT (four study arms). The HD11 trial compared four cycles of ABVD with four cycles of BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) baseline followed by 20 Gy IF-RT vs. 30 Gy IF-RT in a four-arm design. All study centers were required to score disease involvement at a total of 34 possible anatomic sites on case report forms and send them, together with all diagnostic imaging, to the RT reference center in Cologne, Germany. Images were reviewed there by a panel of expert radiation oncologists and radiologists and compared with the case report form. Differences between the disease involvement documented by the participating center and the reference center were recorded. Subsequently, an individualized treatment proposal was compiled. Complete sets of documentation were submitted to the reference center for 89% of the patients in both HD10 and HD11.

RESULTS

A considerable proportion of involved sites were incorrectly recorded on the corresponding case report form by the participating center. For patients with early-stage HD (HD10), there was a correction of disease involvement in 49% (593 of 1214 patients) and for patients with intermediate-stage HD (HD11) in 67% (936 of 1397 patients). Most discrepancies were seen in the lower mediastinum (23%), infraclavicular (17%), upper cervical (16%), supraclavicular (13%), and pulmonary hilar region (13%). This resulted in a change of disease stage in 41 of those 1,529 patients whose documented disease involvement had to be corrected (2.7%). Ninety-three patients had to be treated in a different protocol, because of changes in stage and risk factors. Owing to incorrect lymph node documentation of the participating centers, the RT treatment volume had to be enlarged in 891 (34%) and reduced in 82 (3%) of 2,611 patients.

CONCLUSION

A central prospective review of patient data and consecutive prescription of individual RT treatment volume is feasible within large multicenter trials for HD. Such a procedure has a significant impact on the correctness of stage definition, allocation to treatment groups, and extent of the IF treatment volume.

Quality assurance in clinical trials

From the literature that was initially searched by electronic databases using the keywords quality, quality control and quality assurance in combination with clinical trials, surgery, pathology, radiotherapy, chemotherapy and data management, a comprehensive review is given on what quality assurance means, the various methods used for quality assurance in different aspects of clinical trials and the impact of this quality assurance on outcome and every day practice.

The Quality Assurance programme of the Radiotherapy Group of the European Organization for Research and Treatment of Cancer (EORTC): a critical appraisal of 20 years of continuous efforts

In 1982, the European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy Group established the Quality Assurance (QA) programme. During the past 20 years, QA procedures have become a major part of the activities of the group. The methodology and steps of the QA programme over the past 20 years are briefly described. Problems and conclusions arising from the results of the long-lasting QA programme in the EORTC radiotherapy group are discussed and emphasised. The EORTC radiotherapy group continues to lead QA in the European radiotherapy community. Future challenges and perspectives are proposed.

Quality assurance in radiotherapy

In 1999, the European Organisation for Research and Treatment of Cancer (EORTC), being a European pioneer in the field of cancer research as well as in quality assurance (QA), launched an Emmanuel van der Schueren fellowship for QA in radiotherapy. In this paper, the work that has been done during the first E. van der Schueren fellowship is reported, focusing on four phase III EORTC clinical trials: 22921 for rectal cancer, 22961 and 22991 for prostate cancer and 22922 for breast cancer. A historical review of the QA programme of the EORTC Radiotherapy group during the past 20 years is included.

Radiotherapy quality assurance: time for everyone to take it seriously

Like high-risk industries, radiotherapy requires intense attention to detail, alertness, precision, and adequate human and material resources to minimise the risk of irreversible consequences. Clinical trials data such as that generated by the Quality Assurance programme of the Radiotherapy Group of the European Organization for Research and Treatment of Cancer (EORTC) in this issue of the Journal have been instrumental in identifying problems with technical quality, the understanding of which can have a direct impact on improving the quality of care in the community. Consistency in absolute dosimetry, dose delivery, volume definition and reproducibility are paramount in radiotherapy quality assurance and have become even more important with the advent of conformal therapy. Extension of these principles to other oncological disciplines has added an additional dimension of improvement. Waiting times and measures of access must also be monitored if overall quality at the population level is to be assessed and enhanced. Lessons should be learned from clinical trials methodology in the use of intervention-specific guidelines, physician education and real time audit of treatment planning decisions. In the future, novel approaches, such as web based systems may further improve education and audit. Wider application and audit of evidence-based management guidelines about the use radiotherapy will bring to standard clinical practice the quality benefits that are considered a basic minimum standard for clinical trials.

Current calibration, treatment, and treatment planning techniques among institutions participating in the Children's Oncology Group

PURPOSE

To report current technology implementation, radiation therapy physics and treatment planning practices, and results of treatment planning exercises among 261 institutions belonging to the Children's Oncology Group (COG).

METHODS AND MATERIALS

The Radiation Therapy Committee of the newly formed COG mandated that each institution demonstrate basic physics and treatment planning abilities by satisfactorily completing a questionnaire and four treatment planning exercises designed by the Quality Assurance Review Center. The planning cases are (1) a maxillary sinus target volume (for two-dimensional planning), (2) a Hodgkin's disease mantle field (for irregular-field and off-axis dose calculations), (3) a central axis blocked case, and (4) a craniospinal irradiation case. The questionnaire and treatment plans were submitted (as of 1/30/02) by 243 institutions and completed satisfactorily by 233. Data from this questionnaire and analyses of the treatment plans with monitor unit calculations are presented.

RESULTS

Of the 243 clinics responding, 54% use multileaf collimators routinely, 94% use asymmetric jaws routinely, and 13% use dynamic wedges. Nearly all institutions calibrate their linear accelerators following American Association of Physicists in Medicine protocols, currently 16% with TG-51 and 81% with TG-21 protocol. Treatment planning systems are relied on very heavily for all calculations, including monitor units. Techniques and results of each of the treatment planning exercises are presented.

CONCLUSIONS

Together, these data provide a unique compilation of current (2001) radiation therapy practices in institutions treating pediatric patients. Overall, the COG facilities have the equipment and the personnel to perform high-quality radiation therapy. With ongoing quality assurance review, radiation therapy compliance with COG protocols should be high.

The importance of quality assurance in surgical oncology

AIMS

The aims were to review the existing methods of quality assurance in surgical oncology and to determine a relationship between surgery-related factors and the variety in outcomes in the treatment of solid cancers.

METHODS

The literature was reviewed by searching Medline and Cancerlit databases.

RESULTS

Wide variations were found in virtually all tumour types. Clear evidence was found that an improvement in the quality of the surgical procedure could have major implications for the prognosis and quality of life of cancer patients.

CONCLUSIONS

These findings emphasize the need for strict quality control procedures in surgical oncology and might imply a considerable change in cancer treatment strategies, because the routine use of adjuvant therapies could be questioned.

Quality assurance of the EORTC trial 22911. A phase III study of post-operative external radiotherapy in pathological stage T3N0 prostatic carcinoma: the dummy run

INTRODUCTION

A dry run of a clinical trial (EORTC 22911) is presented in which 12 centres have participated. These are the centres which have contributed the largest number of patients to the trial.

MATERIAL AND METHODS

Each participating centre received data from a suitable patient. Investigators were asked to plan and 'treat' the patient according to the protocol guidelines and return the data for evaluation of compliance.

RESULTS

The results show that compliance to the protocol guidelines was generally good. There were a few minor deviations in the dose and fractionation schedule, in the volume reduction for the booster dose and in the dose prescription point. None of these deviations will affect the outcome of the study. The most important observation is the large inter-centre variation in target volumes.

CONCLUSIONS

The results of this study underlines the need for a strict definition of the target volume and the adoption of the ICRU 50 recommendations in future protocols.

Dosimetric intercomparison for two Australasian clinical trials using an anthropomorphic phantom

INTRODUCTION

Many different factors can affect the accurate delivery of dose to the clinical target volume in radiotherapy. This is particularly important in the context of multicenter clinical trials where different equipment and techniques may be used for supposedly identical treatments. A dosimetric intercomparison employing an anthropomorphic phantom (level III dosimetric intercomparison) can be used to check many of the factors that could affect treatment by mimicking the radiotherapy pathway of a patient as closely as possible.

METHODS AND MATERIALS

An anthropomorphic phantom (ART) was taken to 18 radiotherapy centers in Australia and New Zealand and treated for two different treatment scenarios based on current clinical trials of the Trans-Tasman Radiation Oncology Group (TROG): a two-field treatment of a carcinoma of the tonsil (TROG 91.01), and a four-field prostate treatment (TROG 96.01). The dose distribution was assessed in two consecutive treatments using thermoluminescence dosimeters (TLDs) placed throughout the target volume and in "critical" structures such as the lens of the eye or the rectum. The study also included a check of absolute dose calibration in a slab phantom (level I dosimetric intercomparison). The influence of a variety of treatment parameters on the dose homogeneity in the target and the measured dose in the target and the critical organs was evaluated.

RESULTS

The dose measurements confirmed that in all participating centers the correct dose was delivered to the ICRU reference point (tonsil: 99.8 +/- 2.3%; prostate: 100.9 +/- 1.9% [1 SD]). Also the absolute dose calibration and the mean dose in the target volume were within the specified action levels of plus minus 5% for all participating centers. No influence of shielding, beam modifiers, beam weighting, treatment planning approach (CT, 2D, 3D), and type of equipment used on the dose in the target and its homogeneity could be demonstrated. However, treatment technique and energy used influenced the dose to the critical organs. It was shown that the interpretation of results could be improved by including two complementary treatment scenarios and a level I intercomparison with the level III dosimetric intercomparison.

CONCLUSION

The study demonstrated the feasibility of a level III dosimetric intercomparison service at a cost of approximately $1000(US) per center in Australasia. It confirmed that the dose delivered by all participating centers was as intended in the two treatment scenarios chosen. While this provides reassurance to the oncology community and the general public, the service must be extended to all centers and other potentially more complex treatment scenarios. The present study has built the foundation for this by establishing a baseline and action levels and suggesting improvements in phantom design which will be included in future TROG quality assurance exercises.

Up-front centralized data review and individualized treatment proposals in a multicenter pediatric Hodgkin's disease trial with 71 participating hospitals: the experience of the German-Austrian pediatric multicenter trial DAL-HD-90

BACKGROUND AND PURPOSE

A systematic procedure for up-front centralized data review and the set-up of individualized treatment proposals was integrated prospectively into the German-Austrian multicenter trial DAL-HD-90 for pediatric Hodgkin's disease (HD) in order to introduce local radiotherapy according to the individual patient's spread of disease within a combined-modality treatment. This paper investigates the feasibility of such a procedure and its impact on the final definition of the extent and stage of disease as well as on the choice of treatment.

PATIENTS AND METHODS

Between October 1990 and July 1995, 578 children and adolescents <18 years (259 girls, 319 boys, median age 12.9 years) with HD were enrolled into the HD-90 trial. After clinical and pathological staging (66.4/33.6%), patients were allocated to treatment groups (TG) 1 'early stage', TG2 'intermediate stage', or TG3 'advanced stage'. All groups underwent two cycles of OPPA (vincristine, prednisone, procarbazine, doxorubicin) (girls) or OEPA (E, etoposide) (boys) for induction chemotherapy. TG2 and TG3 continued on as two or four cycles, respectively, of COPP (C, cyclophosphamide). Low-dose local radiotherapy was given to the initially involved sites, with radiation doses of 25 Gy in TG1/TG2, and 20 Gy in TG3. All documentation forms, radiographs, and chest and abdominal computed tomography (CT) scans were centrally reviewed, addressing in particular the individual patient's extent and stage of disease. This review and the set-up of individualized treatment proposals were in the hands of the study coordinator, one additional pediatrician and two radiation oncologists and radiologists at the study center. During a time slot of at least 8 weeks (two cycles of standard chemotherapy in all three TGs) the individualized treatment proposals were to be sent to the participating hospital.

RESULTS

Complete sets of documentation from 564/578 patients (97.6%) were submitted sufficiently early to the study center. A total of 285 out of 574 chest radiographs, 468 out of 553 chest CT scans and 421 out of 548 abdominal CT scans were available from 71 hospitals. A total of 564 individualized treatment proposals were worked out by the review group and sent to the hospitals before radiotherapy began. Re-analysis of images and documentation forms, including laboratory and clinical data, resulted in a revision of stage in 115/571 patients (20.1%) and of TG in 76/571 patients (13.3%). A total of 67/76 patients were shifted into a higher TG, 60 patients on account of additionally detected extralymphatic involvement, five patients because of additionally detected lymph node involvement and two patients due to clinical data which had to be classified as B-symptoms. A total of 9/76 patients were shifted into a lower TG; in three patients extranodal disease and in six patents local lymph node involvement could not be confirmed.

CONCLUSIONS

The up-front centralized review of patient data and consecutive set-up and delivery of individualized treatment proposals for almost every patient are feasible within a large multicenter trial. Sufficient time and manpower at the study center are needed for the review process and the set-up of individualized treatment proposals. Such a procedure has a significant impact on the homogeneity of stage definition, allocation to TG, and individualized treatment proposals.

Quality assurance in surgical oncology (QASO) within the European Organization for Research and Treatment of Cancer (EORTC): current status and future prospects

The European Organization for Research and Treatment of Cancer (EORTC) has a long history in the development of quality assurance, in particular in radio- and chemotherapy. Quality assurance in surgical oncology is considered to be more complicated, because it is a multistep procedure depending on the individual. Because of the growing importance of the quality of surgical intervention in the multi-modality treatment approach of most cancers, the EORTC recently decided to investigate the current status of quality assurance programmes, both outside and within, the EORTC. The review of EORTC involvement in this area has been conducted on the basis of interviews with subcommittee chairmen and Data Center teams of the EORTC clinical research groups. In addition, clinical trial protocols, case report forms (CRFs) and publications by the EORTC groups related to this field were considered as possible sources of information. Several methods have been used or are currently under investigation to ensure the quality of surgery within clinical trials. These include review of reported data, standardisation of surgery and pathology forms, training sessions and site visits. However, there has been no attempt to harmonise these initiatives across the different medical specialties. The EORTC will have to address this problem within its short-term scientific strategy.

Variations in diagnostic and therapeutic procedures in a multicentre, randomized clinical trial (EORTC 10853) investigating breast-conserving treatment for DCIS

AIMS

To evaluate the diagnostic and therapeutic procedures which were followed in a European Organization for Research and Treatment of Cancer (EORTC) randomized clinical trial investigating the role of radiotherapy in breast-conserving treatment (BCT) for ductal carcinoma in situ (DCIS) of the breast.

METHODS

The medical files of 824 of the 1010 randomized patients (82%) were reviewed during site visits to 30 participating institutes.

RESULTS

Large variations occurred, particularly in the surgical procedures and histopathological work-up which were performed. Important risk factors like tumour size and margin status were poorly quantified in the medical files.

CONCLUSIONS

These findings emphasize the need for establishing uniform guidelines for diagnostic and therapeutic procedures for DCIS, and for clearly defined risk factors for recurrence after BCT for DCIS. Because of its randomized nature, the main question of the trial, i.e. the effect of radiotherapy on the risk of local recurrence, will not be influenced by variation. The risk of local recurrence in itself, and hence the success of BCT for DCIS, may however be influenced by the quality of the initial procedures that were conducted.

Quality control in multicentric clinical trials. An experience of the EORTC Gynecological Cancer Cooperative Group

Data Quality is a central requirement of scientific research and external monitoring is essential in multicentric clinical trials (MCT). A quality control (QC) study was conducted in the main Institutions participating in EORTC-GCCG Protocol number 55863 - randomised phase III trial of vindesine, cisplatin, bleomycin and mitomycin-C (BEMP) versus cisplatin (P) in disseminated squamous cell carcinoma of the uterine cervix - in order to assess the impact of variations in data quality on the conclusions of the trial. The reliability of the different centres in following the protocol was investigated by a questionnaire covering drug prescription, local facilities and the procedure for preparation and administration of chemotherapy. The 'treatment protocol adherence' was evaluated by recalculation of the ideal protocol dose and its comparison with the actual delivered dosage at each cycle of chemotherapy. 'Data quality control' was assessed by comparison of data on case report forms (CRFs) with the corresponding items in the medical records. Eleven centres participating in the trial were visited by the same team of reviewers. Striking differences were noted in the chemotherapy administration procedures and between the type and quality of hospital files. Overall, there was an acceptable level of data quality and protocol compliance. Data accuracy was 81.8% (range: 65. 6-97%) of the 4424 items checked. Incorrect data were found in 7.0% (2.3-14.5%), data were missing on the form in 3.6% of cases (0-12%) and data was on the form but not in the file in 7.6% of cases (0. 7-17.5%). Causes of inaccuracy were analysed. Both problems in data management but also in a lack of clarity of the protocol and/or CRFs were to blame. Training and supervision of data managers, precision in writing protocols, standardisation of some aspects of CRFs and the use of a checklist for chemotherapy data and treatment toxicities would have avoided many of these errors. The need for QC in all collaborative groups performing MCT is emphasised. A literature review on QC in MCT dealing with chemotherapy is included.

Quality control in health care: an experiment in radiotherapy planning for breast cancer patients after mastectomy

PURPOSE

The importance of evaluating and improving quality in clinical practice is now generally acknowledged. In this study we estimated different sources of variation in radiotherapy planning for breast cancer patients after mastectomy and sought to test the applicability of a reproducibility and repeatability (R&R) study in a clinical context.

METHODS

Eleven radiation oncologists planned radiotherapy three times for three different kinds of breast cancer patients without knowing they were handling the same patient three times. Variation was divided into different components: physicians as operators, patients as parts, and repeated measurements as trials. Variation due to difference across trials (repeatability), that across the physicians (reproducibility), and that across the patients (variability) were estimated, as well as interactions between physicians and patients. Calculation was based on the sum of squares, and analysis was supported by various graphical presentations such as range charts and box plots.

RESULTS

Some parts of the planning process were characterized by higher and different kinds of variation than the others. Interphysician variation (i.e., reproducibility) was not high but there were some clearly outlying physicians. The highest variation was in repeatability (= intraphysician variation). The major part of the variation was, however, that from patient to patient: 33% of the total in Parameter 1 and 85% of the total in Parameter 2.

CONCLUSIONS

R&R studies are applicable and are needed to evaluate and improve quality in clinical practice. This kind of analysis provides opportunities to establish which kinds of patients require particularly careful attention, which points in the process are most critical for variation, which are the most difficult aspects for each physician and call for more careful description in documents, and which physicians need further training.

Towards evidence based radiation oncology: improving the design, analysis, and reporting of clinical outcome studies in radiotherapy

Although a substantial number of randomized clinical trials (RCTs) with a radiotherapy component have been conducted over time, it turns out that many of the trials have serious methodological flaws. What is even more frustrating is the circumstance that many RCTs, in radiotherapy as well as in other medical fields, are so heterogeneous in their reporting, that it is virtually impossible to judge their quality and thereby to judge the reliability of their conclusions. Recently, a new set of guidelines for reporting of RCTs has been proposed. These CONSORT (Consolidation of Standards for Reporting Trials) guidelines have now been accepted by a large number of medical journals. The present review presents the background for the CONSORT guidelines. Substantial research has been done on the methodological quality of RCTs reported in the literature and some of this will be reviewed here. Specific areas discussed include definition of endpoints, Type I and II errors, use of confidence intervals rather than P-values, randomization procedures, multiple significance tests, the intention-to-treat principle, and publication bias. Special concerns in relation to the reporting of radiotherapy RCTs are discussed as well. The conclusion is that we need to improve the quality of RCTs in terms of their design, conduct, analysis and reporting. As a step in that direction, a new set of guidelines for reports on treatment outcome in Radiotherapy and Oncology are presented. These guidelines meet the minimum criteria for reporting of RCTs as stated in the CONSORT guidelines.

External audit of photon beams by mailed film dosimetry: feasibility study

A feasibility study for mailed film dosimetry has been performed. The global reproducibility of the method is better than 2%. It is shown that the normalized sensitometric curve does not depend on photon beam quality in the range from Co-60 gamma-rays to 18 MV x-rays, although the dose per optical density decreases when the energy increases. The fading of the latent image before film processing is only 3% per month and the normalized sensitometric curve is not modified after a period of 51 days between irradiation and processing. Sets of films were mailed to three different institutes for irradiation and returned for processing and evaluation after more than two months in order to verify that mailing of irradiated and unprocessed films does not produce unwanted artefacts. Finally the feasibility of external audits with mailed film dosimetry is illustrated by comparison of beam profiles measured with films and ionization chambers in a polystyrene phantom.

Quality assurance of the EORTC Trial 22881/10882: boost versus no boost in breast conserving therapy. An overview

BACKGROUND

The initial quality assurance programme of the EORTC Radiotherapy Cooperative Group in trial 22881/10882 is described. The implications of its results for quality assurance in future trials are discussed.

METHODS

In the EORTC trial 22881/10882 patients with stage I or II breast cancer are treated with tumor excision, axillary dissection, 50 Gy whole breast irradiation and then randomized to receive a boost dose of 15 Gy or no boost following complete tumor excision or between 10 Gy or 25 Gy in case of incomplete excision. To avoid or diminish protocol deviations and to quantify inevitable variations an extensive initial quality assurance programme was conducted. The programme consisted of a dummy run procedure an individual case review procedure, in vivo dosimetry studies and phantom dosimetry studies.

RESULTS

This combination of quality assurance procedures allows a good estimation of patient to patient and inter-institutional variations, and early detection of (potential) systematic protocol deviations of 3 types: 1. Deviations due to ambiguities in the protocol prescriptions. 2. Deviations not known to the institution, such as mistakes in implementation of treatment planning algorithms resulting in a systematic overdosage or underdosage. 3. Inability of an institution to cope with (precise) protocol prescriptions for technical or logistic reasons.

DISCUSSION

The first 2 types of deviations may be corrected or avoided by direct discussions and recommendations. With respect to the third type it is up to the trial coordinator to accept participation or not, depending upon the relative importance of the particular deviation(s) for the trial end points. To be effective, such a quality assurance programme must be implemented as early as possible in the course of a clinical trial.

Quality assurance in radiotherapy. European Society for Therapeutic Radiology and Oncology Advisory Report to the Commission of the European Union for the 'Europe Against Cancer Programme'

This document is now in the process of being endorsed by all National Scientific Societies of Radiotherapy and Medical Physics of the European countries. It can therefore not be formally considered as the definitive version and is still susceptible to benefit from further alterations or improvements.

Quality assurance in radiation oncology

Quality assurance in radiation oncology attempts to prescribe consistent, safe, and optimal delivery of radiation to treat disease. It encompasses three major areas of treatment: clinical, physical, and technical. Although national approaches and guidelines of quality assurance in radiation oncology are available, they usually are not adequate to deal with the particular needs of individual institutions, nor are they adequate to ensure uniform standards of diagnosis and treatment among institutions. Therefore, it is important for individual institutions to develop and implement strict quality assurance standards, based on national guidelines as well as their own strengths and needs, to ensure that patients receive the highest quality of radiotherapy and that the successes and failures of treatment are statistically reliable. This paper addresses the importance of quality assurance in radiation oncology and examines the quality assurance program in the Department of Therapeutic Radiology-Radiation Oncology at the University of Minnesota as an example of a program tailored to the needs of an individual institution.

Quality assessment of medical decision making in radiation oncology: variability in target volume delineation for brain tumours

The enormous developments in radiation technology open new horizons for improvements in local tumour control. However, the evolution from conventional external beam radiotherapy planning to conformal therapy might be hampered by the potential risk of over-reliance on the physician's capability of estimating the tumour extent from imaging modalities. The variability between 12 volunteering physicians in the delineation of tumour and target volume on the lateral orthogonal localisation radiograph from CT was assessed for 5 brain tumours. The estimated tumour and target sizes varied, respectively with a factor of 1.3-2.6 and with a factor of 1.3-2.1. The anatomical location of the volumes showed maximum variations from 11 to 27 mm in the cranio-caudal direction and from 14 to 21 mm in the fronto-occipital direction. For the 5 test cases, the tumour area on which all radiation oncologists agreed, represented only 25-73% of the corresponding mean tumour area. Although the introduction of computed tomography in radiation treatment planning was proved to be a major step forwards for treatment planning in many tumour sites, the results of the present study on brain tumours demonstrate that the subjective interpretation of the tumour extent based on CT images might be one of the largest factors contributing to the overall uncertainty in radiation treatment planning. Moreover, this study endorses the need for uncertainty analysis of the medical decision-making process. It may be that the process of making uncertainties explicit can contribute to the improvement of our present concept of radiation treatment planning.(ABSTRACT TRUNCATED AT 250 WORDS)

Influences on inferences. Effect of errors in data on statistical evaluation

BACKGROUND

Inadvertent random and systemic errors introduced into data sets and manipulation of data are well-defined sources of discrepancies in statistical evaluation of clinical trials. In this study, the authors show the influence of errors on the widely used statistical result, P values.

METHODS

Using data from a retrospective study of patients with Hodgkin disease treated at the University of Minnesota between 1970 and 1984 and observed to 1988, we introduced various errors into the data to study the impact on results.

RESULTS

Inadvertent random and systemic errors affect statistical results. Data entry and transcription errors, vague definitions of endpoints and prognostic factors, and the omission and selection of patients are examples of frequent errors that affect statistical evaluation.

CONCLUSION

The results and inferences of many studies are sensitive to systemic errors and data manipulation. Great care must be given to the clear definitions of terms, exclusion and inclusion criteria, group assignments, treatment protocols, and the subgroups on which statistical analysis is performed. Clinicians and statisticians must work together to improve the performance and interpretation of clinical trials.

Hyperfractionation versus conventional fractionation in oropharyngeal carcinoma: final analysis of a randomized trial of the EORTC cooperative group of radiotherapy

EORTC protocol 22791 compared once daily fractionation (CF) of 70 Gy in 35-40 fractions in 7-8 weeks, to pure hyperfractionation (HF) of 80.5 Gy in 70 fractions in 7 weeks using 2 fractions of 1.15 Gy per day, in T2-T3 oropharyngeal carcinoma (excluding base of tongue), N0,N1 of less than 3 cm. From 1980 to 1987, 356 patients were entered. In the final analysis (June 1990), the local control was significantly higher (p = 0.02 log-rank) after HF compared with CF. At 5 years, 59% of patients are local disease-free in the HF arm compared to 40% in the CF arm. The superiority of HF was demonstrated in patients staged T3N0,T3N1 but not in T2. The Cox model confirmed that the treatment regimen was an independent significant prognostic factor for locoregional control (p = 0.007 log-rank). This improvement of locoregional control was responsible for a trend to an improved survival (p = 0.08 log-rank). There was no difference in late normal tissue damage between the two treatment modalities.

Assessment of dose inhomogeneity at target level by in vivo dosimetry: can the recommended 5% accuracy in the dose delivered to the target volume be fulfilled in daily practice?

The inhomogeneity of the dose delivered to the target volume due to irregular body surface and tissue densities remains in many cases unknown, since the dose distribution is calculated for most radiation treatments in only one transverse section and assuming the patient to be water equivalent. In the present study, the transmission and the target absorbed dose homogeneity is assessed for 11 head-and-neck cancer treatments by in vivo measurements with silicon diodes. Besides the dose to the specification point, the dose delivered to 2-4 off-axis points in the midline sagittal plane is estimated from entrance and exit dose measurements. Simultaneously made portal films allow to identify the anatomical structures passed by the beam before reaching the exit diode. The mean deviation from the expected transmission is -6.8% for bone, +6% for air cavities and -2.5% for soft tissue. At the midplane, the mean deviations from the expected target dose are respectively -3.5%, +2.3% and -1.9%. The deviations from the prescribed dose are larger than 5% in 12 out of the 39 target points. The accuracy requirement in target dose delivery of plus or minus 5%, as proposed by ICRU, cannot be fulfilled in 7 out of the 11 patients and is mostly due to irregular body contour and tissue densities. As only a limited number of points are considered, the inhomogeneity in the dose delivered throughout the whole irradiated volume is underestimated as is illustrated from the exit dose profiles obtained from the portal image.(ABSTRACT TRUNCATED AT 250 WORDS)

A dosimetric intercomparison of megavoltage photon beams in UK radiotherapy centres

A dosimetry intercomparison has been carried out for all 64 radiotherapy centres in the UK. Doses were measured with an ionization chamber in an epoxy resin water-substitute phantom of relatively simple geometry. Reference-point measurements were made for all MV photon beams. For 61 Co-60 beams, a mean ratio of measured-to-stated dose of 1.002 was observed with a standard deviation of 0.014, whilst for 100 MV x-ray beams, the corresponding figures were 1.003 and 0.015. 97% of beams lay within a +/- 3% deviation. One measurement was instrumental in discovering a large discrepancy. Doses were also investigated in two planned three-field distributions at one beam quality in each centre. One of these was in a homogeneous phantom, whilst the second included a lung-equivalent insert. Doses were measured at the central point and at four other points in the high dose volume. In both situations, the mean ratio of measured-to-calculated doses for all points was 1.008, with standard deviations of 0.027 and 0.035 for the uniform and non-uniform phantoms, respectively. Discrepancies over 5% were followed up. The work must be viewed in the context of other international intercomparisons and is an essential part of wider radiotherapy audit processes.

Rationale for a quality assurance programme in clinical trials of conservative management of breast carcinoma. European Organization for the Research and Treatment of Cancer

The EORTC Consensus Meeting held at Tübingen on 13-14 December, 1990 reviewed the treatment sequence in conservative management of early breast cancer from the standpoint of quality assurance. These reports considered the most relevant criteria for evaluating pathology, surgery and radiotherapy techniques, not only for selected institutions participating in prospective randomised trials but also aiming at developing quality control procedures that could be used anywhere for routine standard treatment. This paper lists the various steps justifying quality control procedures in radiotherapy of the breast and actions to be taken according to the score of observed deviations. At last, it includes a discussion of the justification of quality control and of its potential consequences on the results of trial in the EORTC trial 22881/10882 (boost treatment versus no boost in conservative management of early breast cancer) in which the accrual of 1500 patients is planned.

Quality assurance of the EORTC trial 22881/10882: "assessment of the role of the booster dose in breast conserving therapy": the Dummy Run. EORTC Radiotherapy Cooperative Group

The EORTC trial 22881/10882 is a randomised trial with the aim to assess the role of the boost dose in breast conserving therapy in stage I and II breast cancer. In order to detect potential protocol deviations concerning irradiation technique and in the dose specification procedure of participating institutions before actual patient accrual, a Dummy Run was performed. Three transverse sections of a patient were sent to 16 participating institutions with a request to make a three-plane treatment plan according to the protocol prescriptions. A treatment chart and beam data were also requested for recalculation of the dose. Additional information was asked in a questionnaire. On evaluation, the techniques differed considerably with respect to photon beam energy, varying between 60Co gamma-rays and 8 MV X-rays, and the use of wedge filters. Two institutions did not apply wedges, whereas wedge angles in the other institutions varied between 6 degrees and 45 degrees. Twelve institutions used collimator rotation and/or a table wedge to diminish the amount of irradiated lung volume. The dose was specified in a point according to the protocol prescription in 11 institutions and to the 90, 95 or 100% isodose curve in four. Twelve institutions applied lung density corrections during treatment planning, while nine reported problems with their planning system in off-axis dose distribution calculation and/or the simulation of collimator rotation. Recalculation of the dose at the isocentre showed agreement within 2% compared with the stated dose. The dose reported in the tumour excision area varied between 93 and 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

The need for immediate monitoring of treatment parameters and uniform assessment of patient data in clinical trials. A quality control study of the EORTC Radiotherapy and Lung Cancer Cooperative Groups

A quality control study was performed during the EORTC phase III study 08844: radiotherapy combined with low dose cisplatin (cDDP) in inoperable non-metastatic non-small cell lung cancer. Radiation alone (55 Gy, split course) was compared to radiotherapy with 30 mg/m2 cisplatin once a week and to radiotherapy with 6 mg/m2 cisplatin daily. The purpose of the control study was to check to which degree protocol guidelines were followed and to measure the extent of differences in assessment of tumour response, recurrence and toxicities between the individual institutes. A review team, consisting of a data manager, a diagnostic radiologist, a chest physician and two radiotherapists reviewed entry criteria, treatment data, tumour responses, recurrences and late toxicity of 177 patients (a total of 300 patients was required for the trial). Only departments which had entered more than 5% of this number of patients were visited. There was a 15% difference in T staging of the patients and a 17% discrepancy in N stage scoring between the review team and the local investigators. Radiotherapy field sizes were insufficient in 15% of the eligible patients during a period of the radiotherapy; in another 17% patients the tumour free margin was less than 1 cm. Radiation doses were incorrectly given to 7% of the patients. The given doses of cisplatin deviated in 10% of the patients treated with combined modalities. The interpretation of chest X-rays and computed tomography (CT) showed important differences in tumour response, tumour recurrence and late toxicity. From these data it is concluded that immediate checks can detect errors in treatments as planned at the local level and will make corrections possible at an early stage in multicentre studies. The quality of trial results will thus be improved. Uniform assessment of treatment outcome, tumour progression and forms of toxicity will lead to more sound trial conclusions.

EORTC joint ventures in quality control: treatment-related variables and data acquisition in chemotherapy trials

In multicentre studies, non-compliance with the protocol may limit the chances of reaching a correct conclusion. A procedure to examine the administration of chemotherapy in multicentre EORTC protocols has been developed. General aspects are covered in a mailed questionnaire on the prescription of drugs with rounding up or down of dosages, local facilities for preparation and the procedure for preparation and administration. More detail is collected during a quality control site visit. Ten centres have been visited and there was significant variation between centres in the organisation of chemotherapy administration. However, more striking differences were noted between the type and quality of hospital files. The lack of systematic recording of sequence, timing and doses of chemotherapy and, in particular, treatment related toxicity, is a major difficulty limiting the effectiveness of quality control. These shortcomings emphasise the need for standardisation of some aspects of case records and a suggested check-list has been drafted.

Impact of initial quality control review on study outcome in lung and head/neck cancer studies--review of the Radiation Therapy Oncology Group experience

The Radiation Therapy Oncology Group (RTOG) initiated cooperative clinical trials in 1971. In 1978, RTOG developed a formalized program of Quality Control (QC) divided into initial and final phases. The initial review process consisted of two steps. The first phase of review is an evaluation performed by a radiation oncologist to verify treatment plan and field borders. The second portion of the initial review process originally consisted of dosimetry calculation verification based on machine data provided by the regional Radiological Physics Center and treatment planning data provided by the accessioning institution. Between 1978 and December 31, 1987, a total of 11,343 cases in 96 RTOG protocols, excluding particle studies, underwent initial review. Of this number, 2227 patients were entered in lung cancer studies and 1341 patients were entered in head/neck cancer studies. Initial review was carried out in 2089 (93.8%) of the lung cancer cases. Missing or delayed data accounted for 138 (6.2%) cases not reviewed initially. In head/neck cancer trials, 1251 (93.2%) received initial review and 90 (6.8%) did not. Our findings suggest that there are sharply defined but long lasting learning experiences involved in clinical trial participation. Consideration may be given to modifying the initial review process to use random sampling of cases accessioned by experienced investigators in ongoing clinical trials and to continuing the total case evaluation on all new studies and cases entered by inexperienced investigators or investigators/institutions with unsatisfactory performance. Recommendations regarding initial review of other sites will await evaluation of the impact of initial review on those sites.

Quality control of validity of data collected in clinical trials. EORTC Study Group on Data Management (SGDM)

In a study initiated by the EORTC Study Group on Data Management, 15 site visits to main participating centers in ongoing cancer clinical trials have been carried out over a 1 year period. The aim was to evaluate the quality level of EORTC clinical trial data, to find out the order of magnitude of possible problems encountered and to test a technique to objectively assess the quality of data. The process of data collection and the quality of data transfer from hospital charts to EORTC case report forms (CRF) were checked. The data quality was scored and the causes of incorrectness were evaluated. Percentages of correct data ranged from 78% up to 98%; 11/15 centers had greater than 90% correct data. The median rate of error encountered in key data was 2.8% (range 0.5-7%). The main source of error was incorrect transfer of the information recorded in the patient chart to the CRF. Equally good overall results have been observed in the centers where data managers fill in the forms (DM) and those centers without an administrative trial structure (PH). The mean percentage of correct data for both types of centers is 91.4%. The wider range in percentage for incorrect data (DM mean value 3.0%, range 0.5-7%; PH mean value 2.3%, range 1.4-3.1) suggests the important impact of the knowledge and experience of the people involved in data management. The data quality evaluation was hampered by the impossibility of checking part of the data present on the CRF, 0.4-14.5%. Besides knowledge and experience, the main aspects influencing good data quality appeared to be the efficacy of the internal organization and good local data monitoring. The importance of the design of CRFs was also highlighted. As this study was run for on-going protocols, the site visiting team had the opportunity to point out and report to the trial coordinator all shortcomings and controversial points that could thus be corrected during the course of the trial.

Dose intercomparison at the radiotherapy centers in The Netherlands. 2. Accuracy of locally applied computer planning systems for external photon beams

As part of a quality assurance program in The Netherlands, the performance of computer planning systems was tested. Relative dose values, determined with an ionization chamber, were compared with dose values obtained from locally applied computer planning systems. Several clinically relevant situations were investigated: perpendicular incident beams, wedged beams, oblique incident beams, variable source-surface distances (SSD) and off-axis planes. The mean value of the ratios of calculated to measured dose values is 0.994, with an uncertainty of 2.4% (1 S.D.) and a maximum deviation of 9%, for all combinations of energies, planning systems and geometries investigated. The uncertainty for each situation separately was less than 2% (1 S.D.), except for the wedged beams and off-axis plane, which showed uncertainties of 2.6% (1 S.D.). Part of the additional uncertainty for the wedged beams originates from the value chosen for the wedge factor. Systematic deviations between calculated and measured dose values were investigated for three commercially available planning systems, separately. The mean deviation was smaller than 1% (1 S.D.), for most situations. Only for the wedged beams, larger deviations, up to a mean deviation of 2.6%, were observed.