Quality assurance in radiotherapy: the importance of medical physics staffing levels. Recommendations from an ESTRO/EFOMP joint task group

Quality indicators for hyperthermia treatment: Italian survey analysis

AIM

Nowadays, no Quality Indicators (QI) have been proposed for Hyperthermia treatments. Starting from radiotherapy experience, the aim of this work is to adapt radiotherapy indicators to Hyperthermia and to propose a new specific set of QI in Hyperthermia field.

MATERIAL AND METHODS

At first, radiotherapy quality indicators published in literature have been adapted to hyperthermia setting. Moreover, new specific indicators for the treatment of hyperthermia have been defined. To obtain the standard reference values of quality indicators, a questionnaire was sent to 7 Italian hyperthermia Institutes with a list of questions on physical and clinical hyperthermia treatment in order to highlight the different therapeutic approaches.

RESULTS

Three structure, five process and two outcome QI were selected. It has been possible to adapt seven indicators from radiotherapy, while three indicators have been defined as new specific indicators for hyperthermia. Average values used as standard reference values have been obtained and proposed.

CONCLUSION

The survey performed on 7 Italian centres allowed to derive the standard reference value for each indicator. The proposed indicators are available to be investigated and applied by a larger number of Institutes in which hyperthermia treatment is performed in order to monitor the operational procedures and to confirm or modify the reference standard value derived for each indicator.

Are Quality Indicators for Radiotherapy Useful in the Evaluation of Service Efficacy in a New Based Radiotherapy Institution?

Aims and background

A number of documents assess the need for quality assurance in radiotherapy, which must be constantly monitored and possibly improved. In this regard, a system that confirms the quality of a department has been suggested and quality indicators have been used to improve the quality of the service. The National Health Service ( Istituto Superiore di Sanità) approved a National Research Project to increase the quality of radiotherapy. The aim of the present study was to analyze the practical feasibility and efficacy of the quality indicators elaborated by the National Health Service study group in a radiotherapy unit.

Patients and methods

The voluntary accredited program was carried out by the Radiotherapy Department of IRCC in Candiolo from June to August 2002. We analyzed 8 of the 13 indicators according to the National Health Service Project. For this purpose, 133 consecutive patients treated in our Unit were analyzed, and the results are reported according to the appropriate indicator (number of staff related to patients treated, waiting list, case history accuracy, multidisciplinary approach, number of treatment plans performed by CT, number of fields per fraction, number of portal imaging performed per overall treatment, and patient satisfaction).

Results

The number of professional staff related to the number of patients treated was easy to calculate and it could be the basis for further evaluation. The overall waiting time was 55.4 days, and it changed for different radiotherapy goals. We obtained 80% conformity in case-history accuracy. The number of multidisciplinary consultations performed ranged between 50% and 100%. The number of CT plans was about 1.6 ± 0.9 plans per patient. The mean number of fields performed per day and per patient is 3.5 ± 1.7 and was in agreement with the fact that more than 50% of treatments in our Center were performed with conformal radiotherapy. An average of 16.7 ±10.0 portal imaging per case was performed. The percentage of patient satisfaction with the staff obtained a very high compliance.

Conclusions

The self evaluation promoted by the National Health Service Project allows the monitoring of the activities of the service in order to asses critical factors and it can be the starting point to improve the quality of the service and to compare national and international quality assurance results.

The Essentials of Locoregional Control in the Treatment of Gastric Cancer

Gastric cancer is the fourth most frequent cancer in the world. For curative treatment and local control of gastric cancer, surgery is essential. The extent of the lymph node dissection is still under debate. Only one available trial showed significantly increased overall survival, whereas in all other randomised trials no significant difference could be found.

As surgery alone often is not sufficient in the curative treatment in gastric cancer, different (neo)adjuvant treatment strategies have extensively been studied. The recently published MAGIC trial showed downstaging, downsizing and an improved overall survival for patients treated with perioperative chemotherapy, compared to surgery alone (difference 13%, p = 0.009). The INT 0116 trial on the other hand, demonstrated the benefit of postoperative chemoradiotherapy compared to surgery alone for patients with a curative resection of gastric cancer. However, the quality of resections in this trial was poor, illustrating the importance of standardisation by quality control. This could be done by the Maruyama index, which quantifies the likelihood of unresected disease.

In the Netherlands, the CRITICS trial has recently been launched, which will be a quality controlled trial comparing postoperative chemoradiotherapy and chemotherapy on survival and/or locoregional control in patients who receive neoadjuvant chemotherapy followed by a D1+ gastric resection.

Characterization of a cable-free system based on p-type MOSFET detectors for "in vivo" entrance skin dose measurements in interventional radiology

PURPOSE

During radiological interventional procedures (RIP) the skin of a patient under examination may undergo a prolonged x-ray exposure, receiving a dose as high as 5 Gy in a single session. This paper describes the use of the OneDose(TM) cable-free system based on p-type MOSFET detectors to determine the entrance skin dose (ESD) at selected points during RIP.

METHODS

At first, some dosimetric characteristics of the detector, such as reproducibility, linearity, and fading, have been investigated using a C-arc as a source of radiation. The reference setting (RS) was: 80 kV energy, 40 cm × 40 cm field of view (FOV), current-time product of 50 mAs and source to skin distance (SSD) of 50 cm. A calibrated PMX III solid state detector was used as the reference detector and Gafchromic(®) films have been used as an independent dosimetric system to test the entire procedure. A calibration factor for the RS and correction factors as functions of tube voltage and FOV size have been determined.

RESULTS

Reproducibility ranged from 4% at low doses (around 10 cGy as measured by the reference detector) to about 1% for high doses (around 2 Gy). The system response was found to be linear with respect to both dose measured with the PMX III and tube voltage. The fading test has shown that the maximum deviation from the optimal reading conditions (3 min after a single irradiation) was 9.1% corresponding to four irradiations in one hour read 3 min after the last exposure. The calibration factor in the RS has shown that the system response at the kV energy range is about four times larger than in the MV energy range. A fifth order and fourth order polynomial functions were found to provide correction factors for tube voltage and FOV size, respectively, in measurement settings different than the RS. ESDs measured with the system after applying the proper correction factors agreed within one standard deviation (SD) with the corresponding ESDs measured with the reference detector. The ESDs measured with Gafchromic(®) films were in agreement within one SD compared to the ESDs measured using the OneDose(TM) system, as well. The global uncertainty associated to the OneDose(TM) system established in our experiments, ranged from 7% to 10%, depending on the duration of the RIP due to fading. These values are much lower than the uncertainty commonly accepted for general diagnostic practices (20%) and of about the same size of the uncertainty recommended for practices with high risk of deterministic side effects (7%).

CONCLUSIONS

The OneDose(TM) system has shown a high sensitivity in the kV energy range and has been found capable of measuring the entrance skin dose in RIP.

Is the in vivo dosimetry with the OneDosePlusTM system able to detect intra-fraction motion? A retrospective analysis of in vivo data from breast and prostate patients

Background

The OneDosePlus^TM system, based on MOSFET solid-state radiation detectors and a handheld dosimetry reader, has been used to evaluate intra-fraction movements of patients with breast and prostate cancer.

Methods

An Action Threshold (AT), defined as the maximum acceptable discrepancy between measured dose and dose calculated with the Treatment Planning System (TPS) (for each field) has been determined from phantom data. To investigate the sensitivity of the system to direction of the patient movements, fixed displacements have been simulated in phantom. The AT has been used as an indicator to establish if patients move during a treatment session, after having verified the set-up with 2D and/or 3D images. Phantom tests have been performed matching different linear accelerators and two TPSs (TPS1 and TPS2).

Results

The ATs have been found to be very similar (5.0% for TPS1 and 4.5% for TPS2). From statistical data analysis, the system has been found not sensitive enough to reveal displacements smaller than 1 cm (within two standard deviations). The ATs applied to in vivo treatments showed that among the twenty five patients treated for breast cancer, only four of them moved during each measurement session. Splitting data into medial and lateral field, two patients have been found to move during all these sessions; the others, instead, moved only in the second part of the treatment. Patients with prostate cancer have behaved better than patients with breast cancer. Only two out of twenty five moved in each measurement session.

Conclusions

The method described in the paper, easily implemented in the clinical practice, combines all the advantages of in vivo procedures using the OneDosePlus^TM system with the possibility of detecting intra-fraction patient movements.

Organizational, technical, physical and clinical quality standards for radiotherapy

BACKGROUND

Indisputably, radiotherapy has become an entirely interdisciplinary specialty. This situation requires efficient planning, verification, monitoring, quality control and constant improvement of all aspects of service delivery, referring both to patients' (including diagnosis, prescription and method of treatment, its justification, realization and follow up) and organizational, technical and physics matters.

AIM

The aim of this work was to develop technical, physics and clinical quality standards for radiotherapy. This paper presents chosen standards for each of the aforementioned category.

MATERIALS AND METHODS

For the development of quality standards the comparison analysis of EU and Polish acts of law passed between 1980 and 2010 was conducted, the universal industrial ISO norm 9001:2008 referring to quality management system was reviewed. Recommendations of this norm were completed with detailed quality standards based on the author's 11 year work experience and the review of articles on quality assurance and quality control standards for radiotherapy published between 1984 and 2009 and the review of current recommendations and guidelines of American, International, European and National bodies (associations, societies, agencies such as AAPM, ESTRO, IAEA, and OECI) for quality assurance and quality management in radiotherapy.

RESULTS

As a result 352 quality standards for radiotherapy were developed and categorized into the following three groups: (1) organizational standards, (2) physics and technical standards and (3) clinical standards.

CONCLUSIONS

Proposed quality standards for radiotherapy, can be used by any institution using ionizing radiation for medical procedures. Nevertheless standards are only of value if they are implemented, reviewed, audited and improved and if there is a clear mechanism in place to monitor and address failure to meet agreed standards.

Clinical quality standards for radiotherapy

AIM OF THE STUDY

The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author.

MATERIAL AND METHODS

In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy.

RESULTS

As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 - organizational standards; 2 - physico-technical standards and 3 - clinical standards.

CONCLUSION

Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards.

A grid to facilitate physics staffing justification

Justification of clinical physics staffing levels is difficult due to the lack of direction as how to equate clinical needs with the staffing levels and competency required. When a physicist negotiates staffing requests to administration, she/he often refers to American College of Radiology staffing level suggestions, and resources such as the Abt studies. This approach is often met with questions as to how to fairly derive the time it takes to perform tasks. The result is often insufficient and/or inexperienced staff handling complex and cumbersome tasks. We undertook development of a staffing justification grid to equate the clinical needs to the quantity and quality of staffing required. The first step is using the Abt study, customized to the clinical setting, to derive time per task multiplied by the anticipated number of such tasks. Inclusion of vacation, meeting, and developmental time may be incorporated along with allocated time for education and administration. This is followed by mapping the tasks to the level of competency/experience needed. For example, in an academic setting the faculty appointment levels correlate with experience. Non‐staff personnel, such as IMRT QA technicians or clerical staff, should also be part of the equation. By using the staffing justification grid, we derived strong documentation to justify a substantial budget increase. The grid also proved useful when our clinical demands changed. Justification for physics staffing can be significantly strengthened with a properly developed data‐based time and work analysis. A staffing grid is presented, along with a development methodology that facilitated our justification. Though our grid is for a large academic facility, the methodology can be extended to a non‐academic setting, and to a smaller scale. This grid method not only equates the clinical needs with the quantity of staffing, but can also help generate the personnel budget, based on the type of staff and personnel required. The grid is easily adaptable when changes to the clinical environment change, such as an increase in IMRT or IGRT applications.

PACS number: 87.55.tm, 87.55.Qr

AAPM Task Group 103 report on peer review in clinical radiation oncology physics

This report provides guidelines for a peer review process between two clinical radiation oncology physicists. While the Task Group's work was primarily focused on ensuring timely and productive independent reviews for physicists in solo practice, these guidelines may also be appropriate for physicists in a group setting, particularly when dispersed over multiple separate clinic locations. To ensure that such reviews enable a collegial exchange of professional ideas and productive critique of the entire clinical physics program, the reviews should not be used as an employee evaluation instrument by the employer. Such use is neither intended nor supported by this Task Group. Detailed guidelines are presented on the minimum content of such reviews, as well as a recommended format for reporting the findings of a review. In consideration of the full schedules faced by most clinical physicists, the process outlined herein was designed to be completed in one working day.

Quality assurance of surgery in gastric and rectal cancer

Multimodality and quality controlled treatment result in improved treatment outcome in patients with solid tumours. Quality assurance focuses on identifying and reducing variations in treatment strategy. Treatment outcome is subsequently improved through the introduction of programs that reduce treatment variations to an acceptable level and implement standardised treatment. In chemotherapy and radiotherapy, such programmes have been introduced successfully. In surgery however, there has been little attention for quality assurance so far. Surgery is the mainstay in the treatment of patients with gastric and rectal cancer. In gastric cancer, the extent of surgery is continuously being debated. In Japan, extended lymph node dissection is favoured whereas in the West this type of surgery is not routinely performed with two large European trials concluding that there is no survival benefit from regional lymph node clearance. Post-operative chemoradiation is part of the standard treatment in the United States, although its role in combination with adequate surgery has not been established yet. These global differences in treatment policy clearly relate to the extent and quality of surgical treatment. As for gastric cancer, surgical treatment of rectal cancer patients determines patient's prognosis to a large extent. With the introduction of total mesorectal excision, local control and survival have improved substantially. Most rectal cancer patients receive adjuvant treatment, either pre- or post-operatively. The efficacy of many adjuvant treatment regimens has been investigated in combination with conventional suboptimal surgery. Traditional indications of adjuvant treatment might have to be re-examined, considering the substantial changes in surgical practise. Quality assurance programs enable the introduction of standardised and quality controlled surgery. Promising adjuvant regimens should be investigated in combination with optimal surgery.

Comparison ofp-type commercial electron diodes forin vivodosimetry

This paper compares the characteristics of three types of commercial p-type electron diodes specially designed for in vivo dosimetry (Scanditronix EDD2, Sun Nuclear QED 111200-0 and PTW T60010E diodes coupled with a Therados DPD510 dosimeter) in electron fields with energies from 4.5 to 21 MeV, and in conditions similar to those encountered in radiotherapy. In addition to the diodes, a NACP plane parallel ionization chamber and film dosimeters have been used in the experiments. The influence of beam direction on the diode responses (directional effect) was investigated. It was found to be the greatest for the lowest electron beam energy. At 12 MeV and an incidence of +/- 30 degrees, the variation was found to be less than 1% for the Scanditronix and Sun Nuclear diodes and less than 3% for the PTW one. The three diodes exhibited a variation in sensitivity with dose-per-pulse of less than 1% over the range 0.18-0.43 mGy/pulse. The temperature dependence was also studied. The response was linear for the three diodes between 22.2 and 40 degrees C and the sensitivity variations with temperature were (0.25+/-0.01)%/degree C, (0.28+/-0.01)%/degree C, and (0.02 +/-0.01)%/degree C for Scanditronix, Sun Nuclear, and PTW diodes, respectively. Finally the perturbation to the irradiation field induced by the presence of diodes placed at the surface of a homogeneous phantom was investigated and found to be significant, both at the surface and at the depth of maximum dose (several tens of percent) for all three diode types. There is an increase of dose right underneath the diode (close to the surface) and a dose shadow at the depth of maximum. The study shows that electron diodes can be used for in vivo dosimetry provided their characteristics are carefully established before use and taken into consideration at the time of interpretation of the results.

Quality assurance study for dosimetry of radiation therapy equipment in Saudi Arabia

BACKGROUND

International standards address the accuracy of dose delivery for radiation therapy machines as well as quality assurance and staffing levels for radiation therapy centers. We performed absolute calibrations of gamma, x-ray and electron radiotherapy beams in all radiation therapy centers in Saudi Arabia. We also assessed quality assurance and staffing levels.

MATERIALS AND METHODS

Dosimetric measurements were made with a portable dosimetry system, which consisted of a calibrated Farmer ionization chamber and an electrometer, small water phantom, barometer, and thermometer.

RESULTS

Differences between the measured and the expected output (cGy/MU or cGy/min) were found to be in the range of -11% + 5%. About 17% of the radiotherapy beams were not within the acceptable tolerance level (+/-3%). Quality assurance in some radiation therapy centers was poor and staffing levels were inadequate.

CONCLUSIONS AND RECOMMENDATIONS

We found poor compliance with internationally accepted tolerance levels for dose calibration of radiotherapy beams at radiation therapy centers in Saudi Arabia. Analysis of medical physics staffing revealed severe discrepancies from those recommended by international guidelines. We recommend that radiation therapy centers be adequately staffed with qualified medical physics personnel and that periodic audit programs be required by a governmental body.

Quality control in radiotherapy of brain tumors

(Conclusion) Radiotherapy techniques for brain tumors are complex and require precision in planning and giving radiotherapy programs. Continual application of quality control should enable achieving better treatment results with minimizing risk for late treatment-related complications. Introduction of uniform and precise parameters for the therapy planning, dose determining and patient's control, makes possible for optimal follow-up and comparison of treatment results between different therapeutic centers.

Consistency in quality control programmes for electron accelerators in radiotherapy centres

BACKGROUND AND PURPOSE

To gain insight into the current practice of quality control (QC) of medical electron accelerators and to reduce possible variations in test frequencies and test procedures.

MATERIALS AND METHODS

An extensive questionnaire on QC procedures of medical electron accelerators was distributed and completed by all (21) radiotherapy institutions in The Netherlands. The questions were related to safety systems, mechanical parameters, beam profiles, beam energy, absolute dosimetry, wedge filters, the dose monitor system and radiation leakage. The data of the questionnaire were compared with recommendations given in national and international reports on QC of electron accelerators.

RESULTS

Large variations in time spent on QC exist, especially for accelerators having dual energy photon beams and several electron beam energies. This diversity is mainly due to differences in philosophy with regard to QC and the differences in resources and machine time available. Furthermore, large variations in test frequencies and test methodologies were observed. The staffing level involved in the QC measurements was evaluated and compared with recent recommendations provided by EFOMP-ESTRO.

CONCLUSIONS

From these recommendations and the results of the questionnaire, a set of minimum guidelines for a QC programme could be formulated and implemented in all radiotherapy institutions in The Netherlands.

Quality assurance of physical parameters in radiation oncology at the University Hospital of Basel--a retrospect

BACKGROUND AND PURPOSE

The necessity for and the benefit of a quality assurance program in radiation oncology are not questioned. Nevertheless, a retrospective analysis of the accumulated results of several years of quality assurance offers the possibility for further optimization.

MATERIALS AND METHODS

The results of the physical quality control in radiation treatment planning and on radiation treatment units in the Institute for Radiation Oncology at the University Hospital of Basel for the years 1985, 1991 and 1994 are analyzed and compared mutually. The frequencies of the deviations from the nominal values for the different tests are stated.

RESULTS

The relevance of the deviations for the different parameters is rated and the manifested influence of the type and age of the equipment on the results of the quality assurance is discussed.

CONCLUSIONS

A condition for the maximum benefit gained from the quality assurance is the oncologist's understanding of the necessity for regular checks and the urgency for eliminating the established deficiencies. In that way the accuracy for the treatment planning, simulation and set-up process and for the realization of the radiation treatment can be increased and the methods can be improved.