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Since 2020, Meditest has been the exclusive distributor of IBA Dosimetry in France. World-class technological excellence combined with local support.
In radiotherapy, precision is not optional: it directly determines the effectiveness of the treatment and the patient's safety. An error of a few percent or a few millimeters can compromise the cure or cause serious adverse effects.
Faced with the increase in cancer cases and the growing sophistication of treatment techniques, quality control is becoming an essential pillar of modern radiotherapy.
In France, a strict regulatory framework governs these practices to ensure that each patient receives the best possible treatment, in complete safety.
Radiotherapy is based on a principle that is as simple as it is crucial: delivering the prescribed dose of ionizing radiation exactly where it needs to act, with maximum precision. This requirement is not only technical, it is vital for the patient .
Too low a dose compromises the effectiveness of the treatment: tumor cells can survive, leading to a risk of recurrence. Too high a dose, or one delivered incorrectly, exposes surrounding healthy tissues to irreversible damage, causing serious side effects that can permanently impair the patient's quality of life.
The acceptable margin of error is minuscule. In modern radiotherapy, we are talking about accuracies on the order of a few percent in dose and a few millimeters in positioning. Beyond these tolerances, the consequences can be dramatic. Each step of the treatment process—from the initial prescription to the daily delivery of the beam—must therefore be analyzed, verified, and monitored.
Quality control is not a regulatory luxury: it is the guarantee that the radiotherapist's prescription will be executed accurately, session after session, for each patient.
The current context further reinforces the importance of quality control. According to the International Agency for Research on Cancer (IARC/WHO), more than 22 million new cases of cancer were diagnosed worldwide in 2022. This continued growth puts significant pressure on radiotherapy facilities: more patients to treat, increasingly complex treatment protocols, and constantly evolving technologies.
Radiotherapy techniques have undergone remarkable sophistication in recent years:
These advances offer considerable therapeutic benefits, but they also impose even stricter quality control requirements. The more sophisticated the technique, the more significant the consequences of even the slightest deviation.
In this context of increasing complexity and high workload, quality control becomes the indispensable safety net to ensure that each treatment delivered corresponds exactly to what has been prescribed and planned.
France has progressively established one of the world's most stringent regulatory frameworks for quality control in radiotherapy. This system has been significantly strengthened since 2008, particularly following serious accidents in several French centers (Épinal, Toulouse), which highlighted the need for absolute vigilance at every stage of the treatment process.
The current framework is based on several reference texts:
These texts structure a quality assurance system encompassing the entire treatment chain , from the justification of the action to the delivery of the result, including the optimization of doses delivered to patients.
The French regulatory system is based on three distinct and complementary levels of control , thus creating several lines of defense to guarantee patient safety.
Internal quality control is carried out by the facility operator or, under their responsibility, by an external service provider. It includes several types of controls:
The initial inspection : carried out when new equipment is commissioned or after a major modification. It verifies that the installation conforms to the technical specifications and meets the acceptability criteria defined by the regulations.
The annual reference control : carried out under standardized conditions (in water, in the plane of the isocenter, at the reference depth), it allows the determination of the reference values of the controlled parameters which will serve as the basis for the consistency controls.
Consistency checks : carried out periodically (daily, weekly or monthly depending on the parameters), they aim to verify that the performance of the installation is maintained over time and remains in accordance with the established reference values.
Post-maintenance checks : any maintenance action likely to affect the performance of the installation (replacement of a part, software modification, recalibration) requires a new check to ensure that the equipment retains its initial characteristics.
All these checks are recorded in a quality control register which ensures complete traceability and will serve as a reference during audits and inspections.
The internal quality control audit must be carried out once a year by an inspection body accredited by the French Accreditation Committee (COFRAC) or any other body signatory to the European multilateral agreement.
This audit aims to verify that the operator is fully complying with all quality control obligations:
The external audit thus constitutes an independent validation of the establishment's internal quality control program.
External quality control is carried out every three years by a laboratory accredited by the ANSM. Unlike an audit, which verifies that controls are properly carried out, external control performs independent dosimetric measurements to verify that the dose actually delivered by the installation corresponds to the prescribed dose.
These dosimetric tests constitute an absolute verification, using equipment and methodologies independent of those used daily by the facility. They allow for the detection of any systematic deviations that might have escaped internal controls.
This triple verification — internal, audit, external — guarantees a maximum level of security and early detection of any anomaly.
Beyond the quality controls themselves, the Nuclear Safety Authority (ASN) conducts regular inspections in radiotherapy centers to verify the effective implementation of the entire regulatory system.
These inspections, which generally take place once a year , cover both:
Following each inspection, the ASN sends a follow-up letter to the management of the facility, the head of the radiotherapy department, the head of medical physics, and the quality manager. This letter lists the points of compliance, the discrepancies observed, and the expected corrective actions, with a deadline for achieving compliance if necessary.
This inspection system represents the ultimate level of verification and ensures that regulatory requirements are not merely a dead letter, but are effectively implemented on the ground to protect patients.
Since 2020, Meditest has been the exclusive distributor of IBA Dosimetry in France , a world leader in quality assurance solutions for radiotherapy and proton therapy. This partnership allows French healthcare facilities to access the most advanced technologies, recognized and used by the largest international radiotherapy centers.
The IBA Dosimetry range covers all quality control needs in radiotherapy:
Ionization chambers : reference instruments for absolute dose measurement with maximum accuracy. Available in various configurations (cylindrical, flat, miniature chambers) to suit all beam types and measurement situations.
Electrometers : conversion of the electrical signal generated by the ionization chamber into a dose value, with accuracy and stability that meet the strictest metrological requirements.
Phantoms : devices that simulate the physical properties of human tissues (electron density, attenuation) to validate dose calculations under representative conditions. From motorized water phantoms for reference measurements to anthropomorphic phantoms reproducing human anatomy, IBA offers solutions for all validation protocols.
myQA Platform : the digital backbone of IBA quality assurance solutions. This cloud platform centralizes all quality control data, enables comparative analysis of results over time, facilitates automatic detection of deviations, and guarantees complete traceability in compliance with regulatory requirements. For hospital groups or networks of centers, myQA also offers multi-site management that simplifies overall monitoring of the equipment fleet.
IBA Dosimetry solutions fully meet the requirements defined by the ANSM in its decision of February 28, 2023 for the quality control of external beam radiotherapy and radiosurgery facilities.
Meditest supports institutions in implementing these solutions :
Gafchromic radiochromic films, manufactured by Ashland and distributed by Meditest , are an indispensable complementary tool for quality control of complex dose distributions.
Unlike traditional radiographic films, Gafchromic films require no chemical development and are relatively insensitive to daylight, allowing for easy handling under normal medical physics department conditions. When exposed to ionizing radiation, they exhibit a blue coloration whose intensity is directly proportional to the dose received.
This ease of use is accompanied by remarkable technical performance:
Gafchromic films are particularly valuable for several quality control applications where high-resolution two-dimensional dosimetry is essential:
Validation of intensity-modulated radiotherapy (IMRT) plans : the complexity of dose distributions in IMRT necessitates high-resolution two-dimensional verification. Videos allow for a complete mapping of the delivered dose and its comparison to the predictive calculation using gamma analysis (2%/2 mm criteria).
Quality control in stereotaxic radiotherapy : the extreme dose gradients and very small fields characteristic of stereotaxy are perfectly suited to the high spatial resolution of Gafchromic films.
Verification of dose distributions in complex geometries : insertion of films into anthropomorphic phantoms to obtain dose distributions in transverse planes representative of real anatomy, taking into account heterogeneities (lungs, bones, air cavities).
Specific quality controls : verification of the dynamic positioning of multileaf collimators, validation of field junctions, control of specific techniques (total body irradiation, arc therapy).
Gafchromic films can be analyzed with a standard flatbed scanner, significantly reducing the necessary hardware investment. Dedicated analysis software allows for quantitative film processing with dosimetric calibration, correction of scanner inconsistencies, and generation of traceable quality control reports.
This complete traceability — archived digitized film, documented calibration, reproducible analysis — meets the documentation requirements of the quality assurance system and facilitates the creation of the evidence file during ASN audits or inspections.
Meditest assists institutions in implementing film dosimetry solutions with advice on choosing films suited to specific applications, training in use and analysis, and technical support for optimizing measurement protocols.
Beyond strict compliance with regulatory requirements, the effectiveness of a quality control program relies on the adoption of sound organizational and methodological practices. These practices, derived from the experience of the French radiotherapy community and professional recommendations, form the foundation of a robust and sustainable quality approach.
Documentation forms the foundation of the quality assurance system. Each control must be described precisely and reproducibly in written protocols that detail:
All control results must be recorded in a quality control register , whether paper or digital. This register must be complete, legible, and easily accessible to allow for analysis over time and to facilitate external audits or ASN inspections.
IBA Dosimetry's myQA platform, for example, automatically centralizes all quality control data, generates alerts in case of deviation and keeps a complete history guaranteeing optimal traceability.
This rigorous documentation is not an administrative constraint : it allows us to detect gradual deviations, identify trends and objectively demonstrate that the performance of the equipment is maintained over time.
In radiotherapy, the principle of independent double-checking is an essential line of defense against human or technical errors. This practice applies at several levels:
Dose calculation : The number of monitor units (which determines the treatment time and therefore the delivered dose) must be calculated on two different planning systems or using two independent calculation methods. This double check allows for the detection of potential errors in parameter input, machine configuration, or the calculation algorithm.
Validation of control results : Quality control results must be validated by two parties: typically a member of the medical physics team and a radiographer. This cross-validation ensures that no anomalies are missed and that the acceptability criteria are correctly applied.
Verification of complex treatment plans : For sophisticated techniques (IMRT, stereotaxic), an independent verification of the treatment plan — including the delineation of target volumes and organs at risk, the planned dose distribution and delivery parameters — must be carried out before the first treatment session.
This culture of cross-checking does not reflect a distrust of individual skills, but recognizes that in a complex process involving multiple steps and stakeholders, redundancy of controls is the best guarantee of security .
Radiotherapy techniques are evolving rapidly: new dose calculation algorithms, new on-board imaging modalities, and new artificial intelligence solutions for autosegmentation. This constant evolution necessitates ongoing training for all stakeholders involved in quality control.
Mandatory radiation protection training : French regulations require radiation protection training in the workplace, to be renewed at least every three years. This mandatory training ensures that all professionals master the fundamental principles of radiation protection and remain informed of regulatory changes.
Technical training on new equipment : When acquiring a new accelerator, planning system, or quality control tool, thorough training for the teams is essential. This training should not be limited to simply learning how to use the tool, but should cover the underlying physical principles, the limitations of the technology, and specific quality control protocols.
Participation in congresses and professional working groups : learned societies (French Society of Medical Physics – SFPM, French Society of Oncological Radiotherapy – SFRO) regularly organize congresses, thematic days and working groups which allow professionals to stay at the forefront of knowledge and share their experiences.
Meditest contributes to this training approach by offering user training on IBA Dosimetry equipment and Gafchromic films, as well as by actively participating in events of the French radiotherapy community.
The Feedback Committee (CREX) , now standard practice in French radiotherapy centers, is a key tool for continuous quality and safety improvement. This multidisciplinary committee (radiation therapists, medical physicists, radiographers, healthcare managers, quality manager) meets regularly to analyze incidents and adverse events that have occurred in the department.
Fundamental principle : a culture of reporting without penalty. Every professional should be able to report an incident, an anomaly, or even a near miss without fear of reprimand. The goal is not to find someone to blame, but to understand the root causes of the event and identify the corrective and preventive actions to be implemented.
Root cause analysis : CREX does not simply note the incident, it looks for contributing factors (work organization, equipment failure, human factor, communication problem) and proposes barriers to prevent it from happening again.
Documentation and traceability : each analyzed event is documented, the actions taken are monitored over time, and their effectiveness is evaluated. This structured approach to feedback enables progressive and continuous improvement of the quality system.
ASN decision no. 2021-DC-0708 has formalized this obligation to provide feedback by requiring radiotherapy centers to implement a process for collecting and analyzing significant events.
Quality control protocols must be adapted to the specific characteristics of the techniques implemented at the center. Standard controls, defined for conventional conformal radiotherapy, may be insufficient for modern techniques that present specific challenges.
Intensity-modulated radiotherapy (IMRT) : the complexity of dose distributions necessitates additional controls. Beyond overall dosimetric verification, it is recommended to verify the dynamic positioning of the multileaf collimator blades with specific tests (garden fence test, blade synchronization test), and to validate each complex treatment plan with a patient-specific dose measurement (Gafchromic films, detector arrays).
Stereotactic radiotherapy : the delivery of very high doses in a few fractions with extreme dose gradients requires submillimeter precision. Patient positioning controls (onboard imaging systems, image registration) must be particularly rigorous. The use of anthropomorphic phantoms to validate the entire treatment chain under realistic conditions is strongly recommended.
Accounting for heterogeneities : Modern dose calculation algorithms (Monte Carlo, convolution/superposition) accurately model the impact of density heterogeneities in the human body (lungs, bones, air cavities). Quality controls must incorporate heterogeneous phantoms to verify the accuracy of these calculations.
International learned societies (American Association of Physicists in Medicine – AAPM, European Society for Radiotherapy and Oncology – ESTRO) regularly publish specific recommendations for quality control of these advanced techniques. It is important to stay informed of these recommendations and to incorporate them into local protocols.
Meditest positions itself as a true long-term partner for radiotherapy establishments, going far beyond simply supplying equipment.
Consulting and auditing your needs : our experts analyze your technical configuration, your clinical practices and your regulatory constraints to offer you the quality control solutions best suited to your specific situation.
Supply of equipment compliant with ANSM requirements : As the exclusive partner of IBA Dosimetry in France since 2020, Meditest gives you access to world-leading technologies in dosimetry and quality assurance. All of the solutions offered fully comply with the requirements defined by the ANSM decision of February 28, 2023.
User training : comprehensive training on IBA Dosimetry equipment and Gafchromic films, with a particular focus on protocols adapted to ASN/ANSM requirements and on the optimal use of control results.
Responsive technical support : Our teams are available Monday to Friday from 8:30 am to 6:30 pm for any technical questions or support needs. In case of an absolute emergency with IBA equipment, the IBA 24/7 technical hotline takes over to guarantee uninterrupted service.
Regulatory monitoring : Quality control requirements are constantly evolving (new ASN decisions, ANSM recommendations, professional best practice guides). Meditest maintains continuous monitoring and informs its clients of regulatory changes that impact their practices.
Meditest maintains a permanent stock of a wide range of quality control products to ensure rapid availability:
Fast delivery throughout France : orders are processed and shipped quickly to meet the urgent needs of medical physics departments. No facility should have to postpone a regulatory inspection due to delivery delays.
Meditest actively participates in the life of the French radiotherapy community by being present at congresses and professional events (SFPM, JFR, ESTRO, SFRO) and by contributing to exchanges on good quality control practices.
This close relationship with medical physicists, technicians and radiotherapists allows Meditest to understand the real challenges on the ground and to continually adapt its offering and services to the needs expressed by professionals.
Quality control in radiotherapy is a demanding field requiring technical expertise and methodological rigor. Whether you are preparing for the commissioning of a new accelerator, wish to optimize your existing protocols, or need advice on choosing your dosimetry equipment, our teams are at your disposal .
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