A Dose of Reality: How 20 Years of Incomplete Physics and Dosimetry Reporting in Radiobiology Studies May Have Contributed to the Reproducibility Crisis

Draeger, E.; Sawant, Amit; Johnstone, Christopher; Koger, Brandon; Becker, S; Vujašković, Željko; Jackson, I.; Poirier, Yannick

doi:10.1016/j.ijrobp.2019.06.2545

Cited by 76 publications

(75 citation statements)

References 34 publications

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“…Small animal radiation delivery to the whole heart or regions of the heart and/or lung, requires careful planning of dose distribution [82,83]. However, no standards have been followed for the performance and reporting of radiation dosimetry in small animal studies, which has made it difficult to reproduce previously published results [84]. In 2011, members of the Centers for Medical Countermeasures against Radiation (CMCR) outlined specific issues related to small animal irradiator calibration and dosimetry, in order to highlight the importance of "accurate and reproducible dosimetry" in preclinical radiobiology studies [85].…”

Section: Inconsistencies In Radiation Dose Deliverymentioning

confidence: 99%

Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity

Schlaak

SenthilKumar

Boerma

et al. 2020

Cancers

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Radiation therapy (RT) is an important component of cancer therapy, with >50% of cancer patients receiving RT. As the number of cancer survivors increases, the short-and long-term side effects of cancer therapy are of growing concern. Side effects of RT for thoracic tumors, notably cardiac and pulmonary toxicities, can cause morbidity and mortality in long-term cancer survivors. An understanding of the biological pathways and mechanisms involved in normal tissue toxicity from RT will improve future cancer treatments by reducing the risk of long-term side effects. Many of these mechanistic studies are performed in animal models of radiation exposure. In this area of research, the use of small animal image-guided RT with treatment planning systems that allow more accurate dose determination has the potential to revolutionize knowledge of clinically relevant tumor and normal tissue radiobiology. However, there are still a number of challenges to overcome to optimize such radiation delivery, including dose verification and calibration, determination of doses received by adjacent normal tissues that can affect outcomes, and motion management and identifying variation in doses due to animal heterogeneity. In addition, recent studies have begun to determine how animal strain and sex affect normal tissue radiation injuries. This review article discusses the known and potential benefits and caveats of newer technologies and methods used for small animal radiation delivery, as well as how the choice of animal models, including variables such as species, strain, and age, can alter the severity of cardiac radiation toxicities and impact their clinical relevance.

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Section: Inconsistencies In Radiation Dose Deliverymentioning

confidence: 99%

Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity

Schlaak

SenthilKumar

Boerma

et al. 2020

Cancers

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“…These units are similar enough in terms of beam quality to the small animal irradiators to be applicable, but assume a large (>4 cm) field with infinite backscatter, which is not the case in most radiation biology experiments. 10,49 This is particularly true for IGCSAI, where the majority of fields are ≤2 cm in size. For this reason, there exist large differences between the dose rate measured under calibration conditions and the dose rate delivered under experimental conditions.…”

Section: Discussionmentioning

confidence: 99%

“…36,37,50,51 Recently, the AAPM has established the Task Group 319 to develop guidelines for accurate dosimetry in radiobiology experiments, 58 but their recommendations will focus nearly exclusively on cabinet irradiators still used in the vast majority of radiation biology experiments. 10 Under these conditions, expecting radiation biology operators to adhere to a full-scale prescriptive QA program such as described by Brodin et al 11 may be unrealistic. In this case, a wider, more indepth FMEA methodology can help focus the efforts of physicists towards those aspects of IGSAI most in need of QA intervention.…”

Section: Discussionmentioning

confidence: 99%

“…According to a recent survey, the vast majority (>75%) of radiation biology experiments are performed using cabinet style irradiators using either Co-60, Cs-137, or kV x rays. 10 Very briefly and generally, cabinet style irradiators tend to operate with a fixed radiation source, be it Cs-137, Co-60, or kV x-ray tubes. Their collimation and source-to-surface distances (SSD) can either be fixed or variable.…”

Section: B Traditional Cabinet Irradiatorsmentioning

confidence: 99%

“…However, despite the rapid influx of new technology, comprehensive quality assurance (QA) protocols similar to the AAPM TG-142 5 for linear accelerator are still virtually nonexistent, and radiation biology study protocols present wide variations from site to site. [6][7][8][9][10] Many attempts have been made to produce rigorous systematic and prescriptive QA [11][12][13][14][15][16][17] methodologies similar to those employed in the clinic for patient radiation therapy (RT) such as the AAPM Task Group 40 18 and 142. 5 These approaches typically focus on comprehensive dosimetry and geometrical tests performed by physics specialists with knowledge and access to specialized equipment such as special dosimetric phantoms, 16,19 GAFChromic EBT film, 15,20 alanine detectors, 21 and ionization chamber measurements.…”

Section: Introductionmentioning

confidence: 99%

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A failure modes and effects analysis quality management framework for image‐guided small animal irradiators: A change in paradigm for radiation biology

et al. 2020

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Purpose: Image-guided small animal irradiators (IGSAI) are increasingly being adopted in radiation biology research. These animal irradiators, designed to deliver radiation with submillimeter accuracy, exhibit complexity similar to that of clinical radiation delivery systems, including image guidance, robotic stage motion, and treatment planning systems. However, physics expertise and resources are scarcer in radiation biology, which makes implementation of conventional prescriptive QA infeasible. In this study, we apply the failure modes and effect analysis (FMEA) popularized by the AAPM task group 100 (TG-100) report to IGSAI and radiation biological research. Methods: Radiation biological research requires a change in paradigm where small errors to large populations of animals are more severe than grievous errors that only affect individuals. To this end, we created a new adverse effects severity table adapted to radiation biology research based on the original AAPM TG-100 severity table. We also produced a process tree which outlines the main components of radiation biology studies performed on an IGSAI, adapted from the original clinical IMRT process tree from TG-100.Using this process tree, we created and distributed a preliminary survey to eight expert IGSAI operators in four institutions. Operators rated proposed failure modes for occurrence, severity, and lack of detectability, and were invited to share their own experienced failure modes. Risk probability numbers (RPN) were calculated and used to identify the failure modes which most urgently require intervention. Results: Surveyed operators indicated a number of high (RPN >125) failure modes specific to small animal irradiators. Errors due to equipment breakdown, such as loss of anesthesia or thermal control, received relatively low RPN (12-48) while errors related to the delivery of radiation dose received relatively high . Errors identified could either be improved by manufacturer intervention (e.g., electronic interlocks for filter/collimator) or physics oversight (errors related to tube calibration or treatment planning system commissioning). Operators identified a number of failure modes including collision between the collimator and the stage, misalignment between imaging and treatment isocenter, inaccurate robotic stage homing/translation, and incorrect SSD applied to hand calculations. These were all relatively highly rated , indicating a possible bias in operators towards reporting high RPN failure modes. Conclusions: The first FMEA specific to radiation biology research was applied to image-guided small animal irradiators following the TG-100 methodology. A new adverse effects severity table and a process tree recognizing the need for a new paradigm were produced, which will be of great use to future investigators wishing to pursue FMEA in radiation biology research. Future work will focus on expanding scope of user surveys to users of all commercial IGSAI and collaborating with manufacturers to increase the breadth of surveyed expert operato...

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Devices for dosimetric measurements and quality assurance of the Xstrahl 300 orthovoltage unit

Lim

Mirković

Wang

et al. 2021

J Applied Clin Med Phys

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The Xstrahl 300 orthovoltage unit is designed to deliver kilovoltage radiation therapy using the appositional technique. However, it is not equipped with some typical linear accelerator features, such as mechanical distance indicator and crosshair projection, which are useful for facilitating equipment setup during various quality assurance (QA) and research activities. Therefore, we designed and constructed slipin devices to facilitate QA for dosimetric measurements of our Xstrahl 300 unit. These include: (a) an ion chamber positioning system for dosimetric measurements, (b) a mechanical pointer for setting dosimeter distance to a nominal 50 cm, and (c) a crosshair projector with built-in light to facilitate alignment of dosimeter to the center of the radiation field. These devices provide a high degree of setup reproducibility thereby minimizing setup errors. We used these devices to perform QA of the Xstrahl 300 orthovoltage unit. One of the QA tests we perform is a constancy check of beam output and energy. Our data since start of clinical use of this unit (approximately 2.5 yr) show dose outputs to be remarkably reproducible (2σ = ±0.4%) for all three clinical beams (75, 125, and 250 kVp). These devices have provided both convenience and high-precision during the unit's commissioning, and continue to provide the same for various QA activities on the Xstrahl 300 orthovoltage unit.

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A Dose of Reality: How 20 Years of Incomplete Physics and Dosimetry Reporting in Radiobiology Studies May Have Contributed to the Reproducibility Crisis

Cited by 76 publications

References 34 publications

Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity

Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity

A failure modes and effects analysis quality management framework for image‐guided small animal irradiators: A change in paradigm for radiation biology

Devices for dosimetric measurements and quality assurance of the Xstrahl 300 orthovoltage unit

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