A poor methodology in making radiation oncology studies impossible to reproduce

Nearly 80% of the National Institutes of Health-funded radiation oncology studies involve investigating the effects of radiation on tumor cells and healthy tissue in a preclinical environment, such as experiments on cell cultures or cell cultures. mouse. A majority of these radiobiology studies, however, have serious flaws in the description of their radiation methodology, which makes them very difficult to replicate, according to a new discovery from the School of Medicine. University of Maryland (UMSOM).

Important details of the irradiation protocol and experimental setup are usually not included in most of these newspaper articles, which could result in dose variations or other errors when others researchers are trying to repeat the experiments in their own laboratories.

"Omissions or flagrant errors in the methodological sections of journal articles on radiobiology make studies very difficult to reproduce, interpret and compare with other research," said the principal investigator. study, Yannick Poirier, Ph.D., Assistant Professor, Department of Radiation. Oncology at UMSOM.

In the new study published this month in the International Journal of Radiology Oncology, Biology and Physics, Dr. Poirier and colleagues at UMSOM and the University of Washington, Seattle, reviewed 1,758 peer-reviewed studies of 469 journals used in preclinical studies to evaluate the effects of radiation therapy on the treatment of malignant tumors and other conditions. Specifically, they reviewed the "methods" section of the journal article describing the radiation protocol used.

The researchers found that the source of radiation used in the study (such as X-rays or low energy or high energy gamma rays) was uncertain or ambiguous in almost 14% of the studies reviewed. They also found that only 1% of the studies indicated the protocol used by the researchers to calibrate the machines and only 16% named the equipment used to measure the absorbed radiation dose.

Several publications have been found to contain glaring errors when a radiation dose amount has been misstated. In a few cases, researchers have found descriptions of "impractical" experiments, including irradiation produced by a linear accelerator at energy levels that would have been impossible to produce for the named device.

The authors ranked the level of physical reporting required to successfully replicate the experience on a scale from 1 (worst) to 10 (best) and found that only 3% of journal articles would receive a score of 8 or more . "What is disturbing is that the articles published in high-impact journals – and, therefore, those mentioned above – are the poorest, which means that these studies with poor physics spread and magnify the problem of reproducibility, "said the co-author of the study. Amit Sawant, Ph.D., Associate Professor and Head of the Physics Division at UMSOM's Radiation Oncology Department.

UMSOM researchers say their discoveries are limited to the physical aspects and irradiation of these radiobiology studies. UMSOM researchers have not examined the quality of the science, the hypotheses or the non-physical aspects of the experimental design.

"This inability to replicate scientific results could have a profound impact on the translation of preclinical research results into clinical practice," said E. Albert Reece, MD, Ph.D., MBA, executive vice president for business Medical, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, Faculty of Medicine, University of Maryland. "UMSOM researchers point to a crucial problem that should be addressed by the radiation oncology research community."

The absence of radiation dose reporting or reproduction in journal articles in radiobiology is likely due to a lack of consultation between the radiation scientists in charge of the study and the physicists specializing in radiation. radiation with the necessary expertise to design, document and validate the protocol UMSOM researchers.

"We are sensitizing to this problem because the problem can be solved by involving physicists better trained in these studies," said Dr. Poirier. "This is because the emission of radiation follows well-understood principles of radiation physics that lend themselves to high accuracy, precision and reproducibility."

Efforts are already underway to address this issue: The National Cancer Institute and the NIH National Institute of Allergy and Infectious Diseases have recently implemented a program to standardize and monitor dosimetry dosing in the US. their preclinical research program funded by the radiation control program. The American Association of Physicists also created a working group last year to develop guidelines for accurate dosimetry in radiobiology experiments.