Introduction: Virtual simulation is a method used for palliative radiation of a patient. Errors can occur at each individual step of irradiation, starting from preparing the patient on the simulator and up to patient irradiation on a linear accelerator. To ensure safety and quality treatment in radiotherapy both retrospective as well as prospective risk analysis methods are used. Prospective risk analysis methods like Process mapping, Failure mode and effects analysis (FMEA), Failure tree analysis complement the retrospective methods of risk analysis. Purpose: The purpose of this master’s thesis is using virtual simulation in palliative treatment as a case in which prospective methods of risk analysis are employed to analyze the risks and suggest the action to be taken to reduce the risks in all steps of this process. Methods: We surveyed 26 healthcare professionals involved in the process of patient irradiation using virtual simulation. Our research included healthcare professionals from different fields such as: doctor – radiation oncologist, medical physicist/dosimetrist, radiation therapist working on a radiotherapy computed tomography (CT) simulator and on a linear accelerator. Survey questions represented failure modes which could occur in the process of preparation and during irradiation of the patient using virtual simulation. Every failure mode was assigned a value from 1 to 10. Healthcare professionals graded the frequency of the failure mode occurrence (O), its severity (S) and likelihood of discovering the mistake before irradiating the patient (D). Afterwards we calculated the median of the risk priority numbers (RPN), calculated as the product of failure mode occurrence, severity and detectability. Results: Radiotherapists working on a radiotherapy CT simulator chose »Incorrect patient, despite identity verification« and »Faulty patient classification« as the most dangerous mistakes, with the maximal median severity of the error (S) 10 and the median RPN value equal to 60. Radiation oncologists chose »Determining too big or too small of a radiation field« as the most dangerous error, with the median RPN value of 245. Error ”Importing a CT set for the wrong patient” has the highest median RPN value of 100.5, as graded by medical physicists. Radiotherapists working on the linear accelerator graded »When checking data, discrepancy in the radiation parameters between the treatment chart and ARIA system are overlooked« as the most dangerous error (RPN = 72). Discussion and conclusion: The group of radiation oncologists were the most critical in their assessment of errors. RPN values in this group are much higher than in other groups of respondents, which does not mean that other errors that occur in the process of patient treatment with palliative care are negligible. This research can be the starting point for the analysis of errors that occur in other methods of irradiation.
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