**10. Discussion**

The need of safe and effective radiotherapy is growing as cancer morbidity is growing worldwide. Modern radiotherapy is used to treat and improve the quality of life of patients undergoing this type of therapy. Currently, radiation therapy is widely recognized as one of the safest areas of modern medicine and errors in radiation therapy are very rare [33].

Patient safety is of paramount importance to medical staff in radiotherapy centers and safety considerations are an element in all aspects of the day-to-day clinical activities. Technological advances and clinical research over the past few decades have given radiation oncologists the capability to personalize treatments for accurate delivery of radiation dose based on clinical parameters and anatomical information. Two major strategies, acting synergistically, will enable further widening of the therapeutic window of radiation oncology in the era of precision medicine: technology-driven improvement of treatment conformity, including advanced image guidance and particle therapy, and novel biological concepts for personalized treatment, including biomarker-guided prescription, combined treatment modalities and adaptation of treatment during its course [34].

Modern radiotherapy is one of most rapidly developing nuclear applications in medicine and today it is a safe and highly effective cancer treatment modality. Precise radiation dosimetry measurements are used to keep radiotherapy safe and effective. The need of dosimetric and geometric accuracy in radiotherapy is well defined [28, 35]. Recommendations of the International Commission of Radiation Units and Measurements (ICRU) given as early as in 1976, state that the dose delivery to the primary target should be within ±5% of the prescribed value (but in some special circumstances it should comply within ±2% to the prescribed dose to the target [36].

Radiation beams produced by radiotherapy machines need to be calibrated. Precise measurement of the dose is crucial for this calibration, since the quality and effectiveness of the medical radiation therapy rely on their accuracy. By the end of 2018, 2364 radiotherapy centres in 136 countries world-wide have been audited by the IAEA/WHO; 4427 machines and 5790 beams were encompassed by the audit programme. The total results of 13,756 individual TLD/RPLD irradiated sets over a period of 50 years were readout, evaluated and analyzed. 86% of them are within the 5% acceptance limit [37].
