Trace elements play an significant role in human healt and disease. Some, as Cd, are non-essential but others are essential for continue of normal metabolizma functions. These elements are take office in different metabolic pathway of cell and tissues. Each of essential and non-essential trace element may be toxic if found in cell, tissue and fluids in large concentrations. In this study, the alteration in trace element levels in blood plasma of patients with lung cancer received radiotherapy during five weeks were determined.

Measurement of trace elements in plasma was carried out by using EDS.

As a result, there was an important alteration in trace element levels depend on exposure time in all patients when compared to controls. Na, Mg, Ca, Se, Rb and Mo levels fairly decreased in plasma of patients during radiotherapy. But Al, S, V, Fe, Cu, Ar, Cd, Co, Mn, Hg and Pb levels showed an increase during radiotherapy. In other words, an increase related with radiation in levels of the toxic trace elements, a decrease in levels of the essential trace elements were observed. Besides, the levels of toxic trace element in plasma were more elevated in cancer patients before radioterapy when compared to controls, and differences were statistically significant.

Consequently, radiotherapy has a lethal effect on cancer cell but causes some toxic effects on vital substrates for cells as trace elements. Therefore, effects of radiotherapy applications on healthy cells and tissues must be minimized and alternative methods should be developed.