Effect of Flattening Filter and Flattening Filter Free beams on radiotherapy-induced peripheral blood cell damage

Abstract

The purpose of this study is to investigate whether Flattening Filter (FF) and Flattening Filter Free (FFF) beams cause any difference on rat peripheral blood levels in a single dose (SD) and fractioned dose (FD) plans.Forty Sprague Dawley rats were randomly divided into five groups. No action was taken on the subjects in the control group (Group 1). FF-SD (Group 2) and FF-FD (Group 4) subjects received radiotherapy at 400 MU/min in SD 16 Gy and 5-day consecutive FD 32 Gy, respectively. FFF-SD (Group 3) and FFF-FD (Group 5) subjects received radiotherapy at 1400 MU/min in SD 16 Gy and 5-day consecutive FD 32 Gy, respectively. Blood samples were collected 24 h after radiotherapy. The levels of white blood cells (WBC), granulocytes (GRAN%), red blood cells (RBCs), lymphocytes (LYM%), hemoglobin (HGB) and platelets (PLT) were analyzed.In SD and FD plans, the levels of hematological parameters except for PLT level due to FF and FFF beams decreased statistically significant when compared with the control group (p < 0.05), but it was observed that the values of these parameters decreased less in the FD plans. In addition, when the effects of FF and FFF beams on peripheral blood cells were compared, a statistically significant difference was observed (p < 0.05).It was shown that FF and FFF beams significantly decrease hematological parameter levels in SD and FD plans. In addition, it was concluded that FFF beams were more dominant when we compared the effects of FF and FFF beams on peripheral blood cells.