Hematologic Toxicity of Conformal Radiotherapy and Intensity Modulated Radiotherapy in Prostate and Bladder Cancer Patients.

Background: The purpose of this study was to compare hematologic adverse effects and hematologic toxicity (HT) of pelvic irradiation in patients treated with conformal radiotherapy (CRT) and intensity modulated radiotherapy (IMRT) for radical treatment of prostate and bladder cancer. Methods: A group of 115 patients with prostate or bladder cancer treated with definitive radical radiotherapy was evaluated retrospectively. Blood test were taken before and after treatment comprising of following indices: white blood cells (WBC) hemoglobin (HGB), red blood cell (RBC), lymphocyte (LC), neutrophil (NC) and platelet (PLT) count. Patients were divided into several subgroups and the data was evaluated statistically using absolute and relative values. Results: There was a statistically significant difference in WBC (p=0.007), NC (p=0.031) and PLT (p=0.026) count decrease (absolute values) after treatment, between two treatment methods (CRT and IMRT), all in favor of IMRT. The relationship still proves to be significant regarding WBC (p=0,02) and (NC) (p=0,049) after presenting the data as relative percentage loss of starting value. However using Common Terminology Criteria for Adverse Effects (CTCAE), PLT count toxicity was more common in IMRT group (p=0.045). Conclusion: IMRT in comparison to CRT in bladder and prostate cancer patients is associated with a lesser absolute and relative decrease of hematologic indices. The hematologic effect of radiation was observed mainly regarding LC. Patients treated with IMRT suffered from significantly lesser decrease in relative and absolute values of WBC and NC. The mean of absolute PLT decrease count was lower in IMRT group; however, toxicity according to CTCAE was slightly more prevalent in IMRT group.