SCATTERED RADIATION AND ASSOCIATED SECOND CANCER RISK FROM PELVIC RADIOTHERAPY

Purpose: The purpose of this study was to evaluate the risk of gonad cancer inductionattributable to pelvic radiation therapy in adult patients. By diagnosing simple methods out-offielddose might be minimized.Methods: By characterizing the peripheral dose the TLDs were placed to the testis and ovaryin two fractions of radiotherapy. All patients delivered a ۴۵ Gy total dose in ۴ field in proneposition with ۳D-planning. The doses from linear accelerator at ۱۸ MV photon beam, wereinvestigated.Results: The mean excess relative risk (ERR) based on the BEIR IIV models of men andwomen after ۵ and ۱۰ years radiotherapy treatment for pelvic radiotherapy ۰.۸۲۵, ۰.۷۰۱, ۰.۹۶۰and, ۰.۸۰۴ respectively.Conclusion: Estimating the second cancer risk of untargeted organs is vital importance forsurvival patients in RT (radiotherapy). By using the single-energy mode linear acceleratorand proper shields can be minimized the out-of-field doses.

Keywords:

Radiotherapy , cancer risk , TLD , Organ dose , Out-of-field