Radyoterapi alan hastalarda integral doz farklılıklarının tedavi cihaz ve tekniklerine göre mosfet ve TLD dozimetrisi ile in vivo doz değerlerinin karşılaştırılması
Abstract
Although radiotherapy is a major modality for cancer treatment on the other hand it may cause the development of the cancer. During the past decade, radiation-induced secondary malignancies have become a major concern and recent studies have shown that radiotherapy treatment is associated with a small, though statistically significant enhancement in the risk of secondary cancers. Integral dose is described as a deposited dose of the outside the treatment field; increasing of the integral dose have been a cause of radiation–induced secondary malignancies especially in long term surviving patients. Although consisting of the secondary radiation has been known during radiotherapy treatment, differences because of the new treatment techniques haven't been evaluated dosimetrically and still maintained hypothetical level. In this study, measurement and comparison of integral dose outside of the treatment field was made by using different devices and techniques (3 Dimensional Conformal Radiotherapy, Intensity Modulated Radiotherapy, Volumetric Modulated Arc Therapy) as in vivo dosimetric. For this purpose, comparision was made using with TLD and Mosfet dosimetry which are one of the in vivo dosimetric systems. Thus, pelvic region was chosen as a target treatment site because of applicability of high doses. Different radiation devices and treatment techniques were used for radiation treatment plans. All here were performed in a rando phantom and irradiated by five different devices. In vivo dosimetry systems were located at 11 localizations outside of the treatment field. Doses were calculated at the organs localizated outside of the treatment field. Values of the doses were compared between treatment plans of rando phantom and using MOSFET and TLD dosimeters. In measuring the integral dose with TLD-100 dosimeters are compared with MOSFET dosimeter system and it is found that more accurate and meaningful results are obtained with TLD dosimeters. The results obtained were found consistent with the literature .