Comparison of Rectal Dose in Different Techniques of Prostate Cancer External-Beam Radiotherapy Based on TLD and XR Type T GAFCHROMIC® Film Dosimetry
نویسندگان
1 Department of Radiotherapy, Imam Reza Hospital, Mashhad University of Medical Science, Mashhad, Iran,
2 Department of BioStatistics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
3
4 Department of Medical Physics,
5 Motahari Clinic, Khoy, West Azarbaijan, Iran,
doi
چکیده
Background: Radiotherapy of prostate carcinoma often results in high doses to surrounding structures, such asthe rectum and bladder. Therefore, these organs should be closely monitored. The aim of this study is to evaluatethe dose received by the target volume and rectum to compare two different methods of dose measurementwith each other and to check the homogeneity of dose in the tumor volume.Methods: The dose distribution throughout a planned target volume and the rectum (OaR) in a phantom exposedto 9 MV photon beam, similar to treatment conditions were studied. Several techniques of external beamradiation therapy such as two-, three- and four-field have been planned. Dosimetry was performed using GAFCHROMIC® film and TLD-100 chips.Results: The rectal and cancer volume measured doses in treatment were similar to the prescribed doses. Theresults of two dosimetry types were compared with each other as well as with treatment planning. Rectal dose inthree- and four-field (equal tumor dose and equal applied dose) techniques were respectively 23.15, 28.87 and15.22% lower than the tumor dose.Conclusion: There was not a statistically significant difference between received and prescribed doses. So, thisstudy showed that the Gafchromic film dosimetry can be used for fast dosimetric evaluations.
