Developing a Verification and Training Phantom for Gynecological Brachytherapy System
Introduction Dosimetric accuracy is a major issue in the quality assurance (QA) program for treatment planning systems (TPS). An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT) of gynecological...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Mashhad University of Medical Sciences
2012-03-01
|
| Series: | Iranian Journal of Medical Physics |
| Subjects: | |
| Online Access: | http://ijmp.mums.ac.ir/article_328_1cf6938a878438dfdcd20545d7046582.pdf |
| _version_ | 1818049771712020480 |
|---|---|
| author | Mahbobeh Nazarnejad Seied Rabi Mahdavi Khadijeh Asnaashari Mahdi Sadeghi Alireza Nikoofar |
| author_facet | Mahbobeh Nazarnejad Seied Rabi Mahdavi Khadijeh Asnaashari Mahdi Sadeghi Alireza Nikoofar |
| author_sort | Mahbobeh Nazarnejad |
| collection | DOAJ |
| description | Introduction Dosimetric accuracy is a major issue in the quality assurance (QA) program for treatment planning systems (TPS). An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT) of gynecological (Gyn) cancer it is usual to insert a combination of tandem and ovoid applicators with a complicated geometry which makes their dosimetry verification difficult and important. Therefore, evaluation and verification of dose distribution is necessary for accurate dose delivery to the patients. Materials and Methods The solid phantom was made from Perspex slabs as a tool for intracavitary brachytherapy dosimetric QA. Film dosimetry (EDR2) was done for a combination of ovoid and tandem applicators introduced by Flexitron brachytherapy system. Treatment planning was also done with Flexiplan 3D-TPS to irradiate films sandwiched between phantom slabs. Isodose curves obtained from treatment planning system and the films were compared with each other in 2D and 3D manners. Results The brachytherapy solid phantom was constructed with slabs. It was possible to insert tandems and ovoids loaded with radioactive source of Ir-192 subsequently. Relative error was 3-8.6% and average relative error was 5.08% in comparison with the films and TPS isodose curves. Conclusion Our results showed that the difference between TPS and the measurements is well within the acceptable boundaries and below the action level according to AAPM TG.45. Our findings showed that this phantom after minor corrections can be used as a method of choice for inter-comparison analysis of TPS and to fill the existing gap for accurate QA program in intracavitary brachytherapy. The constructed phantom also showed that it can be a valuable tool for verification of accurate dose delivery to the patients as well as training for brachytherapy residents and physics students. |
| first_indexed | 2024-12-10T10:42:53Z |
| format | Article |
| id | doaj.art-68d464eae9f8426e9e5b34bd27b9ebc0 |
| institution | Directory Open Access Journal |
| issn | 2345-3672 2345-3672 |
| language | English |
| last_indexed | 2024-12-10T10:42:53Z |
| publishDate | 2012-03-01 |
| publisher | Mashhad University of Medical Sciences |
| record_format | Article |
| series | Iranian Journal of Medical Physics |
| spelling | doaj.art-68d464eae9f8426e9e5b34bd27b9ebc02022-12-22T01:52:15ZengMashhad University of Medical SciencesIranian Journal of Medical Physics2345-36722345-36722012-03-0191334010.22038/ijmp.2012.328328Developing a Verification and Training Phantom for Gynecological Brachytherapy SystemMahbobeh Nazarnejad0Seied Rabi Mahdavi1Khadijeh Asnaashari2Mahdi Sadeghi3Alireza Nikoofar4Science and Research Branch, Islamic Azad University, Tehran, IranDepartment of Medical physics, Tehran University of Medical Sciences, Tehran, IranSchool of allied medicine, Tehran University of Medical Sciences, Tehran, IranScience and Research Branch, Islamic Azad University, Tehran, IranDepartment of Medical physics, Tehran University of Medical Sciences, Tehran, IranIntroduction Dosimetric accuracy is a major issue in the quality assurance (QA) program for treatment planning systems (TPS). An important contribution to this process has been a proper dosimetry method to guarantee the accuracy of delivered dose to the tumor. In brachytherapy (BT) of gynecological (Gyn) cancer it is usual to insert a combination of tandem and ovoid applicators with a complicated geometry which makes their dosimetry verification difficult and important. Therefore, evaluation and verification of dose distribution is necessary for accurate dose delivery to the patients. Materials and Methods The solid phantom was made from Perspex slabs as a tool for intracavitary brachytherapy dosimetric QA. Film dosimetry (EDR2) was done for a combination of ovoid and tandem applicators introduced by Flexitron brachytherapy system. Treatment planning was also done with Flexiplan 3D-TPS to irradiate films sandwiched between phantom slabs. Isodose curves obtained from treatment planning system and the films were compared with each other in 2D and 3D manners. Results The brachytherapy solid phantom was constructed with slabs. It was possible to insert tandems and ovoids loaded with radioactive source of Ir-192 subsequently. Relative error was 3-8.6% and average relative error was 5.08% in comparison with the films and TPS isodose curves. Conclusion Our results showed that the difference between TPS and the measurements is well within the acceptable boundaries and below the action level according to AAPM TG.45. Our findings showed that this phantom after minor corrections can be used as a method of choice for inter-comparison analysis of TPS and to fill the existing gap for accurate QA program in intracavitary brachytherapy. The constructed phantom also showed that it can be a valuable tool for verification of accurate dose delivery to the patients as well as training for brachytherapy residents and physics students.http://ijmp.mums.ac.ir/article_328_1cf6938a878438dfdcd20545d7046582.pdfFilm DosimetryGYN Brachytherapy PhantomQuality Assurance |
| spellingShingle | Mahbobeh Nazarnejad Seied Rabi Mahdavi Khadijeh Asnaashari Mahdi Sadeghi Alireza Nikoofar Developing a Verification and Training Phantom for Gynecological Brachytherapy System Iranian Journal of Medical Physics Film Dosimetry GYN Brachytherapy Phantom Quality Assurance |
| title | Developing a Verification and Training Phantom for Gynecological Brachytherapy System |
| title_full | Developing a Verification and Training Phantom for Gynecological Brachytherapy System |
| title_fullStr | Developing a Verification and Training Phantom for Gynecological Brachytherapy System |
| title_full_unstemmed | Developing a Verification and Training Phantom for Gynecological Brachytherapy System |
| title_short | Developing a Verification and Training Phantom for Gynecological Brachytherapy System |
| title_sort | developing a verification and training phantom for gynecological brachytherapy system |
| topic | Film Dosimetry GYN Brachytherapy Phantom Quality Assurance |
| url | http://ijmp.mums.ac.ir/article_328_1cf6938a878438dfdcd20545d7046582.pdf |
| work_keys_str_mv | AT mahbobehnazarnejad developingaverificationandtrainingphantomforgynecologicalbrachytherapysystem AT seiedrabimahdavi developingaverificationandtrainingphantomforgynecologicalbrachytherapysystem AT khadijehasnaashari developingaverificationandtrainingphantomforgynecologicalbrachytherapysystem AT mahdisadeghi developingaverificationandtrainingphantomforgynecologicalbrachytherapysystem AT alirezanikoofar developingaverificationandtrainingphantomforgynecologicalbrachytherapysystem |