Şahin, Sevim

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Şahin, S.
Sahin, S.
Sahin, Sevim
Job Title
Doktor Öğretim
Email Address
sevim.sahin@fbu.edu.tr
ORCID ID
0000-0002-0886-3762
Scopus Author ID
Turkish CoHE Profile ID
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Scholarly Output

3

Articles

3

Citation Count

2

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    Article
    Citation Count: 0
    Efficiency of Modulated and Dose Rate Altered Flattening Filter Free Beams in High Dose Per Fraction Radiotherapy Applications on the Survival of Prostate Cancer Cell Lines
    (Novin Medical Radiation Institute, 2021) Öztürk, Ayşe; Şahin, Sevim; Güngör, G.; Karabey, A.U.; Şahin, S.; Duruksu, G.; Gündoğdu, Ö.; Mimarlık Bölümü; Elektrik-elektronik Mühendisliği Bölümü
    Background: The radiobiological effect of high dose rate FFF beams on the DU-145 cells was investigated with SBRT plans which have >10 Gy. Methods and Materials: To compare the radiobiological effect on DU-145 cell line four experiments designed: (1) the constant dose rate of 6 MV and 6 MV FFF with increased dose per pulse (2) the effect of dose per pulse while increasing instantaneous dose rate for 6 MV and 6 MV FFF, (3) the effect of increased average dose rate for 6 MV FFF and (4) the effect of protracted treatment time and modulation of 6 MV FFF beams. The survival fraction was counted with WST. Results: FF and FFF for 6 MV with same dose rate and treatment time has no effect on cell survival. Significant differences was observed on survival which were irradiated with 6 MV 600 MU/min and 6 MV FFF 1400 MU/min (p=0.024). There was no difference between 6 MV FFF 600 MU/min and 6 MV FFF 1400 MU/min for 10 Gy. The significant survival difference obtained for 20 Gy. The survival percentages for both 10 Gy and 20 Gy with Cyberknife were obtained higher than FFF. Conclusion: Our in-vitro study presented here show that higher dose rate and reduced treatment time might become a crucial factor for SBRT especially which has >10 Gy fraction dose. © 2021 Novin Medical Radiation Institute. All rights reserved.
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    Article
    Citation Count: 0
    Efficiency of Modulated and Dose Rate Altered Flattening Filter Free Beams in High Dose Per Fraction Radiotherapy Applications on the Survival of Prostate Cancer Cell Lines
    (Ijrr-iranian Journal Radiation Res, 2021) Şahin, Sevim; Ozturk, A.; Gungor, G.; Karabey, A. U.; Sahin, S.; Duruksu, G.; Gundogdu, O.; Elektrik-elektronik Mühendisliği Bölümü
    Background: The radiobiological effect of high dose rate FFF beams on the DU-145 cells was investigated with SBRT plans which have >10 Gy. Methods and Materials: To compare the radiobiological effect on DU-145 cell line four experiments designed: (1) the constant dose rate of 6 MV and 6 MV FFF with increased dose per pulse (2) the effect of dose per pulse while increasing instantaneous dose rate for 6 MV and 6 MV FFF, (3) the effect of increased average dose rate for 6 MV FFF and (4) the effect of protracted treatment time and modulation of 6 MV FFF beams. The survival fraction was counted with WST. Results: FF and FFF for 6 MV with same dose rate and treatment time has no effect on cell survival. Significant differences was observed on survival which were irradiated with 6 MV 600 MU/min and 6 MV FFF 1400 MU/min (p=0.024). There was no difference between 6 MV FFF 600 MU/min and 6 MV FFF 1400 MU/min for 10 Gy. The significant survival difference obtained for 20 Gy. The survival percentages for both 10 Gy and 20 Gy with Cyberknife were obtained higher than FFF. Conclusion: Our in-vitro study presented here show that higher dose rate and reduced treatment time might become a crucial factor for SBRT especially which has >10 Gy fraction dose.
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    Article
    Citation Count: 2
    Effect of Multileaf Collimator Leaf Position Error Determined by Picket Fence Test on Gamma Index Value in Patient-Specific Quality Assurance of Volumetric-Modulated Arc Therapy Plans
    (Springernature, 2021) Şahin, Sevim; Inal, Serpil Yondem; Senol, Elif; Yilmaz, Berrin; Sahin, Sevim; Elektrik-elektronik Mühendisliği Bölümü
    Aim The correlation between the MLC QA (IBA Dosimetry, Germany) results of the picket fence test created with intentional errors and the patient's quality assurance (QA) evaluation was investigated to assess the impact of multileaf collimator (MLC) positioning error on patient QA. Materials and methods The picket fence, including error-free and intentional MLC errors, defined in Bank In, Bank Out, and Bank Both were analyzed using MLC QA. The QA of 15 plans consisting of stereotactic radiosurgery (SRS), stereotactic body radiotherapy (SBRT), and conventionally fractionated volumetric-modulated arc therapy (VMAT) acquired with electronic portal imaging devices (EPID) was evaluated in the presence of error-free and MLC errors. The QA of plans were analyzed with 2%/2 mm and 3%/3 mm criteria. Results The passing rates of the picket fence test were 97%, 92%, 91%, and 87% for error-free and intentional errors. The criterion of 3%/3 mm wasn't able to detect an MLC error for either SRS/SBRT or conventionally fractionated VMAT. The criterion of 2%/2mm was more sensitive to detect MLC error for the conventionally fractionated VMAT than SRS/SBRT. While only two of SBRT plans had <90%, four of conventionally fractionated VMAT plans had a <90% passing rate. Conclusion We found that the systematic MLC positioning errors defined with picket fence have a smaller but measurable impact on SRS/SBRT than the VMAT plan for a conventionally fractionated and relatively complex plan such as head and neck and endometrium cases.