Yazar "Demirtas, Mehmet" seçeneğine göre listele

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    Dosimetric Comparison of Adjuvant Pelvic Radiotherapy for Endometrial Cancer using Intensity-Modulated Radiotherapy (IMRT), Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT)
    (Kare Publ, 2019) Temelli, Oztun; Demirtas, Mehmet; Sisecioglu, Mahmut Serdar; Pepele, Eda Kaya
    Objectives:The purpose of the present study is to compare dosimetrically IMRT, VMAT, HT techniques in endometrium cancer adjuvant radiotherapy practice. Methods: The 10 patients to whom we had applied Pelvic RT due to endometrium cancer previously were selected retrospectively. All patients had received TAH+BSO+BPLND. Three different plans were made for the patients as IMRT, VMAT, and HT. Results: The rectum V40 was found to be 53%, 54%, 45% (p=0.002), respectively; and the bladder V45 was 27%, 26%, 20% (p=0.002), respectively. Bowel V40 was found to be 15%,17%,12%, respectively (p=<0.001). Total monitor unit (MU) and beam-on times were found superior at VMAT (<0.001). Bone marrow V40 was found to be 27%, 26%, 33%, respectively (p<0.001). Conclusion: It was found that the three techniques were suitable in terms of planning criteria and OARs. HI and CI were found to be superior at HT. In risky organs, in rectum, bowel and bladder, HT was found to be superior than the others; in terms of bone marrow, IMRT was found to be superior; and in terms of bone, VMAT was found to be superior. VMAT has the advantage of having short treatment time and low MU.
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    Dosimetric comparison of helical tomotherapy and hybrid (3DCRT-VMAT) technique for locally advanced non-small cell lung cancer
    (Cambridge Univ Press, 2021) Temelli, Oztun; Demirtas, Mehmet; Ugurlu, Berat Tugrul
    Aim: The purpose of the present study is to compare hybrid [three-dimensional conformal radiation therapy-volumetric-modulated arc therapy (3DCRT-VMAT)] and helical tomotherapy (HT) techniques in terms of both planning target volume (PTV) and organs at risk (OARs) in the plans we made in locally advanced non-small cell lung cancer (NSCLC) patients Material and methods: Radiotherapy was planned for 15 locally advanced NSCLC patients with 2 different techniques. Large tumours with positive mediastinal lymph nodes were preferred. The prescription dose was determined as 60 Gy at 30 fractions. Results: Mean PTV volume was 602 center dot 5 cc (range: 265-1461). Mean total lung volume was 4264 cc (range: 1885-6803). Homogeneity index, D-mean, D-max, D-2 and V-105 were found to be lower in HT, V-100, total monitor units (MU) and total beam on time were found to be lower in the hybrid plan. Total lung D-mean was found to be 17 Gy in both techniques. V-10 value was 42 center dot 85 in the hybrid plan and 48 center dot 67 in HT (p = 0 center dot 037). Heart D-mean was 14 center dot 5 Gy in the hybrid plan and 18 center dot 7 in HT (p < 0 center dot 001), and V-30 values were 18 center dot 1 and 22 center dot 9, respectively (p = 0 center dot 009). Conclusion: Suitable dose coverage and OAR doses can be provided with both techniques. Especially the opposite lung, heart and oesophagus doses can be kept lower with the hybrid plan, and lower MU and shorter beam on time can be provided.
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    Dosimetric Evaluation of Deep Inspiration Breath-Hold Technique for Breast Cancer Radiotherapy: A Single-Center Experience
    (Kare Publ, 2020) Temelli, Oztun; Demirtas, Mehmet; Ugurlu, Berat Tugrul; Pepele, Eda Kaya; Yaprak, Bahaddin; Gulbas, Hulya; Eraslan, Fatma Aysun
    OBJECTIVE To retrospectively evaluate the absorbed doses of organs at risk, such as lungs and the heart of the patients who underwent radiotherapy (RT) using the voluntary deep inspiration breath-hold (vDIBH) technique, and to compare the results with the literature. METHODS In this study, 102 patients who underwent adjuvant RT for the treatment of breast cancer in our clinic between November 2018 and December 2019 were included. A breast and/or chest wall, and/or lymph node RT of 50 Gy in 25 fractions was planned for all patients, and an additional boost of 10 Gy in five fractions was planned for patients requiring an RT boost. The treatment plans included 3DCRT, Field in Field (FIF), IMRT and VMAT approaches. RESULTS In the group undergoing supraclavicular fossa RT, the mean V20Gy was found to be 24.8%, compared to 16% in the group not undergoing supraclavicular fossa RT (p<0.01). In the group undergoing mammaria interna RT, the mean heart dose was 3.1 Gy, compared to 2.1 Gy in the group not undergoing mammaria interna RT (p=0.04). CONCLUSION Respiratory motion control techniques can reduce uncertainties in the target related to respiratory motion. The irradiated volume doses of the ipsilateral lung, heart reduce.