Yazar "Doğan, M. H." seçeneğine göre listele

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  • Küçük Resim
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    Dosimetric comparison of prostate radiotherapy between pelvic node-positive and node-negative patients
    (IJRR-Iranian Journal Radiation Research, 2021) Zincircioğlu, Seyit Burhanedtin; Doğan, M. H.; Kaya, M. A.; Teke, Fatma;
    Background: The importance of dose in prostate radiotherapy is well known, and the dosimetric effects of radiotherapy in node-positive or node-negative patients with prostate cancer have become an important issue. Materials and Methods: Helical tomotherapy (TH) plans of 19 pelvic node-positive [THpn(+) plan] or node-negative [THpn(-) plan] patients with prostate cancer were retrospectively created in our clinic. In these plans, the beam angle was set to cover the planning target volume (PTV) of prostate cancer and minimize the dose to the organs at risk, including the bladder, rectum, femoral head, and bowel. Results: There were no differences in the conformity index, D-max, D-mean, and homogeneity index of PTV between the THpn (+) and THpn (-) plans (p>0.05). However, V95 in the THpn (+) plan was lower than that in the THpn (-) plan (p=0.017). Moreover, D-max, V75, V70, V65, V60, V50, V40, V30, and V20 for the rectum were not significantly different between the two plans (p>0.05), whereas D-mean was significantly different (p=0.025). D-max, V70, V65, and V60 for the bladder were not significantly different between the two plans (p>0.05), whereas V55, V50, V40, and V30 were significantly different (p<0.05). Finally, D-max and V50 for the femoral head and bowel were significantly different between the two plans (p<0.05). Conclusion: The THpn (+)] and [THpn(-) plans achieved acceptable target dose coverage in prostate radiotherapy.
  • Küçük Resim
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    Effects of modulation factors in breast cancer treatment with helical tomotherapy
    (IJRR-Iranian Journal Radiation Research, 2021) Zincircioğlu, S. B.; Doğan, M. H.
    Background: The aim of this study was to compare the dosimetric values of TomoHelical (TH) plans using modulation factors 3 and 5 in patients with breast cancer. Materials and Methods: Two different radiotherapy treatment plans, including modulation factors 3 and 5, were generated retrospectively for 12 consecutive intact breast cancer patients. Twelve different plans in terms of the modulation factor were generated. Other optimization parameters (i.e., pitch and field width) were the same for all plans. Results: No differences were found between the conformity index (CI) and homogeneity index (HI) values of both plans (p>0.05). The values of D mean, V5, and V20 of the ipsilateral lung in the TomoHelical plan with modulation factor 5 (TH5) were significantly lower than with modulation factor 3 (TH3) for all 12 patients (4.9 Gy, 20.14%, 3.23%. Vs, 10.95 Gy, 58.9%, 18.7%; p=0.01, p=0.00, p=0.002, respectively). Also, the values of Dmean and V5 of the heart in TH5 were significantly lower than in TH3 (6.45 Gy, 34.33%, vs. 7.12 Gy, 64.22%; p=0.004, p=0.00, respectively). Conclusion: Both the TH5 and TH3 plans provided adequate coverage of the intact breast. TH5 delivered a decreased dose to the ipsilateral organs at risk (OARs), especially in the lung and heart volume, which is the main cause of long-term toxicity. The novelty of this work is the obvious reduction in same-sided lung volume irradiation by increasing the modulation factor.