Dosimetric Comparison of Various Radiotherapeutic Treatment Plans Using Cobalt-60 and Linac for Prostate Cancer

Iranian Journal of Medical Physics

Hasan Nedaie¹  Mahdi Aghili¹  Mahmood Allahverdi²  Ehsan Mohammadi³  Mahbod Esfehani³  Seyed Ali Vaezzadeh⁴ 

[1] Assistant Professor, Radiotherapy Dept., Cancer Institute, Tehran University of Medical Science, Tehran, Iran;Associate Professor, Medical Physics Dept., Tehran University of Medical Science, Tehran, Iran;M.Sc. in Medical Physics, Radiotherapy Dept., Cancer Institute, Tehran University of Medical Science, Tehran, Iran;Ph. D. Student in Medical Physics, Tehran University of Medical Science, Tehran, Iran;

关键词: Prostate Cancer;    Treatment plan;    Integral dose;    Linac;    Cobalt-60;   

DOI  :  10.22038/ijmp.2009.7297

来源: DOAJ

【 摘 要 】

Introduction: This study was designed to evaluate dosimetric parameters such as rectal dose, bladder dose, integral dose (ID), homogeneity index (HI) and conformity index (CI) in various treatment plans for prostate cancer. Materials and Methods: Pelvic computed tomography (CT) scans of 27 patients were acquired and transferred to the RTDosePLAN treatment planning system. For each patient, 8 conventional plans (3, 4, 5 and 6 fields) were planned for the cobalt-60 photon energy. Subsequently, the same plans were performed for 6 MV and 18 MV photon energies. Results: By increasing the energy of the beam relative to the cobalt-60 energy, the Dmean values for rectum and bladder were reduced from 3% to 4% and 4% to 6%, respectively, the dose received by the whole of the bladder volume decreased by 26% for 6 MV and by 58% for 18 MV. Increasing the photon beam energy decreased CI to 7% and 10%, ID was decreased by10% and 20% and Dmax was decreased by 3% and 4%, respectively. Discussion and Conclusion: A six-field treatment plan in comparison to the other plans offers the minimum dose to critical organs and sufficient dose to the prostate. Increasing the photon energy improves the treatment parameters of the bladder and the PTV.

【 授权许可】

Unknown