نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی انرژی، دانشگاه صنعتی شریف، صندوق پستی: 1114-14565، تهران- ایران

چکیده

انتظار می‌­رود که روش‌های مبتنی بر اسکن نقطه‌ای نسبت به سایر روش‌های موجود برای پروتون درمانی، عملکرد بهتری در تحویل دز به هدف موردنظر داشته باشد. در این مطالعه از کد شبیه‌ساز GATE، به‌منظور ارزیابی کمیات دزیمتری مهم در پروتون درمانی، مانند پهنا در نیم بیشینه، محل قله، برد و نسبت دز در قله به دز ورودی (درصد دز عمقی) در فرایند پروتون درمانی تحت شرایط یکسان برای روش‌های مبتنی بر اسکن نقطه‌ای و پراکندگی غیرفعال استفاده شده است. فانتومی از جنس آب انتخاب و پارامترهای انرژی سیستم با استفاده از مجموعه‌ای از داده‌های عمق- دز در محدوده انرژی 120-MeV 235 اندازه‌گیری شد. قله‌های براگ با دقت 7/0 میلی‌متر در برد تولید شدند. گسترش قله براگ با مدولاسیون 7 سانتی‌متر و با دقت دامنه 10 میلی‌متر و اختلاف دز به قله به دز ورودی 8 درصد تولید شدند. جهت بررسی تطبیق‌پذیری پرتو پهنا در نیم بیشینه با اختلاف حداکثر 7 درصد بین دو روش ارزیابی شد. در نتیجه بر اساس شبیه‌سازی انجام شده برای سیستم‌های مختلف تحویل پرتو، توانایی بهتر روش اسکن نقطه‌ای در انطباق‌پذیری با حجم هدف، کنترل بهتر روی توزیع دز و دز خارج از تومور کم‌تر نشان داده شد.

کلیدواژه‌ها

عنوان مقاله [English]

Evaluation of dosimetry quantities in passive scattering and spot scanning methods in proton therapy based on GATE simulation

نویسندگان [English]

  • A. Asadi
  • S.A. Hosseini
  • N. Vosoughi

Department of Energy Engineering, Sharif University of Technology, P.O.Box: 14565-1114, Tehran, Iran

چکیده [English]

Thespot-scan based methods are expected to perform better than other methods for proton therapy in delivering the dose to the intended target. In this study, the GATE computer code is used to evaluate important dosimetric quantities in proton therapy, such as Full width at half maximum, peak position, range and peak-to-entrance dose ratio (percentage depth dose) in the proton therapy process under the same conditions based on spot scanning and passive scattering. Water phantom was selected and system energy parameters were measured using a set of depth-dose curve in the energy range of 120 to 235 MeV. Bragg peaks were generated with an accuracy of 0.7 mm in range. Spread out Bragg-peak were produced with 7 cm modulation and 10 mm range accuracy and peak-to-entrance dose ratio difference at an input dose of 8%. To evaluate the versatility of the beam, the Full width at half-maximum was evaluated with a maximum difference of 7% between the two methods. As a result, based on the simulations performed for different beam delivery systems, the ability of the spot scanning method in adapting to the target volume, better control over dose distribution and less extra-tumor dose was demonstrated.

کلیدواژه‌ها [English]

  • Proton therapy
  • passive scattering
  • Spot Scanning
  • GATE
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