Source Calibration and Radiation Safety in Afterloading Brachytherapy Systems

Öz

Brachytherapy helps to deliver radiation directly to the location of cancer cells through the placement of small radioactive sources inside the body. Today, irradiation with it is considered an essential part of treatment for almost all cancerous areas. Based on the improved localization techniques and treatment planning systems, it is now possible to have precise and reproducible dose distributions. In therapeutic applications, doses are high and deviation from the prescribed level can lead to serious or even fatal consequences. However, the desired clinical results can be achieved only with good clinical and dosimetric practice, in other words, with the comprehensive Quality Assurance (QA) program implementation that includes detailed Quality Control procedures. The most basic element in QA can be achieved by determining the source information accuracy. One of the most necessary elements for source calibration works correctly by means of the equipment that is needed for this calibration according to the existing setup in the center (well-type ion chamber, jig phantom, special calibration phantom, suitable ion chambers, and electrometers). In addition, among the necessary duties for QA are the determination of the task’s distribution, responsible persons’ authorization, and appropriately training of all relevant personnel. In addition, the existence of a center-specific quality control and radiation safety procedure is the basis for correct and high-quality practices.

Anahtar Kelimeler

• brachytherapy
• radiation
• radiation protection
• quality control and assurance

Afterloading Brakiterapi Sistemlerinde Kaynak Kalibrasyonu Ve Radyasyon Güvenliği

Öz

Brakiterapi, kanserli hücrelerin bulunduğu yere doğrudan ışın verebilmek için radyoaktif kaynakların doku içi, vücut yüzeyi ve boşluklarına yerleştirilerek yapılan tedavidir. Günümüzde, brakiterapi ile ışınlama, neredeyse tüm kanser bölgeleri için tedavinin temel bir parçası olarak kabul edilmektedir. İyileştirilmiş lokalizasyon teknikleri ve tedavi planlama sistemleri ile artık hassas ve tekrarlanabilir doz dağıtımına sahip olmak mümkündür. Terapötik uygulamalarda dozlar yüksektir ve reçete edilen dozdan sapma ciddi veya hatta ölümcül sonuçlara yol açabilir. Yüksek dozlar lokal olarak hedefe verilirken çevredeki normal dokularda hızlı doz düşüşü sağlanır. Küçük hacimlerde kısa sürede yüksek doza ulaşıldığı için kalite kontrolü oldukça önemlidir. Ancak, istenen klinik sonuçlar yalnızca iyi bir klinik ve dozimetrik uygulama ile, yani kısaca ayrıntılı Kalite Kontrol prosedürlerini içeren kapsamlı, uygulanabilir ve tekrarlanabilir bir Kalite Güvence (KG) programının uygulanmasıyla elde edilebilir. Bu KG’ nin en temel unsurlarından birisi de kaynak bilgilerinin doğruluğunun tespit edilmesi ve Tedavi Planlama Sistemine (TPS) girilmesidir. Bu kalibrasyon için merkezde mevcut olan düzeneğe göre ihtiyaç duyulan ekipmanların (Kkuyu-tipi iyon odası, jig fantom, özel kalibrasyon fantomu, uygun iyon odaları ve elektrometreler) doğru çalışıyor olması kaynak kalibrasyonu için en gerekli unsurlardan biridir. Ayrıca görev dağılımının belirlenmesi, sorumlu olacak kişilerin yetkilendirilmesi, ilgili tüm personelin görevleri için uygun şekilde eğitilmesi KG için gereklidir. Bunlara ilave olarak merkeze özgü kalite kontrol ve radyasyon güvenliği prosedürünün mevcudiyeti doğru ve kaliteli uygulama yapmanın temelidir.

Anahtar Kelimeler

• brakiterapi
• radyasyon
• radyasyondan korunma
• kalite kontrol

Kaynakça

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