Burak BAŞLANGIÇ, Görkem GÜNGÖR, Gökhan AYDIN, Melih ULUER, Mustafa KARADEMİR, Bülent YAPICI, Bilgehan ŞAHİN, Banu ATALAR, Enis ÖZYAR

Akciğer Kanseri SBRT Uygulamalarının RTOG 0915 Protokolüne Uygun Doz Sınırlamalarına Göre Oluşturulan 3B Konformal Ark ve VMAT SBRT Planlarının Karşılaştırılması

Bu çalışmada 20 erken evre küçük hücreli dışı akciğer kanseri hastasının KHDAK , akciğer stereotactic body radiation therapy SBRT için en son olarak yayımlanan Radiation Therapy Oncology Group 0915 RTOG 0915 protokolünün fiziksel kabul kriterlerine göre tedavi planlamaları yapılmıştır. Planlamalar, volumetric modulated arc therapy VMAT ve 3B konformal ark teknikleri kullanarak 6MV düzleştirici filtreli FF ve 6MV düzleştirici filtresiz FFF enerji modlarında yapılmıştır. VMAT tekniği 3B konformal ark tekniği ile kıyaslandığında RTOG 0915 protokolünün yüksek ve orta doz saçılım kriterleri olan konformite indeksi CI , orta doz saçılmalarını ifade eden %50 izodoz hacminin planning target volume PTV hacmine oranı, 2 cm uzaktaki % doz değeri göre istatistiksel olarak anlamlı sonuçlar ile birlikte daha iyi planlar ortaya koymuştur. Enerji modaliteleri kendi aralarında incelendiğinde FFF modu ile yapılan planlar FF modu ile yapılan planlara göre RTOG 0915 kriterleri bakımından daha avantajlı sonuçlar vermişlerdir. Çalışmanın bütünü ele alındığında VMAT-FFF tekniği, yüksek ve orta doz saçılmalarındaki avantajlarına bağlı olarak akciğer SBRT tedavileri için en uygun teknik olarak bulunmuştur.

COMPARISON OF 3D CONFORMAL AND VOLUMETRIC MODULATED ARC TECH ACCORDING TO RTOG 0915 PROTOCOL TREATMENT PLANNING GUIDELINES IN STEREOTACTIC LUNG RADIATION THERAPHY

In this study, 20 non-small cell lung cancer patients were treated according to the accepted physical criteria of the latest lung SBRT protocol RTOG 0915. VMAT, 3D conformal arc techniques with 6 MV FF and FFF energy modalities were used for treatment planning. VMAT technique has statistical significance and has shown better high dose and intermediate spillage region according to RTOG 0915 definitions; ratio of prescription isodose volume to the PTV volume Conformity index - CI , ratio of 50% prescription isodose volume to the PTV intermediate spillage volume - ISV , maximum dose in % of dose prescribed at 2 cm from PTV intermediate dose spillage location - ISL compared to 3DCA. Investigation of FFF and FF energy modalities demonstrate that FFF plans have advantages in RTOG 0915 criteria over FF plans. Results of all the plans point to VMAT-FFF as the optimal technique for lung SBRT treatments due to the high quality SBRT plans obtained

Keywords:

VMAT, conformal arc, flattening filter, flattenibg filter free energy modes,

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