Eksternal Pelvik Radyoterapi’de Cihaz Seçimi Üzerine Etkili Faktörler ve Yan Etkilerin Karşılaştırılması‡

Abstract

Radyoterapinin amacı iyonizan radyasyon kullanarak malign hücrelerin ortadan kaldırılmasıdır. Günümüzde pelvik yerleşimli tümörlerin tedavisinde diğer tedavi modelleri ile kombine veya tek başına sıkça uygulanmaktadır. Çalışmamızda Ondokuz Mayıs Üniversitesi Tıp Fakültesi Radyasyon Onkolojisi Anabilim Dalında Ocak 2006-Aralık 2007 yılları arasında pelvise radyoterapi uygulanmış 95 hastanın akut radyoterapi toksisitesi, çalışma prensipleri ve ışın özellikleri farklı olan 2 ayrı radyoterapi cihazına göre karşılaştırılmış, cihaz özellikleri dışında toksisite üzerine etkili diğer faktörler de incelenmiştir. Hastaların %43,2’si erkek, %56,8’i kadın, yaş ortalaması 60,71±13,1’dir. Primer tanılar değerlendirildiğinde en sık rektum tümörü (%32,6) nedeniyle radyoterapi uygulanmıştır. Radyoterapi cihazı hastaların %43,2’sinde kobalt 60, %56,8’inde enerjisi 18 MV olan lineer akseleratördür. Hastaların ön-arka yarı çap ortalaması 10,63±1,43 cm, uygulanan toplam radyoterapi dozu ortalaması 5481,68±817,24 cGy’dir. Uygulanan radyoterapi dozu lineer akseleratör kolunda daha yüksek olmakla beraber aradaki fark anlamlı bulunmamıştır (p=0,053). Küratif amaçlı radyoterapi uygulaması lineer akseleratör kolunda (p=0,04), palyatif tedaviler ise kobalt 60 kolunda daha çok yapılmıştır. Çoklu alan düzenlemeleri (p=0,001) ve hasta yarı çapı (p=0,001) lineer akseleratör kolunda anlamlı olarak yüksektir. Radyoterapinin birinci haftasında alt gastrointestinal bölgeye ait (p=0,02), üçüncü haftasında deriye ait yan etkiler (p=0,04) kobalt 60 tedavi kolunda anlamlı olarak daha yüksektir. Sonuç olarak pelvik yerleşimli tümörlerin tedavisinde lineer akseleratör tedavi cihazının kullanılması erken yan etkilerin azaltılmasında daha etkilidir. Anahtar kelimeler: Pelvik radyoterapi, Kobalt 60, lineer akseleratör, erken yan etkiler The Factors that Effects the Choice of Treatment Machine for External Pelvic Radiotherapy and Comparison of the Side-Effects The aim of the radiotherapy is to eliminate the malign cells by using ionizing radiotherapy. Radiotherapy is being used rather frequently for the treatment of pelvic tumors as a primary modality or with the combination of the others. This study is designed in Ondokuz Mayis University School of Medicine Radiation Oncology Department between January 2006 and December 2007. Ninety-five patients were treated with pelvic external radiotherapy in this period. There were two different treatment machines which have differences for the acute radiotherapy toxicity, working principles and beam characteristics. These differences and also, the factors that might be associated with radiotherapy toxicity are analyzed. Of the patients 43,2% were male, and 56,8% were female and the mean age was 60,71±13,1. When examined the primary diagnosis, external pelvic radiotherapy treatment was given for rectal cancer (32,6%) most frequently. The treatment machine was Cobalt 60 teletherapy machine in 43,2% patients and Linear accelerator with energy of 18 MV in 56,8% patient. The mean front to back radius of the patients was 10,63±1,43 cm, the mean overall treatment radiotherapy dose was 5481,68±817,24 cGy. Although the overall treatment dose was higher in linear accelerator treatment group the difference was not significant (p=0,053). The curative treatments were made with linear accelerator (p=0,04), where more palliative treatments were made with Cobalt 60 machine. More complex treatments (multiple fields) were used in Linear accelerator treatments (p=0,001). The front to back radius of the patients in linear accelerator treatment group was higher (p=0,001). When compared for the side-effects; the patients who were treated with Cobalt 60 has more gastrointestinal side-effects at the first treatment week (p=0,02) and skin side-effects at the third treatment week (p=0,04). As a conclusion; for the external radiotherapy of pelvic tumors linear accelerator is more suitable with less side-effect. Key words: Pelvic radiotherapy, Cobalt 60, linear accelerator, early toxicities

Keywords

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