Serviks Kanseri İçin İki Farklı Brakiterapi Tedavi Planlama Tekniğinin Dozimetrik Karşılaştırması

Öz

ÖZ Amaç: Bu çalışmanın amacı, servikal kanserin brakiterapisinde manuel olarak optimize edilmiş (MO) planlama yaklaşımı ile inverse optimize edilmiş (IO) planlama yöntemleri arasındaki dozimetrik farklılıkları değerlendirmektir. Gereç ve Yöntemler: Bu çalışmaya on beş hasta dahil edildi. Yüksek riskli klinik hedef hacim (CTVHR) ve orta riskli hedef hacim (CTVIR) CTV'ler olarak tanımlandı, ayrıca riskli organlar olarak (OAR) rektum, mesane, ince bağırsak, sigmoid ve üretra tanımlandı. Her hasta için iki farklı tedavi planları oluşturuldu. Bütün hastalara 50.4 Gy external ışın radyoterapisi (EBRT) uygulandıktan sonra, 4 fraksiyonda 28 Gy yüksek doz oranı (HDR) tümör merkezine verildi. Bu tedavi planlarından alınan dozimetrik sonuçlar, CTV'ler, OAR'lar, uygunluk indeksi (CI) ve toplam tedavi süresi gibi dozimetrik parametreler karşılaştırıldı. Bulgular: CTVHR’ in D90, CTVIR’in D50 için anlamlı fark bulunamamıştır fakat CTVHR’ in D98 değeri için (p<0.000), CTVIR’in D90için (p<0.000) ve D98 için (p<0.000), CI (p<0.000), toplam dwell time (p<0.002). OAR’ler açısından, IO MO'dan önemli ölçüde daha iyi olduğu bulundu. (rektumun D2cm3 için p<0.043, mesanenin D2cm3, D0.1cm3 ve V5Gy için p<0.000, ince bağırsağın V5Gy için p<0.041, sigmoidin V5Gy için p<0.041, üratranın D2cm3 , D0.1cm3 ve V5Gy için p<0.000). Sonuç: OAR'lar ve hedef hacim göz önüne alındığında, IO serviks kanserinin yüksek doz oranlı brakiterapi için en uygun teknik olarak görülmektedir. Anahtar Sözcükler: Brakiterapi, Serviks kanseri, İnverse optimizasyon, Manuel optimizasyon

Anahtar Kelimeler

• Brakiterapi
• Serviks kanseri
• İnverse optimizasyon
• Manuel optimizasyon

Dosimetric Comparison of Two Different Brachytherapy Treatment Planning Techniques for Cervical Cancer

Abstract

Objective: The purpose of this study was to evaluate thedosimetric differences between inverse optimized (IO) planning methods with the manual optimized (MO) planning approach for brachytherapy of cervical cancer. Methods: Fifteen patients were included in this study. High-risk clinical target volume (CTVHR) and intermediate-risk CTV (CTVIR) were defined as CTVs, and rectum, bladder, smallbowel, sigmoid andurethra, were defined as organs at risk (OARs). Two different treatment plans were created for each patient: MO and IO. After all patients received 50.4 Gy external beam radiotherapy (EBRT), 28 Gy high-dose-rate (HDR) in 4 fractions was delivered to central disease. Dosimetric outcomes from these treatment plans were compared dosimetric parameters, such as CTVs, OARs, conformity index (CI) and total dwell time. Results: There were nosignificant differences in D90values of CTVHR and D50values of CTVIR, however significant differences were found D98values of CTVHR(p<0.000), and D90values of CTVIR (p<0.000), and D98 values of CTVIR (p<0.000), CI (p<0.000), total dwell time (p<0.002). In terms of OARs, IO was found to be significantly better than MO (p<0.043 for D2cm3 of rectum, p<0.000 for D2cm3 ,D0.1cm3 and V5Gy of bladder, p<0.041 for V5Gy of small bowels, p<0.000 for V5Gy of sigmoid, p<0.000 for D2cm3, D0.1cm3 and V5Gy of urethra). Conclusion: Considering the OARs and target volume, IO appears to be the most appropriate technique for high dose rate brachytherapy of cervical cancer. Key Words: Brachytherapy, Cervix cancer, Inverse optimization, Manual optimization

Keywords

• Brachytherapy
• Cervix cancer
• Inverse optimization
• Manual optimization

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