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

Kaynakça

1. [1] Khan F.M: The Physics of Radiation Therapy 3rd Edition. Lippincott Williams & Wilkins Company, USA, 2010.
2. [2] Lee D.H, Cho J.K, Shin K.H, Shin D, Yoon M, Park S.Y, Lee S.B, Kim J.Y, Cho K.H, Lee J.W, Chung J.B, Choe B.Y, Choi K.S, Suh T.K. Intravaginal Packing Efects of CT-Guided Intracavitary Radiotherapy for Cervical Cancer. Korean Physical Society 2009; 54: 250-254.
3. [3] Baltas, Sakelliou D, Zamboglou L. The Physics of Modern Brachytherapy for Oncology 2007.
4. [4] Holloway C, Racine M.L, Cornack R.A, O’Farrell D.A, Viswanathan A.N. Sigmoid Dose Using 3D Imaging in Cervical-CancerBrachytherapy. Radiotherapyand Oncology 2009; 93(2): 307–310.
5. [5] Haie-Meder C, Pötter R, Limbergen E.V, Briot E, DeBrabandere M, Dimopoulos J, Dumas I, Hellebust T.P, Kirisits C, Lang S, Muschitz S, Nevinson J, Nulens A, Petrow P, Serstner N.W. Recommendations from Gy naecological (GYN) GEC-ESTRO Working Group(I): concept sand terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiotherapy and Oncology 2005; 74: 235–245.
6. [6] International Commission on Radiation Unit sand Measurements. Gynaecological brachytherapy, 1985.
7. [7] Limbergen E.V, Pötter R, Hoskin P, Baltas D: GEC ESTRO (European Society for Radiotherapy and Oncology) Handbook of Brachytherapy. ESTRO, 2014.
8. [8] Muller R, Runkel R. Measurement of dosimetric parameters for the Alphaomega high-dose-rate iridium-192 source. Medical Dosimetry 2005; 30(3):139-142.

9. [9] Podgorsak E.B: Radiation Oncology Physics: A Handbook for Teachersand Students. IAEA, 2005.
10. [10] Khan, F.M: The Physics of Radiation Therapy. Third Edition. Baltimore: Lippincott, Williams and Wilkins, 2003.
11. [11] Glenn P. Glasgow, Chairman J. Daniel Bourland Perry W. Grigsby Jerome A. Meli Keith A. Weaver : Remote Afterloading Technology. Published for the American Association of Physicists in Medicine by the American Institute of Physics, 1993.
12. [12] Plato Brachytherapy Remote Afterloading User Manuel.14.0 version. The Nethelands. Nucletron.
13. [13] Perez C.A., Grigsby P.W., Castro-Vita H., Lockett M.A. “Carcinoma of theuterinecervix. I. impact of prolongation of overall treatment time and timing of brachytherapy on outcome of radiationtherapy”. Int J Radiation Oncology Biology Physics (32): 1275-1288, 1995.
14. [14] Anbumani S, Anchineyan P, Narayanasamy A, Palled SR, Sathisan S, Jayaraman P, et al. Treatment planning methods in high dose rate interstitial brachytherapy of carcinoma cervix: a dosimetric and radiobiological analysis. ISRN Oncol 2014; 2014:125020.
15. [15] Gelover E, Katherine C, Mart C, Sun W, Kim Y. Patient's specific integration of OAR doses (D2 cc) from EBRT and 3D image-guided brachytherapy for cervical cancer. J Appl Clin Med Phys 2018; 19(2):83-92.
16. [16] Kannan RA, Gururajachar JM, Ponni A, Koushik K, Kumar M, Alva RC, et al. Comparison of manual and inverse optimisation techniques in high dose rate intracavitary brachytherapy of cervical cancer: A dosimetric study. Rep Pract Oncol Radiother 2015; 20(5):365-9.
17. [17] Palmqvist T, Dybdahl Wanderas A, Langeland Marthinsen AB, Sundset M, Langdal I, Danielsen S, et al. Dosimetric evaluation of manually and inversely optimized treatment planning for high dose rate brachytherapy of cervical cancer. Acta Oncol 2014; 53(8):1012-8.
18. [18] Kannan R.A., Gururajachar J.M., Ponni A., Koushik K., Kumar M., Alva R.C., Harjani R., Murthy A. Comparison of manual and inverse optimisation techniques in high dose rate intracavitary brachytherapy of cervical cancer: A dosimetric study. Reports of Practical Oncology & Radiotherapy 2015; Volume 20, Issue 5, 2015, Pages 365-369
19. [19] Trnkova P, Pötter R, Baltas D, Karabis A. New inverse planning technology for imageguided cervical cancer brachytherapy: Description and evaluation with in a clinical frame. Radiotherapy and Oncology 2009; 93:331-340.
20. [20] Swamidas V. Jamema, Christian Kirisits , Umesh Mahantshetty. et al. Comparison of DVH parameters and loading patterns of standard loading, manual and inverse optimization for intracavitary brachytherapy on a subset of tandem/ovoid cases