Burcu İBİCİOĞLU, Meral KURT, Sema GÖZCÜ TUNÇ, Candan DEMİRÖZ ABAKAY, Sibel KAHRAMAN ÇETİNTAŞ, Abdulhamit TURAN, Ece Ayfer CURA, Habibe ALTAŞ

Pankreas Kanseri Radyoterapisinde 3 Farklı Tedavi Tekniğinin Dozimetrik Karşılaştırılması: Retrospektif Çalışma

Çalışmamızda amacımız pankreas kanseri tanısıyla radyoterapi görmüş, 20 hastaya konformal radyoterapi (3B-KRT), yoğunluk ayarlı radyoterapi (IMRT), hacimsel ayarlı ark terapi (VMAT) teknikleri ile tedavi planlaması yapılarak tekniklerin dozimetrik açıdan karşılaştırılmasıdır. Bu çalışmada 2012-2017 yılları arasında kliniğimizde tedavi görmüş, primer pankreas başı tümörü olan 20 hasta retrospektif olarak değerlendirilmiştir. Her hastaya tümör, tümör çevresi ve bölgesel lenf nodlarına yönelik 5 farklı tedavi tekniği planlanmış, tüm planlar hedef hacim dozları 54/45 Gy olacak şekilde seçilmiştir. Planlar VMAT ve IMRT için 6 MV X-ışını, 3BKRT için 6/15 MV X-ışını kullanılarak hazırlanmıştır. Planlanan hedef hacim dozları (PTV), Conformite indeksi (CI), Homojenite indeksi (HI), riskli organlar (böbrekler, spinal cord, karaciğer) açısından teknikler karşılaştırılmıştır. PTV54 ve PTV45 için ortalama CI indeksleri VMAT 1 ark planlarında sırasıyla 1,16 ve 1,03 VMAT 2 arkda ise 1,01 ve 1,00 bulunmuştur. CI açısından iki grup arasında anlamlı fark olmamasına rağmen en uygun CI değeri VMAT 2 ark planlarında bulunmuştur (PTV45 için p=0,806-PTV54 için p=0,595). IMRT ile 3B-KRT teknikleri arasında CI açısından fark bulunamamış, en uygun değer IMRT tekniğinden elde edilmiştir. Kritik organ dozları açısından VMAT 1 ark ve VMAT 2 ark planları arasında istatistiksel farklılık olmamasına rağmen VMAT 2 ark planlarının dozları daha düşük bulunmuştur. Pankreas tümörleri yerleşim yeri olarak böbrekler ve karaciğer gibi kritik organlara yakın oluşundan 3BKRT planları karaciğer açısından kabul edilebilir; ancak böbrekleri koruma açısından yeterli değildir. VMAT 2 ark tekniği diğer tekniklere göre doz sarımı, CI, HI ve kritik organ dozlarında üstünlük sağlamıştır. Bu yüzden yan etkiler göz önüne alındığında tedavi tekniği olarak VMAT tercih edilebilir.

Anahtar Kelimeler:

VMAT, Pankreas Kanseri, 3BKRT, IMRT

DOSIMETRIC COMPARISON OF 3 DIFFERENT TREATMENT TECHNIQUES IN PANCREATIC CANCER RADIOTHERAPY: RETROSPECTIVE STUDY

In our study, our aim is to treat 20 patients with pancreatic cancer who had radiotherapy, with conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT), volume modulated arc therapy (VMAT) planning and comparison of the techniques in terms of dosimetric. In this study, 20 patients with primary pancreatic head tumor who were treated in our clinic between 2012-2017 were retrospectively evaluated. Five different treatment techniques were planned for each patient’s tumor, around of tumor and regional lymph nodes, and all plans were implemented so that target volume doses would be 54/45 Gy. Plans were prepared using 6 MV X-rays for VMAT and IMRT and 15 MV X-rays for 3BKRT. Techniques were compared in terms of planned target volume doses (PTV), conformity index (CI), homogeneity index (HI), organs at risk (kidneys, spinal cord, liver). The mean CI indices VMAT 1 arc plans for PTV54 and PTV45 were found to be 1.16 and 1.03 for VMAT 2 arc 1.01 and 1.00. Although there was no significant difference between the two groups in terms of CI, the most appropriate CI value was found in VMAT 2 arc plans (p = 0.806 for PTV45 and p = 0.595 for PTV54). There was no difference in terms of CI between IMRT and 3D-CRT techniques, the best value being obtained from IMRT technique. Doses of VMAT 2 arc plans were found to be lower, although there was no statistical difference between VMAT 1 arc and VMAT 2 arc plans in terms of critical organ doses. Since pancreatic tumors are located close to critical organs such as kidneys and liver as a settlement, 3DCRT plans can be accepted in terms of liver; but the kidneys have not succeeded in terms of protection. The VMAT 2 arc technique excelled in dose sprinning, CI, HI and critical organ doses according to other techniques. Therefore, VMAT may be preferred as a treatment technique when side effects are taken into account.

Keywords:

VMAT, Pancreatic Cancer, 3D-CRT, IMRT,

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1.A. Murat Tuncer ve ark. Türkiye’de Kanser Kontrolü. T.C. Sağlık Bakanlığı. 45-49. (2009).
2.Siegel R, Ma J, Zou Z, Jemal A. Cancer statistics, CACancer J Clin 2014;64(January–February (1)):9–29.2014
3.Ma J, Siegel R, Jemal A. Pancreatic cancer death rates by raceamong US men and women,1970–2009. J Natl Cancer Inst2013;105(November(22)):1694-700
4.Kelsen D.P. ve ark. Principles and Practice of Gastrointestinal Oncology. 2th edition, Philadelphia: Lippincott Williams & Wilkins, 2008.
5.Nima Nabavizadeh, M.D., Anna O. Simeonova,M.D.,Joseph G.Waller, M.D.,M.P.H.,Jeanna L. Roer, B.A., Debra L. Monaco ,C.M.D., David A.Elliott, M.D. James A. Tnayi, Ph.D.,Martin Fuss, M.D.,Ph. D., Charles R. Thomas Jr, M.D., and John M.Holland,M.D:Volumetric-modulated arc radiotherapy for pancreatic malignancies: Dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3- dimensional conformal radiotherapy(2014)
6.LoehrerSr Pj, Feng Y, Cardenes H, et al: Gemcitabine alone versus gemcitabine plus radiotherapy in patients with locally advanced pancreatic cancer: An Eastern Cooperative Oncology Group trial. J Clin 29(31)4105-4112, 2011
7. Hammel P, Huguet F, Van Laethem Jl, et al: Comparasion of chemoradiotherapy (CRT) and chemotherapy (CT) in patients with a locally advanced pancreatic cancer (LAPC) controlled after 4 months of gemcitabine with or without erlotinib: Final results of the international phase III LAP 07 study. J Clin Oncol(31), 2013
8. Henry A.M, Ryder W.D.J, Moore C, Sherlock D.J, Geh J.I, Dunn P, Price P:Chemoradiotherapy for locally advanced pancreatic cancer:A radiotherapy dose escalation and organ motion study; Clinical Oncology 2008;20:541-547.
9.Philips T.L.P ve ark. Leibel’s Textbook of Radiation Oncology. 3th edition, Philadelphia; Elsevier Saunders, 2010.
10. Abeloff M.D. ve ark. Abeloff’s Clinical Oncology. 4th edition, Philadelphia; Churchill Livingstone Elsevier, 2008
11.Willett, C.G.; Czito B.G.; Bendell, J.C. Cancer of the pancreas. In: Halperin, E.C.; Perez, C.A.; Brady, L.W., editors. Principles and Practice of Radiation Oncology. Philadelphia: Lippincott Williams& Wilkins; 2008.
12. Regine, W.F;Winter, K.A.;Abrams,R.A.; et al. Fluorouracil vs gemcitabine chemotherapy before and after fluorouracil-based chemoradiation following resection of pancreatic adenocarcinoma: A randomized controlled trial.J. Am.Med. Assoc, 299:1019-26; 2008.
13. Agulnık M. Head and Neck Cancer. Editor. PUATAWEEPONG P, Advanced Radiation Therapy for Head and Neck Cancer: A New Standard of Practise, 1st Edition, Intech, Thailand, page 232-235, 2012.
14. Xin Wang, M.D, Ph.D.,Guangjun Li, M.S., Yingjie Zhang, M.S.,Sen Bai,Ph.D., Feng Xu,M.D.,Yuquan Wei, M.D.,Ph.D., and Youling Gong, M.D.,Ph.D.:Single-arc volumetric-modulated arc therapy(sVMAT) as adjuvant treatment for gastric cancer: Dosimetric comparasions with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy.2013
15. Otto K (2008) :Volumetric modulated arc therapy: IMRT in a single gantry arc. Medical Physics 35(1): 310-317.
16. Deluca, P. M.(2007) The international commission on radiation units and measurements.
17. Loic F, Georges N, Jean-Jacques M, Pıerre B. Conformity index: a review. Int. J. Radiation Oncology Biol. Phys. 2006,2:333-342
18.ICRU (International Commission on Radiation Unıts and Measurements), Prescribing, Recording and Raporting Electron Beam Therapy, Report No.71, Bethesda, MD.2009
19. Van't Riet A, Mak AC, Moerland MA et al (1997) A conformation number to quantify the degree of conformality in brachy therapy and external beam irradiation: application to the prostate. International Journal of Radiation Oncology Biology Physics 37(3): 731-736.
20. Katherine L. Chapman, M.S.Matheww E . Witek, M.D.Hongyu Chen, B.S.Timothy N.Showalter, M.D.,Voichita Bar-Ad,M.D., and Amy S. Harrison M.S :Pancreatic cancer planing: Complex conformal vs modulated therapies
21. Martın-Immanuel Bittner, Anca-Ligia Grosu, Thomas B. Brunner: Comparison of toxicity after IMRT and 3D- conformal radiotherapy for patients with pancreatic cancer- A systematic review
22. Arif N. Ali,M.D.Aness H. Dhabaan, Ph.D., Christie S. Jarrio, M.S.Arsalan K.Siddiqi,M.S. and Jerome C.Landry M.D:Dosimetric comparison of volumetric modulated arc therapy and intensity-modulated radiation threapy for pancreatic malignancies (2011)
23. Van Der Geld, Van Triest B, Verbakel WF et al. Evaluation of Four-Dimensional Cmoputed Tomograpy- Based Intensity- Modulated and Respiratory-Gated Radiotherapy Techniques for Pancreatic Carcinoma, International Journal of Radiation Oncology, Biology, Physics, 72:1215-1220;2008.
24. Glowacki G: The Comparison of The Conformal Radiotherapy(CFRT-2,3 and 4 fields) and Intensity Modulated Radiotherapy (IMRT) in Adjuvant Radiochemotherapy for Patients with Pancreas Cancer. EJC Supplements, Joint ECCO 34th ESMO Multidisciplinary Congress, Abstract Book USA: Elsevier, 2009. 386
25. Mıchael W. Brown, M. D, Holly Nıng, Ph. D: A Dosimetric Analysis of Dose Escalation Using Two Intensity-Modulated Radiation Therapy Techniques in Locally Advanced Pancreatic Carcinoma