Nazofarenks kanseri tedavisinde üç boyutlu konformal radyoterapi ve yoğunluk ayarlı radyoterapi tekniklerinin karşılaştırılması
Özet
In this thesis, treatment plans of 9 patients with nasopharyngeal cancer diagnosis were done with Three Dimensional Conformal Radiotherapy (3DCRT) and Intensity Modulated Radiotherapy (IMRT) techniques using cross-sectional images of pre-treatment Computed Tomography (CT) and the data obtained were compared.Phased lateral fields in 3DCRT technique and "inverse", "sliding window" technique, 5 fields (00, 600, 1400, 2200, 3000), in IMRT technique were used. Dose constraints is determined as of brainstem 54 Gy, optic chiasm 50 Gy, optical nerves 50 Gy, eyes 35 Gy, lenses 6 Gy. . The prescribed dose was total dose of 70 Gy to PTV. For 3DCRT daily dose is 200 cGy at 35 fractions. For IMRT treatment daily dose is 212.1 cGy at 33 fractions.When compared with the 3DCRT, in IMRT plans, minimum dose value of target volume was increased by 6,91 Gy , mean dose value of target volume was increased by 3,86 Gy . When considered to 3DCT IMRT plans dose taken by %95 of PTV increased %34. IMRT plans provided 6% more homogeneous dose distribution and critical organ doses decreased by 3.86 Gy for brainstem, 2,14 Gy for spinal cord, 8,59 Gy for right optical nerve, 7,47 Gy for left optical nerve and 18,50 Gy for right temporomandibular joint,26,82 Gy for left temporomandibular joint. It was observed that in IMRT technique mean dose of right parotis decreased 44,02 Gy and left parotis 42,19 Gy rather than 3DCRT.IMRT technique is more appropriate than 3DCRT, with minimum critical organ doses.