Özet:

Purpose: The aim of this study is to compare two radiotherapy techniques in early stages of glucose larynx cancer in patients diagnosed in terms of carotic artery doses. Methods: In this study, we included the patient diagnosed with 10 early stages (T1 / 2) of glothic larynx cancer. For each patient, both intensity-adjusted radiotherapy (YART) and 3D conform radiotherapy (3BKRT) treatment plans have been prepared. Treatment volumes (CTV, PTV) were created for all patients. All larynks, real and false vocal cords, anterior-posterior commissors, arithenoids, aryepiglottic curves, subglottic area were formed to include the clinical target volume (CTV). To create the planned target volume (PTV), 5 mm is added to the CTV in all directions, and 3 mm marge is given in the posterolateral direction for the protection of the carotenous artery and spinal cortex. Since the risk of lymph nodal metastasis in T1/T2 glottic cancer is very low, there is no elective nodal radiation. The spinal cord and carotic arteries are converted into critical organs (OARs). The target volume doses, the OAR volumes, the homogenity index (HI) were compared. In addition, V30 <20%, V10 <50% for the carotenous artery was assessed and the maximum dose of the spinal cord was limited to 45Gy. The conformity index (CI) is calculated. For statistical analysis, Mann Whitney test was used and p <0.05 was considered meaningful. Results: PTV parameters (Dmin, Dmean, Dmax, D90, D95) were compared in two different techniques. Compared to 3BKRT, YART significantly decreased high-dose volumes (V30, V35, V50) in the carotic artery (p < 0.001), while low-dose volumes (V10) looked high in both techniques. In both techniques, CI was similar (0.9 vs. 0.9, p = 0.3), and HI was better in YART (0.1 vs. 0.08, p < 0.001). The maximum doses of the spinal cord were lower at 3BKRT (18 Gy vs. 44Gy). The result: IMRT is an excellent radiotherapy (RT) technique in terms of the protection of the carotic artery in patients with T1 / T2 glottic cancer.

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