The present study aims to compare the treatment plan parameters of different radiotherapy techniques
[3D-Conformal Radiotherapy (3D-CRT), Dynamic – Intensity Modulated Radiotherapy (D-IMRT), Intensity Modulated Arc Therapy (IMAT) and Helical Tomotherapy (HT)] in Early-Stage Glottic Larynx
(EGL) cancer to increase the treatment dose from 63 Gy to 70 Gy.
The dose prescription was defined as 2.12 Gy per fraction to a total of 33 fractions. 95% of Planning
Treatment Volume-63 Gy (PTV-63) and Planning Treatment Volume-70 (PTV- 70) treatment volumes
received the treatment dose of at least 63 and 70 Gy, respectively. The conventional-boost technique
was used for 3D-CRT and the simultaneous integrated boost technique was used for other techniques.
The doses obtained from carotid arteries, thyroid and submandibular glands using IMRT, IMAT, and
HT were significantly lower than 3D-CRT. The study results pointed out the possibility of giving a treatment dose of 70 Gy to the PTV of EGL with all planning techniques, with some advantages and disadvantages between them. All IMRT techniques provided superiority to 3D-CRT on the doses of the
carotid artery, the thyroid gland, the submandibular glands, and the pharyngeal constrictor muscles
with less variation between them.
The IMAT and 3D-CRT techniques yielded lower monitor unit values compared to other techniques.
Normal tissue radiation exposure was lowest with the 3D-CRT technique. We recommend to increase
the treatment dose from 63 Gy to 70 Gy in the radiotherapy of EGL cancer but to select the technique
according to the patient’s condition.