TURKISH JOURNAL OF ONCOLOGY 2017 , Vol 1 , Num 1
Dosimetric Comparison of Plans Obtained by Applying 3DCRT-VMAT and Tomotherapy Radiotherapy Methods in Patients with Thyroid" Ophthalmopathy Diagnosis
Özlem DILDAN1,Sinan HOCA1,Nezahat OLACAK1,Emine Serra KAMER1
1Department of Radiation Oncology, Ege University Faculty of Medicine, İzmir-Türkiye DOI : 10.5505/tjo.2024.4343

Summary

OBJECTIVE
The aim of our study is to compare the effectiveness of Lateral Three Dimensional Conformal Radiotherapy (3DCRT), Volumetric Modulated Arc Therapy (VMAT) and Helical Tomotherapy (HT) treatment planning systems (TPS) in patients receiving radiotherapy (RT) for thyroid ophthalmopathy (TO).

METHODS
In our study, each of 10 patients who received TO treatment between 2012 and 2019 were retrospectively planned with three different TPS and dosimetrically obtained data of the doses received by the planned target volume (PTV) and normal tissues for three TPS were compared.

RESULTS
When the Conformity Index (CI) and Homogenity Index (HI) were evaluated in terms of homogeneous coverage of the PTV target volume, it was shown that HT and VMAT techniques covered the target volume better than 3DCRT. Although the Monitor Unit (MU) value of HT was higher than the other two techniques, it was clearly seen that HT gave better results in the lenses and optic chiasm, which are critical organs. The VMAT technique, on the other hand, gave lower results than HT in the lacrimal glands. It was also observed that HT and VMAT techniques gave better results than 3DCRT in other organs at risk such as eyes, optic nerves and retinas.

CONCLUSION
The results of the study showed that all treatment techniques can be recommended as safe and effective in the treatment of TO.