Summary
OBJECTIVEThe 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.