Evaluation of Dose Distribution in Field Junction Area and Risk Organs for Supine and Prone Treatment Techniques in Craniospinal Irradiation
Onur ÜNLENEN1,Serra KAMER1,Nezahat OLACAK1,Murat KÖYLÜ1,İbrahim OLACAK1,Yavuz ANACAK1,Deniz YALMAN1
1Department of Radiation Oncology, Ege University Faculty of Medicine, İzmir-Turkey DOI : 10.5505/tjo.2021.2628 OBJECTIVE
The aim of this study is to investigate dose distributions in junction regions and organs at risk in asymmetric collimation techniques and divergence matching techniques used in craniospinal treatments.

In the anthropomorphic phantom, the junction area and organ at risk doses were determined for eight different craniospinal irradiation (CSI) techniques with the help of thermoluminescent dosimeter (TLD) and treatment planning system (TPS). These techniques differ in terms of the parameters of the table being angled/un-angled, using block/multi-leaf collimator, and being in supine/prone position.

There was no statistically significant difference between TPS and TLD doses of all techniques. The lowest doses of cribriform plate are 1.82 Gy in PM, and 1.84 Gy in PAM. The lowest dose in lenses is 0.19 Gy in PB. The lowest dose of thyroid is 1.27 Gy in PB and highest dose of PAM is 1.35 Gy. Average small intestine dose of 1.92 Gy in non-table angle decreases to 1.08 Gy with table angle. The highest kidney doses are 0.14 Gy in SM. Ovaries take an average dose of 0.09 Gy in non-table angled and average of 0.13 Gy in table-angled techniques.

It has been determined that CSI technique in supine without table angle and protected with special blocks, is superior to other techniques due to its better dose homogeneity in treatment volume, providing immobilization in daily use and ease of application. Keywords : Awareness; educational level; electronic survey; knowledge; oral cancer; public health