TURKISH JOURNAL OF ONCOLOGY 2009 , Vol 24 , Num 1
Preparation of tissue compensator and investigation of resultant dose distribution effects on treatments performed with Co-60 teletherapy machine
Kadir YARAY1, Halil KÜÇÜCÜK2, Oğuz Galip YILDIZ1, Hatice BİLGE3
1Erciyes Üniversitesi Tıp Fakültesi, Radyasyon Onkolojisi Anabilim Dalı
2Acıbadem Kozyatağı Hastanesi, Radyasyon Onkolojisi Kliniği
3İstanbul Üniversitesi Onkoloji Enstitüsü, Tıbbi Radyofizik Bilim Dalı
OBJECTIVES
In this study, it was purposed to design an aluminium material using compensator in order to obtain homogeneous dose distribution in irradiated volume on an irregular treatment field.

METHODS
For preparation of the compensator for large body curve, the anterior supra field of 25x26 cm and the lateral field of the face of 13x12 cm were selected. For the selected fields, the compensators were prepared using a man-shaped special phantom. The selected lateral face and anterior supra field without using the compensator and on Co-60 apparatus, dose distribution was obtained by film dosimetry method from man- shaped sagittal two-segmented special phantom. Findings were controlled using another measuring system thermoluminescent dosimeter. The experimental studies made without using the compensator were repeated with the compensator. The dose distributions obtained with and without compensator were compared and any positive contribution to dose distribution was investigated.

RESULTS
The data obtained from this study using compensator on the treatment field with excess surface irregularity, on lateral face, medial line and vertical axis, showed 5% more homogeneous dose distribution, and for supra field, parallel axis to radiation field to isodose distribution was 11.1% more homogeneous.

CONCLUSION
Consequently, in the case of curved or irregular treatment surfaces, a more homogeneous dose distribution can be produced using tissue compensators prepared for each patient separately. This will increase treatment quality in clinical use. Keywords : Dose distribution; compansator; radiotherapy