TURKISH JOURNAL OF ONCOLOGY 2017 , Vol 1 , Num 3
Comparison of Contouring Results for Prostate Cancer Treatment Planning Obtained by Two Different Radiology Specialists
İlknur ALSAN ÇETIN1,Ayşe DAĞLI DEĞERLI1,Rabia ERGELEN2,Erkan ÖZGEN1,Merve SEVINDIK1
1Department of Radiation Oncology, Marmara University Faculty of Medicine Hospital, İstanbul-Turkey
2Department of Radiology, Marmara University Faculty of Medicine Hospital, İstanbul-Turkey
DOI : 10.5505/tjo.2016.1524 OBJECTIVE
This study is a comparison of contoured diagnostic images derived from computed tomography (CT) and magnetic resonance imaging (MRI) by both a radiation oncologist (RO) and a radiologist (R) using volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) techniques.

METHODS
CT and MRI sections of 16 patients were contoured by the RO and the R. Planning target volume (PTV) criteria assessed were conformity index (CI), homogeneity index (HI), volume covered by 98% isodose line (V 98%) and maximum dose (Dmax). In critical organs, 40 Gy organ area volume (V40), 65 Gy organ area volume (V65), and Dmean criteria were evaluated. Paired samples t-test was used for statistical analysis.

RESULTS
PTV and critical organs were compared. MRI PTV and bladder volume drawn by R were lower. Comparison of CT images revealed IMRT plans were superior in terms of Dmax and CI, while V40 and Dort values for rectum and bladder were lower in MRI-based VMAT plans. In MRI plans, IMRT was superior in terms of PTV, Dmax, CI, V65, and Dort for critical organs; however, critical organs were well preserved with both planning techniques.

CONCLUSION
There was some difference between contouring of the R and the RO, which was reflected in the treatment plans. Keywords : Planning techniques; prostate cancer; radiotherapy.