WORLD JOURNAL OF ADVANCE
HEALTHCARE RESEARCH

Dr. Ahmed Mardan*, Dr. Manwar Abdulelah, Dr. Israa Hamzah Hammadi, Sura Yosif Ezzulddin and Nawras Ali Mousa

ABSTRACT

Background: Recently, pelvic radiation therapy for treatment rectal malignancies had been increasingly used. The use of portal images has been shown to have a positive impact on treatment, and common practice is to obtain portal images at the beginning of treatment and throughout after. Objectives: The study aimed to defining the optimal planning target volume using three-dimensional conformal radiotherapy in rectal malignancies. Methods: A retrospective study of 40 patients with rectal cancer treated with 3DCRT were included. The study conducted in Baghdad Radiotherapy and Nuclear Medicine Center, Baghdad Medical City Complex, Baghdad, Iraq, in period between December 2020 and May 2021. Results: In rectal cancer, the lateral verification including right and left, and posterior portals were significantly influenced by PI, whereas superior, inferior and anterior direction were unchangeable by portal verification. The highest mean set-up error was 2.18 mm for S-I in Portal 1#. The systematic set-up error for S-I, R-L and A-P were 0.56, 0.53 and 0.34 mm, respectively. The population random errors for S-I, R-L and A-P were 0.33, 0.29 and 0.18 mm, respectively. As a results, the CTV-PTV margins were 7 mm for S-I, 4.7 mm for R-L and 1 mm for A-P. Conclusions: CTV-PTV margins were range from 0.9 mm to 7 mm.