Comparison of Radiation Dose in Planning Target Volume and Organs at Risk for Prostate Cancer Patients with Three–Dimensional Conformal Radiotherapy and Intensity Modulated Radiation Therapy in Sakon Nakhon hospital

Abstract

           This study aimed to compare the radiation dose in planning target volume (PTV) and organs at risk (OARs) in prostate cancer patients between the 3–dimensional conformal radiotherapy (3DCRT) technique and intensity–modulated radiotherapy (IMRT) technique. The sample was ten 3DCRT and ten IMRT radiation treatment plans from five high–risk prostate cancer patients. The radiotherapy treatment plans including 3DCRT technique and IMRT technique with total prescription dose between 76 and 78 Gy were created for each of five prostate cancer patients. Conformity index (CI) and dose volume parameters of PTV and OARs were compared between both techniques.

         The results showed that the CIs of PTV from both techniques were between 0.99 and 1.48. The percentages of prescription dose covering 95% of PTV (D95) from both techniques were equal or greater than 95. The volume of PTV receiving more than 110% of prescription dose (V 110) from 3DCRT technique was significantly greater than IMRT technique (p < 0.001). In all 3DCRT plans, the radiation doses received by OARs were exceeding the Radiation Therapy Oncology Group (RTOG)’s standards while they were within the limits for all IMRT plans.

           The IMRT technique can escalate the radiation dose to PTV and reduce the radiation dose to OARs in prostate cancer patients which could decrease the risk of acute and late radiation toxicity, resulted in better quality of life for patients.

           Keywords: 3–Dimensional conformal radiotherapy, Intensity modulated radiotherapy, Prostate cancer