Advantages of 3D-CT Based Conformal Radiotherapy Treatment Planning Over 2D Conventional Tera Six Planning for Cervical Cancer Treatment at Ocean Road Cancer Institute

Abstract

Although External Beam Radiation Therapy (EBRT) is essential tool for the radiation therapy of cervical cancer; only one cancer institute in Tanzania performs 3-Dimensional Conformal Radiation Therapy (3DCRT) Computed Tomography (CT)-based planning. To identify benefits and advantages of 3D-CRT over 2D- conventional radiation therapy (2D-CRT), dosimetric parameters for tumor targets and organs at risk (OARs) were compared between these modalities for 23 cervical cancer patients. 11 cervical cancer patients were CT scanned after proper positioning and immobilization and transferred to Eclipse Treatment Planning System (TPS) for dose planning. The remaining 12 curative intent patients were planned using 2D-CRT system and treatment times were calculated for each patient. From the CT based planning, the minimum dose (D min), maximum dose (D max) and mean dose (D mean) to Planning Target Volume (PTV) and organs at risk (OAR), were compared for each plan. On average, the optimized maximum doses for bladder, rectum, femoral heads, PTV and Gross Tumor Volume (GTV) were 46.56 Gy, 42.65 Gy, 28.76 Gy, 48.56 Gy and 48.53 Gy. For 2D-concentional planning, the dose rate was 75.75 cGy/min and the average treatment time was 1.6075 minutes. This study confirms that 3D CT-based planning is a good choice in the treatment protocol for carcinoma cervix as it delivered a highly homogeneous and conformal plan with superior dose coverage to PTV and better OARs sparing.