Comparison between Three-Dimensional Conformal Radiation Therapy (3DCRT) and Intensity-Modulated Radiation Therapy (IMRT) for Radiotherapy of Cervical Carcinoma: A Heterogeneous Phantom Study

BACKGROUND: Radiotherapy plays a major role in the treatment of the cervical cancer. OBJECTIVE: Dosimetric comparison of intensity-modulated radiation therapy (IMRT) with three-dimensional conformal radiation therapy (3DCRT) in cervical cancer treatment was performed by modifying the beams arrangements to achieve better organ at risk (OAR) sparing. MATERIAL AND METHODS: The analytical evaluation study was made by modifying the IMRT plan, subtracting the rectal volume from planning target volume (PTV), and applying the field-in-field technique in 3DCRT. Eight patients in various cervical cancer stages, from I‒III, were inducted for this investigation. The prescribed dose was 5000 cGy in 25 fractions. For all cases, both IMRT and 3DCRT plans were generated. For PTV and OARs, dose volume histogram (DVH) comparative analysis was carried out. For safety checks and quality control, pre-treatment verification of all the plans was performed using an indigenously developed pelvic phantom (for IMRT and 3DCRT) and gamma analysis with Delta4 phantom (for IMRT). RESULTS: This study indicated that IMRT can treat cervical cancer more efficiently with less damage to OARs as compare to 3DCRT. CONCLUSION: In this study, we observe that the IMRT plans with subtracting rectal volume achieve better OAR sparing.