Establishment of diagnostic reference level and radiation dose variation in head & neck and pelvis treatment planning in radiation therapy computed tomography

Abstract

Background: This observational study aims to establish a discrepancy in the radiation dose distributed for head & neck and pelvis localization in Computed Tomography (CT) imaging in radiation therapy. The objective and need of the current study are to establish Diagnostic Reference Level (DRL) for head & neck and pelvic CT protocols in Radiation Therapy planning and compare them with other regional, national and international DRL. The established DRL will be used to find further optimized DRL for Radiation Therapy Computed Tomography (RTCT). Methods: A total of 120 patients with Head & Neck cancers and 90 patients with pelvic cancers to be treated with radiotherapy prescribed for the RTCT with ages above 18 years old and above were included in the current study. The advanced Philips 16 slice big bore CT acquired all the CT simulation images. Results: Third quartile standards of Dose Length Product and effective dose for Head & Neck, and pelvis were 790.65mGy.cm, 2.45179 mSv, and 999.7 mGy.cm, 15.48mSv respectively. The third quartile CTDIvol value for the same order of procedure is 17.6 mGy. Tube voltage of 120kVp and 300mAs and used for radiotherapy planning. Conclusion: The first regional Radiation therapy Computed tomography simulation Diagnostic reference levels have been projected and deliver a platform for dose evaluation and optimization due to the limited number of papers on radiation therapy, computed tomography, and diagnostic reference levels. Comparison with previously available RT CT diagnostic reference levels indicated some radiation dose variation, so exposure parameters should be revised and improved.