International Journal of Radiation Research

en Dosimetric characteristics of tomotherapy and three-dimensional conformal radiotherapy for head and neck cancer Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: This study aims to evaluate and compare Three-Dimensional Conformal Radiotherapy (3D-CRT) versus Helical Tomotherapy (HT) based on treatment planning and selection of the most appropriate method to reduce side effects. Materials and Methods: Treatment planning was performed on images of 20 patients with head and neck cancer with lymph node involvement by HT and 3D-CRT techniques in Seyed Al-Shohada hospital, Isfahan, Iran. The quality of target coverage, the exposure of normal tissue, and radiation delivery efficiency in two studied methods were compared. Results: Tomotherapy showed significant improvement over 3D-CRT in terms of D2%, D50% Dmean, V95%, CI (conformity index), and HI (homogeneity index) for PTV (planning target volume) and in terms of D2%, D98%, Dmean, V95%, CI and HI for PTV Nodal. The mean dose received by 98% of PTV (D98%) increased in HT compared to 3D-CRT. Whereas, higher doses received in organs at risk (OARs) in 3D-CRT compared to HT. Conclusion: Results showed improvements in target quality for HT over 3D-CRT, including dosimetric coverage of target volumes, homogeneity and conformity indices, and reduction of the volume of cold and hot spots. Tomotherapy also performed better than that of 3D-CRT in OARs. Overall, with the satisfactory results obtained here, HT technique has considerable promise for treating head and neck cancers with the involvement of regional lymph nodes.</div> Head and Neck Cancer, Conformity index, Homogeneity index, Radiotherapy, Three-Dimensional Conformal Radiation Therapy, Helical Tomotherapy. 427 434 http://ijrr.com/browse.php?a_code=A-10-1-1062&slc_lang=en&sid=1 N. Monadi 7900319475328460024253 7900319475328460024253 No Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran D. Shahbazi-Gahrouei shahbazi@med.mui.ac.ir 7900319475328460024254 7900319475328460024254 Yes Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran S. Monadi 7900319475328460024255 7900319475328460024255 No Department of Radiation Oncology, Seyed Al-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran L. Mahani 7900319475328460024256 7900319475328460024256 No Department of Radiation Oncology, Seyed Al-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran A. Shams 7900319475328460024257 7900319475328460024257 No Department of Radiation Oncology, Seyed Al-Shohada Hospital, Isfahan University of Medical Sciences, Isfahan, Iran A. Akhavan 7900319475328460024258 7900319475328460024258 No Assistant Professor of Radiation Oncology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran R. Mohammadi 7900319475328460024259 7900319475328460024259 No Department of Mathematics, Isfahan University of Technology, Isfahan, Iran