Aim: To compare intensity modulated radiotherapy with simultaneous integrated boost (IMRT-SIB) and a 3-dimensional conformal parotid gland-sparing radiotherapy (ConPas 3D-CRT) in treatment of nasopharyngeal carcinoma with regard to outcomes and dose distribution to the planning target volumes (PTVs) and to the organs at risk (OARs).
Methods: The treatment records of 24 patients with histologically proven carcinoma of the nasopharynx treated with ConPas 3D-CRT or IMRT-SIB technique between May 2009 and December 2016 were assessed.
Results: The mean dose and dose to 50% parotid glands volume as well as the maximal dose to the spinal cord were significantly lower in the IMRT-SIB than in the ConPas 3-CRT group (p < 0.05; p < 0.05; p < 0.01, respectively). IMRT-SIB was also superior in coverage of PTVs. The 3-year overall survival (OS) and disease-free survival (DFS) of patients in the IMRT-SIB and ConPas 3D-CRT groups were 77 and 81% (p = 0.93), 51.9 and 70.7% (p = 0.83), respectively.
Conclusion: IMRT-SIB provided additional spearing to parotid glands and spinal cord in comparison to ConPas 3D-CRT technique but without improvement of OS and DFS.
Keywords: Nasopharyngeal cancer; Organs at risk; Radiotherapy; Treatment techniques.