Affiliations: Department of Radiation Oncology, the First Affiliated
Hospital of Anhui Medical University, Hefei, Anhui, China | Department of Radiology, the First Affiliated Hospital
of Anhui Medical University, Hefei, Anhui, China
Note: [] Corresponding author: Wang Fan, Department of Radiation
Oncology, the First Affiliated Hospital of Anhui Medical University, Hefei
230022, Anhui, China. Tel.: +86 15375330581; E-mail: xujianming1305@126.com
Abstract: PURPOSE: To explore the value of diffusion-weighted imaging (DWI)
and magnetic resonance imaging (MRI) on the follow-up of nasopharyngeal
carcinoma (NPC) after radiotherapy. MATERIAL AND METHODS: Eighty-three NPC patients after radiotherapy
were divided into two groups: 4 cases of residual tumor and 33 cases of
non-residual within 6 months, the cases of recurrent and non-recurrent were 5
and 41 over 6 months, respectively. MRI and DWI imaging of these cases were
closely analyzed, and the apparent diffusion coefficient (ADC) of the
nasopharyngeal residual mass and nasopharyngeal wall thickening, skull base
destruction and lateral pterygoid muscle were measured. RESULTS: The ADC of the lateral pterygoid muscle was (1.501 ±
0.069) × 10^{ - 3} mm^{2}/s in 83
cases. The ADCs of the non-residual group, residual group, non-recurrent group
and recurrent group were (1.843 ± 0.133.4) × 10^{ -
3} mm^{2}/s, (1.097 ± 0.183) ×
10^{ - 3} mm^{2}/s, (1.884 ±
0.134) × 10^{ - 3} mm^{2}/s and
(0.787 ± 0.067) × 10^{ - 3}
mm^{2}/s respectively.The ADCs of the residual group and
recurrent group were lower than that of the lateral pterygoid muscle, while the
ADCs of the non-residual group and non-recurrent group were higher than that of
the lateral pterygoid muscle.The differences were statistically significant (P
< 0.05). CONCLUSION: DWI can provide qualitative and quantitative information
about the tumor cellular level; it can also identify residual, local fibrosis
and recurrence after NPC radiotherapy sensitively and accurately by measuring
the ADC of the region of interest.
Keywords: Magnetic resonance imaging, diffusion, nasopharyngeal neoplasms, radiotherapy
